Water Requirement of Drip Irrigated Pomegranate.

Pomegranate is an ancient crop having been cultivated for several thousand years. Despite this period of cultivation, very little research has been done to quantify the water and fertilizer requirements of this crop. Pomegranate production in California has increased because of the purported health benefits due to antioxidants in the fruit. Pomegranate is thought to be both salt and drought tolerant. We developed two projects; 1) to determine the nitrogen requirement of fully irrigated crop; and 2) to determine the drought tolerance using a range of applied water based on lysimeter measured ET. The nitrogen experiment used a multi-trunk tree while the water requirement study used single trunk pruned with several branches. We will compare the fully irrigated crop ET of the two projects as relates to the canopy structure and determine resulting crop coefficient for each canopy configuration. The drought tolerance will be evaluated based on the yield response to the range of applied water in the single trunk configuration. Fractional canopy cover has been correlated to the crop coefficient in several field crops. We evaluated the relationship between fractional canopy cover and crop coefficient for these two projects with a range of applied irrigation water and differing canopy structures. Yields were reduced with deficit irrigation in each year. There was a good correlation between crop coefficient and fractional ground cover across the projects despite the difference in canopy architecture.