Here is this week's issue of AgFax Tree Crops.
Our thanks to BASF’s California team for once again sponsoring our coverage of tree crops in the Central Valley.
Owen Taylor, Editor
Leaffooted plant bugs have required treatments over the last week in both almonds and pistachios. Again, we’re not hearing about widespread problems but the pest has not faded into the background.
A few more spider mite applications have cranked up in the lower SJV.
Kernel filling continues but we’re also hearing additional reports about variability in how the fill is progressing. An elongated bloom period is being cited. This at least hints at a prolonged hull split, which would extend the window for protecting nuts from worms.
Franz Niederholzer, UC Farm Advisor, Sutter/Yuba Counties:
“Insect numbers are either low or kind of normal with the exception of the obliquebanded leafroller, and I don’t know what to make of that. NOW trap numbers are bouncing around, depending on location and maybe how well neighbors sanitized blocks.
“In places, adult NOW numbers are way up but I’m not seeing any overall trend. In the traps I’m monitoring, PTB numbers seem low compared to what I normally expect in mid-May. No one has called lately about leaffooted bugs. Mites aren’t jumping up in almonds.
“I am hearing reports about higher numbers of codling moths in some walnut blocks but they appear to be low in others. However, I have noticed several walnut sprayers on the road, so someone is likely treating for something. The forecast hints at rain, so I suspect growers are getting coverage out for blight on certain varieties and maybe adding something for codling moths, too.”
Kris E. Tollerup, IPM Cooperative Extension Advisor, Kearney AREC, Parlier:
“We’ve seen quite a bit of pressure from leaffooted plant bugs this year, especially early on. We really need to monitor and remain diligent, especially where they’ve turned up in the past. The danger isn’t over and I’ve seen them cause staining – or what’s referred to as black spot – nearly up to hull split. You’ll find more information in our IPM guidelines.
“People are still finding them. They can cause early nuts to fall off the trees in April and cause necrosis later on. In those later cases, nuts are damaged but stay on the tree.
“Generally, we had a lot of NOW pressure last year and this year looks like it could trend that way. If you’re going with mating disruption, use other techniques, as well. Monitor egg traps and also evaluate egg laying on newly-split almonds. At that point, you can kind of tell what’s happening.
“We’ll likely have to apply insecticides at hull split. That’s a decision between the grower and the PCA, of course, but we’re seeing enough activity to indicate a need to spray a big portion of the crop.
“I haven’t seen spider mites really pop up yet where we’re monitoring for them in Kern County. That’s not to say they haven’t started building in places. Generally, I discourage growers from making prophylactic treatments for mites. However, I’m not in the grower’s boots. How he chooses to approach this can depend on how much spraying capacity he has and how quickly he can treat if mites begin building.
“I would suggest putting out sticky cards and monitoring for six-spotted thrips, which are a very effective predator on mites. I can’t guarantee that the thrips will completely prevent damage but they can play a role in suppressing mite populations. You may, in fact, sustain some early damage while you wait, but I’ve also seen those thrips come in and clean up mite populations. At the very least, put those cards out and get a better idea about whether you’ve got that beneficial population in a given orchard.”
Dale Deshane, PCA, Supervised Control, Bakersfield:
“This week we started seeing mites flaring up a little, and we’ve set up some treatments to go out right at the end of the week. These are the first instances of mites building this season and it really just started in the last few days (from 5/18).
“Also this week, we began finding some alternaria popping up for the first time this year. We’re seeing traces of rust here and there, nothing bad.
“All of our NOW traps are running pretty consistently now – 20 to 40 adults per week. Mostly, numbers are hanging in that range with nothing jumping up anywhere.
“Nut fill is kind of scattered. One guy said he’s seeing wide variations. Some nuts are virtually filled and others have barely started. A lot of this has to do with how extended the bloom was, I think. It ran nearly a month in places. Even 3 weeks after trees started blooming, some still had blooms.
“That wide span of blooming will complicate NOW management since we’ll have nuts splitting early and then have an extended split once it does start. It will be tricky trying to protect it all. That’s just how this year is shaping up. I’m expecting that we’ll make multiple sprays to protect nuts from the worms.
“In pistachios, we have some mealy bug treatments going out. Timing depends on the material used. Some treatments went out with water earlier. Now, we’re making foliar applications. Pistachio nut clusters look pretty good. No issues have turned up with plant bugs or stink bugs.
“Considering this year’s weather, pistachios look pretty good, and this is an ‘on’ year for a lot of our orchards. A few blocks look weak but those tended to do well last year. Overall, 60% to 70% of our producing pistachio orchards do look pretty good.
“Our cotton is on about the fifth node this week and we started sweeping for lygus. So far, lygus counts are all zeros. The earliest cotton is pushing the sixth node and a few squares are starting to form. We’re finding a single aphid here and there. We’re getting across most fields with a miticide before we start watering.
