Monday, August 14, 2017

Almond Growers Poised to Get Crackin’ on the Harvest and Taking Harvest Samples

The orchard is some 50 miles west of Fresno, 37 miles west of Raisin City and 20 miles southwest of Mendota. It borders the Westside Freeway, better known to most travelers as Interstate 5.

The locale also is the first almond orchard that field scout Jenna Mayfield spotted this season shaking nuts off the trees. “They usually are the first area to start harvesting almonds,” Jenna said, citing the combination of hot weather and a dry climate as reasons for the earlierharvest start than other areas in the Valley.

Westside almond orchards are the first to be harvested.
So we can officially say the almond harvest has begun. From now until early fall, growers will be busy shaking and sweeping in their orchards. More specifically, that’s shaking trees to knock off the nuts, letting them dry on the ground for about a week and then sweeping up the nuts to haul to the huller.

“It’s going to get busier for growers,” Jenna says.

You might liken the almond harvest as a marathon rather than a sprint. Because more than one variety of almonds is planted in orchards, growers will go in more than once to shake the trees. Of course, that means crews have to pick up the almonds more than once as well.

The soft shell varieties, especially nonpareils, ripen early and are the first to harvest. The hard shells such as Monterey ripen later and usually are harvested some40 to 60 days later. In fact, Jenna points out hulls of hard shell almonds aren’t even close to showing a sign of splitting.

Almonds drying on the ground are waiting to be gathered.
Right now, a number of growers are still wrapping up pre-harvest spraying, especially for mites. “The mite pressure is increasing,” Jenna notes.

Yes the to-do list is long for growers this time of year. “There are so many things to do,” Jenna says.

Foremost, according to UC Integrated Pest Management advisers, is moving to harvest as early as possible. As we mentioned earlier, almonds should be harvested when at least 95 percent of the hulls have split. The longer the nuts stay in the orchard the greater chance pests will move in and damage the crop.

While drying the nuts on the orchard floor is
important, it also is vital to pick them up as quickly as possible. “Ants are major pest threat

for nuts on the ground,” Jenna says.

Jenna also reminds growers to do one more task before gathering the nuts off the ground: Take nut samples. No, we’re not talking about Costco-like samples being handed out to snack on.

Almond kernels with NOW damage.
In this case, sampling involves collecting nuts from the ground and cracking them open to check for pest damage. A harvest sample lets growers assess the pest management program this season and lets them plan for next year. The results offer insights about damage from navel orangeworm, peach twig border, fruit moths or ants during the harvest process. The information also can be compared with numbers from the processor. Discrepancies could be costly for growers.

To collect samples, Jenna snatches up about 70 nuts from three different orchard locations, areas where pest traps have been placed. This lets her compare the damage with the pest information collected from the traps during the season. Later, she’ll crack each nut to inspect them for evidence of pests and pest damage and report the results to growers,

While Jenna and UC advisors regularly urge growers take samples, the practice isn’t widely practiced. Sampling, Jenna says, makes sense and will pay financial dividends in the long run
So let’s get cracking on those harvest samples.

Saturday, August 12, 2017

Cotton Aphid Population Explodes Seemingly Out of the Blue in Some Communities

It’s a funny thing about Mother Nature.

One day, everything is going just fine for farmers. A few days later it was another story.

Aphids are showing up in big numbers in some Valley fields.
Cotton field scout Damien Jelen offers a prime example how nature can throw a sudden curveball at farmers. After completing one of his scouting rounds in cotton, Damien noted aphid populations were under control. A few days later, “aphid numbers kind of exploded. They have become a problem,” he says.
The aphid issue appears most prevalent in the Mendota Firebaugh and Kerman areas of the Valley. It’s hard to say why the problem is concentrated in this region.

Experts say the higher populations often surface after heavy watering and fertilizer applications. That may be the case here because the outbreak surfaced a few days after irrigation, Damien says.Certainly, growers are less focused on the why and more focused on the how – like how am I going to stem the infestation. Damien points out the answer has been swift pest treatment. 

Cotton leaf curling is a sign of aphid damage.
Their reasoning: During mid-season, high aphid numbers – more than 50 per leaf – can shrink the size of bolls, stunt plant growth and cause more bolls to be shed from the plant, according to the University of California Integrated Pest Management.

Growers know they have a problem when leaves become cupped or crinkled and experience a build-up of honeydew and sooty mold. In extreme cases, the leaves will start falling off.
The cotton aphid is the most common aphid in California. They can emerge anytime during the season. Here how UC IPM describes the pest: 

Dark colored aphids can reproduce very quickly.
“Cotton aphid is highly variable in body size and color, and adults may be winged or wingless. Nymphs and adults of wingless cotton aphids vary in color from yellow to green to nearly black. The darker forms tend to be substantially larger. Nymphs that are developing into winged adults look very different from the nymphs developing into wingless adults: they bear small welts or protuberances on their bodies and may be covered with a coat of dusty-appearing whitish wax. Their body color is often greenish blue, or amber and blue.”

It’s important to determine the color of the bugs in the field. “The small yellow aphids develop slowly from newborn nymph to adult and do not produce many offspring; thus, their populations rarely increase rapidly. The larger, darker aphids (green and black) are quite different; they develop more rapidly, produce many more offspring in a rapid burst, and can generate rapid population growth rates,” UC IPM says.

The minute pirate bug is a natural enemy to aphids.
 Natural enemies such as minute pirate bugs, bigeyed bugs, green lacewings and damsel bugs can offer some biological control. But UC IPM notes that “although these natural enemies do provide some control, they generally are not able to strongly suppress aphid populations, or cause strong suppression after severe damage has occurred to the plant.”
Meanwhile on the almond front, field scout Jenna Mayfield says pest pressure is down in orchards.
Hulls continue to split and growers are treating for mites on the edge of the orchards where the pest often wind up after migrating from neighboring farms and dusty roads.“I haven’t seen any pest issues,” Jenna says. She also hasn’t seen any shakers rumbling through orchards. “Everyone is waiting to harvest.”
Growers are still waiting to shake their trees.