Getting vegetables to market earlier can improve both production opportunities and profitability. This article reviews practical ways to increase earliness and yield, including variety selection, windbreaks, frost protection, row covers, plastic mulch, healthy transplants, drip irrigation, fertility and staggered planting.
Topics Covered in This Article!
Selection of the Land
Light, sandy soils warm up faster than heavier, poorly drained soils. Of course, we don’t always have a choice, but if you are going to spend money on transplants and fertilizer, choose your best land for vegetables. The heat to warm up wet soil 1 degree will heat up dry soil 15 degrees.
Selection of Variety
Check the days to maturity. There is a big difference between many varieties, and this area needs careful consideration. The early variety may not be the best overall, but it can get you into the market earlier, which can be advantageous.
This is perhaps the most important based on work I have done with melons. Windbreaks can decrease time to maturity by a week. Windbreaks are simply plantings with taller plants done weeks or months before your vegetable crop is planted. For example, a rye crop planting in October will be heading out when you plant melons April 1st. The melon crop is stripped into the standing rye.
In the past, I have worked with growers who went to the trouble and expense to bring in helicopters when an early morning freeze was predicted. It is not unusual to see vineyards with ‘wind machines’ to circulate air when a frost is predicted. Water sprinklers will coat plants with ice which is a freeze protection – sounds crazy I know! Some orchard owners will have bales of hay they set on fire to generate a smoke layer that holds in heat. The basic message is to be prepared if you plant early.
High-value crops like strawberries really benefit from the use of row covers. These can be expensive, so the crop must generate good income to justify the cost. Floating row covers can protect plants from early-season pests and cold temperatures, allowing for earlier planting and faster growth (4 above). These covers can be removed once the danger of frost has passed or may be left on to protect from insect pests.
These increase earliness by warming the soil, conserving moisture, preventing weed problems, and increasing total plant yields. In our Texas soils, plastic mulch can also help keep the plant row from becoming too wet or too dry.
Transplants will greatly increase earliness but only if the transplant is healthy and vigorous. You must use organic sourced transplants! Currently we are working to develop better organic transplants and methods for growing transplants in a TDA supported Specialty Crop Grant. Some transplants that have been grown too long in the greenhouse don’t do well in the field so check your source constantly for when they will be ready so you will be ready.
Providing water in small amounts often is the job of drip irrigation. Used with plastic mulch, drip irrigation increases earliness and yield. Drip irrigation is fairly easy to install and relatively inexpensive. You generally need a pressure regulator, filter, hoses or pipes to carry the water and drip tape to deliver to the crop.
High levels of nutrients ensure rapid growth and utilization of water and sunlight. Many growers struggle to provide stored nutrients in soil, provide pop-up nutrients at planting, and fertilize with organic nitrogen sources through harvest. Regular soil testing helps determine nutrient deficiencies and allows for proper soil amendment before planting. Balanced soil fertility is crucial for early and vigorous plant growth.
Effect of fulvic acid on yield performance of organic bell pepper (Capsicum annuum L.) under open‑field conditions in Tennessee. 2023
Certain growth-promoting substances, like seaweed extracts or microbial inoculants or even Fulvic Acid, can enhance earliness, plant growth and development, potentially leading to earlier harvests.1
Planting in staggered intervals (planting tomatoes on a 2-week schedule) can help manage for frost losses and increase the harvest window and ensure a continuous supply of produce, allowing entry into the market over a longer period.
“Twinning” or “doubles” in peaches refers to the phenomenon where a single peach flower bud develops into two closely connected fruits. This occurrence is often related to the conditions experienced by the tree during the bud initiation phase of the previous year. I have been thinning my peach trees and I am seeing a large number of doubles and yet I still have plenty of fruit – so far! Several factors can contribute to the development of doubles in peach trees, with stress playing a significant role. Let’s explore these factors in more detail:
Temperature Fluctuations: Extreme temperature variations, especially during the critical period of bud differentiation, can cause abnormalities in the developing fruit. If cold temperatures follow a period of warm weather that initiated early bud development, the stress can lead to the formation of doubles.
Water Stress: Both excessive water and drought conditions can stress the tree and disrupt the normal development of fruit buds. Proper water management is crucial during the growing season to prevent such stress. I think this was a big part of the issue because we had very little rain and also hot temperatures last year.
Nutritional Stress: An imbalance in essential nutrients, particularly during the bud initiation and development stages, can lead to the formation of doubles. High nitrogen levels, for example, can promote excessive vegetative growth at the expense of normal fruit development, potentially causing abnormalities.
Genetic Factors: Some peach varieties are more prone to producing doubles than others. This genetic predisposition can be exacerbated by environmental stresses.
Pesticide or Herbicide Exposure: Certain chemicals, if applied improperly or at sensitive stages of development, can cause physiological stress to the trees, leading to abnormalities in fruit development. 2,4-D, a common lawn and pasture weed killer, can also act as a plant hormone and cause deformities.
Addressing these stress factors can help reduce the incidence of doubles in peach production. Careful management of orchard conditions, including temperature control where possible, appropriate watering, balanced nutrition, and cautious use of chemicals, can improve the overall health of the trees and reduce the occurrence of doubles. Selecting varieties less prone to this issue can also be a strategic decision for orchard management.
Larry Stein, Ph.D., AgriLife Extension horticulturist and professor in the Texas A&M College of Agriculture and Life SciencesDepartment of Horticultural Sciences and located at the Uvalde center is a very good friend and mentor. He spoke about both chill hours and peach doubles in a recent AgriLife News article. He said, “chill hours have been sufficient in the mid-to-low chill areas, but were marginal in the higher chill areas, with a lot of growers reporting “doubles” on plant blooms.”
“Doubles or multiple fruit come about as the result of stress during the flower initiation stage, which would have been May and June of 2023,” he said. “These doubles seem to be the consensus when talking to area producers, with some saying they are getting three and four fruit from a single bloom.”
According to Dr. Stein, irregular or inadequate watering has also been identified as a likely cause of fruit splitting and doubling.
“Consumers usually consider conjoined fruits less visually appealing,” Stein said. “For producers, sometimes the extra piece of fruit is so small as to be insignificant and can be safely removed without harming the main fruit. To avoid the conjoined fruit, producers typically thin their fruit trees to get as many double or multiple fruits back to singles as possible.”
Typical tree fruit load before thinning! We must thin to a fruit every 4-6 inches.It’s hard to remove fruit especially since we don’t know what the weather will bring!
Creating an adapted and sustainable organic farming system requires a comprehensive approach that encompasses both the selection and maintenance of crop varieties and an understanding of their interaction with the local environment and soil microbiome. This post aims to guide organic growers in developing a resilient agricultural practice by focusing on crop variety adaptation, seed saving, and leveraging the soil microbiome. In the realm of organic agriculture, the selection of seeds is a critical decision that influences not only the immediate productivity and health of the farm but also its long-term sustainability and economic viability. But before we dive into selecting seeds let’s talk about the organic standard for plantings seeds.
205.204 Seeds and planting stock practice standard – Organic Rules
(a) The producer must use organically grown seeds, annual seedlings, and planting stock: Except, That,
(1) Nonorganically produced, untreated seeds and planting stock may be used to produce an organic crop when an equivalent organically produced variety is not commercially available: Except, That, organically produced seed must be used for the production of edible sprouts;
(2) Nonorganically produced seeds and planting stock that have been treated with a substance included on the National List of synthetic substances allowed for use in organic crop production may be used to produce an organic crop when an equivalent organically produced or untreated variety is not commercially available;
(3) Nonorganically produced annual seedlings may be used to produce an organic crop when a temporary variance has been granted in accordance with § 205.290(a)(2);
(4) Nonorganically produced planting stock to be used to produce a perennial crop may be sold, labeled, or represented as organically produced only after the planting stock has been maintained under a system of organic management for a period of no less than 1 year; and
(5) Seeds, annual seedlings, and planting stock treated with prohibited substances may be used to produce an organic crop when the application of the materials is a requirement of Federal or State phytosanitary regulations.
