INFLUENCE OF SEED INVIGORATION ON SEED QUALITY AND YIELD IN CHICKPEA (Cicer arietinum L.)
Acharya N.G. Ranga Agricultural University
The present investigation was carried out in the Department of Seed Science and Technology, Advanced Post Graduate Centre, Lam, Guntur (laboratory studies) and Agricultural Research Station (ARS), Jangamaheswarapuram, Guntur (field studies) during 2017-18 to study the influence of seed invigoration treatments on field performance and seed quality of aged seed of chickpea variety NBeG-3. Initially standardization was done to know the best duration of soaking for the hydration treatments in aged (Rabi, 2015-16 harvested) seed of chickpea variety NBeG-3. Hydration was done for various durations ranging from 2 to 24 hours with an equal increment of 2 hours and the seed quality traits were studied by testing in between paper method and sand method of germination. Among the hydration durations, highest germination (%), root length (cm), shoot length (cm), seedling length (cm), root / shoot ratio and seedling vigor index were recorded with 8 hours of hydration and beyond that the seed quality declined gradually upto 24 hours. Standardization was also done to know the best concentration of PEG and duration of osmo-conditioning in aged seed of chickpea. The aged seed was subjected to osmo-conditioning with different concentrations of PEG 6000 (0, -0.5, -1.0, -1.5 and -2.0 MPa) for various durations (3, 6, 9, 12 and 24 hours) and the seed quality traits were studied by testing in between paper method and sand method of germination. Among the various concentrations and durations, osmo-conditioning with -0.5 MPa PEG for 6 hours recorded highest germination (%), root length (cm), shoot length (cm), seedling length (cm), root / shoot ratio and seedling vigor index. The aged seed of chickpea was subjected to invigoration treatments viz., hydration, hydration followed by seed treatment with thiram, 50 ppm GA3, 2 % KH2PO4, 2 % CaCl2 and 2 % KNO3 for 8 hours and osmo-conditioning with -0.5 MPa PEG for 6 hours and shade dried to reach 9 % moisture content. The invigorated aged seed along with untreated aged (Rabi, 2015-16 harvested) seed and fresh (Rabi, 2016-17 harvested) seed was used for assessing seed quality and field performance. Among the invigoration treatments, seed treated with CaCl2 and osmo-conditioning with PEG showed significantly higher germination and other seed quality traits over untreated aged seed. The germination and seedling vigor index in CaCl2 treated seed were significantly higher than that in fresh seed also. In the field studies also, seed treated with CaCl2 showed highest improvement in most of the field parameters viz., field emergence, plant height at 60 DAS and maturity, number of branches per plant, number of pods per plant, seed yield per plant and seed yield per plot which were superior to that of untreated aged seed as well as fresh seed. Minimum number of days taken to reach 50 % flowering was recorded in seed treatment with GA3 followed by CaCl2. Seed invigorated with KNO3 and hydration also showed improved field performance in all the above mentioned parameters and was on par with the fresh seed. The seed yield recorded per plot was statistically superior in all the invigoration treatments over the untreated aged seed. The seed quality studies from the harvested crop indicated that there was no significant difference among the different invigoration treatments for seed germination but significant variation was observed for root length, shoot length, seedling length and seedling vigor index, which were highest in the seed harvested from invigoration treatment with CaCl2. The root / shoot ratio was highest in the harvested seed of KNO3 treatment. Correlation studies showed highly significant positive association of number of pods per plant, number of branches per plant, field emergence and plant height at maturity with seed yield. The increase in any of these traits led to increase in the seed yield. Path coefficient analysis revealed that plant population m-2, number of pods per plant, shelling percentage, seed yield per plant, field emergence, plant height at maturity and days to 50 % flowering had positive direct effects and number of branches per plant and 100 seed weight exhibited negative direct effect on seed yield. The present study proved that seed invigoration with 2 % CaCl2, 2 % KNO3 and hydration treatment may be suggested for improvement of seed quality and field performance in aged seed of chickpea.