Barevadia, T. N.Patel, Kirit K.2018-06-132018-06-131990http://krishikosh.egranth.ac.in/handle/1/5810052580A field experiment was conducted on loamy sand soil of the College of Agronomy Farm Gujarat Agricultural University, Anand Campus, Anand during the rabi season of 1989-90 to study the effect of various dates of last cutting, irrigation schedules and plant proection measures on seed yield of lucerne (Medicago sat iva L.) Cv. "Gujarat lucerne-1'. Different combinations of three levels of irrigation (0.25, 0.50 and 0.75 IW/CPE ratio) and two levels of plant protection measures (without and with plant protection measures on the basis of need application) were allotted as main plot treatment. While, three different dates of last cuttin (15th February, 2nd March, 17th March) were allotted as sub plot treatment of split plot design with four replications. Lucerne crop was sown at 25 cm inter row spacing using seed rate of 5 kg/ha on 6th November 1989. The crop was uniformly fertilized with 20 kg N and 40 kg P2O5 per hectare before sowing. Three forage cuttings were taken before seed crop under 15th February and 2nd March date of last cutting while, 17th March date of last cutting offered four forage cuttings before the seed crop. Owing to lower insect-pests population, treatments of plant protection measures could not be imposed during whole experimental period. Irrigation treatments were imposed at bud stage of the lucerne seed crop and depth of irrigatin was maintained to 50 mm by applying measured quantity of water through Parshall Flume. The experimental results revealed that scheduling of irrigation at 0.5 IW/CPE ratio produced significantly the highest seed yield (341 kg/ha). Simultaneously, it recorded significantly the highest value of various yield attributing parameters viz., number of racemes/ pod (15.00), number of filled pods/head (11.89), number of seeds/pod (7.13), number of mature seeds/pod (6.72) and test weight (2.494 g) as compared to remaining two levels of irrigation. IW/CPE ratios of 0.5 and 0.75 were found alike in recording numlier of effective tillers/metre row length and size of head however, both were significantly superior to 0.25 IW/CPE ratio. Consumptive use of water, total biomass yield and all the morphological parameters increased significantly with successive increase in levels of IW/CPE ratio from 0.25 to 0.75. While contradictory to this, decreasing trend was observed in case of water use efficiency and water expense efficiency with each increment in IW/CPE ratio from 0.25 to 0.75. Among different dates of last cutting, 17th March established its superiority by giving significantly the highest seed yield (329 kg/ha) along with green forage (260.51 q/ha) yield. Conspicuously the highest value of all the yield attributes viz., number of effective tillers/metre row length (40.96), number of racemes/shoot (15.10), number of filled pods/raceme (11.43), size of head (2.73 cm), number of seeds/pod (7.03), number of mature seeds/pod (6.57) and test weight (2.424 g) were recorded when the lucerne crop was left for seed on I7th March. Harvesting of last forage cutting on 17th March produced the lowest total biomass yield (1907 kg/ha) and all the morphological parameters at 20 days after last cutting as well as at harvest. It was observed that each delay by 15 days in leaving the crop for seed showed significant reduction in consumptive use of water and simultaneously, increased the water use efficiency and water expense efficiency. Lucerne crop left for seed on 17th March and irrigated at 0.5 IW/CPE ratio turned out to be best for reaping maximum seed yield (389 kg/ha) and green forage yield. This said treatment combination was found c conducive for recording remarkable higher values of various parameters viz., number of effective tillers/ metre row length (47.50), number of racemes/shoot (17.50), number of filled pods/raceme (12.65), size of head (2.97 cm), number of seeds/pod (7.64), number of mature seeds/pod (7.31), test weight (2.580 g), harvest index (18.55%), water use efficiency (1.691 kg seed/ha mm), water expense efficiency (1.555 kg seed/ha mm). Treatment combination involving 0.25 IW/CPE ratio of irrigation and 17th March date of last cutting recorded significantly the lowest value of total biomass yield (1369 kg/ha) and consumptive use of water (146.15 mm). However, just reverse to this» it recorded significantly the highest vaue of water use efficiency (1.759 kg seed/ha mm) and water expense efficiency (1.714 kg seed/ha mm). Lucerne crop left for seed production on 17th March and irrigated at 0.50 IW/CPE ratio gave maximum net profit (Rs. 14073/ha) and cost benefit ratio (1 : 3.30). From this investigation, it is indicated that lucerne crop (Cv. 'Gujarat lucerne-l') should be left for seed on 17th March and irrigated at 0.50 IW/CPE ratio after the bud stage which required only three irrigations each of 50 mm depth of water to get maximum seed yield and net profit under middle Gujarat conditions.enAGRONOMY, AGRICULTUREA STUDYThesis