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Owen Taylor, Editor


Bacterial blast has become more apparent this season, as several of our contacts this week noted. In the Worth Noting section you’ll find photos sent to us by PCAs Chris Morgner and Sara Savary.

Petal fall has wrapped up on a wide basis and more small nuts are evident.

Warmer and sunnier conditions have taken shape. Some rain is in the forecast in the middle of the week. Decisions are being made about if or when to line up a post-petal-fall fungicide application.

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Chris Morgner, PCA, Agri-Valley Consulting, Merced

“The Sonoras are shedding jackets, splitting and are growing to the point that we can kind of see the small nuts now. The Nonpareils are starting to split and other varieties should be following suit.

“We’re supposed to move into the 70s over the weekend. Things are finally drying out. We still have puddles (as of 3/13) but they’re shrinking. This was a stretched-out bloom due to a long period of below-normal temperatures. We’re not in a big hurry to go out right now with fungicides because today is absolutely gorgeous, with temperatures in the low to mid 60s and a light breeze.

“That said, people are poised to apply another fungicide because we’re not done with the rain. At this point, we’re playing it by ear as far as timing goes. A good share of my growers only have one fungicide on. Leaves are coming out. We’ll probably go through with a treatment in the next 7 to 10 days. At this point, we’ll see how the weather plays out. A potential storm is in the forecast for the middle to latter part of next week.

“I’m not aware of any fertilizer that’s gone out and there’s no need to water yet.

“This long bloom may be beneficial because it’s given the crop a chance to progress slowly. Based on that, the crop probably won’t put any huge demand on resources in a compacted timeframe, so maybe the trees can meet the needs of the developing crop as it moves along.

“We did have a beautiful bloom. What I’m seeing on the trees looks good right now. Some early drop is evident but it’s too early to get any idea about how much will finally be set. On one hand, we didn’t have the best conditions for pollinations. On the other hand, bees were getting out there, even when the air was cold. I’m hearing some reports that the pollen level was heavy in the hives.

“How much the crop’s progress might have been delayed by below-normal temperatures remains to be seen. The idea is that much of the crop’s potential is determined in the first 90 days, but we still have 70s days left, so we still have plenty of time.

“We’re finding bacterial blast. I began detecting it 3 weeks ago on blooms and some buds that were infected before they fully expanded. It’s like the buds were frozen in time and some had already fallen off. If we were going to find it, this would be the season. We had plenty of cold weather and rain almost every day during the first 10 days in February.

“We haven’t had any of these tested but they do show the classic symptoms of bacterial blast. Once we found those first symptoms, I went around to other orchards and started finding it at very low levels in a lot of locations. Some orchards were severely affected.

“I’ve seen photos from other people in the field that show some trees that were hit hard. With exceptions, it’s mostly turning up in younger trees and where you find sandy ground and cold spots in orchards. This could easily be misidentified as brown rot, but brown rot grows spores and we’re not seeing any brown rot or spores.

“Bacterial blast kills back the wood a little – maybe a half-inch of the tip of the wood was burned – but the leaves below that were pushing. Some areas were maybe more affected by that than others.

“In alfalfa, I just wrote up a bunch of weevil sprays. They’re beginning to get active now, so we need to get ahead of them before the highs begin moving into the 70s.”


Kris E. Tollerup, IPM Cooperative Extension Advisor, Kearney AREC, Parlier

“This is an extended bloom, which may lead to a later split because development was slowed earlier. How that lines up with NOW physiology isn’t entirely clear. They could just follow suit and sync up. It’s hard to say.

“At least where I’ve been monitoring, mummy infestations were not tremendously high this year. What I’ve seen have mostly been the later instars and fifth-stage pupae. Once we have a couple of weeks of really warm weather, they should start popping – probably around the end of this month or into early April.

“That’s when we can expect to make a biofix. Obviously, there are variations in that, depending on local conditions. Last year it was funny how things lined up with NOW. The pistachios did really well and many growers got them out ahead of the third flight. To some extent, we also had an early harvest with almonds. That was really beneficial.

“So far, I’m not seeing a big difference in the size of the crop. Although bloom was extended, that doesn’t necessarily mean that the stage of the nuts is spread out, too. The crop still might be fairly uniform in terms of development.

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“I’ve seen some leaffooted bugs around but they are still mostly in overwintering spots. I haven’t found any in almonds because the nuts are so small. However, we do need to be monitoring for them in areas where they turned up last year. I’ve seen a lot of individuals in citrus but haven’t noticed any big aggregation yet. When scouting, check the outside of the tree on the sunny side. Those bugs enjoy the heat, so carefully look in that outside canopy.”


Nathan Stewart, PCA, AgVantage Consulting, Inc., Visalia

“The rain has subsided, the sun is out and we have good weather for a change. We’re right at the tail end of bloom. The pollinators are left and are getting some bee hours. With the Nonpareils, it was pretty wet during full bloom, so we’ll see what pollination was like as we get into May.

“For right now, I’m holding off on another fungicide to see how any further rain develops. A little is in the forecast for next week. When we do some nutritional sprays, we’ll decide whether to include a fungicide. At least right now (3/13), it doesn’t sound like much rain will develop. We’ll maybe start the first of those nutritional sprays later next week or somewhat after that.

“We have started fertilizer applications and are even on the second round in places. We’ll start supplanting more nitrogen now that we’re through full bloom. I’m encouraging growers to look at how wet the soil is but hold off on any real irrigation, maybe just fertilize with short sets.”


