[Part of a continuing series on navel orangeworm control.]

Skimping on Navel orangeworm treatments and cultural practices to save money can be more costly than it sounds. Skipping a well-timed spray or worse, avoiding good winter sanitation and other scientific recommendations can quickly create significant losses.

How much money can you net with good NOW control? That depends on a variety of factors, but Mel Machado, director of member relations with Blue Diamond Growers has figures to prove his point that spending some money up front on NOW control can net more returns from the processor. Assuming a 2,500-pound per acre Nonpareil crop at $2.50 per pound the losses can quickly add up to $1,000 per acre or more, depending on the extent of the damage.

"Keep in mind that a 2% loss at the huller and sheller tends to be a 4% loss by the time you get to the processor," Machado said.

NOW damage leaves nuts unmarketable. Shellers and hullers can clean out some of this damage, but not all of it. Processors too must spend money cleaning out the damaged nuts, leading to costs on their end and reduced payments to growers. For grower-owned cooperatives like Blue Diamond, this can affect grower returns. For each half-percent in reject levels at Blue Diamond, growers can see their resulting returns fall from about $60 to $100 per acre. But that does not tell the entire story.

Related:Nut growers urged to avoid pyrethroids for NOW control

By the numbers

Based on Machado's numbers, a 2% reject level under Blue Diamond's price structure means a loss of almost $250 per acre when compared to the perfect crop. At 3%, that loss quickly becomes $720 per acre. Losses above 5% will cut more than $1,000 per acre from a producer's check. At 10%, that loss almost doubles to over $1,700 per acre.

Machado likes to promote the 2% figure because that's where Blue Diamond members are paid premiums for a clean crop. This figure is common throughout the industry.

During meetings Blue Diamond held up and down the state last year, including one sponsored by the Almond Board of California, Machado repeated these numbers to anyone who would listen.

"I believe we've opened up some eyes with these figures," Machado says.

He believes heeding the numbers is a win-win for growers and their processors. Encouraging the grower to produce a cleaner crop puts more money in his or her pockets. At the same time, processors win because they too have larger supplies of quality almonds that need minimal processing for global buyers.

"This may sound strange to some, but I want to pay you more," Machado likes to tell Blue Diamond members during grower meetings. "For me it's all about improving their quality because nobody loses. They get better quality and they get better returns. We get better products in the plants that we can process at a lower cost, which we turn around and return to our members."

Related:Mating disruption shows promise for NOW control

Four-pronged approach

The University of California recommends growers employ a four-pronged approach to NOW control. Sanitation, mating disruption, timely insecticide treatments and early harvest are tenets of what farm advisors recommend. Though he agrees that a multi-pronged approach is good, Machado says harvesting too early can bring on other problems. Instead, he would like to hear the UC promote "timely" harvest, rather than simply pressing growers to push the envelope to get nuts off ahead of the next NOW flight.

While Machado has been told that an early harvest for pistachios may help get some nuts out of the trees ahead of a late-summer flight of NOW moths, Machado says this does not work for almonds for a couple reasons. First, pistachio growers tend to shake trees at least twice, whereas almond growers shake trees only once. Second, and perhaps most importantly with almonds, harvesting too early removes nuts from the trees before they are physiologically mature.

"You wind up with diverse maturities within the crop and you wind up with diverse moisture levels," he said. "If you shake too early your peel does not adhere well and you wind up with peelers."

Peelers describe when the skin of the almond kernel can be rubbed lose during processing.

"That counts towards chipped and broken," he said.

"People think almonds dry in a stockpile; they do not," Machado says. Instead, moisture collects, and molds develop. This creates an unmarketable crop.

Machado also cautioned growers to better understand spray coverage as most of the nuts are in the top half of the canopy, which can present a challenge when using ground-based spray rigs. Also, the newer chemistries are all contact based.

"In the old days we had insecticides that were more of a fuming nature," he said. "Those days are gone now. You've got to get that coverage in the tree."

While he does not have the numbers or data to back it up, anecdotal reports suggest coverage by air can be helpful, especially when trying to cover orchard blocks in under five days. This can be important if spray rigs are having a tough time reaching the top of the orchard canopy.

"Arial coverage isn't going to get more than about six feet into a fully leafed-out canopy, but that may be the six feet your ground rigs aren't reaching," he said. "I'm not making the blanket statement that everything needs to go on by air, but it's something that we're thinking about."

Also, spraying during the extreme heat of the day when materials can evaporate before hitting the tree may not be the best practice, he said.

"Anything that's not hitting the suture of the nut is lost," he said.

Growing pains

As almond acreage grows across the state so too does the need for processing, shelling, and hulling capacity to increase. Likewise, the need for more spray rigs and harvest crews is apparent as growers struggle to make timely insecticide applications and hit their harvest windows. This growth may be leading to the push for some growers to harvest too early and stockpile their almonds when they are too green.

Part of the issue compounding this appears to be the two popular varieties – Nonpareil and Independence – harvest about the same time. That is a lot for existing harvest crews to handle in a timely manner.