AgFax Tree Crops: Insects More Apparent, Some May Sprays Commence


Owen Taylor, Editor


May sprays have been going out in places over the last week.

Moth trap counts are increasing somewhat, depending on the area and the species.

Hotter weather is bringing the crop along. Drop has been obvious in more areas but nothing out of the ordinary has been noted.

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Mark W.F. Carter, PCA, Agri-Consultants, Los Banos:

“In almonds, we’re getting all of our May sprays wrapped up for both stink bugs and NOW. Stink bugs aren’t as obvious this year but we’re spraying on the NOW timing and are adding a pyrethroid for stink bugs. The stink bugs aren’t as heavy as normal but you can see them.

“We did not include a fungicide with the application. I’ve checked for disease in the last 2 weeks and haven’t seen anything. We made a fungicide application 4 weeks after petal fall and have had no rain since then.

“Growers continue cleaning up the centers. With more rain this year, we have more weeds than usual. Overall, the crop looks pretty good. If trees weren’t hit with bacterial blast, they’re in decent shape this year.

“My NOW trap counts have been up and down. Our PTB traps were light in the beginning but those numbers began coming up in the last 2 weeks. One reason we included a pyrethroid with the May spray was to knock down some of those adults.”

Franz Niederholzer, UC Farm Advisor, Sutter/Yuba Counties:

“Our PTB biofix at the Nickels Soil Lab has been set at April 17 and the NOW biofix has been set at April 26. It may be helpful for people to know where our biofixes are but every location is different. If you can compare biofixes from different areas, it at least gives you an idea about how things might be trending.

“The earliest biofix I can remember was a month before we set this year’s dates, but that was in a dry year. This year definitely isn’t dry, and that can influence insect development. The dates for this year might be a couple of weeks later than normal, depending on how you define normal. Overall, I’m not hearing about a lot of moth catches.

“People who use puffers are putting them in place for mating disruption.

“The weather has heated up and we’ve turned the corner towards summer. Temperatures have been in the mid to upper 80s today (5/3), which is a little above normal but certainly not scorching. The forecast puts the chance of rain at 20% to 30% for the weekend but that’s not high enough for anyone to get too excited about in terms of disease potential.

“The delay in insect activity is maybe an indicator that the crop will be late, too. It was pretty cool early, so that would have slowed development. Chances are that hull split and other key points will happen a bit later on the calendar than we typically expect.

A reminder: our Nickels Soil Lab field day is this coming week on May 7.” Editor’s Note: See info on the field day in our Also Of Note section.

Dwaine Heinrich, PCA, Stanislaus Farm Supply, Modesto:

“In almonds, some guys are starting to put on what they’d call their May spray for PTB or NOW. That’s happening this week and several have already finished. It’s about the right time for the applications.

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“We’re still putting on fertilizer and keeping the nitrogen going. Some herbicide applications are being made, too.

“In walnuts, the first codling moth flight is coming on, the 1A timing. The only people who’d spray would be those who sustained a lot of insect damage last year. A few people will treat the 1B flight to kind of reduce moth populations, and the degree-day model projects that timing around May 23.

“The weather has warmed up and the forecast for the net 10 days indicates we’re on the way to summer. With these higher temperatures, not too many people will be considering a walnut blight spray now.”

Tony Touma, PCA, Bio Ag Consulting, Bakersfield:

“In almonds, we’re starting on our second alternaria spray where we have a history of it. Also, we’re finding a little bit of rust here and there, nothing significant. Mites continue to be very light, with no indication of issues.

“Probably the main thing in almonds right now is stink bugs. They built into high numbers a couple of years ago. Stink bugs aren’t that heavy right now but they’re spread all around. We’re detecting some damage that seems due to stink bugs, not leaffooted bugs.

“Some leaffooted bugs are around edges but nothing significant. Right now (5/3) we’re doing just limited treatments for stink bugs and leaffooted bugs.

“Over the last 10 days, the so-called June drop started. The trees are adjusting their crop load, and we were expecting it, especially in the Montereys. The crop is heavy on those trees and the adjustment has been more noticeable on them, too.

“Overall, the crop still looks very promising. The temperature right now is 86. Trees look happy, not stressed. The forecast says we’re in for a cooling trend in the next few days, down in the low 70s.

“My feeling is that NOW moth trap counts – up to this point – are significantly lower than up during that period last year. In pistachios, trap counts are a lot higher than in 2018 during the same period. That’s kind of crazy and runs counter to what we would have expected.

