Tag: food

I have been asked on numerous occasions “Where Do Seedless Watermelons Come From?” or “How do you get seed from a seedless watermelon?” Well, the process is simple but lengthy, taking two generations but the end result is fantastic.

First, you need to understand a little about chromosomes, the threadlike bodies that contain genes for development. A regular watermelon has two sets of chromosomes and is called a diploid (di for two). A plant breeder will take a diploid watermelon seed and treat it with a chemical called colchicine. Colchicine will cause the seed to develop a melon with four sets of chromosomes called a tetraploid (tetra for four). This melon is grown out and the seed harvested for the next growing season. This tetraploid seed is planted and begins to grow but the plant is covered with a spun row cover to prevent any pollination so that the plant breeder can pollinate at the right time with a diploid melon variety. These melons will grow and the seed from them will be harvested. The cross of tetraploid plant with a diploid plant result in triploid seed. This plant has three sets of chromosomes and is the “mule” of the watermelon family. This seed when planted will produce a seedless melon meaning it is sterile. You may see some sort of seed like “carcass” but that is soft and not developed shown in the picture below. They don’t affect the taste or the quality.

Seedless melons are really a favorite of the urban clientele. They don’t buy grapes with seeds, and they don’t like melons with seeds (what do you do with the seeds in a nice restaurant). They are excellent for salad bars and are sold in grocery stores sliced and ready to eat. Seedless watermelons are typically smaller and so fit easily in the refrigerator, another plus for the urban American. One of the first and most popular seedless varieties was Tri-X 313. I was told that the Tri-X meant triploid, the first 3 was 3 months maturity and the 13 was the typical weight of 13 pounds per melon. Sounds good anyway!

Growing seedless melons are a little different than the typical watermelon. First this seed is very fragile and must be germinated under higher-than-normal germination temperatures. We will germinate seeds in chambers with 90+ degree temperatures. This forces the seed to quickly germinate and begin to grow versus a cold soil in the field which will slow seed germination enough that most seedless plants won’t make it. Because of its temperamental nature a seedless watermelon is grown as a transplant first and then moved into the field later after getting a good root system established. These seeds cost from 17¢ to 50¢ a piece and growing the actual plant in a pot to be transplanted costs another 15¢ for a total of approximately 50¢ per plant. The germination percentage is low for seedless, around 80%, so that cost can go up even more. It takes about 1500 to 1700 plants per acre or about $600.00 per acre of planted seedless melons, a lot of money and still 80 days till harvest.

Seedless has other good traits besides being seedless. They are very productive, generally producing more melons than any other hybrid if grown properly. They are also disease tolerant plants resisting many of the diseases that other melons quickly die from and seedless are good shippers, holding flavor for a long time.

I mentioned that the seedless is the “mule” of melons, well a watermelon produces both male and female flowers so that we can plant one variety in a field and bees can pollinate with no trouble. A seedless melon produces a male flower that cannot pollinate another melon so to get by this we have to plant seeded variety melons in rows next to the seedless rows to insure good pollination. I have seen mix-ups in the field where seedless plants covered 10 solid rows so that the outside two rows were the only ones with melons. Having a pollinator row for seedless is mandatory if you want seedless melons, a fact you should know if you want to try growing seedless melons.

Is a seedless melon organic?  Absolutely. Colchicine is a naturally occurring alkaloid compound found in certain plant species, primarily the Colchicum autumnale plant, also known as autumn crocus or meadow saffron. Colchicum autumnale is native to Europe and Asia. The alkaloid colchicine is extracted from the seeds, corms (underground storage organs), and other parts of this plant. It can be applied to the seeds or plants, and this causes the doubling of the chromosomes. This process seems unnatural but in nature it is not that rare to find naturally occurring tetraploid melons!

Colchicine has been used for centuries in traditional medicine, particularly in the treatment of gout and certain inflammatory conditions. However, it is important to note that colchicine can be toxic in high doses, so it should only be used under medical supervision. In organic production the melons should be treated with the naturally derived colchicine not the synthetic. As always, check with your CERTIFIER first!