Monday, March 23, 2015

Growers Prepare for First Alfalfa Harvest of the Season

It has been a race against time for alfalfa growers.

Weevil populations have been on the rise and alfalfa has been growing quickly, spurred by the unseasonably warm temperatures, including that 90 degree weather a week ago.

Field scout Carlos Silva says weevil counts are running 10 to 12 pests for every sweep of his sweep net. Those numbers are climbing closer to the treatment threshold of 18 to 20 bugs per sweep.

Alfalfa growers are nearing the first harvest of the season.
 “Some growers already have treated for weevils,” Carlos points out.

The Egyptian alfalfa weevil poses the most serious threat to the crop, according to University of California IPM. Adult females will insert their eggs in the alfalfa stems. The larvae will hatch and start feeding on the terminal buds and leaflets.

Growers need to focus on managing the pest before the first cutting of the season. UC IPM says: “Weevil management in alfalfa is focused on the period 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.”

Alfalfa is cut when the plant is about 24 inches tall.
Right now, alfalfa is about 18 to 20 inches tall – growers usually cut around the 24-inch mark. Carlos anticipates this year’s first alfalfa harvest to start in a week or two.

Meanwhile, cotton growers have been pre-irrigating their fields and starting to purchase their plant seeds.  A number of long-time cotton growers remain committed to the crop, despite the ongoing drought and water availability issues.

Cotton growers have been pre-irrigating their fields.
It’s too early to predict how the prolonged drought will affect cotton acreage this season. Last year, growers planted 213,000 acres of cotton, down 23 percent from 2013, according to the U.S. Department of Agriculture.  Cotton production fell an estimated 24 percent to about 730,000 bales.

Sunday, March 15, 2015

Pest Traps Key Tool for Battling NOW in Almonds This Season

Spring officially arrives this Friday. That means it’s time to step up bug watch in almond orchards.

Field scout Jenna Horine has been busy visiting orchards throughout the San Joaquin Valley and setting out traps for navel orangeworm (NOW) monitoring. She should have all in place soon.
Field scout Jenna Horine holds a navel 0rangeworm trap,

These traps play an important role in treatment decisions for the   battle against NOW infestation. Jenna will check the traps, record eggs laid in the traps and rely that information to growers throughout the season.

Long-time almond expert and UC IPM emeritus Walt Bentley has worked with Jenna over the years about the placement locations of traps. Usually, Jenna places traps in three corner locations of an orchard block, depending on prevailing wind direction, nearby fields or orchards when pests may migrate from and grower advice.

The traps are placed about at least five trees from the orchard edge, 6 to 7 feet above the ground, 1 to 3 feet inside a tree drip line and in the shade away from water. As a rule, there never are less than three traps per orchard. For orchards of 20 to 80 acres, UC IPM recommends 1 trap per 10 acres for acres 20 to 80 acres in size. For orchards over 80 acres, the rule is 1 trap for every 20 acres.

Here’s what UC IPM says about using the traps:
  • Check twice weekly to determine the bio fix – this is the first of two dates in which egg laying increases in 75 percent of the traps in a given location.
  • Record the biofix date.
  • Continue monitoring traps, counting and recording egg numbers of a monitoring form. Remove eggs as you monitor.
  • NOW trap should be 6 to 7 feet above ground.
  • Change bait – a mixture of almond meal and almond oil – about 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.
Degree-Day Calculations
  • Use the biofix determined by egg trap monitoring to start accumulating degree days for following navel orangeworm development and to time hullsplit treatments.
  • Egg laying by the second flight of moths is predicted to begin 1056 DD after the biofix.
  • Shake trees before third generation egg laying takes place.
  • Early stage of NOW development.
  • If treatments are planned and hullsplit begins before egg laying predicted, apply the hull split spray at the beginning of egg laying. If hull split begins after egg laying is predicted, apply the spray at the beginning of hull split. Back up degree-day predictions by checking egg traps.
Of course, UC IPM officials point out the need to treat for NOW is based on three factors:
  • Whether there was significant loss the previous three years.
  • The prospects of infestation from nearby orchards, including pistachios.
  •  Orchard sanitation, meaning trees had two or less mummy nuts.
Jenna is quick to point out she already can spot troublesome orchards likely to experience NOW problems this season. These are the ones that have had a poor track record in removing mummy nuts.
In one orchard with lax sanitation regularly, for example, Jenna sees lots of mummy nuts that have fallen to the ground. “You can see the worms in the mummies,” she says. It’s going to be another tough year in that orchard.