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

“For the most part, almonds are well into petal fall and most every variety is starting to leaf out. We still see a bit of straggling bloom, mostly on top of trees, more than I would expect. In general, though, things look pretty good right now.

“Pollination was a concern and everyone is talking about the low number of bee hours. But even on the worst days, we might have had 2 or 3 hours when they were moving. It wasn’t a big amount of activity but they were working to some extent.

“I’m not seeing much on the ground yet and everything seems to be stuck at this point (3/13). The biggest nuts I’ve found this week are kind of the size of a Jelly Belly.

“We are finding bacterial blast in places. I’ve read about it in northern California over the last 2 years but haven’t found it here until now. It’s localized in a couple of blocks. One is a planting with only Independence and the other is an Independence-Nonpareil block.

“Both have bacterial blast to varying degrees. One is a 6-leaf block, the other is at fourth leaf. In the 4-leaf block, individual trees in certain areas are 20% to 30% affected but the entire block has around 15% to 20% damage. Based on photos I took, farm advisors say it’s likely bacterial blast, but I pulled a couple of samples to get 100% confirmation.

“One of those blocks generally has a lot of humidity and I’ve found scab in one part of that block. That’s a disease I haven’t seen elsewhere. It surprised me to find bacterial blast in the 4-leaf block because those trees are smaller, so you might expect more ventilation.

“The weather this week has been really good and growers are off to the races with tomato planting. The pistachio root stock has been pushing for over a week but the Golden Hills and Kerman varieties aren’t yet. In one Sur walnut block the catkins are about 1.5 inches long.”


Franz Niederholzer, UC Farm Advisor, Sutter/Yuba Counties

“I think everyone is scrambling now that it’s stopped raining. With better conditions, people are trying to catch up on all the tasks they couldn’t do in the rain. Now, it’s a big ASAP push. It rained last week and over the weekend but it’s been dry since then, with a north wind that’s also dry. It’s 63 right now at the Nickels Soil Lab with 18% humidity and winds at 8 mph and gusts at 17 mph.

“As many folks have pointed out, this has been a really, really long bloom. The last of our varieties are tailing off now. The forecast talks about a change of weather in the middle part of next week but we’ll have normal temperatures or maybe a little above that until then. The high for next Monday (3/18) is 71.

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“I'm hearing about blast and jacket rot down in the San Joaquin Valley but I’m not hearing about much of anything in this part of the state. They tend to be a few days ahead of us, so it’s hard to say how diseases might play out here. In 2017, we had a very similar spring and blast and other bloom disease symptoms appeared. Where I’ve heard about any blast in the Sacramento Valley so far this year, it’s been very limited.

“Peaches are blooming. Prunes are a week out from bloom.”


Jack Gonzales, PCA/CCA, Supervised Control Service, LLC, Bakersfield

“We’re mostly in the post-petal-fall stage, although there’s some variability, depending on what part of the county the almonds are situated. In the majority of soft-shell varieties, we’re 2 to 3 weeks post-petal-fall. Again, though, it varies. I was in a block of soft shells on Monday that still were carrying a ton of blooms. The hard shells, of course, are trailing behind them. Overall, the bloom has been spread out this year.

“We did get a fair amount of rain during bloom but still had a number of acres that never received a bloom spray. However, the bulk of our clients made 1 to 2 sprays.

“Brown rot or jacket rot haven’t turned up except in a block of Independence where some botrytis jacket rot is evident. That grower did a very late bloom spray. What we’re finding there is slight and would have a negligible effect on yields. That’s the only block where I’ve seen any disease at all. Otherwise, all the trees around here seem to have a tremendous crop on them.

“No real threat of rain is in the forecast for the next 7 to 10 days (from 3/13). We’re entering a brief warmup with highs in the low 80s by the weekend. It should stay like that for a few days before dipping into the high 60s and low 70s.

“In almonds, some growers want to do a micronutrient foliar spray as trees leaf out. In those cases, we’ll include a fungicide just to continue to cover against jacket rot and shot hole. Also, this isn’t a bad time to treat for scab.

“A few grape varieties are into bud break and the vines are pushing now. Most are in the bud-swell stage.”


John Moore, PCA, Growers Crop Consulting, Bakersfield

“We’re putting out PTB traps in the almonds this week and hustling to get that done, plus putting out codling moth traps in apples and walnuts and also placing the NOW traps in pistachios.

“Some petal fall treatments are still going out. Everybody has at least one application on almonds and several have a couple. A third application has started going out now, I think. It would be considered a petal fall treatment. To me, petal fall implies that the last petal is off the trees but we’ve got to be a little ahead of that in terms of treatment timing.

“It’s too early to tell how the crop is setting up. In a month from now we should have a better idea.

“In alfalfa, we’re finding weevils. Counts aren’t critical yet. If a grower won’t cut soon, we’ll treat some of those fields. We’re finding 3 to 10 weevil larvae. The university threshold is 20, but if we wait that long we could get into problems. For us, 10 to 15 is what we consider threshold if the grower isn’t about to cut.

“The weather has delayed cotton planting. The cotton I’ll work this year is on heavy ground and the beds hadn’t been worked on Monday (3/11), the last time I was there.”

Crop size also up from 2018 totals.
Weed ID and drift management on the program.
Focus on weed identification and effective spraying.
Bacterial Blast
Photo: Sara Savary, PCA, Crop Care Associates, Fresno
Photo: Chris Morgner, PCA, Agri-Valley Consulting, Merced
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