Boiled down these rules mean you need to use only organically sourced seeds if at all possible. If there are not organic seeds available for the crop you want to plant or the organic varieties available are not adapted to your area, then you can select nonorganically produced seed varieties provided they are not treated of if they are treated the seed treatment is on the list of approved organic substances.
If you meet all the rules, then organic farmers are faced with the choice between 1. hybrid seeds, which dominate much of conventional and organic farming due to their high yield and disease resistance, 2. open-source seeds, which are freely available for use without intellectual property restrictions, and 3. traditional on-farm seed saving practices.
Hybrid seeds
Hybrid seeds created through the crossbreeding of two different parent plants, offer consistency and performance but require farmers to purchase new seeds each season, leading to increased costs and dependency on seed producers. A farmer must purchase hybrid seeds each season because the unique characteristics of first-generation (F1) hybrids—such as improved yield, disease resistance, and uniformity—do not reliably pass on to the next generation. This means seeds saved from hybrid crops typically result in plants that vary widely in their traits, losing the specific advantages that hybrids are valued for. Thus, to maintain consistency and performance in their crops, farmers need to buy new hybrid seeds each year. There are tremendous benefits to buying hybrids each year not the least of which is the almost guaranteed consistency of germination, overall plant health and yield. But what about these other methods for buying planting seed?
Open-source seeds
Open-sourced seeds on the other hand, are part of a movement aimed at ensuring seeds remain a shared resource. These seeds can be saved, replanted, and shared by anyone, promoting agricultural diversity and resilience. This system stands in stark contrast to the patented seeds of the large GMO seed industry, providing an alternative that supports the principles of organic farming by enhancing biodiversity and reducing farmers’ reliance on purchased seeds. However, despite the potential benefits, the majority of organic farming still relies heavily on hybrid seeds due to their immediate productivity benefits.
Open-source seeds emerge from a collaborative, transparent process aimed at keeping seeds as a shared resource accessible to all, without the encumbrance of patents or restrictive intellectual property rights. This model allows for the free exchange, use, and modification of plant genetic materials, encouraging innovation and adaptation in agriculture. Here’s a closer look at how open-source seeds are developed and maintained:
Development Process
Breeding and Selection: The initial development of open-source seeds involves traditional breeding techniques where plants are selected based on desired traits such as resilience to pests or diseases, adaptability to local climate conditions, nutritional value, or yield. This process can be undertaken by individual farmers, researchers, or through collaborative efforts among a community of breeders and farmers.
Open-Source Pledge: Once a new variety is developed, it can be pledged as open-source. This means the breeder commits to making the genetic resources of that variety freely available under an agreement that prohibits patenting or applying any other form of intellectual property restriction that would limit its use or redistribution. The Open Source Seed Initiative (OSSI) https://osseeds.org/ is one of the organizations that facilitate this pledge, ensuring the seeds remain free for anyone to use, breed, and share.
Maintenance and Distribution
Seed Companies: While open-source seeds are free from intellectual property restrictions, they still require meticulous cultivation to maintain their genetic purity and desirable traits. Specialized seed companies and cooperatives play a crucial role in this, producing these seeds under controlled conditions to prevent cross-pollination with other varieties, ensuring the seeds remain “true to type” from one generation to the next.
Cleaning and Quality Control: These companies also undertake rigorous cleaning processes to remove weed seeds and other contaminants, ensuring that the seeds are of high quality and ready for planting. This includes both physical cleaning methods and sometimes treatments to enhance seed viability and health without altering their genetic makeup.
Community Engagement and Support: Beyond production, the distribution of open-source seeds often involves educational efforts to inform farmers about the benefits and practices of using and saving these seeds. This includes training on how to save seeds and select for desirable traits, thus empowering farmers to become active participants in the cultivation and improvement of open-source varieties.
Open-source seeds represent a collective effort to promote biodiversity, resilience, and sustainability in agriculture. Through the dedicated work of breeders, seed companies, and the broader farming community, these seeds are developed, maintained, and distributed with the goal of keeping plant genetic resources accessible and adaptable to the changing needs of farmers and ecosystems around the world. This approach not only supports ecological and economic sustainability but also fosters a sense of community and cooperation in the agricultural sector. For more information check out the Organic Seed Alliance.
The Practice of Seed Saving
The practice of seed saving, a cornerstone of traditional agriculture, allows farmers to select seeds from plants that have thrived in their specific growing conditions, leading to a gradual improvement of crop genetics tailored to local ecosystems. This practice supports biodiversity and ecological balance, key components of organic farming. If you have any interest at all in seed saving to have plants adapted to your own farm you will enjoy this little discussion about these benefits. Just click: Growing for Flavor and Health – April 2024, Acres U.S.A.
Saving seed on the farm indeed encapsulates a blend of potential benefits and challenges that require careful consideration. Let’s explore these aspects in detail:
Benefits
Cost Savings: One of the most immediate benefits of saving seeds is the reduction in costs associated with purchasing new seeds each season. This can be particularly advantageous for small-scale and resource-limited farmers.
Adaptation to Local Conditions: Over time, seeds saved from plants that thrive in the local environment can lead to the development of plant varieties that are better adapted to local conditions, including climate, soil, and pests.
Preservation of Genetic Diversity: Saving seeds from a variety of plants helps to maintain and even increase genetic diversity within crop populations. This diversity can be crucial for resilience to disease and changing environmental conditions.
Challenges
Germination Issues: One challenge with saved seeds is the potential for lower germination rates. Factors such as improper storage conditions, age of the seed, or damage during processing can affect viability. It requires meticulous management to maintain high germination rates from season to season.
Seed Cleaning Problems: Proper seed cleaning is crucial to remove debris, weed seeds, and diseased seeds, which can be labor-intensive and requires specific equipment. Without effective cleaning, the quality of saved seeds can be compromised, leading to reduced crop quality and yield.
Genetic Drift and Diversity: While genetic diversity is a benefit, managing it can also be a challenge. Without careful selection, genetic drift can occur over time, potentially leading to the loss of desired traits. Moreover, in the case of open-pollinated and especially cross-pollinated crops, there is the risk of unwanted crossbreeding, which can result in off-type plants that do not have the desired characteristics of the original variety.
Navigating the Challenges
To address these challenges, farmers engaged in seed saving can adopt several strategies:
Education and Training: Learning about best practices in seed selection, harvesting, cleaning, and storage can improve the quality and viability of saved seeds.
Investment in Equipment: While initial investments may be required for cleaning and storage equipment, these can pay off in the long term through improved seed quality and crop yields.
Community Networks: Participating in local or online farming communities can provide valuable support and knowledge sharing around seed-saving practices. Sharing seeds and experiences can help in managing genetic diversity and solving common problems.
Selective Breeding: Careful selection of plants for seed saving can help maintain or enhance desired traits, ensuring the continuity and improvement of crop varieties over time.
The interplay between these seed systems—hybrid, open-source, and saved seeds—presents organic farmers with a complex set of choices, each with its own set of benefits and challenges. Understanding these options is crucial for anyone looking to support sustainable, productive, and resilient organic farming operations.
