By the middle of April, Colusa County tree-nut grower Leon Etchepare should know how much surface water he and other members of the Glenn-Colusa Irrigation District can expect to receive this year. That figure will determine if he plants or fallows the row crop fields this season and how much water he will need to purchase to keep the orchards alive.
Etchepare is a partner in Emerald Farms, where he manages 3,500 acres of walnuts, almonds and several hundred acres of vegetable seed crops near Maxwell, Calif.
In February, the Bureau of Reclamation notified the District that the 2014 allocation, under its Sacramento River Settlement Contract, would be reduced to 40 percent of the contract total.
If the 60 percent reduction occurs, Etchepare will be forced to fallow several hundred acres of row crops, including squash, tomatoes, watermelons, onions, peppers, and cucumbers, which are grown for seed. Furthermore, he will be forced to transfer the water that would have been used for the row crops to sustain his walnut and almond orchards through the season.
In a February letter to GCID landowners and users, the District notes that the Sacramento River Settlement Contracts provide for an allocation of either 100 percent of supply in a normal water year or 75 percent of supply in a critical year. “No other provision of the Contracts addresses any discretion on the part of Reclamation to make an alternative allocation,” the District reports.
Etchepare and other growers in the District hope that talks between GCID and The Bureau of Reclamation officials, along with the March rains, will result in increased 2014 water allocations to the contracted 75 percent allocation.
“Regular irrigation practices, at 75 percent of normal allocation, would mean adequate water for both the orchards and row crops,” says Etchepare. Normally, he’s working up his row crop ground by mid-March. Regardless, a 75-percent water allocation in mid-April will likely have little impact on his row crop production.
Currently, Etchepare’s tree nut fields are in good shape for water, since he irrigated with micro-sprinklers in February. “We were able to purchase water from other growers in a neighboring water district and irrigated as much as we could. Even during the rain, we were able to recharge soil moisture to adequate levels,” he says. “Also, we had a good amount of rain in March, which helped significantly.”
Close eye on botryosphaeria
Warm weather in February, with temperatures well above average, pushed the walnut trees off to an early start, about two weeks ahead of normal, Etchepare reports. By the first week of April many of the walnut varieties, especially the Vinas, had leafed out. Catkins began appearing on the Vinas in mid-March. By the first of April, catkin development was almost complete on the Howards. Other varieties, such as Chandlers, were just starting.
Etchepare has made multiple fungicide applications since early March to control the usual threat from walnut blight. This year, he’s keeping a close eye on an emerging botryosphaeria threat to his walnut orchards.
The disease, which can infect spurs, shoots, and nuts, has been a serious threat in pistachio orchards for some time. Research, funded by the California Walnut Board, has been underway since 2012 to learn more about the cause and spread of the disease and how to manage it in walnuts.
Over the past four years, University of California Cooperative Extension farm advisors, PCAs, and orchard managers have noted an increase in the disease frequency in walnut orchards.
“Botryosphaeria has reared its ugly head in our operation over the last two years,” Etchepare says. “We started combatting it last year in an attempt to mitigate it using a combination of irrigation, cultural, and spray practices. At this time, the disease hasn’t progressed.”