I am fortunate to live in Central Texas pretty much in the middle of a huge pecan area containing both native and improved orchards. I don’t have to walk far to see pecan trees or keep an eye on their progress. I usually put out pecan nut casebearer traps and monitor them for growers and I also check regularly to make sure growers are producing the best quality pecan possible. In other words, I eat all the pecans I can!
As you can tell from the photo, we are about to enter pecan budbreak. You can see the old bud cap is breaking off as the bud swells and with the unseasonably warm weather the leaf buds are unfolding. It won’t be many days before we enter the “parachute stage” where the tiny leaves form a small looking parachute. Also, in this explosion of growth, there will be nutlets, catkins and more!
The reason for the post is to remind growers that budbreak is the beginning of the crop year and because of that it is also the beginning of crop problems. We have been extremely dry and so pecan scab is not on anybody’s mind, but it is not hard to find scab spores on the tree branches. Here is a picture from Dr. Bill Reid’s blog on Northern Pecans and you can see the lesions on this northern pecan variety called Hirschi. I did see lesions on branches in what I call orchard “hot spots” for pecan scab on Wichita and Kiowa varieties.
The question then becomes what can I spray in an organic or regenerative pecan program? Actually, the product list is longer than you might think. Some work done in 2018 points to organic fungicides with Reynoutria sachalinensis (Regalia, Marrone Bio) as having the best control of the tested products. The test in 2018 did not include organic fungicides with Bacillus mycoides isolate J (Lifegard, Certis Bio) which showed a good level of control in testing done in 2008.
The two products just mentioned had some research done specifically in pecans, but many other products can be mentioned because of their effectiveness with other diseases similar to pecan scab or their relationship to the two biologicals mentioned. They include Double Nickel, Cueva, Aviv, Taegro, Timorex Gold, Stargus, Serifel, Sil-MATRIX and probably more than I can find! Basically, there are products, they can be mixed if needed, but the main issue is getting a product out in a timely manner. Remember, always check with your organic certifier before making any applications!