The Importance of Crop Variety Selection in Organic Systems
Choosing crop varieties suited to organic systems is important and too little emphasis is placed on this today. These varieties need to be resilient—capable of withstanding pests and diseases without synthetic chemicals, adaptable to local environmental conditions, and efficient in their use of nutrients from organic inputs. Moreover, their ability to outcompete weeds and their synergy with organic crop rotations make them an important part of your organic program. Key traits for organic varieties include:
Disease and Pest Resistance: Natural resistance reduces the need for interventions.
Adaptability to Local Conditions: Varieties should thrive under local climate and soil conditions.
Competitiveness with Weeds: Rapid growth and canopy development can help suppress weeds.
Nutrient Use Efficiency: Varieties should efficiently utilize nutrients from organic matter.
Quality and Market Preference: High-quality crops meet consumer and market demands.
Synergy with Organic Crop Rotations: Varieties should complement organic rotations to enhance soil health and manage pests.
The only way to evaluate, know and understand these traits are acting in your area or on your farm is to talk to other organic growers and to experiment on your own farm.
Enhancing Soil Microbiome Interactions
A healthy soil microbiome is vital for nutrient supply, disease resistance, and stress tolerance. Strategies to enhance this interaction include:
Selecting Microbiome-Friendly Varieties: Some plants are better at recruiting beneficial microbes. Selecting and breeding these varieties can enhance nutrient uptake and stress resilience. Knowing this may involve utilizing the “Haney Test” for measuring CO2 in soil to determine microbial activity and the PLFA test for knowing microbe diversity.
Soil Health Practices: Incorporating organic matter, reducing tillage, and using cover crops to support a diverse and active soil microbiome. Some varieties, especially open-pollinated varieties grown for multiple seasons in the same area become adapted to these practices.
Emphasis on Plant Root Interactions with Soil Microbiome
Understanding and Measurement: The ability of a plant to recruit and maintain a beneficial soil microbiome is pivotal for nutrient acquisition, disease suppression, and stress tolerance in organic systems. How do you know? These traits can be measured by some sophisticated tools:
Microbial Diversity and Abundance: Using DNA-based techniques (such as 16S and ITS rRNA gene sequencing) to identify and quantify the microbial communities associated with plant roots. This is how scientists are learning to characterize microbes specific to crops.
Plant Exudate Profile: Analyzing root exudates to understand the chemical compounds released by roots that attract beneficial microbes.
Microbial Activity: Measuring soil enzyme activities or microbial respiration rates as indicators of microbial activity and health around the root zone (Haney test and PLFA test).
Beneficial Associations: Quantifying specific beneficial associations, such as mycorrhizal colonization rates or the presence of nitrogen-fixing bacteria, through microscopy or molecular markers. (Some companies are now offering this service, but it is several $$ to use!)
Legal Considerations! Before you try being your own plant breeder be sure you know your seeds…..
Plant Variety Protection (PVP) Certificates
Plant Variety Protection (PVP) certificates are a form of intellectual property protection specifically designed for new varieties of seed- and tuber-propagated plants. Administered in the United States by the Plant Variety Protection Office (PVPO), part of the USDA, a PVP certificate grants breeders exclusive rights to their new plant varieties for a period of 20 years from the date of issuance (25 years for trees and vines). To qualify, a variety must be new, distinct, uniform, and stable.
One of the key features of the PVP system is the “farmer’s exemption,” which allows farmers to save seeds from PVP-protected plants for their own use in planting subsequent crops. However, they are not permitted to sell the saved seeds for planting purposes without the breeder’s permission. This exemption is crucial as it recognizes and preserves traditional farming practices while still providing incentives for breeders to develop new varieties.
Utility Patents
Utility patents, on the other hand, offer a broader scope of protection and can apply to any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof. In the context of agriculture, utility patents can protect genetically modified organisms (GMOs), specific plant genes, methods of breeding, or methods of creating a plant with specific characteristics.
Utility patents on plants offer strong protection because they prevent others from making, using, selling, offering for sale, or importing the patented invention without authorization for up to 20 years from the filing date. Unlike PVP certificates, utility patents do not include a farmer’s exemption, meaning that even saving and replanting seeds from a patented plant can infringe on the patent holder’s rights.
Distinctions and Implications
The distinction between PVP and utility patents lies not only in the scope of what they protect but also in their implications for breeders, farmers, and the agricultural industry at large. PVP is specifically designed for plant varieties and includes provisions that balance the interests of breeders with traditional farming practices, such as seed saving. Utility patents provide a broader and stronger level of protection, including for biotechnological inventions, but also impose more stringent limitations on the use of patented materials.
Revision Note – November 2026: This publication has been substantially revised and expanded to provide updated guidance on soil sampling, interpreting routine soil fertility tests, and evaluating soil health. The revision clarifies the differences between soil fertility and soil health, expands information on the Haney Soil Health Test and aggregate stability, and emphasizes the importance of consistent sampling, laboratory methods, and long-term soil testing records. Additional information on soil biological activity, carbon measurements, and soil testing laboratories has also been updated to help producers make more informed soil management decisions.
Table of Contents
Why Test Soil?
I have taken thousands of soil samples over the years, and one thing I have learned is that a single soil test rarely tells the whole story.
A soil test is a snapshot of what was happening in that soil when the sample was collected. It can tell us a great deal about soil fertility, pH, salinity and other properties, but its value increases tremendously when we sample the same field consistently over time. Then we can begin to see trends. Is phosphorus accumulating? Is soil pH declining? Is salinity becoming a problem? Is soil organic carbon increasing? Are our management practices actually changing the soil?
That is why I encourage producers to think of soil testing as a long-term record rather than simply a fertilizer recommendation.
We also need to distinguish between a routine soil fertility test and the growing number of soil-health tests available today. They answer different questions. A conventional soil test remains the foundation for making nutrient and amendment decisions. Soil-health measurements can add information about soil structure, carbon cycling and biological activity, but they do not replace the basic soil test.
In this publication I will look at how to collect a good soil sample, what common soil tests actually measure, several soil-health tests now available, and some laboratories that producers may want to consider.
A soil test is only as good as the sample that goes to the laboratory. The laboratory may analyze the sample very precisely, but it cannot correct for a poor or unrepresentative sample collected in the field.
The first step is to divide the field into areas that are reasonably uniform. Differences in soil type, slope, drainage, cropping history, irrigation, manure application, or management may justify separate samples. Avoid mixing obviously different areas into one composite sample.
Above is a standard soil probe that will last you for years – well worth the cost.
Within each sampling area, collect multiple soil cores and combine them into one composite sample. The goal is to represent the field or management zone rather than one particular spot. Avoid unusual areas such as field entrances, old fence rows, livestock concentration areas, fertilizer spills, wet spots, or locations close to roads unless those areas are being sampled separately for a specific reason.
Sampling Depth Matters
Use the sampling depth recommended by the laboratory and by the soil-test calibration used for fertilizer recommendations. For many annual crops, routine surface soil samples are commonly collected from approximately the upper 6 inches of soil, although recommended depths vary by crop, region, and laboratory.
Consistency is especially important when comparing results over time. Changing from a 6-inch sample one year to an 8-inch sample the next can change nutrient concentrations simply because a different volume of soil was sampled.
Some nutrients require deeper sampling. Nitrate-nitrogen, for example, can move below the surface soil, so profile sampling may be needed when residual soil nitrate is important for fertilizer recommendations.
Sample Consistently Over Time
If the goal is to monitor changes in the soil, try to sample at approximately the same time of year, at the same depth, and under similar field conditions each time.
This becomes even more important when measuring soil health indicators such as respiration or other biological properties because soil moisture and temperature can strongly influence the results.