“Tomatoes are doing well. No worm problems yet. We’re finding a few fruit worm eggs this week but no hatches yet with fruit worms, loopers, armyworms or anything else. We did end up with a little leafhopper in Buttonwillow where tomatoes were planted a bit later and we also found some curly top there – but nothing really bad like we saw a few years ago. Again, it’s more in the later fields than where they were planted early.”
Sara Savary, PCA, Crop Care Associates, Fresno:
“In almonds, we’ve had to clean up a little leaffooted bug activity. They just kind of came in. I thought they were gone but then I started finding them yet again. That was in a location where we were dealing with them 2 years ago but not last year. In a couple of places, I pretty much know that we will find them every year but then we have these other spots where they may or may not turn up.
“We’re not doing any May sprays. Our trees are sanitized and it’s hard to find any mummy nuts at all. Where I can find mummies, worms aren’t in them. We had fairly low damage last year.
“In walnuts, we just completed spraying for the 1B codling moth flight. That’s just in the early varieties and in places where we picked up some high trap counts.
“Our cotton is now at 4 leaves. In alfalfa, we’re starting the second cutting and haven’t been finding anything. My earliest tomato field has begun blooming. No worm activity. We’ve been spraying thrips because they carry tomato spotted wilt virus and leafhoppers because they carry curly top, and that’s been it.”
David A. Doll, Pomology Farm Advisor, Merced County:
“We’re seeing a lot of variability in kernel fill, at least in Nonpareils. In places, they are two-thirds to three-quarters filled and progressing relatively fast this week. The weather mostly remains mild and not many issues are surfacing. Based on the forecast, conditions will be clear, so the crop should be running at full steam ahead.
“I suspect this will be a later harvest than what we might consider average. At first, I expected it to run a couple of weeks later. But where I cut nuts today (5/18) it might be 7 to 10 days later than normal. That puts it maybe a couple of days later than last year.
“In pistachios, it looks like we’re nearing the end of stage one and will be transitioning into shell hardening in another week or two. Once we get into June, people can start backing off on irrigation if they’re short on water or if they want to apply a bit of deficit irrigation.
“In walnuts, the forecast carries a slight uptick in rain chances next week but I’m generally not hearing about any blight pressure. I’m getting reports of an occasional codling moth spray.”
Gary Gliddon, PCA, Treevine Consulting, Modesto:
“Almond trees have good color and are loaded with nuts. Limbs are starting to break, which will probably increase over the next month. I’m telling my growers to keep up with fertilizer and irrigation.
“NOW moths are flying, and we’re detecting a lot of activity this week. Once we get through this flight, I don’t expect to see much from them until hull split – and I hope we don’t see much then. We haven’t left them too many places to lay eggs. Most of the trees are clean, and we hope we don’t have problems with NOW like we did last year.
“It wasn’t an easy winter to shake trees because things were so dry, and we do have some fields with mummy nuts, so it’s not 100%. But most of our trees are clean. Flights we’re seeing now are mainly from off the ground, I suspect. No mite problems.
“All my walnuts are late varieties – Chandlers and Howards – so they’re not big codling moth magnets and we’re not catching many right now. We’ll look ahead to treating the 2A flight after mid-June. That also should be the best timing for botryosphaeria, so we can address both at the same time. Walnuts are growing well. The biggest thing has been a bit of a spread in the size of nuts, which is probably due to the bloom being so spread out.”
Todd Fukuda, Weinberger and Associates, Hanford:
“In almonds, there’s not a lot of bug damage. Nuts are starting to harden a little. Moths keep on turning up in pretty good numbers and traps are maxing out on available space. Otherwise, we’re just sitting and waiting.
“In some pistachios in northern Kern County and southeastern Tulare County, we’re finding adult leaffooted bugs, their egg casings and related damage, and we’ve sprayed a few blocks in those areas. In Kings and Tulare Counties, we’ve found a lot of damage, especially in the last 10 days. We’re not actually seeing bugs, so it’s hard to say which are causing these new strikes. As it happens, treatments for those bugs is lining up with our mealy bug applications, so it will only take one trip. Alfalfa is being cut in the area, which may be causing some of this insect movement.
“We’ve treated false chinch bugs on two fields of young trees where they had built to a problem.”
Subscribe To This Weekly Report
AgFax Tree Crops, formerly AgFax Almonds, is published weekly during the crop production season.
AgFax Tree Crops span> is published byAgFax Media LLC 142 Westlake DriveBrandon, MS 39047-9020. 601-992-9488 Owen Taylor, Editor and Publisher.
For subscription inquiries, please contact Laurie Courtney -
© 2018, AgFax Media LLC