In today’s Almond Matters, brought to you by Valent, Alternaria issues are most commonly seen in the south San Joaquin Valley and western areas of the Sacramento Valley, but the disease can also be problematic for growers in other areas with high humidity and stagnate air.
“I always go by the old adage, ‘an ounce of prevention is worth a pound of cure.’ Alternaria, like most fungal pathogens, is easier to prevent than it is to control after it’s already showing itself in the orchard,” said Field Market Development Specialist for Valent USA Todd Burkdoll. “If they’ve got a history there, you need to be on the front side of the disease rather than on the back side because once it’s infected it’s hard to stop.”
Depending on the individual growing conditions and what is being reported from the orchards, most fungicide treatments would begin around the middle part of April. Leaf moisture combined with warm temperatures can create an ideal environment for Alternaria issues to develop and being diligent with field monitoring is a high priority. “Probably the biggest thing is to be monitoring your orchards, especially if you have a high-density planted almond orchard,” said Burkdoll.
Along with growing conditions, some trees may be more vulnerable to infection than others because of varietal sensitivity. “Probably the most susceptible varieties would be Monterey and Carmel, which are popularly planted with nonpareil,” Burkdoll noted. “You’ve got to have an idea of what varieties you’re going after, and then the moisture issue is definitely problematic.”
Along with cultural preventative methods, Burkdoll mentioned some of the fungicides that are available to growers that do a good job with prevention. “A program with alternating [polyoxin–D] and Quash together…those two work in a rotation as a very good fungicide preventative program,” Burkdoll stated.
Listen to Burkdoll’s interview below.