Productivity of Cassava (Manihot esculenta) as affected by drip fertigation in humid tropics

Abstract

Field experiments were carried out at Central Tuber Crops Research Institute, Kerala, India during three seasons, 2009-2010, 2010-2011 and 2011-2012 to investigate the response of cassava to precision approaches in irrigation and fertigation.   The experiments were laid out in split plot design with three replications. The main plots included three levels of drip irrigation viz., (I1- irrigation at 100% pan evaporation (PE), I2- 80% PE and I3- 60% PE). The sub plots comprised of   three fertigation schedules viz., three ratios of   recommended nitrogen and potassium fertiliser doses applied at growth stages of 1-40 days, 40-80 days and 80-120 days (F1-50:30:20, F2-30:50:20 and F3-50:40:10). Minisetts of cassava variety 'Sree Vijaya' was planted at a distance of 60 x 45 cm during the dry spell (Dec- May) in all the years. Results indicated that irrigation at 100% PE yielded maximum tuber yield in all the seasons (43.9 t ha-1). There was no significant difference in   yield among the fertigation schedules. However, interaction effects showed that I1F1 resulted in better growth characters, yield attributes and yield followed by I1F3. On an average, 280 mm, 224 mm and 168 mm of water were applied in I1, I2 and I3 irrigation levels respectively during the growing season. Water use efficiency determined was also higher for irrigation at I1   level of irrigation.