Now is the Time to Put Out Pest Traps in Almond Orchards

Drive around almonds orchards across the Valley and you’ll see growers and their crews busy on spring chores.

Except for a few rainy days, everyone has been busy applying fungicidesto tackle fungus and other diseases brought about by the wet weather and adding fertilizers and nitrogen to the soil.

Mummy nuts left on the ground over the winter.

Field scout Jenna Mayfield has been out and about as well, visiting orchards and setting up pest traps for the upcoming season. While walking through the orchards, she’s noticed a common theme.

“Many growers left so many mummy nuts on the trees,” she says.

That could spell trouble with navel orangeworm (NOW) down the road. NOW is the main pest of almonds. The mummy nuts serve as a winter home for NOW larvae.

That’s why Jenna stresses the importance of growers launching an aggressive mummy nut removal program during the fall and early winter. Without such a program, growers may wind up treating for NOW at hullsplit.

However, orchard sanitation apparently hasn’t been high on the to-do list for a number of growers.  That means Jenna will be watching closely for NOW – as well as other pests throughout the season. To prepare, she has spent the past couple weeks placing traps for NOW and peach twig borer (PTB). (PTB is another pest, which overwinters in cracked bark and trunks of trees.)

This is a PTB trap in placed in an almond orchard.

UC IPM notes that egg traps will help follow NOW development and determine when “navel orangeworm eggs will hatch in relation to hullsplit so treatment can be timed precisely.”

For growers setting out their own traps, here’s a checklist from UC IPM:

Timing

• After setting the traps in early spring, check twice weekly to determine the biofix—this is the first of two dates in which egg laying increases in 75 percent of the traps in a given location.Jenna will set her traps seven trees deep from the edge and spaces them apart based on wind direction.
• Record the biofix date.

Method

• Use traps baited with almond meal and 10 percent (by weight) crude almond oil. Black traps work best, but their caps do not need to be black.
• Place one trap per every 10 acres, for at least four traps per orchard.
• Choose trees that are at least seven trees in from the edge of the orchard.
• Hang traps at head height on the north side of nonpareil trees, one to three feet inside the drip line of the tree. Avoid areas where traps will be hit with sprinkler irrigation.

This is one of the NOW traps Jenna will be monitoring.

Trap reading

Continue monitoring traps, counting and recording egg numbers on an egg trap monitoring form.

• Change baits every four weeks.
• Look for flat eggs that are laid mostly on the ridges of the trap or on the raised lettering on the top and bottom of the trap. Eggs will be white when first laid but turn orange-red before hatching.
• Graph numbers of eggs laid at each trap reading on the monitoring form. This will give you an idea of when new generations of navel orangeworm are laying eggs.
• Use this information to verify degree-day calculations. If you wish to use this information for timing a hullsplit spray, continue monitoring for the entire season.

Meanwhile, Jenna says many trees remain in bloom. “It has been one of the longest bloom periods in a long time.” Last year, the Valley saw what was described as a “flash bloom” – a very short bloom period.

Growers are hoping the extended bloom will lead to a good fruit set, which could translate into a good yield at harvest. Ah yes, spring does bring optimism.

FIELD DAY: Almond growers will learn about honey bee health and receive valuable disease, fungicide and pest management tips at a field day on Tuesday. The free event will be from 10 a.m. to noon at the Cook Orchard, 15640 Avenue 22 1/2, Chowchilla. David Doll, a Merced County UCCE pomologist, will review bloomtime diseases found in almonds, chemical treatments, including the proper selection of fungicides and nitrogen applications. FlorentTrouillas, UCCE fruit and nut specialist at the UC Kearny Ag Center, will explain the complexities of many wood cankers found in almond trees. He also will offer tips about treating the problem, including chemical and mechanical management practices. Sponsored by San Joaquin Sustainable Farming Project, the field day offers one hour of continuing education credit. For more information contact Project Director Marcia Gibbs at (530) 370-5325 or at marcia@sustainablecotton.org.

