California Almonds: Rains Set In, Fungicides Going Out On A Wide Basis – AgFax

    Almonds post bloom, early fruit development. ©Sara Savary, AgFax Media

    • Here is this week’s issue of AgFax Tree Crops.
    • Our thanks to BASF and its California team for sponsoring this coverage.
    • Got questions or comments? Let us know.
    Owen Taylor, Editor
    Jenny Holtermann, Contributing Editor


    The warm, dry winter turned cold and wet as we welcomed the beginning of spring. Temperatures dropped into the low 30s at one point in the Sacramento Valley but probably didn’t go low enough for long enough to cause problems.

    Foliar development and protection are a concern with the wet weather, and growers in several areas of the state have been making preventive fungicide applications.

    Insect monitoring has begun in most of our coverage area, and navel orangeworm eggs are turning up in places. On the other hand, this round of cooler weather will likely slow any insect activity.

    Walnuts and pistachios are progressing into budswell and bloom on a wide basis.

    From our sponsor



    Sara Savary, PCA, Crop Care Associates, Fresno

    “We have not found any navel orangeworms or peach twig borers in traps yet.

    “Most orchards are due for another fungicide spray. It has been two weeks or more since the last application. A few growers are flying on a fungicide Saturday (3/21) before the next storm rolls in.

    “In the storm from last Sunday and Monday, we received over an inch of rain in places, and water is still standing in a number of fields. More rain fell today, just enough to keep things wet. The forecast calls for another rainstorm again this weekend, starting on Sunday and then into Monday.

    “Select orchards have had problems with alternaria in the past and will warrant monitoring. When rain occurs after bloom, there is a possibility for jacket rot, green fruit rot or shot hole.

    “Most growers are finishing fertilizers for this timeframe. A small percentage of growers who don’t have drip irrigation will lag behind on fertilizer work. They’ll have to wait for fields to dry out before they can get in to apply granular products.

    “Walnuts are starting to push buds and catkins. Growers are spraying for blight in Ivanhoe and Sunland varieties. In wet fields, growers are flying on copper and Manzate for protection.

    “Citrus is in pre-bloom and growers are applying foliage nutrients and fungicides. Nets will be going up on tangerines in the next few weeks.

    “Stonefruit is finishing up the bloom. Thrips applications are going out in some nectarine orchards.

    “In grapes, buds are starting to push out, and mildew sprays are going out next week on early varieties.”


    Dale Deshane, PCA, Supervised Control, Bakersfield

    “We need rain but rain can cause issues this time of year.

    “Growers have been treating for scab and rust protection. We have found areas with rust on the new foliage. With the cold weather and wet ground, we will be sure to find more rust once temperatures increase.

    “A considerable concern now is where growers have a history of alternaria. In the first week of April, we will start sprays in those problem areas.

    “Only a few growers applied a fungicide at petal fall. We are now getting into a 5-week post-petal fall period when general protection for foliar diseases should occur. With rain in the forecast for next week, growers will gear up for a fungicide spray again.

    “Pheromone traps in almonds tend to be normal, depending on grower and sanitation methods. We see small traces of mites, although nothing too concerning.

    “Growers are trying to apply fertilizer, but 50% of my guys haven’t started yet. This year with the late rain and heavy winter orchard maintenance, some have not had the chance to begin fertilizing. Others have applied fertilizer but haven’t watered to ensure soil retention.

    “A few egg traps in pistachios had high numbers of navel orangeworm, ranging from 300 to 400, but counts dropped quite a bit this week after the cooler temperatures. Navel orangeworm moth counts seem reasonable.

    From our sponsor…


    “Pistachios are pushing green tip, with a quarter to a half an inch out. Males are very swollen and close to bloom, looking a little early. Rains during bloom could increase the chance of botrytis.

    “Growers are monitoring for frosted scale and mealybug crawlers.  However, what we’ve seen has been minimal.

    “Growers are applying preventive sprays for blight in tomatoes and also for bacterial speck. Downy mildew and botrytis are concerns in onions, and rust treatments are underway in garlic.

