Bhatti, Deedar SinghDhaliwal, Jaspreet Singh2019-01-242019-01-242018http://krishikosh.egranth.ac.in/handle/1/5810092306A pot experiment was conducted to evaluate the response of rabi oilseed genotypes to boron (B) application in a B deficient soil (HWS-B; 0.39 mg kg-1 soil). Eight kg of well processed soil was filled in plastic pots with three replications. Boron was applied @ 0, 0.25, 0.50, 1.00, 2.00 and 4.00 mg kg-1 soil as borax. Pots were allowed to equilibrate for 20 days at field capacity. Six seeds of different genotypes of raya (RLC 3, PBR 357, PBR 210, PBR 97, PBR 91) and gobhi sarson (GSC 7, GSC 6, PAC 401, GSL 1, PC 6) were sown during rabi season of 2015-16, which were thinned to 3 plants per pot after germination. Application of B @ of 0.50 mg kg-1 soil significantly increased the seed yield and B concentration in both raya and gobhi sarson. The genotypes PBR 210 and PAC 401were found to be B efficient. The genotype RLC 3 of raya was susceptible to B toxicity while PC6 (african sarson) was resistant to B toxicity. The critical levels of HWS-B in soil to produce 90% of the maximum seed yield were 0.57, 0.58, 0.47, 0.60, 0.38, 0.49 and 0.70 mg kg-1 for RLC3, PBR357, PBR210, PBR97, GSC6, PAC401 and GSL1, respectively. The corresponding values of B concentration in seed to produce 90% of maximum seed yield were observed as 18.1, 14.1, 11.0, 14.4, 20.6, 15.7 and 16.3 µg g-1.Another pot experiment was conducted in a similar manner in which five genotypes each of chickpea (PBG 7, PBG 5, GPF 2, PBG 1, L552) and lentil (LL 931, LL 699, LH84-8, LH82-6, HM 1) were supplied with five levels of B (0, 0.25, 0.50, 1.00 and 2.00 mg kg-1 soil) as borax. Seed yield of chickpea and lentil increased significantly with B application @ 0.25 mg kg-1 soil. The critical levels of HWS-B in soil to produce 90% of the maximum seed yield were 0.41, 0.45, 0.41, 0.51, 0.45, 0.41, 0.53 and 0.48 mg kg-1 soil for PBG 7, PBG 5, GPF 2, PBG 1, L 552, LL 931, LH 82-6 and HM 1, respectively. The corresponding values of B concentration in seed to produce 90% of maximum seed yield were observed as were 18.7, 19.9, 19.4, 21.1, 23.0, 16.0, 13.6 and 12.9 µg g-1. The chickpea genotype L 552 was found to be resistant to B deficiency as well as toxicity. The lentil genotype LL 931 was B efficient and LH 84-8 and HM 1 were found to be resistant to B toxicity. A pot experiment was also conducted to study the relative efficiency of soil and foliar applied B in rabi oilseeds and pulses. Boron was applied @ 0, 0.25, 0.50, 1.00, 2.00, 3.00, 4.00 and 5.00 mg kg-1 soil as borax and foliar application of 0.2 % borax at 30 DAS and pre flowering stage. Foliar application of B was found to be relatively more superior to soil application in increasing the seed yield of raya. In gobhi sarson soil applied B @ 0.50 mg kg-1 soil and two foliar sprays of B were equally effective to produce significant response over control. For chickpea, B application @ 0.25 mg B kg-1 soil and one foliar application at 30 DAS were equally effective, but for lentil, foliar applications were not effective. Transformation studies of B in soil after the harvesting of oilseed and pulses crops revealed that content of B in different pools increased with its application to soil. The readily soluble and specifically adsorbed B decreased after harvesting of crops either due to plant uptake or conversion to other pools. Oxide and organically bound fractions increased whereas residual forms remained unaffected with cropping. In a B adsorption study it was observed that both Freundlich and Langmuir adsorption isotherms satisfactorily explained the B adsorption behavior of five different textured soils (sand, loamy sand, sandy loam, loam and clay loam). Highest values of bonding energy constant (Kf) predicted by Freundlich adsorption isotherm (2.291 mg kg-1) was observed for clay loam soil whereas lowest was recorded with sandy soils (1.409 mg kg-1). Bonding energy constant was also significantly correlated with organic carbon (r=0.803*) and clay content in soil (r=0.837*) which signified the increased adsorption of B with increased clay and organic matter in soils.enThesis