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Farmers protect crops in rain’s aftermath

Issue Date: March 13, 2019
By Ching Lee
The storm that came through Stanislaus County last week brought hail, strong winds and heavy rains that flooded this almond orchard in Denair. Farmer Darrell Cordova describes the scene as akin to “a Mississippi River running through the orchard.”
Photo/Darrell Cordova

Extended periods of soggy weather this season have farmers looking to the skies—not just for how much more rain nature will provide but for help from agricultural aviators to protect their crops.

"Most anytime you see adverse conditions, aerial applications will increase, so we're extremely busy," said Doug Thiel, who operates Thiel Air Care in Chowchilla.

With the state's 1.07 million bearing acres of almonds and trees in full bloom, Thiel said his business has experienced at least a 50 percent surge in demand for aerial fungicide applications, from farmers who couldn't get into their muddy orchards or cover the number of acres they have using ground rigs during the short window between storms.

Even with a fleet of five airplanes and one helicopter, Thiel said he's had to rent an extra plane and seek help from out-of-state operators to cover more ground.

Agricultural aircraft can't fly when it's raining, and winds need to be no more than 15 mph for planes and less than 10 mph for helicopters.

Aside from almonds, Thiel said his pilots have been busy since December doing herbicide applications on field-crop ground. That work also has been slowed by fog, rain and wind. Though he hasn't had to turn away any farmers, he said, he added that "we haven't been able to be there as timely as we want to."

John Brigham, an agricultural pilot who runs Bettencourt Flying Service in Atwater, said he's been trying to catch up since mid-January because of the increased acreage he has to work this year.

"We're swamped," he said. "Normally, if we get a phone call, we do the job. I've got guys on my books that are a couple of weeks behind."

It began with herbicide applications in field crops such as oats and wheat, much of which his clients normally could do themselves—but not this year. After the almond bloom came last month, Brigham said, "we just couldn't keep up anymore."

"We're becoming 911," he said. "And the almonds all came at the same time, so everybody wants to be sprayed at the same time, and there's less and less of us to do it."

He noted his family business used to operate six aircraft; now he's down to one helicopter.

The state has been losing agricultural aerial operators for years, according to Terry Gage, president of the California Agricultural Aircraft Association. She noted her group had 122 operator-members in 2002, but the number dropped to 73 in 2018, even though the number of pilot-members has increased during that time—from 338 in 2002 to 352 last year.

"The operator numbers are really telling, as without the business licensing, aircraft, facilities and crew, the pilots can't fly," she said.

What has helped this winter, Brigham said, is that the weather has been fairly cool, which slows disease pressure.

Franz Niederholzer, University of California Cooperative Extension farm advisor in Colusa, Sutter and Yuba counties, said though cold weather does reduce the risk of most fungal diseases, other problems such as bacterial blast and jacket rot—also a fungal disease—are more prevalent during cool weather.

Cooler weather, however, does help to extend the bloom, he said. That allows farmers more time to apply fungicide, which is recommended at the beginning of bloom and again at full bloom, he said.

Brent Holtz, UCCE farm advisor in San Joaquin County, said he hasn't seen too many problems with fungal diseases at this point, because of how cool it's been, but there have been more incidents of bacterial blast, which can infect trees under stress. In orchards with high nematode populations, the bacteria can enter wounds on the surface of the plants created by frost, he noted.

"It blights the blossoms, and if the blossom is dead, they don't produce fruit," Holtz said.

For Darrell Cordova, who grows almonds and walnuts in Denair, a big concern has been the amount of standing water in his orchards. The storm that came through his area last week brought rain, hail and heavy wind that knocked blooms off his almond trees. Flooding in some cases was so excessive that it was "like a Mississippi River running through the orchard."

"With all this water and the wind, we're concerned about trees blowing over," he said, noting that in one young orchard, he probably lost some trees.

Longer term, he said there may be problems of Phytophthora root rot due to the severe soil saturation.

More troubling, Cordova said, is the lack of bee activity during bloom. Even though his trees had what he described as "a really good bloom," he noted it was short-lived, and the rainy, cool weather did not allow many bees to come out.

"With all this wind and rain and hail, there's a lot of factors that could play a major role in what the crop is going to look like," he said.

Niederholzer said if strong winds blew off just the flower's petals, that shouldn't hurt crop set so long as pollination occurred. Bees are most active at 55 degrees or warmer with no rain and winds below 10 mph, he added. Strong beehives will forage below those thresholds, and "if ever there was a year for growers to have good bees, this certainly would be the year for it," he said.

"Mother Nature is remarkable," he said. "You can set a crop under extended bloom like this. It's possible to set a good crop."

Mel Machado, director of member relations for Blue Diamond Growers, said it will be the first week of April before almond growers can assess crop set. Although farmers throughout the Central Valley experienced some degree of adverse weather, he noted those in the North State endured more wet, cold conditions. Flooded orchards and downed trees have been more concentrated in some areas but not widespread, he noted.

"Post-bloom weather, to me, is as important as bloom weather," Machado said, adding that sunny days are needed for photosynthesis to produce enough carbohydrates for the trees to maintain the nuts they've set.

(Ching Lee is an assistant editor of Ag Alert. She may be contacted at

Permission for use is granted, however, credit must be made to the California Farm Bureau Federation when reprinting this item.

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