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Hull split sprays have started on what sounds like a scattered basis. A few more applications will likely begin in the early part of the week.


More of our contacts have used terms like “aggressive” to describe the approach they and their growers will take in terms of their upcoming NOW campaign. That means multiple sprays at hull split – 2 treatments when a single shot is usually the standard practice or 3 applications where only a couple are typically made. In certain cases, a fourth might be in the plan in the very latest blocks.


Spider mite activity has picked up enough that applications are going out on a somewhat wider basis. With hotter weather now, PCAs are trying to stay ahead of potential blowups. It’s a field-by-field call and no real problems are reported.




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

“We’re kind of in the calm before the storm. Mostly, everyone is waiting for hull split. This variable weather continues. It’s supposed to get really hot today (6/22) and then reach 103 to 108 over the weekend, depending on the area. Next week, though, it will slip into the 90s again.


“I’m starting to see just a very vague hint of hull splitting in places. I still would be surprised to find any real splitting right now unless is was in an area that might be a little dry. But we really haven’t had a lot of drought stress to push things. As springs and summers go, the weather has been mostly seasonal.


“I suspect that everyone is watching closely for splitting. NOW damage was bad in places last year and nobody wants to miss the bus this year on spray timing.”


Editor's Note: The day after we talked with Franz Niederholzer for this week's report, he emailed us with a brief followup report: "No blanks splitting at Nickels Soil Lab, but I found a few splitting, whole nuts on one edge tree (low nut numbers on that tree). It's too early to spray based on that, but will watch. For Nickels, the second generation of NOW egg laying should start around next weekend, with PTB treatment timing (1330-1430 DD from original biofix) falling at the same time. Low numbers of walnut husk fly catches in the Arbuckle area (nothing, yet, at Nickels). Codling moth counts are bounching around -- high in some locations not so much in other."


David A. Doll, Pomology Farm Advisor, Merced County:

“The crop is still progressing. I suspect we’ll see hull split around July 7 to July 10. Of course, that’s always a guess but a lot of consensus seems to fall in line with those dates.


“We’ll likely see blanks splitting in the week after next. I think it’s still too early for anyone in this area to spray. We shouldn’t spray until we at least see that deep V as the suture starts to form. Blanks begin splitting pretty close to that point. Spraying earlier than that probably doesn’t help because the moths really don’t see the nut until it does start to split.



“It’s important to get ant bait out if you haven’t already done so. Also, if you’re interested in applying AF36 to prevent aflatoxin, this is the time to make that happen.


“No reports of any pistachios starting to fill but maybe in another week that should begin.”


Rick Foell, Field Manager, Capay Farms, Hamilton City:

“We are at early, early hull split and are just starting to see some blanks splitting. We will start our first hull split sprays tonight (6/22). Both our first and second applications will go out at night. That’s partly because of the hot weather, so spraying at night will maybe reduce spray evaporation. Also, we’ll gain a little knockdown on adults because they fly at night.


“In terms of what we were seeing in the traps, it wasn’t so much the number of NOW males but the fact that egg laying had been steadily increasing – then suddenly dropped off. We figured it was time to go. The second round of spraying will begin 14 days later, which puts it in the second week of July.


“We’re not messing around up here with NOW this year. We figure we will do 3 hull split sprays and maybe a fourth treatment on the late, late varieties, depending on how the pressure looks.


“In walnuts, we’re just finishing our 2A codling moth spray. Codling moth counts had been on the low end but we started treatments Tuesday night (6/19) because of the degree-day calculations. Then on Tuesday morning, those trap numbers jumped, so we’re confident that we did the right thing on timing.


“Mites are low. We’re not seeing enough to matter in anything. A few might turn up on a tree here and there but on the next check, they’re gone. They’re making appearances but then disappearing just as fast. We feel like that’s mainly due to the mild temperatures but we have 3 days of hot weather coming up, with highs into triple digits, and we anticipate some increase in mite activity.


