Abstract
The study was conducted during summer 2012-13 at Krishi Vigyan Kendra Farm, Bagalkot (16.18°N 75.7°E, Northern dry zone-III of Karnataka Agro-climatic Classification), Karnataka, India under irrigation on medium black clayey soil(Vertisols) with neutral pH, low in organic carbon, nitrogen, medium in phosphorous, high in potassium and deficient in zinc and iron to study the effect of different levels of borosan(12.5, 25 and 37.5 kg ha-1 ) and time of application(12.5 kg at sowing and 12.5 kg at 20 days after sowing(DAS), 25 kg at sowing and 12.5 kg at 20 DAS and 12.5 kg at sowing and 25 kg at 20 DAS) along with recommended dose of fertilizer Nitrogen(N) : Phosphorus(P) : Potassium(K) @ 25: 75 : 25 kg ha-1). Application of 37.5 kg borosan along with 100 % NPK at the time of sowing recorded significantly highest pod yield of 2180 kg ha-1 and haulm yield of 5200 kg ha-1 as compared 100% recommended NPK( 1435 and 3300 kg ha-1 of pod and haulm yield, respectively). Growth and yield attributes, quality parameters and economic indicators viz., plant height, root length, number of developed and underdeveloped pods, hundred kernel mass, shelling percentage, oil content, highest gross return and B:C ratio were also highest with the application of NPK @ 25: 75 : 25 + Borosan @ 37.5 kg ha-1. Split application of 37.5 kg borosan either 12.5 kg at the time of sowing and 25 kg at 20 DAS and vice-versa did not influenced groundnut yield.