Tillering pattern, growth and productivity of promising sugarcane genotypes under various planting seasons and nitrogen levels in subtropical India

An experiment was conducted at the Indian Institute of Sugarcane Research, Lucknow, Uttar Pradesh, during 2000-2001 and 2001-2002 with 2 planting seasons (spring and summer), 3 genotypes ('Co H 94202', 'CoLk 9606' and 'CoLk 9617') and 3 nitrogen levels (112.5, 150 and 187.5 kg/ha). Higher tiller number, vigour and retention along with mean cane length (176.7 and 236.9 cm), cane diameter (2.46 and 2.23 cm) and cane weight (916.3 and 1106 g) were observed with spring planted cane than summer cane during both the cropping seasons respectively Mean tiller population increased from 89,350/ha to 218,600/ha and 85,250 to 197,800/ha during first and second cropping seasons respectively. Thus higher tiller retention (66.6%) was observed during the first year than second year (52.9%). Genotype 'CoLk 9617' produced highest number. of millable canes (153,500/ha and 114,020/ha during both the cropping seasons respectively), cane yield (92.19 and 109.4 tonnes/ha) and commercial cane sugar (10.72 and 12.95 tonnes/ha) and found superior to 'CoLk 94202' and 'CoLk 9606'. Spring planting produced highest cane (92.81 and 110.67 tonnes/ha) and commercial cane sugar (11.07 and 12.89 tonnes/ha) yields compared with the summer planting. The highest level of nitrogen also resulted in better tiller vigour, number and retention, besides better expression in growth parameters, cane (90.92 tonnes/ha and 103.75 tonnes/ha) and commercial cane sugar yields (10.69 and 12.59 tonnes/ha) during both the cropping seasons.