Scheduling of Drip Irrigation for Hybrid Cotton (Gossypium hirsutum L.) in Northern Dry Zone of Karnataka

摘要

The response of hybrid cotton (Gossipium hirsutum L.) DHH-11 to drip irrigation (DI) at 50, 75 and 100% potential evaporation (PE) throughout the crop growth period (TCGP) or DI at 50 or 75% PE up to 45 DAS and 75 or 100% PE thereafter was tested, incomparison with alternatively alternate Furrow irrigation (AAFI) and every Furrow irrigation (FT) at IW/CPE ratio of 0.8. The trial was carried out on medium black soil during summer for three seasons froml 998-2000 at Agricultural Research Station, Arabhavi, situated in northern dry zone of Karnataka. The Kapas yield varied significantly in two out of three seasons (1998 and 1999) and also in pooled data analysis. During 1998 and 1999, DI at 50% PE TCGP (2582 and 2706 kg ha~(-1), respectively) or DI at50% PE up to 45 DAS + 75% PE there after (2512 and 2603 kg ha~(-1), respectively) recorded higher kapas yield thanfurrow irrigation (FI) at IW/CPE of 0.8 (2107 and 2081 kg ha~(-1), respectively). However, these treatments were on a par with AAFI at IW/CPE of 0.8 during 1998 only (2532 kg ha~(-1)). Pooled data analysis revealed that, DI at 50% PE TCGP (2805 kg ha~(-1)) or DI at 50% PE up to 45 DAS +75% PE thereafter (2663 kg ha~(-1)) registered significantly higher kapas yield than other irrigation treatments. The extent of increase in yield with these two treatments was 25.9 and 19.5 % over FI and 13.5 and 7.7% over AAFI, respectively. DI at 50 % PE TCGP recorded higher water use efficiency (WUE) than all other treatments. Cotton quality parameters did not vary significantly due to irrigation methods and scheduling of DI, except Micronaire value during 1999-2000. The Micronaire value was higher with DI at 50, 75 and 100% PE TCGP than other treatments. This indicates that the quality parameters were not affected due to reduced level of irrigation under drip. Therefore, it can be concluded that, scheduling of DI to hybrid cotton at 50% PE TCGP will save 50% irrigation water and enhances WUE and cotton productivity without affecting the quality parameters.