California Almonds – Rain Persists, Fungicide Decisions In Play – AgFax Tree Crops

OVERVIEW

More rain – that’s been the overriding factor in almond country over the last week. Rainfall amounts have been more like you’d expect in Louisiana in late May. Rain also was in the forecast for the weekend as we closed out this issue on Saturday morning. After this next system, temperatures are supposed to heat up, at least a bit.

Fungicide decisions are being made on a wide basis. Plenty of factors are being considered – an orchard’s history, how much it’s rained, how long has it been since the last fungicide application and – of course – the grower’s aversion to risk.

It’s a nice crop, our contacts continue to tell us. Plenty of tying and bracing have been necessary.

CROP REPORTS

Gary Gliddon, PCA, Treevine Consulting, Modesto:

“I’m pretty amazed about how things are shaping up. We’ve gone through all this wet weather and cold temperatures during the spring and I didn’t have particularly high expectations. But with a few exceptions, most of the almonds I work have more crop than you’d expect – to the point that limbs are breaking.

“Growers are saying they don’t know where all these almonds came from. I’m telling them that the Almond Fairy has been skimming over their orchards and tapping the trees with her magic wand. That’s about the only explanation I can come up with. I’m like them – I don’t know where those nuts came from, either.

“We also have zero disease. I can’t find any shot hole or brown rot. By now, you’d expect them to show up. All the leaves are green, with no marks unless it’s from a little herbicide drift. Trees also are putting on plenty of new growth. All that is happening, despite one of the toughest springs anyone can remember.

“The only sign of a problem has been that earlier bacterial blast on certain trees, but with most orchards it’s very minimal. Where it hit some of the younger trees, they won’t do anything this year but they’re still growing. One grower said that he guesses those trees will make a big crop next year.

“This is the most rain we’ve had in May and another storm is in the forecast for Sunday (5/26), plus warm weather will follow. That should lead toward disease outbreaks, in theory, but my trees are clean. We do have to worry about rust, scab and anthracnose, and these conditions are perfect for anthracnose, in particular. If scab were around, I think we would have found it earlier.

“But nothing is out there, no issues or symptoms. If rust shows up, we can spray for it, but most of the other PCAs in this area aren’t finding it either.

“Anthracnose hasn’t been a problem for us for years. It did show up last year in one client’s organic almonds and then we found it in another guy’s block. But I decided that we wouldn’t do any wide-area spray for something that 95% of my growers don’t have in their orchards.

“In fact, it’s been so long since we’ve detected anthracnose in this area that some of our younger guys have never even seen it.

“We’ll ride this out with the exception of spraying in those two cases where it did appear. That said, Monterey seems more susceptible to anthracnose. I told growers with Montereys to spray if they were at all worried and include some nutrients. But they decided to ride it out.

“Some guys got 1.25 to 2 inches of rain in Merced and Stanislaus Counties after that last big storm and a little more rain fell on Tuesday. The next storm is supposed to come in tomorrow night (5/25).

“I wouldn’t expect much insect activity with these conditions, and NOW trap numbers were down anyway, so that flight probably peaked. Mites are pretty much nonexistent.”

Dan Prentice, Prentice Ag Consulting, Bakersfield:

“It rained again last night (5/23) and areas in the south end of the valley got another inch or so.

“In almonds, we’re trying to line up a lot of fungicide applications. With this rain, we’re worried about rust and alternaria blowing up, so we’re trying to get everything covered. Plus, we’re shortening spray intervals from 3 or 4 weeks to 2 weeks.

“We don’t get these late May rains often, maybe every 10 to 12 years – maybe even not that often. This weather has really been something. One guy the other day remembered a year like this. It was 1978, and I was 3 years old at the time.

“We still have 2 blocks where mites were increasing before this rain started. While the rain knocked them down, they’ll still require a treatment when we get in the field again. Otherwise, mites are in the background – to the point that they’re hard to find if at all. Stink bugs are still on the radar but they’re mostly cleaned up. I’m seeing minimal activity in places but not enough to treat.

“These storms came through in just little cells. One area has maybe got a quarter-inch but 10 miles away it rained 1.5 inches. Several of those moved through, and it seems like it’s happened more in the extreme southern valley than around Bakersfield. But it’s rained often enough that everyone has probably gotten some.

“Over the last 10 days, the lighter totals have probably been around an inch but in places as much as 3 inches of rain fell.

“Overall, the almond crop looks really good. Trees are heavy and guys have been scrambling in the last month to tie and prop up branches.