Monday, March 9, 2015

Drought Part IV: Valley Growers Press Ahead Amid Uncertainly Over Water

It is no surprise we’re headed into a fourth straight dry year and growers are getting quite anxious around the Valley as the prospects of a March Miracle or April showers appear slimmer by the day.
State Water surveyor finds a skimpy snowpack in the Sierra.
It also was no surprise that state Department of Water Resources surveyors found dismal conditions last week during their monthly wintertime snowpack measurements in the Sierra Nevada. They reported the water content in the snow was less than an inch, the lowest level since 1991. Even the foot of snow that fell in the high country a week ago won’t make much difference to reverse what is certainly going to be a fourth straight year of drought, water officials say. 

Normally, Mother Nature’s water savings account – the Sierra snowpack – supplies about a third of our water needs. Not this year – again. And, it was no surprise when water managers also last week indicated farmers probably won’t get any federal water for a second year in a row.

As you recall, farmers left acres of fields fallow (an estimated 400,000 to 500,000 acres), uprooted almond trees, turned water well drilling into a booming business and diverted water to more profitable crops. Once again, growers are trying to navigate through these rough waters. 

Alfalfa growers are irrigating for the first time this season.
Growers, however, are a resilient bunch. Despite these challenging times, growers are pressing ahead this season.

Field scout Carlos Silva reports many alfalfa growers are sticking it out again and have been irrigating their crop in the past week. It’s too early to tell how many cuttings they’ll have this season.

Last year, some growers thought they would harvest until early summer, figuring water supplies would go dry by then. Somehow, though, many growers were able to harvest alfalfa until the fall – about the same as a normal season.

For now, the season’s first alfalfa is growing nicely, standing about 8 to 10 inches tall. Carlos plans to start scouting for pests soon.

 Field Day Alert: Here’s a reminder the San Joaquin Sustainable Farming Project’s first event of the year is this Thursday, March 12. Learn about pesticide and pest management issues in almonds, alfalfa cotton at this free event scheduled from 10 a.m. to noon at the Scout Hut, 1910 Marguerite Street, Dos Palos. Our speakers are UC IPM extension advisor Dr. Pete Goodell, state Department of Pesticide Regulation environmental scientist Brandi Martin and Chris Linneman, program manager and engineer with the Westside San Joaquin River Watershed Coalition.  For more information, contact program Director Marcia Gibbs at (530) (530) 370-5325. There should be lots of useful information, especially with another challenging year ahead.

Monday, March 2, 2015

Winter Wonderland Blossoms Across the San Joaquin Valley

From afar, the scene resembles a winter wonderland – snow covered tree tops and fresh white powder dusting the ground below.
No, the late-winter storm that passed through the Valley over the weekend didn’t transform almond orchards into a Sierra-like landscape for skiers or snowshoe hikers. It’s the acres and acres of almond trees in full white bloom across the Valley. 

“We have a lot of bloom and a lot bees out in the orchards,” field scout Jenna Horine says. It looks just like snow with white pedals dotting the orchard floors. It’s a sight to behold.

Right now, we’re at the height of the pollination period.  The bee boxes placed at the orchard margins expect to be out there for another couple of weeks. 
The small amount of weekend rain was welcomed by all. These days no one is complaining about free water from Mother Nature. Jenna is quick to note that any amount of the wet stuff gives growers a break from turning on the irrigation faucet. At the same time, she adds that the rainy weather shouldn’t create any pest or disease problems or interfere with pollination.

It’s hard to believe we’re at the start of another almond season. In the coming weeks, Jenna will start setting out traps in the orchards to monitor for troublesome pests, including navel orangeworm.  It won’t be long before she’s making her rounds again through the orchards, providing a second set of field scouting eyes for almond growers.

Field Day Alert: Circle Thursday, March 12 on your calendar for the San Joaquin Sustainable Farming Project’s first event of 2015. Learn about pesticide and pest management issues in almonds, alfalfa cotton at this free event scheduled from 10 a.m. to noon at the Scout Hut, 1910 Marguerite Street, Dos Palos. Our speakers are UC IPM extension advisor Dr. Pete Goodell, state Department of Pesticide Regulation environmental scientist Brandi Martin and Chris Linneman, program manager and engineer with the Westside San Joaquin River Watershed Coalition.  For more information, contact program Director Marcia Gibbs at (530) (530) 370-5325. See you there.