MSc

The research work 'Effect of seed treatments on growth, seed yield and quality in okra (Abelmoschus esculentus L. Moench)', was conducted in the Department of Seed Science and Technology, College of Horticulture, Vellanikkara, during 2017-18 with an objective to find the effect of seed treatmentwith growth regulators on growth, seed yield and quality in okra and to delineate their effect on seed quality and longevity. Two separate experiments were conducted. Freshly harvested okra seeds of variety Arka Anamika, were treated with different concentrations of growth regulators namely GA3, IAA, NAA, Cycocel, Maleic hydrazide and Thiourea for two different time period (12 hours and 24 hours) and used to conduct the field experiment (Experiment 1) immediately. The experiment uses the treated seeds was laid out in Randomised Block Design with three replication and twenty five treatments including control. Observations on growth and yield parameters were recorded at appropriate stages. The results revealed that seed treatment with different plant growth regulators exhibited significant differences for all the characters studied. Growth characters like plant height, internode length, number of fruits per plant and seed yield per plant were found to be high in T24 (Thiourea 1000 ppm for 24 hours), while T16 (CCC at 150 ppm for 24 hours) and T14 (CCC at l50ppm for 12 hours) registered higher values for nodes per plant and branches per plant respectively. Among the treatments T3 (GA3 50 ppm for 24 hours) flowered early at 36.26 days. Higher values for fruit length and seeds per fruit were recorded in GA3 100 ppm for 24 hours (T4) and fruit weight was found to be higher in NAA 100 ppm for 24 hours (Tu). The seeds obtained under the field experiment were used to conduct the seed storage studies (Experiment II). The seeds from each treatment of experiment I were dried separately to a moisture content of less than 8 per cent and packed in 700G polythene covers and sealed. Seeds were stored under ambient conditions and seed quality parameters evaluated at monthly intervals for a period of seven months. Experiment II was laid out following a Completely Randomized Design (CRD) with twenty five treatments (To to TZ5) as in experiment I and three replications. Significant differences existed among the treatments for all seed quality parameters studied except time taken for 50% germination, seed moisture and seed microflora. It was clearly evident from the storage study that, as storage period increases the seed quality decreases irrespective of the treatments. In case of germination, all treatments including the control maintained the Minimum Seed Certification Standard (MSCS) of 65 percent up to fifth month of storage. At the end of the storage period (7 MAS) only two treatments (T11-NAA 50ppm for 24 hours and T3-GA3 50ppm for 24 hours) retained MSCS (65%). Vigour index I and II had higher values in Til which was statistically on par with TIZ, TlO, T3 and T4. Seed quality parameters such as germination, vigour indices and seedling dry weight decreased with the advancement of storage period, whereas EC of seed leachate, germination time, time taken for 50% germination increases over the storage period. The effect of growth regulators on seed microflora was found to be non-significant at the start and the end of the storage period. But the per cent of seed infection by seed microflora increased at the end of storage period, irrespective of the treatments. Ranking of characters in experiment I along with germination percent and vigour index I of experiment II was undertaken to identify the superior treatments. Based on the total score obtained GA3 at 50 ppm for 24 hours (T3) was adjudged as the best treatment followed by NAA at 50 ppm for 24 hours (T11). Hence it is concluded that soaking seeds with GA3 at 50 ppm and NAA at 50 ppm effectively enhances the growth, fruit and seed yield, seed quality and longevity in okra.