Deep Freeze Means There’s No Time for Growers to Chill Out during the Night

 Weather Watchers issued the chilling news to growers: 

“FREEZE WARNING REMAINS IN EFFECT FROM 2 AM TO 8 AM PST
SATURDAY... Sub-freezing temperatures are imminent or highly likely. These conditions will kill crops and other sensitive vegetation.”

That’s what the U.S. National Weather put out over the weekend for the Valley. The low temperatures were dipping down to the mid-20s. Worst yet, forecasters were warning everyone the freezing temperatures would last as long as six hours.

“Long durations of below freezing temperatures will kill unprotected vegetation. Agricultural interests should closely monitor minimum temperature forecasts and make preparations to protect frost and freeze sensitive vegetation,” the Weather Service goes on to add.

It certainly wasn’t the best way to wrap up a week that endured several days of freezing temps last week. Suddenly, this rain-starved winter became even tougher for growers who are forced to spend the bone-chilling nights rushing to protect their valuable crops. 

Almond growers have been out irrigating their crop to raise the temperature, trying to build up humidity to slow the drop in temperature. They fear the subfreezing temperatures will damage the buds during this critical bloom period. It may be a few weeks before growers see if there is an increase in buds dropping off the trees.

It’s not just the overnight frost growers are worried about. The cool daytime temperatures could slow the pollination process. Bees work best when the weather is at least 55 degrees

.

Our long-time collaborator, David Doll, a Merced County UC Cooperative Extension pomology farm advisor specializing in almonds, has offered freeze warning protection tips on his online Almond Doctor column.

“The point to turn on irrigation is dependent on dew temperature and the expected low temperature. Starting the irrigation too late when the dew temperature is low can increase the risk of damage. Turning off too early can also increase the risk of damage. Techniques utilized to determine when to start and turn off irrigation usually revolve around the use of a ‘wet bulb,’ ” he wrote in his February 17 column.

Irrigating an orchard to protect against the freeze.

He goes on to say: “Irrigation application rates need to be high enough to provide an increase in air temperature. Application rates should exceed 30 gallons per minute per acre. Rates less than 15 gallons per minute per acre may lead to freezing of irrigation lines/spaghetti tubing. The critical temperature of damage will vary by bloom stage and variety. At full bloom, temperatures at or below 27-28F can cause crop loss. As trees leaf out and nuts begin to develop, the sensitivity to cold temperature increases.”

Finally, he adds: “in flood and drip-irrigated orchards it may not be possible to have high enough discharge to have a warming effect of the water, but adding moisture to the soil can increase the warmth of the field – which is why mowing any vegetation is advised within these systems. Mowing may not be as critical in orchards that are able to apply irrigation water over the top of a cover-crop.”

Go to his Almond Doctor website to learn more about frost protection methods for almonds.

Let’s hope March brings warmer temperatures and some much-needed rain.

In a Flash – Almond Trees Suddenly in Bloom

 The calendar says it is winter, but the weather around the Valley makes it seem more like spring.

Certainly spring colors are full force in the almond orchards. “The bloom is super early. We’re at around 70 percent bloom,” says almond field scout Jenna Mayfield.

Almond bloom has come early this season.

Yes, a rainless February with daily temperatures averaging 70 degrees this month has accelerated the almond bloom. For landscape photo buffs, the almond bloom is a spectacular opportunity to capture the breathtaking colors of the almond blossoms. 

In the orchards, millions of bees are pollinating the almonds. Experts estimate more than half of the nation’s bees are brought into the Golden State to do their work in the almond orchards.

“The weather is perfect for the bees,” Jenna says.

Of course, the rain-starved winter once again is creating another buzz among growers. The question circulating is ‘how much water will they have this season?’  It’s a familiar question farmers had been asking during the historic drought a few years ago.

Jenna notes growers already are turning on the spigots to irrigate their almond trees. Of course, last year’s drought-busting rains gave growers a break from irrigating until spring.

“We haven’t had a winter yet. Some trees still have their leaves from last season,” Jenna says.

A dry winter is prompting growers to irrigate their orchards.

Two years ago, bloom came and went very quickly as well. That’s called flash bloom. The concern among growers is whether bees can reach every bloom in time before the trees start greening – meaning pollination could come up short.

Weather forecasters still point out we have one more month of the traditional rainy season. We’ll have to see what Mother Nature has in store for us and how things play out as the season progresses.

For now, Jenna says growers are checking for San Jose scale. The pest will suck plant juices from tree twigs and limbs and inject a toxin that eventually reduces tree growth and can kill limbs. To spot scale, growers should check for a red halo around the feeding area. 

UC IPM says natural enemies such as beetles can keep scale under control. But broad spectrum insecticides used in orchards can impact beetles. 

Here is scale shown on an almond branch. (UC IPM photo)

“These natural enemies are helpful in reducing scale numbers, but insecticides used during the growing season for other pests disrupt this natural control, and scale numbers can increase as a result,” UC IPM says. “Many orchards that have not used broad-spectrum sprays for two or three years do not have San Jose scale problems. Low to moderate numbers of scale can be managed with oil sprays during the dormant season. The best time to spray is during the dormant season, and low to moderate numbers can be managed with oil sprays alone at this time. The scale is monitored as part of the spur sample during the dormant season and with pheromone traps in the spring.”

Central Valley Program Promotes Sustainable Farming Practices for Local Growers

Good environmental stewardship and profitability can go together to provide quality products that our state is proud of. 

Cynics may think otherwise. But a group of Valley almond, cotton and alfalfa growers have proven they can protect our water, soil and air while making a good living. These growers are part of a unique program that promotes sustainable farming.

Coming off another successful year, the San Joaquin Sustainable Farming Project is recruiting new almond, alfalfa and cotton growers in Merced, Madera and Fresno counties for the 2018 season. The program is looking to expand its reach in the Lower San Joaquin River Watershed.

Sounds interesting?

Well, growers can learn more about the program during a field day from 10 a.m. to noon on Thursday, Feb. 15 at the Firebaugh Mendota United Methodist Church, 1660 O Street, Firebaugh. Tom Casey of the Fresno County Agricultural Commissioner’s Office and Orvil McKinnis of the Westside San Joaquin RiverWatershed Coalition will provide updates about 2018 pesticide regulations and the watershed. By enrolling in the program, growers learn valuable strategies to improve yields while becoming better environmental stewards in today’s tough economic and regulatory climate. Sponsored by the Sustainable Cotton Project (SCP), the program connects growers with some of the state’s leading University of California extension advisors and researchers.

Over the years, the program and its growers have gained recognition nationally and internationally.  Growers will receive these benefits:

·         SCP field scouts who work with growers’ existing pest control advisors to augment field scouting.

·         Six field days per year focusing on pest and crop management issues, crop diseases and management, biological farming and water and regulatory issues.

·         Access to top UC farm advisors and integrated pest management experts who will help farmers deal with current issues ranging from pest and disease management to irrigation.

·         Best Management Practices implementation planning and annual hedgerow seeds and beneficial insects, when needed.

For more information or to inquire about enrolling, please contact SCP Director Marcia Gibbs at (530) 370-5325 or  marcia@sustainablecotton.org