Where practical, record sampling locations with GPS or consistently sample the same management zones. Good records make it much easier to determine whether a change in a soil-test result reflects management or simply a change in where the sample was collected.
Use Clean Sampling Equipment
A soil probe or auger usually provides the most consistent sample, but a clean shovel can also be used when necessary. Use clean equipment and a clean plastic bucket for mixing composite samples.
Avoid introducing oils, fertilizers, manure, dust, or other materials that might contaminate the sample. This is particularly important when samples will be analyzed for carbon, micronutrients, biological activity, or contaminants.
Handling the Sample
After the cores are mixed thoroughly, place the amount requested by the laboratory into the appropriate sample container and label it clearly.
Follow the receiving laboratory’s instructions for drying, refrigeration, shipping, and sample preparation. Routine fertility samples and biological soil-health samples may require different handling procedures, so one method should not automatically be used for every type of analysis.
Good soil sampling is not complicated, but consistency matters. If I want to know whether a field is changing over time, I need to make sure I am comparing similar samples collected in similar ways.
A routine agricultural soil test is designed primarily to help us evaluate soil fertility and identify chemical conditions that may limit crop growth. It does not measure every aspect of soil health, but it remains one of the most useful and economical management tools available to farmers.
Depending on the laboratory and the analyses requested, a routine soil test may include soil pH, salinity or electrical conductivity (EC), nitrate-nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, and selected micronutrients. Some laboratories also offer soil organic matter, texture, cation exchange capacity (CEC), or lime requirement as part of the basic package or as optional analyses.
Soil pH
Soil pH tells us how acidic or alkaline the soil is. This matters because pH strongly influences nutrient availability, microbial activity, and the effectiveness of some soil amendments.
An unexpected pH result deserves attention because correcting soil pH across an entire field can be expensive. If a result does not fit the field history or previous soil tests, I would rather verify it with another sample before making a major lime or amendment decision.
Salinity and Electrical Conductivity
Electrical conductivity is an indirect measure of soluble salts in the soil. Elevated salinity can reduce water uptake, interfere with nutrient availability, and injure sensitive crops.
In irrigated areas, greenhouses, high tunnels, dairies, and fields receiving repeated manure or compost applications, salinity deserves particular attention.
Nitrogen
Routine soil tests may measure nitrate-nitrogen, but nitrate is mobile and can change rapidly with rainfall, irrigation, crop uptake, and microbial activity. For this reason, nitrate testing is especially dependent on sampling depth and timing.
Where residual nitrate is important for fertilizer decisions, deeper profile sampling may be more informative than a surface sample alone.
Phosphorus and Potassium
Soil-test phosphorus and potassium are among the most common measurements used to guide fertilizer recommendations.
These tests do not measure all of the phosphorus or potassium present in the soil. Instead, laboratories use specific chemical extractants that have been calibrated against crop response to estimate the portion that is related to plant availability.
This is one reason it is important to know which laboratory and analytical method were used when comparing soil-test results over time.
Secondary Nutrients and Micronutrients
Calcium, magnesium, sulfur, zinc, iron, manganese, copper, boron, and other nutrients may be measured when needed.
Micronutrient results require careful interpretation because soil pH, organic matter, drainage, and crop species can strongly affect whether a measured nutrient is actually available to the plant.
Soil Organic Matter
Many laboratories report soil organic matter, and it can be useful for monitoring long-term changes in soil condition. Organic matter contributes to nutrient cycling, water-holding capacity, aggregation, and biological activity.
However, soil organic matter is not the same thing as soil organic carbon, and the two measurements should not be used interchangeably without understanding how the laboratory determined them.
The Value of Consistency
When I am tracking a field over time, I prefer to use the same laboratory, the same sampling depth, and the same analytical methods whenever possible.
Different laboratories may use different extractants, instruments, reporting units, or interpretation systems. If I switch laboratories, an apparent change in phosphorus, organic matter, or another measurement may reflect a change in method rather than a real change in the field.
The purpose of a routine soil test is not simply to generate numbers. It is to provide information that can guide nutrient management, identify developing problems, and help us make better decisions over time.
Of course, a normal soil test or what you might call a Regular Soil Test discussed above is a must. These are not usually expensive, +/- $15 or more with micronutrients. This test is of less value to me unless I have previous year’s results to see what is going on. I have taken literally thousands of soil samples and often I will see something show up that is off the charts. I am not known to panic when I see a problem because I am not going to react to that test unless I know it has steadily been a problem that is just getting worse. For instance, we can see pH swings in sand from one year to the next. Before I lime a soil, I may take a second sample just to verify I need lime. $15 soil test is cheaper than $60 per acre lime application.
Soil fertility and soil health are closely related, but they are not the same thing.
Soil fertility focuses mainly on whether the soil can supply the nutrients a crop needs and whether chemical conditions such as pH or salinity may limit growth. A routine soil test is designed primarily to answer these questions.
Soil health is broader. It considers how well the soil functions as a living system. That includes physical properties such as aggregation, compaction, and water movement; chemical properties such as pH, salinity, and nutrient availability; and biological processes such as microbial activity, decomposition, and nutrient cycling.
A soil can be fertile without functioning particularly well as a soil ecosystem. For example, a field may test adequately for phosphorus and potassium but still have poor aggregation, surface crusting, restricted infiltration, or low biological activity. The opposite can also occur: a soil may have active biology and good structure but still have a nutrient deficiency or an unsuitable pH.
That is why I do not view soil health testing as a replacement for routine soil testing. Instead, the two approaches complement each other.
A routine soil test helps answer:
“Do I have the nutrients and chemical conditions needed to grow this crop?”
Soil health measurements help answer:
“How well is this soil functioning, and is that function improving or declining over time?”
As interest in soil health has increased, laboratories have developed many additional measurements, including soil respiration, soil organic carbon, aggregate stability, active or labile carbon, biologically available nitrogen, phospholipid fatty acid analysis (PLFA), and DNA-based microbial testing.
These tests can provide useful information, but they do not all measure the same thing. Understanding what each test actually measures is more important than simply ordering a large soil health package and receiving a single score.
The next sections look at several of these measurements and how they can fit alongside a routine soil fertility test.
The Haney Soil Health Test was developed to provide additional information about biologically active carbon and nitrogen pools and microbial activity in soil. It does not replace a conventional soil fertility test; instead, it helps answer some different questions about how carbon and nutrients are cycling through the soil.
One of the best-known measurements associated with the Haney approach is soil respiration. A dried soil sample is rewetted and the carbon dioxide released during a defined incubation period is measured. This CO₂ release reflects microbial activity as soil organisms begin using available carbon after rewetting.
The Haney approach also measures water-extractable organic carbon (WEOC) and water-extractable organic nitrogen (WEON). These represent relatively soluble portions of the soil organic carbon and nitrogen pools that can participate in biological cycling.
Understanding a Haney Soil Health Test Report
A Haney Soil Health Test report provides several measurements related to soil biological activity, carbon and nitrogen cycling, and nutrient availability. The exact information reported depends on the laboratory and the analytical package selected.
Three measurements are particularly important:
Soil respiration (CO₂-C burst): Estimates potential microbial activity following rewetting and incubation.
Water-extractable organic carbon (WEOC): Measures a soluble carbon pool that may provide energy for soil microorganisms.
Water-extractable organic nitrogen (WEON): Measures water-extractable organic nitrogen that may participate in microbial nitrogen cycling and subsequent mineralization.
