LOWER AND UPPER BASELINES FOR CROP WATER STRESS INDEX AND YIELD OF GOSSYPIUM HIRSUTUM L. UNDER VARIABLE IRRIGATION REGIMES IN IRRIGATED SEMIARID ENVIRONMENT

作者：Usman M^*; Arshad M; Ahmad A; Ahmad N; Zia ul Haq M; Wajid A; Khaliq T; Naseem W; Hasnain Z; Ali H; Ahmad S

来源：Pakistan Journal of Botany, 2010, 42(4): 2541-2550.

Cotton (Gossypium hirsutum L.) is an important cash crop of Pakistan. The study regarding determination of lower and upper base lines for crop water stress index (CWSI) for cotton was conducted during summer, 2006 at Post Agricultural Research Station, University of Agriculture, Faisalabad situated at latitude 31 degrees 25'N, longitude 73 degrees 09'E and altitude 184.4 m from sea level. Experiment comprised of five treatments of irrigation levels replicated thrice under randomized complete block design. Vapor pressure deficit (VPD) was also measured for this purpose. Upper baseline was established by growing a separate treatment T(5) without any irrigation or excessive rainfall. While lower baseline was established by using air and canopy temperature attained on clear sunny days within 5-8 days of irrigation and rainfall application. Effect of treatments on leaf area index (LAI) was observed and a relationship was established between yield and LAI. The relationship between yield and seasonal mean CWSI was found to be linear. No significant differences were found in yield of treatments T(3) and T(4), suggesting that an extra irrigation may be saved in treatment T(4) without any significant loss in yield. Water use efficiency (WUE) was found non significant among different irrigation treatments with overall mean value of 0.54 kg m(-3).

• 出版日期2010-8