    “In alfalfa, growers are finishing up Egyptian alfalfa weevil treatments. Pyrethroids are controlling a fair amount of stink bugs in alfalfa. When it comes time to cut the alfalfa, we could see stink bugs migrate into the orchards. We are finding more stink bug in alfalfa than usual, and that’s due to the dry, mild weather we’ve had up until now.

    “Farmers are working cotton and corn beds ahead of plantings, which should start at the beginning of next month.”


    Franz Niederholzer, UC Farm Advisor, Colusa, Sutter and Yuba Counties

    “A few growers around the Sutter Buttes ran sprinklers for frost protection this morning (3/19). Reports were that low temperatures got a few degrees away from real damage potential, running from 31 to 35 degrees in areas of western Sutter and Colusa Counties. I have not heard about any areas where dangerous temperatures were measured, which I hope means we dodged any problems.

    “We have been in a cooldown since last Friday (3/13) in this part of the state. We went from a high last week of 83 to yesterday’s high temperature of 51 degrees. We are back to the low 60s today (3/20).

    “Scattered rain occurred most of the week, with another storm starting Monday. Even better, the mountains have been getting snow.

    “From a disease standpoint, it has been wet and cold for extended periods. A majority of growers have or will put on a fungicide ahead of the rain that’s predicted to start next Monday (3/23). Fungicide sprays are generally effective for 10 to 14 days unless there is a heavy rain – for example, over two inches. Length of tissue wetness is key to infection. Even in cool weather, extended wetness can trigger infection.

    “Insect traps are out, and we found navel orangeworm eggs last week at Nickels Soil Lab. The eggs were probably laid last Friday night during the last warm weather.

    “We also caught a fair number of males during the warm weather earlier last week, but the egg laying really signaled the start of NOW activity. Other PCAs told me about finding eggs at the end of last week.

    “A biofix for March 13 or March 14 is a week earlier than the earliest we’ve seen in decades, which will be important for timing spring sprays and hull split. It’s certainly critical to get a handle on insect populations in a year like this.”


    Brian Gogue, PCA, Helena Agri-Enterprises, LLC, Hanford

    “Our area received a half to three-quarters of an inch during the last storm on Monday. It was just starting to dry out when a smaller rainstorm landed Tuesday night. Today (3/19), we received a quarter to a third of an inch, with scattered showers on and off in Hanford. The forecast is predicting four-tenths to half an inch for Monday through Wednesday of next week.

    “All of our growers except one applied a fungicide at the end of last week and into the weekend. Timely fungicide applications are essential.

    “In a few orchards, we’re already finding good nut sizing. With the recent rains and wind, trees did lose some leaves and viable nuts that were developing. In the worst fields, maybe 2% to 3% of the viable nuts are on the ground.

    “We have seen very minimal insect populations in our area. As soon as traps were out, the weather cooled down.

    “Almond growers are between fertilizer applications. Growers are mainly applying phosphate, nitrogen and zinc. The next round of fertilizers should be applied in the next week or two.

    “Golden Hills pistachios are starting to push green growth. Kerman and Lost Hills are currently at budswell.

    “In walnuts, the Serrs are pushing noticeable catkins and leaf growth. Nutlets also are showing on trees along the edges of the orchards. ReTain will be applied in the coming week for pistil flower abscission. ReTain can aid as an ethylene gas blocker to prevent nuts from falling off the trees. Serrs are more sensitive to excess pollen than other varieties.

    “Early grape varieties are starting to push buds and leaves. Fungicide applications are being lined up for earlier blocks. Last-minute herbicide applications are finishing up.

    “Transplanting tomatoes shut down due to rain. Hopefully by the middle of next week that can start again, weather permitting. Bacterial speck is a concern with showers during this timing, especially after the pressure we had last year. Bacterial speck can hinder the leaves and growth of young plants.

    “Cotton planting is on hold due to weather and lack of access into fields.”


    Luke Milliron, Area Sustainable Orchard Research Advisor, Butte, Glenn and Tehama Counties

    “Rain is in the forecast in parts of the northern Sacramento Valley for Monday through Wednesday next week.

    “Growers were busy spraying fungicides before the last storm. Many growers also were spraying fungicides on prunes ahead of the previous storm. Many prunes in the area were at the critical full bloom stage ahead of the storm, and people had concerns about brown rot and russet scab.