These three measurements are also used to calculate the Haney Soil Health Score. The score summarizes selected biological indicators, but it should not be interpreted as a complete measurement of soil health. Soil structure, water infiltration, compaction, and other important soil properties are not directly included.1
Depending on the laboratory, a Haney report may also provide pH, electrical conductivity, nitrate and ammonium nitrogen, extractable phosphorus and potassium, other nutrients, and estimates of potentially mineralizable nitrogen. Some laboratories provide additional conventional analyses or fertilizer recommendations.
An important distinction is that the Haney test uses water extractions and the H3A extractant for certain nutrient measurements. These results are not necessarily equivalent to those obtained using conventional soil-test methods calibrated for fertilizer recommendations.
**For making fertilizer decisions, I prefer to use regionally calibrated soil fertility recommendations while treating Haney measurements as additional information about soil carbon and nitrogen cycling.**2
Example of a Haney Soil Health Test report showing biological activity, water-extractable carbon and nitrogen, and other soil measurements. Report components and interpretations may vary among laboratories.
I encourage producers to examine the individual measurements rather than concentrating only on the Soil Health Score. Consistent sampling, comparable laboratory methods, and results collected over several years are more useful for evaluating management changes than a single report.
It is important not to confuse these measurements with the conventional nutrient extractions used for fertilizer recommendations. A routine soil test and a Haney-type test are measuring different soil pools and answering different management questions.
The Haney measurements can be particularly useful when I want to monitor changes associated with practices such as cover crops, reduced tillage, manure or compost applications, crop rotations, or other practices intended to increase biological activity and carbon cycling.
However, a single Haney Soil Health Score should not be treated as a complete description of soil health. Soil texture, climate, cropping system, sampling conditions, and inherent soil properties all influence biological measurements. I place more value on the individual measurements and how they change over time than on comparing one overall score among very different soils.
The Haney approach has also become more closely connected with current USDA soil-health testing. NRCS now recognizes water-extractable organic carbon as an alternative method for measuring labile carbon and water-extractable organic nitrogen as an alternative method for measuring bioavailable nitrogen under its CEMA 216 Soil Health Testing framework.3
That does not mean the Haney test measures everything we need to know about soil health. It does mean that several of its measurements provide useful information about important biological processes when they are interpreted alongside routine soil fertility tests and other physical and biological indicators.
One of the most useful physical measurements of soil health is aggregate stability.
Soil particles naturally bind together into groups called aggregates. These aggregates create pore spaces that allow water and air to move through the soil and provide pathways for roots. Good aggregation is one reason a well-structured soil can absorb rainfall rather than sealing over and producing runoff.
Aggregate stability measures how well those soil aggregates resist breaking apart when they are exposed to water or other physical forces.4
This matters because unstable aggregates can break down during rainfall or irrigation. Fine particles may then clog surface pores, form a crust, reduce infiltration, and increase runoff and erosion. A soil may contain adequate nutrients and still perform poorly if its physical structure has deteriorated.
What Helps Build Stable Aggregates?
Aggregate stability develops through a combination of physical, chemical, and biological processes.
Plant roots help bind soil particles and create channels through the soil. Fungal hyphae can physically connect particles, while bacteria and other microorganisms produce compounds that help bind particles together. Organic matter also plays an important role in forming and stabilizing aggregates.
Management practices can therefore influence aggregate stability. Crop rotations, cover crops, living roots, organic amendments, and reduced soil disturbance may help improve aggregation over time. Intensive tillage, low residue return, erosion, and other disturbances can weaken soil structure.
Soil type also matters. A sandy soil naturally behaves very differently from a clay soil, so aggregate stability should not be interpreted without considering texture, mineralogy, climate, and management history.
How Is Aggregate Stability Measured?
There are several ways to measure how well soil aggregates resist breaking apart when exposed to water. Some methods are simple enough for farmers to use themselves, while others require specialized laboratory equipment. The methods differ in how water is applied and how aggregate breakdown is measured, so their results are not necessarily interchangeable.
Slaking Image Analysis — The SLAKES Smartphone App
One of the easiest methods for farmers to use is the free SLAKES smartphone application developed by the Soil Health Institute.
The procedure involves placing three dry soil aggregates into water and using a smartphone camera to photograph how they change over a 10-minute period. The application analyzes the images and calculates an aggregate stability index.
I particularly like this approach because farmers can use it themselves without expensive laboratory equipment. It provides a practical way to compare soil from different fields, management practices, or locations within a field, although soil type and sample preparation must be considered when interpreting the results.
The application also makes an excellent teaching tool. Farmers can actually watch soil aggregates break apart or remain intact when exposed to water.
The Cornell Soil Health Laboratory uses a rainfall simulation approach to evaluate wet aggregate stability. A known quantity of soil aggregates is placed on a sieve and exposed to water droplets from a rainfall simulator.
Aggregates that break apart pass through the sieve, while the material remaining is used to calculate the percentage of water-stable aggregates.
This approach is especially useful because it simulates the impact of raindrops on soil aggregates, one of the processes contributing to surface sealing, crusting, and erosion.
Wet Sieving Procedure
Wet sieving is a widely used laboratory approach for measuring aggregate stability. Soil aggregates are placed on sieves and exposed to water, often with controlled movement of the sieves.
The amount and size distribution of aggregates remaining after the procedure are used to evaluate stability.
Wet sieving can provide quantitative measurements for comparing treatments and tracking changes over time. However, the results depend on details such as sample preparation, sieve sizes, wetting procedures, and agitation, making consistent methods particularly important.
Mean Weight Diameter (MWD)
Mean weight diameter is not a separate testing procedure but a calculated measurement commonly obtained from aggregate size distribution following wet sieving.
It represents the weighted average diameter of the aggregate fractions remaining after testing. A larger MWD generally indicates that larger aggregates have remained intact, although interpretation depends on the soil and testing method.
MWD is frequently used in soil research to compare management practices and evaluate changes in soil structure.
Which Method Should Farmers Use?
For farmers interested in learning about aggregate stability without sending samples to a laboratory, I would begin with the SLAKES application. It is inexpensive, relatively easy to use, and provides a way to observe the physical behavior of soil aggregates.
For research trials or long-term monitoring programs requiring standardized quantitative measurements, laboratory methods may be more appropriate.
Regardless of the method, I would emphasize collecting comparable samples, following the same procedure each time, and interpreting results in the context of soil texture and management history.
Why I Like This Measurement
Aggregate stability tells us something that a conventional nutrient test cannot.
A routine soil test may tell me that phosphorus, potassium, and pH are all within acceptable ranges. Aggregate stability helps tell me whether the soil itself has the physical structure needed to accept water, resist erosion, and support roots.
For that reason, I think aggregate stability is one of the more practical soil-health measurements available. It connects a laboratory number with something farmers can often see in the field after a hard rain: does water enter the soil, or does the surface seal and the water run off?
Like most soil-health measurements, aggregate stability is most useful when it is followed over time and compared with similar soils under similar conditions.
Soil Organic Carbon: A Long-Term Measure of Soil Health
Soil organic carbon (SOC) is one of the most important measurements we can use to evaluate long-term changes in soil health. Carbon enters the soil primarily through plant roots, crop residues, cover crops, and organic amendments such as manure and compost. Some of that carbon is rapidly decomposed by soil organisms, while other portions can remain in the soil for years or even decades.5
Soil organic carbon is closely associated with many of the functions we want from a healthy soil.6 It contributes to aggregate formation and stability, supports microbial activity and nutrient cycling, and can improve water-holding capacity. Increasing soil carbon is often an important goal of regenerative and organic production systems.
Soil Organic Carbon Is Not the Same as Soil Organic Matter
Many farmers are familiar with soil organic matter (SOM) because it has been reported on soil tests for decades. However, soil organic matter and soil organic carbon are not the same measurement.
