Diversity Studies in Plant and Ratoon Crops for Selection of Profitable Sugarcane Genotypes Tolerant to Water Logging.

Abstract

Studies on genetic divergence in sugarcane plant and ratoon crops involving sixteen genotypes planted at RAU Pusa Farm, Samastipur, Bihar during 2012-13 and their consecutive ratoon during 2013-14 under low land area with water-stagnation 2 to 3 months to select profitable genotypes tolerant to water logging. Cane yield of plant crop was higher than the ratoon while for juice quality traits of ratoon crop showed better. All genotypes differed significantly with regard to the traits studied and displayed distinct marked divergence, grouped into five clusters for both crops following Tocher's method. only Cluster I and II had more than one genotypes while Cluster III, IV and V were monogenotypic. In plant crop maximum inter cluster distance was observed between cluster IV and V (5763.19) followed by cluster III & V(4350.43), Cluster I & V (2297.2) and between Cluster II & IV(1835.66) while in ratoon crop between cluster II and V (1050.77), cluster III & V (817.02), Cluster III & IV(623.84), Cluster II & IV (567.85), Cluster I & V (419.80) and between Cluster I & II(319.39).In plant crop highest contribution in the manifestation of genetic divergence was exhibited by cane yield (52.50) followed by CCS per cent at harvest (20.83), pol % in juice at 11 month stage (9.17) while in ratoon crop pol % in juice 9 month stage (45.0) had highest followed by brix 11 month(15.0),CCS per cent at harvest (10.83), purity % at 11 month (8.33), single cane weight (7.50). Profitable offspring will be obtained after crossing between the genotypes of Cluster I and II with Cluster V. Maximum average cane yield (91.83 t/ha) and CCS t/ha (10.60 t/ha) were recorded in CoP 09437 followed by BO 154, CoP 2061, BO 155 and CoX 07067. Minimum average yield gap between plant and ratoon crop was observed in CoP 09437(losses 8.93%) and its ratoon contributed highest 47.7 % towards average cane yield, 26.7 and 17.4% higher cane yield 45.80 and 41.15% higher CCS t/ha than BO91 & BO147, respectively followed by BO 154 and CoP 2061. Selection on the basis of percentage increase over checks and minimum loss in cane yield and CCS t/ha CoP 09437, BO 154 and CoP 2061 were found profitable one to cultivate under low land (water logging) sugarcane growing areas which will enhance productivity and sugar recovery.