ABSTRACT
Cassava is a highly prospective crop among tropical tuber crops having food, feed, fuel, and industrial demand. Traditionally, cassava has been cultivated depending on the rainfall availability. Being a photo-insensitive crop, cassava can be grown throughout the year irrespective of the season, provided sufficient moisture is assured through irrigation. In the present-day context of climate change when precipitation has become irregular and scanty, it is essential to economize the use of irrigation water without compromising tuber yield. Field experiments were carried out in Kerala, India for three summer seasons, 2009–2010, 2010–2011 and 2011–2012 to investigate the response of cassava to micro irrigation. The treatments comprised of three levels of drip irrigation (I1-Irrigation at 100% pan evaporation (PE), I2–80% PE and I3–60% PE) along with surface irrigation and a rainfed crop for comparison. Two node cuttings or Minisetts of variety Sree Vijaya (6 months) were planted during December every year, irrigation treatments were imposed, and data were collected on growth and yield parameters. Pooled data analysis indicated that irrigation at 100% PE resulted in maximum tuber yield (44 t ha–1) and the benefit-cost ratio (4.27). Water productivity of cassava was 8.2 kg m–3 for I1 level of irrigation compared to 4.2 kg m–3 under rainfed conditions and 2.6 kg m–3 under surface irrigation. On an average, water requirement of cassava was 3.0 mm per day during summer months.
