Tactics for Producing Plump, Perfect Peaches Scrutinized

Some of the sweetest, juiciest peaches in the world come from the sunny orchards of California's central valley. A three-year study being conducted by Agricultural Research Service scientists and their university colleagues may help California growers cut back the amount of water and fertilizer currently used to produce the luscious fruit.

Researchers are varying the timing and amount of water and nitrogen fertilizer that they apply to about 1,800 young peach trees in an experimental orchard at Parlier, Calif. They're looking for differences in growth that result from delivering varying amounts of water through furrows, sprayers called microjets, or drip-irrigation tubing.

The scientists fitted the orchard with more than 500 probes and sensors to monitor the amount of water in the soil and the supply of nutrients such as nitrogen, phosphorus and potassium. The researchers also are using a miniature video camera to scrutinize root growth.

The study, now in its second year, focuses on young peach trees because very little is known about their water and nutrient needs. That's according to ARS plant physiologist David R. Bryla at Fresno, Calif. He leads the investigation.

Findings should be applicable not only to peaches, but also to orchards of other stone fruits, including nectarines, apricots and plums. California produces more of those crops than any other state.

The research is funded in part by a grant from California State University, Fresno.

Bryla will describe the investigation today to guests at a dedication ceremony for the new ARS San Joaquin Valley Agricultural Sciences Center, a 125-acre complex that includes the experimental orchard. The nearly completed research campus, built at a cost of about $22 million, has 80,000 square feet of lab and office buildings, greenhouses and other facilities.

Plans call for the 86 scientists, technicians and others currently based at the ARS Water Management Research Laboratory and ARS Horticultural Crops Research Laboratory in Fresno--about 25 miles away--to move to the new complex early next year.

ARS is USDA's chief scientific research agency.

Scientific contact: David R. Bryla, ARS Water Management Research Laboratory, Fresno, Calif.; phone (559) 453-3106; fax (559) 453-3122, bryla@pwa.ars.usda.gov.