“Navel orangeworm egg counts are slightly below average for this point. We will continue assessing things as the weather warms up over the next 3 to 4 weeks. Typically, we don’t see high populations in wet and cool weather.
“In pistachios, navel orangeworm counts were running high initially, then they leveled off. The rain came early enough that we do not see botrytis or other leaf diseases.
“We are monitoring for plant bug past bloom as shells start to size.”
Aaron Heinrich, Independent Crop Advisor, AgriWest Inc., Escalon
“We deployed egg, pheromone and kairomone traps in almonds and have seen a sharp increase in navel orangeworm over the last week as temperatures increased. Several growers will apply a mummy spray over the last two weeks of April. We detected a large overwintering flight, so knocking down populations now will be essential for pest management at hull split.
“Almond growers will be making their second or third applications of fertilizer over the next few weeks. Mostly, those are going out through irrigation, with a few using dry materials or liquid nitrogen followed with irrigation.
“We have found a few mites. Mostly, we are monitoring for leaffooted plant bug. Although we have not seen large numbers of leaffooted bugs yet, we know they are out there, and we will treat if necessary.
“Almonds are shaping up like a mega crop and, so far, most orchards look very clean. Most growers made at least two or more fungicide sprays during bloom, along with a later treatment to protect against tissue disease.
“In walnuts, the first flight of codling moth is increasing, and that trend will likely continue because the forecast for the Ripon area calls for highs into the 90-degree range into next week. We are 180-degree days from the biofix for codling moth in Modesto. Treatment for the first flight will be at 300-degree days, which will be the last week of April and into the first week of May.
“We are finding fruit tree leafrollers in moderate levels across Stanislaus and San Joaquin Counties. Depending on treatment time, we may be able to combine applications to control first generation codling moth when we spray for leafrollers. Walnuts can generally sustain damage, but when levels rise above moderate and high amounts, the leafroller can feed on nutlets and cause a problem that justifies a treatment.
“Frosted scale has shown up, with heavy populations in a couple of walnut blocks that were treated during delayed dormant timing. We are monitoring them closely with sticky tape for crawler emergence to determine if a follow up treatment will be necessary.
“Growers are starting to fertilize walnuts, and irrigation will begin as temperatures continue to remain high. Growers have a variety of tools available for irrigation monitoring, like pressure bombs, soil moisture readers and tensiometers.”
Nathan Stewart, PCA, AgVantage Consulting, Inc., Visalia
“We’re into our May spray in almonds and are including a fungicide where we have seen alternaria in the past or in locations with historic pressure. Plus, we’re monitoring areas with dense canopies, low winds and standing water.
“Sunday night through Monday (4/20), we received roughly half an inch of rain in the Corcoran and Tipton areas. Going from cold weather and rain showers to 85 degrees this week creates perfect condition for alternaria. Growers are being extra cautious and are keeping an eye out.