“In pistachios last year, we ended up with one of the cleanest crops in the 15 years. There were no NOW in pistachios but it’s a completely different situation this year.

“Nuts are sizing up in our pistachios. Most growers are finishing their first nutrient spray, and there’s no sign of problems. It looks like most of my growers will have an off year, which is predictable, considering the strong pistachio yields last year.

“Cotton is doing well and is almost at the second true leaf. Most of the stands look good. A lot of people are making Roundup applications. A few cabbage loopers are turning up in cotton. In a lot of years, they come into cotton but just kind of trickle out and go away.

“We usually expect more worms in a number of crops in a really wet year like this. If anything, worms could be quite bad this season. Last year, we hardly sprayed any alfalfa for worms. We probably won’t get by like that this year, although nothing is going on in alfalfa yet.”

Nick Groenenberg, Independent PCA, Hanford:

“Almonds are doing pretty good. We made a mummy spray 2 weeks ago around April 20 or so. The spray included a NOW material, a miticide and something for nutrition. The timing on that mummy spray may be a little better with some guidance that Joel Siegel (USDA entomologist, Parlier) has been providing.

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“Other than that, people are applying fertilizer and herbicides and dealing with irrigation. The almond crop looks really pretty. Some of these trees that are 5 or 6 years old are carrying a lot of nuts and aren’t strong enough yet to hold all that, so growers are tying them. I’ve looked at some of their neighbors’ orchards that weren’t tied and I’m seeing splitting and trees are already coming apart.

“Pistachios look pretty good. We’re wrapping up nutritional sprays. Blooming was kind of spread out, so we’ve got a mix of larger and smaller berries. Again, though, it’s a nice crop.

“This was a good year to plant cotton and stands are solid. Just at the end of this week we began finding an occasional beet armyworm in the field. It’s nothing widespread, just in certain areas. In spots, we might find 2 worms. No mites or thrips in cotton. Herbicides are going out.

“Alfalfa looks good and it’s clean. Tomatoes are growing like a weed. They’re loving this weather, and there’s no insect or disease pressure. We’re trying to grow as big a bush as we can as fast as we can to have a frame for growing fruit. In garlic, growers are cutting off water this week or next week.”

Jhalendra Rijal, Area IPM Advisor, Northern San Joaquin Valley:

“In the northern San Joaquin Valley, we’re seeing high NOW male moth counts in pheromone traps compared to the previous week. That count was made on April 30. In the 3 orchards we monitor with 3 traps in each orchard, counts for this most recent monitoring period averaged 40 moths per week.

“That’s a big jump from the previous period, which was about 10 moths during that 7-day period. In other words, we’re finding a 4-fold increase.

“With the male moths, we’re potentially in the peak of the first flight, although we’ll have to see how next week’s count goes. Female activity in mummy pistachio-bait traps has increased as well.

“We’re in that period around the end of April and in the first week of May when growers make that May spray for NOW if there’s a need. UC does not recommend May sprays for navel orangeworm unless there are heavy mummies present and a need for the PTB spray.

“We also discourage the use of pyrethroids as they are detrimental to the mite predators, especially six-spotted thrips. Based on 2017 and 2018 monitoring in almond orchards, we found six-spotted thrips activity beginning April and May in San Joaquin Valley.

“We’re not hearing much about leaffooted bugs. Activity is mild, more or less. With stink bugs, our trap counts for brown marmorated stink bugs (BMSB) are increasing in places. In 6 peach orchards we monitor, we caught BMSB in 5 of them. The numbers were low, maybe 1 to 2 per trap in a week but this indicates they are at least present in sites where we have traps.

“In almonds, we caught BMSB in 2 out of the 5 monitoring locations, and I expect those numbers to increase. PTB counts also increased in peaches in the 7-day trapping period that just ended. If you intend to spray, the timing for PTB is around the early part of next week.

“We also picked up more codling moth activity in walnuts during this last cycle compared to the previous week. The biofix was set at April 16 in that area. Right now, we’re in the first peak of the first flight, the 1A period. There is no need for a spray for this 1A timing unless the damage last year exceeded 3%. Wait until 1B timing to spray, and that timing this year will be around the third week of May based on codling moth activity in our traps.

“Also, we recommend growers and PCAs use two lure types, CM (pheromone) and CMDA (pheromone plus kairomone) for accurate assessment of the population in the orchard.”

Wide range of topics covering almonds and walnuts.
“My visitations to many orchards, young and old, suggest there could be 750 million to 800 million pounds out there.
The pattern of affected trees has been highly variable across these orchard blocks.
Plenty of scouting this month – here’s the list.
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