Effect of fertility levels on productivity and sustainability of sugarcane (Saccharum spp. hybrid complex) varieties under various planting seasons in clay loam soil of south-east Rajasthan

A field experiment was conducted from 2008–09 to 2010–11 at Agricultural Research Station, Kota, to find out suitable sugarcane (Saccharum spp.) varieties (‘CoPK 05191’, ‘CoPK 05192’ and ‘Co 05011’) for different planting season (spring and summer) under 3 levels of recommended dose of NPK (150:45:30, 200:60:40 and 250:75:50 kg/ha), laid out in randomized block design with 3 replications. The variety ‘CoPK 05191’ recorded the highest number of millable cane (99,400 and 85,050/ha), cane yield (81.20 and 65.43 t/ha), commercial cane sugar (9.82 and 8.45 t/ha), pol % juice (18.4 and 18.5) across the seasons, hence it could be adopted in the region for optimizing sugar productivity and regulating crushing schedule at factory level. The results also revealed that yield attributes, viz. number of millable cane (95,650 and 83,310/ha), single cane weight (885 and 905.5 g), cane yield (75.90 and 63.90 t/ha), pol % juice (18.1 and 17.7), CCS (10.08 and 8.60 t/ha) and net profit (88,680/ha) were significantly influence due to increasing levels of fertilizers up to 200:60:40 kg NPK/ha over 75% RDF of NPK (150:45:30 kg/ha) and at par with 125% RDF of NPK (250:75:50 kg/ha) in spring and summer season respectively. Nutrient uptake followed the similar trend as the yield attributes and cane yield in different fertility levels. Thus, the results indicated that fertility level of 200:60:40 kg NPK/ha was found optimum for improving yield attributes, cane yield and juice quality of sugarcane variety ‘CoPK 05191’ for spring as well as summer planting.