Abstract

Field experiments were conducted at Agricultural Research Station, Bhavanisagar, Tamil Nadu in Inceptisols (Typic Ustropepts) to evaluate boron fertilizers, (Borax, Boric acid and Agribor) and to assess the right mode, level of boron application on the B content and yield of the residual crop greengram. The experimental field was deficient in available B (0.35 mg kg). Sunflower was raised as a main crop. Different B levels 0.5, 1.0, 1.5 and 2.0 kg B ha as soil application and two levels of foliar spray 0.2% and 0.3% were compared with control. The treatments were super imposed with recommended dose of NPK. After harvesting the main crop, green gram was raised as a residual crop on the same field without any alternation. The grain haulm yields of green gram were significantly increased by the residual effect of boron applied to the previous crop. Application of B at the rate of 2.0 kg ha recorded highest grain and haulm yields of 958 and 2663 kg ha¹, respectively. The residual effect was not observed at the lower level of B (0.5 kg ha¹) application. The interaction between two source showed that the performances of borax and Agribor were equal at lower levels, while at higher levels Agribor was found superior to borax. Significant correlations existed between B availability and B concentration in grain and haulm and B uptake with yield indicated the residual effect of B on the yield of green gram.

Keywords: Boron nutrition, B concentration and uptake, Residual effect of B, Green gram