Syngenta US: Stay ahead of soilborne diseases in high-yielding tree nut orchards

Proactively protecting tree nut orchards from soilborne diseases like Phytophthora root rot is essential for long-term productivity in commercial stands. Damage from the disease starts underground, causing tree health to silently decline over time. This damage can easily go unnoticed when walking orchards day in and day out; but once above ground symptoms of the disease are visible, it may be too late.

Combatting Phytophthora is grounded in preventive management and a strong root system that can handle the pressure of disease. Overall tree health, stemming from healthy roots, is critical in permanent crops since Phytophthora, if left unchecked and untreated, can carry over into following seasons.

"Phytophthora is a root rotting pathogen that feeds on and lives in root tissues. Growers need to control it or else the root system will be so damaged that it won't be able to produce efficiently, and trees can eventually die," says Garrett Gilcrease, agronomy service representative at Syngenta. "If you have an uncontrolled Phytophthora situation, tree health will decline and sizing will be off. This means less yield and profit for the grower."

Preventive action against Phytophthora bolsters long-term orchard health, which can help trees stand the test of time and increase their potential to produce higher, more marketable yields. Fungicides like Orondis^® offer highly effective control of oomycete diseases, including Phytophthora root rot. In a 2020 study, orchards treated with Orondis applied at a 9.6-fluid-ounce rate showed zero incidences of Phytophthora root rot compared with untreated trees, which demonstrated 35 incidences of the disease. Orondis fungicide is especially helpful for young trees, which are more vulnerable to the disease.

"Orondis is a soil-applied fungicide that is the best option for Phytophthora control. It provides great resistance management, is extremely active at low use rates and provides excellent residual control," Gilcrease says. "It goes into the soil and not only protects the root system but also reduces propagule count in the soil."

Putting tree nut health at the core of your management practices can help produce high-quality, high-yielding trees for seasons to come. For more information on tree nut management, visit Syngenta-US.com/TreeNuts.