“So, we are including a miticide in this hull split spray. It’s not that it’s needed immediately, but we know that if we didn’t include a miticide, we might wish later that we had. For Redding, they’re forecasting 105 today and 106 or 107 tomorrow. If we waited for the second hull split spray to put out a miticide, we might already be behind the 8 ball and couldn’t catch up.


“We talked this over and decided to include a miticide at the beginning. It doesn’t cost that much and we’re crossing the field anyway.


“We just finished our walnut harvest forecast. Primarily, we have Chandlers and Howards. Our Chandler crop appears to be down by 20% to 25% and the Howards are maybe 10% off. We don’t see any low-hanging or cracked limbs, particularly in the Howards. It’s a fairly brittle tree, and lack of limb breaking indicates fewer nuts.


“We don’t know why these yields are probably off. Maybe this is due to the cold weather early in the season. That could have had an effect on the tree, itself, even though the tree wasn’t pushing or blooming when the cold snap hit. Maybe the dry spring figures into that, too.


“Last year we harvested a bumper walnut crop and 2017 was a lot like this year, aside from the cold weather this year. There’s nothing we can do about that. It all gets back to playing the cards you’re dealt.”


Dan Prentice, Prentice Ag Consulting, Bakersfield:

“We’re getting very close to hull split. So far, I haven’t started any sprays but I think some will go out next week. I have heard that some guys are slowly beginning their applications.


“By the end of next week, we also will have some going and by the first week of July the equipment will be running pretty good.


“I’ve seen just a little splitting on edges on some of our very early, early blocks, plus blanks were opening. Where anything is splitting, it’s nothing consistent, just a few nuts on edges and nothing opening inside the block.


“We will be quite a bit more aggressive than usual at hull split, taking into account the trap numbers we saw earlier this year. We will spray more often in a lot of fields than we normally do. That won’t be the case with every block, but in the majority of our blocks we will treat twice and in some cases we probably will make a third application.


“We’re starting to see mites more frequently but it’s still nothing bad. Where we will spray multiple times, we won’t include a miticide with the first application. We’ll see what happens with mites after that initial round and then include a miticide on the next spray if mites are building. Where we’ll likely just spray once at hull split, we will include a miticide in the tank.


“In pistachios, we’re just kind of holding and observing. Shells are hard enough that it’s difficult to open them with your hands. No sign of kernel fill yet. We don’t really have any issues with plant bugs and the nuts are staying pretty clean. No mealy bugs since we sprayed earlier. No flat mites have appeared, although we expect that they will show up now that the weather has heated up.”


Todd Fukuda, Weinberger and Associates, Hanford:

“A little bit of mite is coming back, just a small amount of webbing in places and 3 or 4 mites on a leaf. We are treating where we’re seeing them like that. With this heat, they could blow up. The forecast calls for extremely high temperatures every day and we don’t think we’ll be able to make it to the hull split spray without heavy webbing and a good deal of damage.



“So, we want to get ahead of the game. A good part of our acreage received a miticide with the May spray and the weather was relatively mild in the spring and going into summer, which kind of helped with mites. By now, the abamectin has worn off.


“A couple of weeks after we spray mites on this round, we hope we’ll be at the start of hull split applications.


“In pistachios, we’re waiting for the second round of fungicide sprays in July for alternaria. In spots with a history of NOW, we’re hoping the degree days for NOW line up so that the first NOW treatment can go out with the fungicide. That would put us in a July 5-15 application window.


“Bug damage has slowed down quite a bit and I haven’t sprayed much for bug damage. We are moving into our AF36 applications for aflatoxin prevention. That will begin next week and then going into July.


“On the far east side in the Porterville area, we will be treating thrips in young, non-producing pistachio trees. These are in the vicinity of citrus and thrips are coming in from those trees. They feed on new shoots and tender leaves.”




California Almonds: Alkaline Treatments Reduce Hull Rot   6-22


California Almonds: Deficit Irrigation – Making the Most of Your Water 6-19




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