Counting the Degrees to Find the Best Time for Planting Cotton in the Central Valley

Drive around the Valley and you’ll see future cotton fields in waiting

“All the fields are ready. The rows are ready,” says field scout Carlos Silva. “I’ve even seen some pre-irrigation.”

Some cotton growers have started to pre-irrigate their fields.

Certainly, the recent string of sunny, warm spring-like days (How did everyone like the near-90 degree weather last week?) certainly put growers in the mood for planting the seeds for another cotton season. 

On paper, March 10 was the first official day that San Joaquin Valley growers could plant cotton. That date marks the end of the 90-day host-free period for the pink bollworm control program. Of course, that date usually isn’t a realistic start time. 

Carlos believes the first planting could come at the end of March or early April. Right now, growers are checking the weather forecasts, measuring the temperatures and working on calculations. 

Growers have prepared fields for this year's cotton season.

Of course, Mother Nature will have a big say. While today marks the first day of spring, the weather forecast this week is more winter like. Predictions call for a few days of rain and cooler 60-degree temperatures this week.

“If growers see any rain in the forecast, they are likely to hold off planting,” Carlos says.

When is the best time to plant?

Here’s what UC IPM says: “To determine the best planting date to establish a healthy stand, use a 5-day forecast of accumulated degree-days (heat units) and on-site soil temperature readings. Good stand establishment requires sufficiently warm air (measured in heat units) and suitable field soil temperatures.” Growers can use UC IPM’s Cotton Planting Forecast online site plus soil temperatures until an optimal planting date is determined.

“Cotton seed requires approximately 50 degree-days to accumulate in order to emerge when planted at an optimum planting depth. It is also important that temperatures be consistently warm and don't drop during the first 5 days after planting,” UC IPM adds.

 

FIELD DAY: Almond growers will learn about honey bee health and receive valuable disease, fungicide and pest management tips at a March 28 field day. The free event will be from 10 a.m. to noon at the Cook Orchard, 15640 Avenue 22 1/2, Chowchilla.  David Doll, a Merced County UCCE pomologist, will review bloomtime diseases found in almonds, chemical treatments, including the proper selection of fungicides and nitrogen applications. Florent Trouillas, UCCE fruit and nut specialist at the UC Kearny Ag Center, will explain the complexities of many wood cankers found in almond trees. He also will offer tips about treating the problem, including chemical and mechanical management practices. Sponsored by San Joaquin Sustainable Farming Project, the field day offers one hour of continuing education credit. For more information contact Project Director Marcia Gibbs at (530) 370-5325 or at marcia@sustainablecotton.org.

Looking at Rain, Bugs and Pest Management This Season

 Will the wet winter meanfarmers will be dealing with fewer pest problems this season?

The answer is yes … and no. 

“My crystal ball is a bit fuzzy,” Dr. Pete Goodell, extension adviser of University of California Statewide Integrated Pest Management Program, told a group of farmers at a recent field day.

Pete explains that in some instances the near-record rains are likely to keep crop-threatening pests at bay, especially overwintering populations. In other instances, it might not have much of an impact.

Other factors come into play such as daily temperatures, including the number of freezing nights.

Here’s Pete’s run down about the possible impact of the rain on pests in alfalfa, cotton and almonds in 2017:

Alfalfa

Weevils. A warm January and February brought out weevils a little early this year.  In the Fresno area, for example, January recorded daytime highs averaging 2 degrees higher than normal, according to the National Weather Service. It even hit 71 degrees on January 8. 

Weevil larvae cause the most damage in alfalfa.

“They are out there,” Pete says about weevils. One grower told the field day gathering that he recorded a count of 20 weevils per sweep of a sweep net in one field.That’s about normal right now, Pete says. If this was harvest time, the grower would want to start cutting the crop to avoid damage to the plants.