“With pistachios, we’ve also been lining up fungicides. We’re approaching the timing for mealybug sprays and also will include a fungicide in a lot of those treatments, plus sulfur for citrus flat mites. We’ll probably start the mealybug treatments in 6 to 8 days (from 5/24).”

Todd Fukuda, Weinberger and Associates, Hanford:

“In almonds, we finally finished our May spray and got a free ride for a fungicide. Everybody is talking about the storms and whether another fungicide should go out. It mostly just depends on how worried you might be that something will pop up.

“With these cooler conditions, bug development has slowed.

“In pistachios, we just finished fungicide sprays, so that timing was pretty good. Where we could get in by ground and make a mealybug application, we included a fungicide. Where it was too wet to spray by ground, we flew on a fungicide and applied imidacloprid through irrigation for mealybugs.

“We’ve found leaf burn in some pistachios but aren’t sure what it is. To be on the safe side, we’re having it analyzed for disease, but this may be related to nutrition applications. We made our zinc-copper spray in the early season when leaves were still soft. Right after that, we got a rain – and then right after that we got yet another rain. The nutrients may have solubilized again and moved to part of the leaf, causing a little leaf burn.

“Some bug damage has turned up on large nuts in certain pistachio blocks, and that’s worrying me a little. But with the rain and cooler temperatures, insects are slowing down a bit. In almonds, we’re seeing very little bug activity.

“Over the last 10 days, some blocks received a half-inch of rain while the total in others reached 1.25 inches. I can’t remember when we’ve had rain this heavy this late. Sure, we might see a few sprinkles in May, but enough rain has fallen in places to keep equipment out of the orchards.”

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

“We had rain over the weekend (5/18-19) in the Sacramento Valley, from an eighth of an inch to over an inch, plus scattered showers on Monday and Tuesday, but things have gotten progressively better. However, they are talking about a 50% chance of rain on Sunday, then we’ll move back into warmer conditions.

“I see some sprayers going today (5/24), and growers are trying to get a fungicide on ahead of this next rain, I think. I suspect that some growers are playing catchup. They maybe didn’t spray in front of these last storms or didn’t make it around to all their trees.

“It started raining last Wednesday (5/15) and remained rainy and blustery through that weekend. It was more of an actual storm system, not one of those showers that sneaks in and deposits a couple of tenths, all of which dries up when a north wind immediately follows.

“It was widespread and cold enough that it snowed in the mountains. In places in the valley, 2 to 3 inches of rain fell and here at Nickels we measured at least 1.6 inches.

“How much disease risk we’ll have if it rains on Sunday will partly depend on when the last fungicide went on. The forecast says totals on Sunday will range from a trace to almonds an inch, and how much it rains will likely depend on where you are in the valley.

“At the Nickels Soil Lab, we decided not to spray this week. I hope we’re right. Conditions will turn warmer and drier after that, if the prediction holds.

“With our next irrigation at Nickels, we will include nitrogen for walnuts and another shot of nitrogen and potassium for almonds. In almonds, kernels are still filling, so they’re also still consuming plenty of nitrogen. It’s a good time to continue supplying nitrogen to almonds – depending, of course, on a block’s history with hull rot.”

Aaron Beene, PCA, Simplot Grower Solutions, Merced:

“Over the last 7 days it’s rained about 2.5 inches in this area, and I’ve read and heard that this already is among the 3 wettest Mays ever recorded in this part of the state. It seems like it’s raining about every other day, with heavy downpours and thunderstorms.

“One more system is coming this weekend (5/25-26) before the weather clears up again. If the forecast is right, we’ll move into the mid to high 80s by the end of next week, which will be a drastic temperature change.

“A lot of my guys are lined up for a fungicide application on almonds. For most, the last fungicide spray was 4 to 6 weeks ago (from 5/24). This treatment will cover late-season leaf diseases like rust and scab that might blow up in June when temperatures increase and humidity rises due to all this wet ground.

“With a few guys, we’re including a miticide, which hopefully will protect them up to hull split. As the weather heats up, I anticipate that mites will increase.

“We’re finishing the last little bit of nitrogen on almonds. Trees have put on good vegetative growth with all this moisture and cooler weather, and they look great. With the moisture and warmer weather, weeds will be popping up, too, so we’re into weed control and are starting to put out ant bait.

“In walnuts, we got some copper on about 10 days ago, so we’ll see what happens with blight. Our 1B codling moth spray will probably go out toward the end of next week. We’re deciding whether to include copper, based on the chance for more rain. We’re also lining up the last nitrogen application in walnuts.”Persists

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