Soil organic matter includes carbon along with oxygen, hydrogen, nitrogen, sulfur, and other elements found in decomposed plant and animal materials. Soil organic carbon measures only the carbon portion of that organic material.
Historically, soil organic matter has often been estimated by multiplying soil organic carbon by 1.724, based on the assumption that organic matter contains approximately 58% carbon.7 However, the carbon content of soil organic matter varies among soils, so this conversion is only an approximation.
When monitoring changes through time, it is important to know whether the laboratory reports measured organic carbon, measured organic matter, or a value calculated from another measurement.
How Is Soil Organic Carbon Measured?
Dry combustion is a widely accepted method for measuring soil carbon. However, the laboratory must distinguish organic carbon from inorganic carbon, particularly in calcareous soils containing calcium carbonate. Depending on the analytical procedure, this may involve removing or separately determining inorganic carbon.8
For this reason, I want to know whether my laboratory is reporting total carbon or specifically soil organic carbon, particularly when working with calcareous soils.
Why Soil Organic Carbon Changes Slowly
Unlike soil nitrate or microbial respiration, soil organic carbon generally changes slowly. Even when management practices improve soil carbon storage, detecting those changes through routine soil sampling can be difficult. Research by Wuest and Durfee (2024) demonstrated substantial variation in soil organic carbon measurements between sampling dates, emphasizing that small differences between individual soil tests may not represent meaningful changes in soil carbon.9 For this reason, I place greater confidence in carefully collected measurements over several years than in comparisons between just two sampling dates.
In many agricultural fields, measurable changes may require several years or longer. Small differences between annual soil tests may reflect normal sampling and laboratory variability rather than a real change in soil carbon.
For that reason, I generally view soil organic carbon as a long-term measurement rather than something that needs to be tested every year. Establishing a reliable baseline and repeating the measurement at consistent intervals, perhaps every three to five years, may be more useful for many producers.
Carbon Concentration Versus Carbon Storage
There is another important distinction. A laboratory usually reports soil organic carbon as a concentration, often expressed as a percentage of the dry soil.
That percentage is not the same as the total amount of carbon stored in a field.
To estimate carbon storage per acre, we also need to know the soil depth and bulk density, which describes the mass of dry soil within a given volume. This distinction becomes especially important when comparing tilled and no-till soils because changes in soil density can affect carbon storage calculations.10
What I Want Farmers to Remember
I would not judge the success of a soil management program by whether soil organic carbon increased a small amount in a single year. I would look for a consistent trend over time, supported by other measurements such as aggregate stability, infiltration, and biological activity.11
Soil organic carbon is an important indicator of soil condition, but it is not a complete soil-health measurement by itself. A field may have relatively low organic carbon because of its texture and climate yet still be functioning well for that particular soil.
The goal is to understand the soil we have, measure it consistently, and determine whether our management is improving its ability to support productive agriculture over time.
Soil is a living system, and the organisms living in it are constantly using carbon as an energy source. As microorganisms decompose crop residues, roots, and soil organic matter, they release carbon dioxide (CO₂) through respiration. Plant roots and soil animals also contribute to total soil respiration.
Measuring soil respiration provides information about biological activity and the decomposition processes involved in nutrient cycling. Unlike soil organic carbon, which measures a relatively large pool of carbon stored in the soil, respiration measures carbon being released through biological processes.12
How Is Soil Respiration Measured?
Several methods are used to measure soil respiration. Some measure CO₂ released directly from soil in the field, while others use soil samples incubated under controlled laboratory conditions.13
One commonly used laboratory method is the 24-hour CO₂ burst test, which is associated with the Haney Soil Health Test. A soil sample is dried, rewetted, and incubated under controlled conditions. The CO₂ released during the following 24 hours is measured as an indicator of potential microbial activity.
Rewetting dry soil often produces a rapid increase in microbial respiration as microorganisms respond to the availability of water and organic substrates. Research has demonstrated that this CO₂ flush is related to biologically active soil organic matter and other indicators of soil microbial activity.14
Other laboratory methods use longer incubation periods, such as three or four days. Because incubation time, temperature, moisture, and measurement procedures can influence the results, values obtained using different methods should not be assumed to be directly comparable.15
Does Higher Respiration Mean Healthier Soil?
Not necessarily.
Higher respiration under standardized laboratory conditions often indicates greater potential microbial activity or more readily decomposable organic material. However, respiration also represents carbon being released from the soil as CO₂.
For example, tillage can temporarily stimulate microbial activity by exposing previously protected organic matter to decomposition. The resulting increase in respiration does not necessarily mean that soil health has improved.
Likewise, low respiration may reflect limited organic material, but it can also result from unfavorable conditions such as drought, excessive moisture, or low temperatures.
I would be cautious about assigning universal ratings of good or poor soil health based on a single respiration measurement. Soil texture, carbon content, management history, and analytical methods all affect the results.16
Why I Find Respiration Useful
Soil respiration provides information that a conventional fertility test cannot. It helps us understand how actively microorganisms are processing organic material and participating in carbon and nutrient cycling.
For organic and regenerative producers, respiration measurements may be useful for monitoring changes associated with cover crops, crop rotations, organic amendments, and reduced tillage.
However, I would not use respiration alone to judge whether a management practice is improving soil health. I would interpret it alongside soil organic carbon, aggregate stability, routine fertility measurements, and the history of the field.
Soil organic carbon tells us something about the carbon stored in the soil. Soil respiration tells us something about the biological activity using that carbon. Both measurements are useful, but neither tells the complete story.
As with other soil-health indicators, the greatest value comes from consistent sampling, comparable laboratory methods, and measurements collected over time.
Advanced Soil Biological Testing: PLFA and DNA Analysis
Soil microorganisms play essential roles in decomposing organic matter, cycling nutrients, forming soil aggregates, and interacting with plant roots. While soil respiration provides a general measurement of biological activity, other laboratory tests can provide information about the size and composition of soil microbial communities.
Two approaches used in soil research and commercial soil testing are phospholipid fatty acid (PLFA) analysis and DNA-based microbial testing. These methods provide different types of information, and neither should be considered a complete measurement of soil health.
Phospholipid fatty acids are important components of microbial cell membranes. Different microbial groups contain characteristic fatty acids, and laboratory analysis of these compounds can provide estimates of microbial biomass and broad differences in community composition.
PLFA analysis generally involves extracting lipids from a soil sample, separating the fatty acids, and measuring them using specialized laboratory instruments.
Because phospholipids break down relatively quickly after microorganisms die, PLFA analysis is commonly used as an indicator of the living microbial community rather than the total microbial material present in soil.17
What Can PLFA Tell Us?
PLFA results may include estimates of total microbial biomass, bacterial and fungal biomass, and the relative abundance of broad microbial groups.18
These measurements can help researchers evaluate how soil microbial communities respond to crop rotations, cover crops, tillage, organic amendments, and other management practices.
For example, a long-term cropping experiment might use PLFA to determine whether microbial biomass or community composition changes following the introduction of cover crops or reduced tillage.
Some laboratories also report a fungal-to-bacterial ratio. While changes in this ratio may reflect differences in soil conditions or management, there is no universal ratio that defines a healthy agricultural soil.
PLFA does not ordinarily identify individual microbial species, and it does not directly measure whether microorganisms are actively performing particular functions such as nitrogen fixation or phosphorus mineralization.19
Limitations of PLFA Testing
Microbial communities respond rapidly to environmental conditions, including soil moisture, temperature, plant growth, and recent management activities.
For this reason, PLFA measurements can vary considerably between sampling dates. Sample handling and storage are also particularly important because microbial lipids can change or degrade after collection.
