Disease is becoming more obvious in more areas. Along with bacterial blast, jacket rot is evident in places.
A few NOW eggs are turning up on traps in the lower San Joaquin Valley, although the weather hasn’t favored much moth movement.
Rains continue, with another stretch of showers during the first half of the week. Temperatures also will go up in portions of the Central Valley.
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Jhalendra Rijal, Area IPM Advisor, Northern San Joaquin Valley
“Insects still aren’t actively flying in this part of the valley. It seems like it’s been raining all the time and temperatures have been on the cool side, so insects aren’t moving.
“On Tuesday, we took trap counts across several types of traps in three orchards and only a couple had anything, and nothing went beyond a 3-count. The rest were at zero.
“Even though we had a couple of warm days about a week ago, the weather has mostly been unfavorable for insects to do much. Also, it looks like we will have some chance of rain for a couple of days and then into next week, so I doubt if we’ll see any surge with NOW in the near term.
“Other places may, in fact, have more activity, but not here.
“One almond orchard was kind of blasted by bacterial blast. The same thing happened in it two years ago when we had similar weather conditions. It’s in a bad situation – light soil and a cold area.
“The orchard is kind of on the edge of Fresno. The grower said that he had plums on that land 10 years ago and the same thing happened then.
“I’m seeing a small amount of bacterial blast in other places but it’s nothing alarming. Mainly, I’m finding it in Montereys. Someone said that they’re spotting it in Aldrich, too, but none of mine are affected, even where you’d expect to maybe find it this year.
“I have almonds in a cool spot by the river south of Woodlake with 3- and 4-year Aldrich and Independence, and I expected to see bacterial blast there. But except for a little frost damage, those trees are okay. Some people said they can’t find it because they made a dormant copper spray, but I didn’t have a copper spray there, either.
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“I’m not putting on a third fungicide application. It’s been raining off and on but we’ve had good drying conditions between the rains. Jackets are pretty much off or coming off and I’m now waiting for leaffooted bugs to show up.”
Franz Niederholzer, UC Farm Advisor, Sutter/Yuba Counties
“It’s raining right now (afternoon, 3/22) and it’s supposed to rain into Saturday, then more rain will follow on Monday through Wednesday.
“Depending on the location, they’re forecasting some significant totals for this time of the year. Generally, accumulation over the period will be over an inch. The prediction for Chico is 1.5 inches. Even on the west side where it tends to be drier, they say 1.25 of an inch could fall.
“We had rain a couple of days ago, maybe a third of an inch in places. The rain next week is supposed to be in cool conditions, with highs in the low 60s. If the weather were warmer, that would really be alarming.
“If I were a grower, I’d probably still want a fungicide on ahead of all this. Some varieties – Butte, for example, and maybe other later varieties – still have flower parts. That might be a factor with botrytis, so things like jacket rot and green fruit rot could develop.
“Quite a bit of jacket rot has turned up in parts of the San Joaquin Valley, based on a credible report. It was confirmed with sampling. If jacket rot is apparent down there, we could see it here, too.
“The weather has been cold, which helps hold back a lot of diseases, but extended cold and wet conditions can favor botrytis. That, in turn, can trigger jacket rot. Bacterial blast also has shown up in a few blocks.
“If you’re going with a fungicide for this, choose carefully. Some of the cheaper, off-patent fungicides aren’t all that effective on botrytis, so check the UC efficacy tables.
“The fact that I’m even talking about this now really illustrates how unusual this winter and spring have been. In most years by March 22 we don’t have these weather conditions with flowers still on the trees.
“Overall, the nuts continue to look pretty good in the orchards where I’ve been. It’s still way too early to know for sure what kind of crop is out there. But I haven’t seen anything that’s stopped me in my tracks. The more time that’s passed, the better I’m feeling about what I’m seeing on the trees.
“In prunes and peaches, everything has blooms, so those growers are right in the middle of this weather pattern.”
“The rain has continued and the forecast says there’s a 100% chance tonight (3/22). Things will briefly clear up but then another 4 or 5 days of rain are still predicted, with temperatures running from 65 to 70 over the next week.
“The majority of my almond growers have now made 3 to 4 bloom sprays. For us, that’s really unusual. In the past, we maybe had a season with that much spraying, but it’s been long enough ago that I really can’t say what year that was. Growers have been going by both ground and air and applicators have been backed up. So far, I haven’t seen a whole lot of bacterial blast.
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“We’re pretty much at the end of bloom, with just a few left on trees in my area, so now we’re looking at leaf diseases and how to approach that. In the next couple of weeks, we’ll also take leaf samples and look at nutrients.
“As far as any residual nutrients in the soil, we’re probably starting with nearly a clean slate. All the rain may have leached away some of it. But at the same time, we’re so much more precise in putting out what the tree can use during the season that there couldn’t be much of it carried over from last year.
“In walnuts, a few growers are finishing scale control. It’s been hard to make those applications by ground in some areas. We’ll gear up next for blight sprays in walnuts.”
“We’re lining up alternaria sprays for blocks where we historically have pressure, and those treatments probably will start in the first week of April.
“Our first fungicide application this year probably went out on 30% of our almonds at 80% to 100% bloom. It was cold enough that we didn’t feel like any disease issues would develop. The second spray went out on 60% to 65% of our almonds at probably 2 weeks after petal fall. The temperatures had warmed up and it rained pretty regularly, so we treated.
“We are seeing a lot of leaf spotting this week in all stages of trees, even in some young orchards where herbicides haven’t been applied and there probably hasn’t been any herbicide drift, either. There’s some discussion that this might be an early stage of shot hole. It doesn’t look like textbook-type shot hole to me, but we’ll keep watching it.
“We’ll probably make a rust spray around April 10-15, which is roughly 5 weeks after petal fall. We definitely will treat some orchards where it came in late last year. But with all this rain, we could end up with a lot of rust and maybe scab, too.
“We moved into warmer weather, with a couple of days in the 80s. The forecast for next week says temperatures could run in the mid to upper 70s for several days. So, we’re anticipating more potential for rust and will likely schedule some treatments around April 15 but will get across our alternaria blocks first.
“Our pheromone and egg traps have been out, and in the first couple weeks we found nothing. But in the second half of this week we started picking up eggs in pistachios and almonds.
“We’re trying to treat earwigs in smaller trees. We’ve had to go with bait due to so many restrictions on Lorsban, plus the fact that several applicators say they won’t deal with it. The weather has been holding us up on that. The bait quickly breaks down if it gets too wet, so we’re trying to work around all the rain.
“In pistachios, we’re seeing a little leaf push-out. They usually start blooming in the first part of April, so we’ll be into that pretty soon.
“As of today (3/23), I don’t know of anyone who’s planted cotton. A couple of growers say soil temperatures are into the 60s but I think everyone is waiting for a more consistent stretch of good planting conditions. We’re still planting tomatoes between rains and should finish up next week. In alfalfa, we’re still spraying weevils. The first treatments went out 3 weeks ago and are still holding.”