Kingsburg cherry farmer Allen Jackson laments last season’s paltry harvest. Dry and warmer than normal temperatures contributed to fewer cherries and less revenue. 


“There were some areas where there wasn’t enough fruit on the tree to even try picking it,” said Jackson, who grows 11 varieties of cherries. “But things are looking much better now.”


Jackson and other tree fruit farmers are welcoming the return of cooler daytime temperatures and foggy weather – staples of San Joaquin Valley winters and two factors needed for good fruit development.


The National Weather Service said December’s temperatures in Fresno were normal – meaning lows in the upper 30s and daytime highs in the upper 40s to low 50s.


Scientists say that fruit trees, like cherries, require a certain number of hours of cool temperatures. In the plant world, that is known as chilling hours. Although some trees require more chill hours than others, cherries and pistachios did not get enough last winter. Farmers say a temperature in the low-to-mid 40s is ideal. 


Without the optimum chill hours, the tree’s reproductive development is stunted, resulting in poor fertilization and fewer fruit buds. 


“It is like the female flowers were ready to party but the male flowers weren’t around,” said David Doll, University of California pomology farm adviser in Merced County.


In pistachio trees, the shells develop, but without any nuts inside. It’s called blanking. Add a lack of water, and the 2015-16 crop could be down by at least 30 percent, Doll says. 


It’s doubtful the new crop will surpass last season’s crop of 520 million pounds.


The good news is the cooler weather is getting the trees off to a good start. Already, some regions on the west side of Fresno County have accumulated 70 percent of the total chill necessary.


“And January is the biggest chill month,” Doll said.


Farmers are optimistic this will be a better year than last. 


“We are hoping this cold weather sticks around,” Jackson said. 


Jackson said two of his most popular varieties of cherries – Brooks and Tulare – were down significantly last season. On the whole, he estimates his crop was 50 percent of normal. 


In Merced County, farmer Raj Iyer is also thankful for more normal winter weather. 


“Last year, we had 70-plus degrees in January,” Iyer said. “That’s not winter.”


Iyer said the foggy weather, while treacherous for driving, helps keep the daytime temperatures down.


“We have had a normal weather pattern since November, so hopefully we will be back on track to producing a nice cherry crop,” Iyer said.


This article was published on the McClatchy website on Jan. 1, 2016.