“We are finding minimal stink bug in weeds throughout some orchards.
“With this dry winter, more irrigation is being applied now versus the past several years. Unseasonably more leaves are out this year, making fertilizer and irrigation more critical. Growers tend to be applying fertilizer through their drip systems, as well.
“Egyptian alfalfa weevil populations are evident and are being controlled through sprays. The weevils can eat leaves and chew the plant if uncontrollable. They come once a year and we treat them.”
Franz Niederholzer, UC Farm Advisor, Colusa, Sutter and Yuba Counties
“Our area had a change in weather since mid-week when we almost hit record temperatures, with highs in the low-80s in some areas of the Sacramento Valley. As of today (Friday, March 6), things are cooling, with a chance of rain this weekend.
“The predicted rainfall amounts depend on where you are in the Sacramento Valley, ranging from zero to a half-inch. The north and east side of the valley tend to get the most rain, around Chico and along the Highway 99 corridor north. Winds are coming out of the south right now (3/6), which is the wind that brings rain.
“Most growers sprayed a fungicide this week. We are generally past petal fall. Having a fungicide on at petal fall with a chance of rain in the forecast is a good idea. With the remaining flower tissue left on the buds of later varieties, as well as leaf development, the trees could be susceptible to a wide range of diseases. Anything from rust, scab, shot hole or even brown rot can occur as the bloom season tails off. It is a time where fungus and bacterial infections can happen, given the proper conditions.
“For a majority of growers, this was their first fungicide spray because it has been so dry. Some growers applied a full bloom spray with a FRAC 11 fungicide targeting plant-health benefits. Opinions this year have been mixed on the need for sprays.
“Irrigation is underway across the north state in both almonds and walnuts because we haven’t had measurable rain since the middle of January. Water on almonds has generally included nitrogen fertilizers.
“We began putting up pheromone traps for oriental fruit moth and obliquebanded leafroller last week. Navel orangeworm, peach twig borer and San Jose scale traps will go up next week at the Nickels Soil Lab. Traps have been going up early this year because it has been so warm. Heat unit accumulations since January 1 this year are similar to what we recorded in 2015, which was the earliest navel orangeworm biofix in many decades at the Nickels Soil Lab.
“If you are planning to use navel orangeworm mating disruption this year, it is better to get dispensers up early – before March 20 to ensure the pheromone is out in the orchard ahead of female emergence. Also, carefully mow any remaining sanitation windrows to ensure all mummies have been shattered.
“Prune bloom is well underway, about three weeks ahead of last year. We have completely different conditions this year versus 2019. Prune bloom started late in 2019, while this year it’s earlier than average.
“I’m hearing reports about early signs of walnut catkins emerging. That’s very unusual for this time of year.”
Aaron Beene, PCA, Simplot Grower Solutions, Merced
“We are gearing up to get wet this weekend. Rain is in the forecast for Saturday with a couple of tenths of an inch predicted. It’s supposed to clear up for a day or two after that, then more rain is expected on Monday night through Tuesday. The forecast calls for a quarter to a third of an inch.
“Full bloom in our area was two weeks ago. We are now at petal fall and leaf expansion. Any remaining petals will be gone by the first of the week after this storm.
“With the warm storms coming on, there are concerns of jacket rot, shot hole, the beginning of scab, and possible anthracnose. Sitting at two weeks post-petal-fall and with storms in the forecast, leaf diseases are a consideration. A significant amount of plant debris is in the trees now in the form of petal jackets, and that increases the probability of botrytis developing.
“About 75% of my growers completed their first spray at full bloom 2 to 3 weeks ago. Then, they were applying fungicide and plant activator enhancement products to increase nut retention. Now, they are coming back at petal fall and applying fungicides with nutrients for jacket rot. Only a few growers elected to hold off.