There are several strategies deployed by almond growers to help keep their trees safe from nematode damage. The most effective means for getting good nematode control early in an orchard is with pre-plant fumigation. There are also some rootstocks available that have resistance to certain nematodes, but not all species that impact California orchards. Failing to get nematodes under control can have serious consequences for growers.
“Nematode damage can lead to problems with soil-borne diseases such as bacterial canker or phytophthora root rot,” said Manuel Jimenez, Customer Business Advisor for Bayer CropScience. “But in terms of yield loss, they’ve shown that you can lose up to 50 percent of your yield from nematode feeding if the problem is severe.”
The three most common nematode species that are found in almond orchards are root knot, root lesion, and ring. Orchards in sandy soils are most susceptible to nematode infestation, particularly when it comes to ring nematodes. Fumigation has been the primary tool for combatting nematodes, but it can also require the application of supplemental materials to be more effective. “Work that’s been done by nematologists in the University of California system has determined that nematodes can come in after about as little as 24 months after fumigation. So, you see a reinfestation of the field. That’s the importance of having these tools like Velum One and Movento as a post-plant nematicide,” said Jimenez.
Nematode damage can develop slowly, making it difficult to detect early on. Some of the symptoms of infestation include smaller leaves and stunted tree growth. For growers who suspect they may have nematodes in their orchards, Jimenez suggests taking a soil nematode sample to be sure.
“Bayer has a program called the Soil Nematode Analysis Program,” Jimenez noted. “Through that program growers can submit a nematode sample to an approved lab and that lab will send back a report as to whether or not you have a problem with nematodes. The cost of that lab analysis is covered by Bayer.”
Listen to the interview below.