干旱区生态环境知识资源中心

A drip irrigation system was installed above ground at 30, 45, and 60% of the weekly-accumulated evaporation depth to evaluate productivity of harvested green cladodes (leaf-like stem segments) of the prickly pear cactus. Results showed that irrigating above 30% does not increase crop production. This percentage represents an annual irrigation depth of 0.74 m, which is one of the lowest in the regional irrigation district of "La Laguna" in the state of Coahuila. Nopal Opuntia ficus indica cv. C-69 showed the highest green cladode "nopalitos" yield, with 108 tonnes (ha(-1) year(-1)) and sustained growth except during the cold season. Leaf area index was 80, net assimilation rate was 0. 178 g (dm(-2) day(-1)), and dry-weight at maximum productivity was 9.2 g for the confidence parameters for the week representing average green cladodes growth. (C) 2004 Elsevier B.V. All rights reserved.