PhD

The field experiment of the project entitled “Fodder production technology under light and moisture stress situations” was undertaken at the Instructional Farm, College of Agriculture, Vellayani, Thiruvananthapuram, during January 2012 to March 2014. The main objectives of the project were to identify drought tolerant varieties of fodder cowpea and their performance evaluation in varying proportions of grass legume mixtures under open and shaded conditions. The project comprised of two investigations. The Investigation-I entitled “Drought tolerance studies in fodder cowpea under open and shaded situations” was conducted during the summer season (January to March) of 2012. The Investigation-II on “Evaluation of grass-fodder cowpea mixtures under open and shaded situations” was conducted for two years from March 2012 to 2013 and from March 2013 to March 2014.
In Investigation-I, five fodder cowpea varieties (V1-UPC-618, V2-UPC-622, V3-Bundel Lobia-1, V4-COFC-8 and V5-CO-5) were evaluated for their drought tolerance under four soil moisture stress levels (M1 - pre sowing irrigation + life saving irrigation; M2 - pre sowing irrigation + irrigation at IW/CPE ratio of 0.4; M3 - pre sowing irrigation + irrigation at IW/CPE ratio of 0.6 and M4 - pre sowing irrigation + irrigation at IW/CPE ratio of 0.8). The investigation was conducted as two separate experiments one in open and other in shade. Both the experiments were laid out in split plot design with four replication. Based on the results of this investigation, two drought tolerant fodder cowpea varieties were selected each under open and shaded situation, for conducting Investigation-II. The fodder cowpea varieties COFC-8 (V4) and UPC-622 (V2) which recorded significantly higher green fodder yield (24.21 t ha-1 & 21.36 t ha-1, respectively), crude protein yield (0.79 t ha-1 & 0.66 t ha-1, respectively) and net returns of Rs 44880 ha-1 and Rs 36011 ha-1, respectively were selected for open condition. The fodder cowpea varieties COFC-8 (V4) and UPC-618 (V1) which recorded significantly higher green fodder yield (11.50 t ha-1 and 11.00 t ha-1 respectively), crude protein yield of 0.41 t ha-1 & 0.34 t ha-1 respectively and net returns of Rs 13498 ha-1 and Rs 11873 ha-1 respectively were selected for shaded situation.
Investigation-II on the evaluation of grass-fodder cowpea mixtures were also conducted as two separate experiments, one in open and the other in shade. The experiments were laid out in RBD with three replications, comprising of two grasses [G1-Hybrid napier (Suguna), G2-Guinea grass (Harithasree), two best fodder cowpea varieties from the first investigation (V1-COFC-8(open and shade), V2-UPC-622 (open), UPC-618 (shade) and three grass legume row ratios (R1-1:1, R2 -1:2, R3 -1:3). The results indicated the superiority of the grass legume mixture of hybrid napier cv. Suguna and with both the fodder cowpea varieties in the grass legume row ratio of 1:2 with respect to green fodder yield, crude protein yield and net returns.
Based on the results, it can be concluded that hybrid napier cv. Suguna intercropped with fodder cowpea varieties COFC-8 and UPC-622 in open condition and with COFC-8 and UPC-618 in partial shade (30 per cent) in the row ratio of 1:2 is the best for obtaining maximum yield, quality and net returns.