Historically, date palms are grown along riverbeds or in areas with groundwater because they require an abundance of water to produce a good crop. Unlike lettuce or table grapes, date palms are deceptive in that they do not immediately wilt if underwatered. Eventually, however, the lack of water hurts yields and fruit quality. 

The default for date growers is to apply excessive water, but doing so is neither economically nor environmentally sound. To help growers, Ali Montazar, UC Cooperative Extension irrigation and water management advisor for Imperial, Riverside and San Diego counties, has developed knowledge that...