PLFA is useful for research and for monitoring changes in microbial communities under controlled sampling conditions. However, I would not recommend it as a routine replacement for conventional soil testing or the more established soil-health indicators.
For most producers, the additional cost and difficulty of interpreting the results should be considered before ordering this analysis.
DNA-Based Soil Microbial Testing
DNA-based soil testing uses genetic information extracted from soil to characterize microorganisms and, depending on the analytical method, identify particular organisms or genes associated with biological functions.
Unlike PLFA, which characterizes broad microbial groups through cell-membrane lipids, DNA sequencing can provide much greater detail about the organisms represented in a soil sample.
Some commercial services use this technology to assess microbial communities, detect genetic signatures associated with plant pathogens, or evaluate genes involved in nutrient cycling.
One example is Trace Genomics, whose technology and products were acquired by Miraterra in July 2025. The company has developed soil analysis services combining genomic information with conventional soil chemistry and agronomic interpretation.20
What Can DNA Testing Actually Tell Farmers?
DNA testing can be especially useful when there is a specific question, such as whether a soil contains genetic evidence of a particular plant pathogen or whether management practices are associated with changes in microbial community composition.
However, detecting an organism or a gene does not necessarily mean that the organism is alive, actively performing that function, or affecting crop growth under current field conditions.
For example, detecting genes associated with phosphorus solubilization indicates biological potential, but it does not establish how much phosphorus is actually being released and made available to a growing crop.
Similarly, detecting DNA from a plant pathogen does not necessarily mean that disease will develop. Disease depends on a susceptible host, a capable pathogen, and environmental conditions favorable for infection.
These technologies are advancing rapidly, but interpretation remains challenging. For most producers, DNA-based analyses are likely to be most useful when addressing a specific management or plant-health question rather than as a routine annual soil-health measurement.21
I encourage farmers to begin with the question they are trying to answer.
If I want to know whether biological carbon cycling is changing, soil respiration may be a useful starting point.
If I want to study changes in microbial biomass or broad community composition, PLFA may provide additional information.
If I am investigating particular microorganisms, soilborne pathogens, or microbial genes, DNA-based testing may be more appropriate.
The most expensive or technologically advanced test is not necessarily the most useful. The value of any soil test depends on whether its results help us understand the soil and make better management decisions.
Great publication you can read on understanding these Soil Health Tests. Just click the link below:
The “take home” message is not soil testing only, but records of soil tests you can see over time!
Putting Soil Testing to Work
After years of collecting soil samples and working with producers, I have come to appreciate that the value of soil testing is not simply the number of measurements we can obtain. It is understanding what those measurements tell us and how we can use them to make better management decisions.
For most producers, I would begin with a good routine soil fertility test. If I want to understand changes in soil health, I might add measurements such as soil organic carbon, aggregate stability, or biological activity. More specialized tests, including PLFA and DNA analysis, may be useful when there is a specific question about the soil microbial community.
Regardless of the tests selected, consistent sampling and good records are essential. A single soil test provides useful information, but a series of comparable tests can help us recognize trends, evaluate management practices, and identify developing problems.
The goal is not to collect more soil-test numbers. The goal is to understand our soil well enough to manage it better.
Bellows, B., Morris, M., & Mitchell, C. (2020). Soil Health Indicators and Tests.ATTRA Sustainable Agriculture, Publication IP603. National Center for Appropriate Technology. ↩︎
USDA Natural Resources Conservation Service. (2026). Soil Health Testing. Conservation Evaluation and Monitoring Activity (CEMA) 216, January 2026R. U.S. Department of Agriculture. ↩︎
USDA Natural Resources Conservation Service. (2026). Soil Health Testing. Conservation Evaluation and Monitoring Activity (CEMA) 216, January 2026R. U.S. Department of Agriculture. ↩︎
USDA Natural Resources Conservation Service. (2026). Soil Health Testing. Conservation Evaluation and Monitoring Activity (CEMA) 216, January 2026R. U.S. Department of Agriculture. ↩︎
USDA Natural Resources Conservation Service. (n.d.). Soil Health Assessment. U.S. Department of Agriculture. ↩︎
USDA Natural Resources Conservation Service. (2026). Soil Health Testing. Conservation Evaluation and Monitoring Activity (CEMA) 216, January 2026R. U.S. Department of Agriculture. ↩︎
USDA Natural Resources Conservation Service. (2026). Soil Health Testing. Conservation Evaluation and Monitoring Activity (CEMA) 216, January 2026R. U.S. Department of Agriculture. ↩︎
Scales are sucking insects that insert their tiny, straw-like mouthparts into bark, fruit, or leaves, mostly on trees and shrubs and other perennial plants. Some scales can seriously damage their host, while other species do no apparent damage to plants even when scales are very abundant. The presence of scales can be easily overlooked, in part because they do not resemble most other insects.
Lecanium scales in the picture above (there are about 12 species) are known as “soft” scales and are common pests on many ornamental plants all over North America. Holly, elm, redbud, walnut, citrus, apricot, pear, persimmon, beech, box elder, grape, pecan, rose, and willow are a sample of the diverse range of hosts that Lecanium scales can parasitize.
As these scales feed, they excrete large quantities of honeydew which serves as a substrate for sooty mold fungi.
Here is a link to a previous post I wrote about this scale on pecan. Scale on Pecan?
San Jose Bark Scale
San Jose scale, Quadraspidiotus perniciosus (Comstock) (Homoptera: Diaspididae). Photo by C. L. Cole.
San Jose Bark Scale is one of the major insect pests of peaches and maybe one that causes the most damage. The first signs of infestation include a decline of tree vigor, leaf drop and appearance of sparse yellow foliage, particularly on the terminal growth. Reddish spots on the underside of bark and around scales on leaves or fruit result from feeding of immature stages. In severe cases, the entire surface of bark can become covered with layers of overlapping grayish scales. Cracking and bleeding of limbs occur, and heavily injured trees may die.
Life Cycle: Intermediate. Mature females and immature (second nymphal instar) stages survive the winter. Rather than eggs, female scale insects produce tiny six-legged, mobile, yellow-colored young, called “crawlers.” This stage spreads the infestation to new areas on the host plant, including bark, leaves and fruit, and to new hosts. After inserting their thread-like mouthparts into the plant and feeding for 2 to 3 days, female crawlers secrete their initial scale coverings and never move from that spot. Males develop into 2-winged adults in 2 or 3 weeks and emerge from their scales to seek females to mate. Up to six generations may be produced annually. All stages of development can occur throughout the year except during the winter.
Crape Myrtle Bark Scale
The crape myrtle bark scale, Acanthococcus (Eriococcus) lagerstromiae (Kuwana) was first confirmed in the USA in 2004 in the landscape near Dallas (TX), although it was likely introduced earlier. The scale is a sucking insect that feeds on the phloem (sap) of plants. As it feeds, it excretes a sugary solution known as “honeydew” (similar to aphids, whiteflies, and other sucking insects). Heavy infestations of crape myrtle bark scale produce sufficient honeydew to coat leaves, stems and bark of the tree. This honeydew, in turn, will eventually turn black as it is colonized by a concoction of fungi, called sooty mold. Although crape myrtles rarely die as a result of crape myrtle bark scale infestation, the sticky leaves and black trunks greatly reduce the attractive appearance of the tree.
Photo by Erfan K. Vafaie, Texas A&M AgriLife Extension.
Immature crape myrtle bark scale is hard to see with the naked eye, but adult scale covers, and egg sacs are frequently visible on the upper branches and trunk of the tree. These scales include larger, white, oval (female) and smaller, elongate (male) scales. Both male and female scales of the crape myrtle bark scale are immobile and will “bleed” pink blood when crushed.