According to UC IPM, weevils overwinter as adults in field trash or other hiding places and come out in late winter or early spring.  That’s when adult females start inserting eggs into alfalfa stems. It is the young larvae that feeds on the plants and causes the most damage.

Growers should start monitoring for weevils now. Pest management should be focused before the first cutting.  “Control options are insecticides and early harvest. Biological control is not effective at preventing economic damage in most areas because populations of natural enemies are not sufficient to provide control in the spring.” UC IPM says.

Armyworm: The rains will spur growth for host plants. That means growers are likely to see larger worm populations this season.

Cotton

Lygus bugs expect to be a problem for cotton this season.

Suppliers are reporting an increase in seed orders. That bodes well for the California cotton market. Look for more planted acreage due to anticipated increases in water availability this season.

Lygus – The flip side of the wet winter are weeds such as London rocket should thrive this spring, providing a nice home for lygus. Pete says an extra generation of lygus is likely to emerge in early summer as weeds dry out and the pest looks for a new home such as cotton.“We’re probably going to see some widespread outbreaks of lygus. I have no doubt about it. “Growers should check weeds for the presence of lygus through the end of this month.  This could be a really bad year for them.”

Mites and aphids: Pete says the winter impact on these pests is uncertain. Whitefly tends to increase during a drought. “Ithas to get really cold to freeze some of the overwintering insects out.”

Almonds

Leaf-footed plant bugs can pose a problem in almonds.

 Leaf-footed plant bug – The forecast is unclear. The soggy soil won’t impact this pest because it doesn’t overwinter in the ground. You need really freezing temperatures below 28 degrees to have an effect on the population. “They’re still out there,” Pete says.

Navel orangeworm (NOW) and peach twig borer – the rain has been a positive to reduce the overwintering population. The same goes for mites. “It’s not a nice environment for them,” Pete says. 

We’ll have to wait and see how these predictions play out. Meanwhile, Pete stresses that it is  important for growers to remain vigilant and keep monitoring their fields or orchards for pests.

Blossoming Almond Trees Make for iPhone Moment

They used to call it a Kodak moment during the age of film-loaded cameras.

In today’s digital age, you might call it the iPhone or Android moment – when the picture perfect photo opportunity arises.

Almond trees are ablaze with blossoms across the Valley.

Once again the perfect photo op has arrived in the Valley.

 Drive along Interstate 5 through region, especially around the Los Banos area, and look east to gather in breathtaking views of acres and acres of almond trees in full bloom. It resembles a white canopy of snow glistening on the tree tops.

“It’s so beautiful. Everything is blossoming,” says almond field scout Jenna Mayfield.  She couldn’t resist the moment and snapped lots of breathtaking photos of blossoming almond orchards.

Here’s another incredible sight, reports Jenna. It’s the Eastside Bypass, which is full of water flowing down the mountains from this year’s major storms. “I haven’t seen the bypass so full in close to 10 years. The water goes as far as you can see.”

Of course, all that water comes from our very wet weather, which is both good news and bad news for almond growers. No one is complaining about the rains after experiencing five years of drought, which left many trees stressed and prompted some growers to ripe out orchards because of the lack of water availability.

On the flip side, the wet stuff could trigger fungus and tree diseases. With the recent spate of sunny weather, growers have been moving quickly to apply fungicides, especially in the older trees, which are more susceptible to diseases than younger ones, Jenna says. You don’t want diseases harming the crop.

In the meantime, bees are out in full force pollinating the orchards. Jenna reminds growers to be mindful of bee health.

The blossoms are attracting lots of bees.

Studies have shown a reduction of bees foraging on almond blossoms shortly after fungicide applications and bee toxicity in some cases.

What can growers do? One tip is making sure the tank sprayer is clean and free of insecticide residue. If possible, it’s best to apply fungicides at the end of blossom.

Jenna points out that the weather is warming up as we head toward spring. That means growers need to be very vigilant because the orchard environment can change suddenly.


“Insects can flare up. Fungus and tree diseases can spread like wild fire,” Jenna said.