Review of Crop Water Productivity for Tomato, Potato, Melon, Watermelon and Cantaloupe in Iran
Population increase and the improvement of living standards brought about by development will result in a sharp increase in food demand during the next decades. Most of this increase will be met by the products of irrigated agriculture and this increase needs to be accomplished under increasing scarcity of water. This challenge has lead to the notion that Crop Water Productivity (CWP) needs to be increased. The current investigation was planned to review the measured crop water productivity values for irrigated tomato, potato, melon, watermelon and cantaloupe in Iran. The review based on of 39 literature sources with results of experiments not older than 20 years. The range of CWP is very large, i.e. tomato (2.58-11.88 kg m ), potato 3 (1.92-5.25 kg m ), melon (2.46-8.49 kg m ), watermelon (2.70-14.33 kg m ) and cantaloupe (4.18-8.65 kg m ) 33 3 3 and thus offers tremendous opportunities for maintaining or increasing agricultural production with 20-40% less water resources. The variability of CWP can be ascribed to climate and irrigation water management among others. The vapor pressure deficit is inversely related to CWP. Vapor pressure deficit decreases with latitude and thus favorable areas for water wise irrigated agriculture are located at the higher latitudes.