On a personal note, this is a problem I have in my landscape and use Certis Biologicals – Des-X Insecticidal Soap as a treatment. Seems to work well but it does require repeat applications.
Mealybugs are prominent now in Greenhouses and Houseplants
Mealybugs are soft-bodied, wingless insects belonging to the family Pseudococcidae. These pests are known for their damaging effects on a wide range of plants, including crops, ornamentals, and houseplants. Their appearance is distinctive: adults are covered with a white, waxy, cotton-like secretion, making them resemble small tufts of cotton. This protective coating helps conserve moisture and offers some defense against predators and pesticides. Understanding the biology of mealybugs is crucial for developing effective management strategies in agricultural and horticultural systems.
Mealybugs have a complex life cycle that includes egg, nymph (crawler), and adult stages:
Egg: Female mealybugs lay hundreds of eggs within an ovisac, a protective sac made from waxy secretions. The color and size of the ovisac can vary among species.
Nymph (Crawler): After hatching, the nymphs, or crawlers, emerge to find feeding sites. This is the most mobile stage of the mealybug life cycle, and it’s when they are most vulnerable to control measures. Crawlers are tiny, yellowish, and lack the waxy coating seen in adults.
Adult: As they mature, nymphs undergo several molts before reaching adulthood. Adult females are larger than males and retain the waxy coating. Males may develop wings, depending on the species, and do not feed on plant sap as adults.
Mealybugs feed by inserting their long, slender mouthparts into plant tissues and sucking out sap. This feeding behavior can weaken plants, reduce growth, and cause leaf yellowing, wilting, and even death in severe infestations. As they feed, mealybugs excrete honeydew, a sticky substance that can lead to the growth of sooty mold, further impairing photosynthesis and plant health.
Mealybug reproduction can be sexual or asexual, varying by species. Some species are capable of parthenogenesis, where females produce offspring without mating. This ability allows for rapid population increases under favorable conditions.
Mealybugs spread primarily through human activity, such as the movement of infested plant material, and natural means, like crawling to adjacent plants or being carried by wind, animals, or ants. Ants, in particular, are known to farm mealybugs for their honeydew, protecting them from natural enemies and inadvertently aiding in their dispersal.
Introduction of Natural Predators or Disease
Controlling scale or mealybug insects in an organic farming system emphasizes the integration of biological and ecological methods to maintain pest populations below damaging levels. Biological control, one of the cornerstone practices in organic agriculture, involves the use of living organisms—predators, parasitoids, and pathogens—to regulate pest populations. Here are some effective methods to manage these insects through biological or predator-based strategies:
Lady Beetles (Coccinellidae): Many lady beetle species are voracious predators of scale insects in their larval and adult stages. For instance, the vedalia beetle (Rodolia cardinalis) has been successfully used to control cottony cushion scale in citrus groves.
Cryptolaemus montrouzieri: Often referred to as the mealybug ladybird, this beetle is a voracious predator of mealybugs in both its larval and adult stages. It has been used successfully in various agricultural systems to control mealybug populations.
Lacewings (Chrysopidae): Green and brown lacewings consume scale insects during their larval stages. Green lacewing larvae are effective predators of mealybugs, consuming them at various stages of their development. Their larvae are known as “aphid lions” for their predatory efficiency.
Parasitic Wasps: Tiny wasps, such as Aphytis melinus and Encarsia spp., specialize in parasitizing scale insects. They lay their eggs in or on the scale insect, and the developing larvae consume the scale from the inside. Several species of parasitic wasps, such as Leptomastix dactylopii, target mealybugs specifically. These wasps lay their eggs in or on mealybug larvae, and the hatching wasps consume the mealybugs from the inside.
Beauveria bassiana and Metarhizium anisopliae are fungi that infect and kill a wide range of insect pests, including scale and mealybug insects. These fungi are particularly useful in humid environments where they can naturally proliferate and infect scale populations.
Isaria fumosorosea (formerly known as Paecilomyces fumosoroseus) is a naturally occurring entomopathogenic fungus that acts as a biological control agent against a wide range of insect pests, including mealybugs, aphids, whiteflies, thrips, and other soft-bodied insects. It infects its hosts through the cuticle, leading to the pest’s death, and is particularly useful in integrated pest management (IPM) systems in organic agriculture and greenhouse settings.
Below you will see a list of organic products that have scale and/or mealybugs on their labels. These include some of the beneficial fungi listed above as well as botanical oils and the still very popular Azadirachtin extracted from the neem tree. You can just look through this short list or click on the link below to either see it on your computer or download and use as an Excel file.
This is a picture of the “Purple Tomato” developed and sold by Norfolk Healthy Produce. According to the press release from the John Innes Centre it is a high-anthocyanin purple tomato developed nearly 2 decades ago. Here are a couple of paragraphs from the article below.
Nathan Pumplin, CEO of Norfolk Healthy Produce, said: “We are thrilled to offer these first-of-a-kind seeds to home gardeners. Our tomato is just a tomato – you can grow it in your garden next to your Sun Golds and Purple Cherokees, and other favorite varieties. We share our gratitude to the thousands of fans who have expressed their interest and encouragement through our website.”
The company says that surveys with American consumers showed that 80% are interested to eat, purchase and grow the purple tomato, knowing that it is bioengineered (as a genetically modified organism, or GMO). Only 5% of consumers were not interested. I seriously doubt this last sentence and wonder how accurately they surveyed customers!
These pictures are of the YOOM tomato. This purple tomato was introduced last year and as you can see also has the purple color and because of that color it has high anthocyanins like other purple vegetables and fruit.
The Yoom tomato is not developed using GMO technology like the “Purple Tomato.” Instead, Yoom tomatoes are the result of conventional breeding techniques. These techniques involve selecting parent plants with desirable traits and crossbreeding them over multiple generations to produce offspring that express those traits. The Yoom tomato, known for its distinctive purple color and high levels of antioxidants, particularly anthocyanins, was developed through this traditional method of plant breeding.(Article in Vegetable Grower News)
The purple color is a natural trait that some tomato varieties exhibit, enhanced through the selection process to appeal to consumers looking for novel and potentially healthier options in their diets. The development of such varieties focuses on enhancing flavor, nutritional content, and visual appeal without the need for genetic modification techniques like CRISPR-Cas9 or GMO.
Conventional breeding remains a powerful tool in developing new plant varieties, allowing for the gradual improvement of crops with respect to taste, yield, disease resistance, and nutritional content. While CRISPR technology offers precise gene editing capabilities, it’s important to distinguish between crops developed through genetic modification and those, like the Yoom tomato, that are the result of selective breeding practices.
Organic growers need to be aware of this powerful difference and don’t be fooled by others who want you to grow the Purple Tomato without realizing the difference. Recently I was asked about organic farmers growing the Purple Tomato. I was caught completely unaware because I knew about YOOM and so thought this was the tomato they were referring to. It was not the YOOM, and you need to know it is not legal or ethical for you to grow the “Purple Tomato” unless you grow the YOOM Purple Tomato.
Lastly, YOOM is not a certified organic seedvariety (YET), at least that I can find. There may be some organic seed offered soon but you will need to talk to your certifier about using conventional YOOM seed based on the fact that it is from conventional breeding and is the only tomato variety with these traits.
News Updates below: Click links for a new twist to this story!
Plant breeders and seed retailers are increasingly living in fear of legal threats from GMO developer companies. Report: Claire Robinson
The company that is commercializing the GM purple so-called “anti-cancer” tomato has targeted a non-GMO heirloom seed company over alleged patent infringement.
(Click the heading above for a link to this article)