    “Walnuts look to be progressing early this year, with concerns about blight in early varieties that are pushing catkins and are into the prayer stage. A few growers even see a low percentage of prayer stage in Chandlers. Growers with a history of blight are more aggressive with early control.

    “In almonds, several Monterey growers on Krymsk 86 are reporting issues with leafout, similar to a bud failure appearance. In minor cases, growers are seeing leafout delays and in severe cases there are no viable vegetative buds, only nuts.

    “The reports are mainly in mature orchards, but I’ve seen symptoms in blocks as young as third leaf. Some growers with orchards that should be in their prime or approaching prime yield, have experienced the issue multiple years and report declining Monterey yields.

    “Fertilizer applications were well underway before the last storm occurred.”


    Rodney Ratzlaff, PCA/CCA, Nutrien, Merced

    “With the rain last weekend, most growers have applied their second fungicide spray for the year. We received anywhere from one inch to almost two inches in certain areas. Spotty showers fell in the northern Merced area all week, with some areas receiving small amounts of hail.

    “More rain is expected for next Monday through Wednesday, prompting the growers that haven’t applied the second fungicide to do so quickly.

    From our sponsor…


    “Along with a fungicide, growers are also applying an array of foliar nutrients for what looks like a large nut set in the Atwater and Livingston areas. With the tissue still soft, it’s an excellent time for rapid absorption of nutrients. Certain micronutrient deficiencies are starting to show, including some chlorosis on the leaves, and it’s most likely due to lack of zinc, iron or manganese.

    “The nuts are growing rapidly now with ample moisture and with the addition of fertilizer through the irrigation systems. A few orchards are showing a large gap between what was first pollinated, with varying sizing of the nuts. Almonds vary from well out of the jacket to just starting to size up.

    “We are gaining a better idea of what actual crop loads look like. Nonpareil seems to be hit and miss this year, with the majority not looking as expected after a stellar bloom. Other soft-shell varieties look very good, while we’re unsure how the Butte and Padres will set.

    “Naval orangeworm traps are up, and we are noticing no shortage of leaf rollers this year.”


    Gary Gliddon, PCA, Treevine Consulting, Modesto

    “Almond trees in our area look like they could have a heavy crop this year. The first drop of non-viable nuts has occurred and what remains is sizing. More will continue to drop. How many more remains to be seen.

    “Almonds are not as alternate bearing as pistachios, but given the conditions, they could produce an alternate bearing crop this year. Last year, we got hit with bacterial blast, frost and cold temperatures – and ended up with a dismal crop. This year looks much better.

    “The majority of growers are approaching 14 days past the last fungicide application, and they are considering another round of fungicide. However, we currently don’t see signs of botrytis or jacket rot. Growers are assessing the need for another fungicide spray on a variety or orchard basis. Growers have also been adding zinc or potassium to fungicide applications when needed.

    “We are within the 2- to 5-week post-petal fall window when diseases may start. Carmels tend to be more susceptible to scab, Fritz had issues with bacterial spot a few years ago and Monterey has seen historical jacket rot and scab issues. Variety-specific assessments like this will warrant another fungicide spray when we move beyond that 14-day window after the last application.

    “Navel orangeworm moths are quite active and flying. Egg traps are not all up yet. No significant mite activity is visible either.

    “Growers need to ensure fertilizer is applied, especially when we see large crops developing on the trees. The majority of growers have already applied 10 to 20 pounds in the first round by drip irrigation and will continue this program.

    “Growers need to re-analyze their nitrogen management plans, considering the crop they see on the trees. Growers may want to start thinking of larger applications to take advantage of higher potential.”

    Sponsored By


    AgFax Tree Crops is published by:

    AgFax Media LLC, 142 Westlake Drive, Brandon, MS 39047-9020.   

    601-992-9488, Owen Taylor, Editor and Publisher.

    For subscription or advertising inquiries, please contact Owen Taylor.

    © 2020, AgFax Media LLC

    The Latest

    Send press releases to

    View All Events

    Send press releases to

    View All Events