Chilling hours also won’t be a problem for walnuts going into the 2009 season. As of February 10, most locations were reporting cumulative chilling hours significantly above or at least on par with last year. Over 1,000 hours is not uncommon.
“Anything over 700 is good,” says Bill Thompson, Four Season Ag Consulting, Livingston, Calif.
“I think we’ll have a good bloom in walnuts. In almonds, the abundance of chilling hours will help pollination of nonpareils. However, I’ve heard that some growers are actually thinking of trying to shake some of the blooms off almond trees to lighten the load and reduce water requirements.”
Water is again the most challenging issue going forward. “We’re all hoping for some more rain,” Thompson says. “We’ve been cut back on our surface water allocations from the Turlock, Modesto and Merced irrigation districts where I work.”
The implications of limited water supply will most likely affect yield, if not quality, for the 2009 season. “We may produce smaller nuts simply because we don’t have enough water to fill them,” he says.
Water shortages are rapidly changing the way growers view various irrigation systems. “Flood irrigation is becoming a luxury that we will probably lose in favor of more efficient systems,” Thompson says. “Whenever possible, growers are trying to switch to micro-sprinklers or drip or anything that uses less water.”
In addition to the capital investment of switching to more cost effective irrigation systems, there is often a lag time in production efficiency.
“There’s always an adjustment for the trees,” Thompson says. “If you suddenly switch from flood to some other form of water delivery, it may mean a loss of production until the tree gets used to the new system.”