Effect of different planting density on thermal time use efficiencies and productivity of guar genotypes under southern transition zone of Karnataka

Abstract

A field experiment was conducted during Kharif seasons of 2014 at University Agricultural and Horticultural Sciences, College of Agriculture, Shivamogga, Karnataka, to study the dry matter accumulation, and various thermal time use efficiencies viz., accumulated growing degree days (GDD), heat use efficiency, helio thermal use efficiency (HTU), photo thermal use efficiency (PTU) of guar cultivars grown under different Planting Density. The guar varieties RGC-1003, HG 365 and RGC 936 were sown with four different planting density viz., 45 cm x 15 cm, 30 cm x 15 cm, 45 cm x 10 cm and 30 cm x 10 cm. the experiment was laid out in RCBD with factorial concept and replicated thrice. The experimental results indicated a high degree of linear relationship between GDD and dry matter accumulation of guar with all the genotype across planting density. among different planting density significantly higher thermal time use efficiencies viz., heat use efficiency (1.82 x10-2), helio thermal use efficiency (3.47 x10-3), photo thermal use efficiency (3.73 x10-2) was recorded with the crop grown in 30 cm x 10 cm of spacing also recorded significantly higher grain yield (898.18 kg ha-1) and stover yield (1931.39 kg ha-1) as compared to other spacing. Among genotypes RGC 1003 recorded significantly thermal time use efficiencies viz., heat use efficiency (1.91 x10-2), helio thermal use efficiency (3.64 x10-3), photo thermal use efficiency (3.90 x10-2) and grain yield (743.89 kg ha-1), stover yield (1629.94 kg ha-1) as compared to HG 365 and RGC 936.