MSc

An experiment on ‘Seed quality enhancement in okra and oriental pickling melon with film coat’’ was conducted at the Department of Seed Science and Technology, College of Horticulture, Vellanikkara during 2016-18 to standardise the optimum dose and effect of polymer coating on okra and oriental pickling melon seeds and to evaluate the storage potential of polymer coated seeds under ambient storage condition
Seeds of okra variety, Arka Anamika and oriental pickling melon variety Mudicode local were used in this study. Polykote and Hitron were the polymers used. Seeds were treated with polymers either alone or in combination with plant protection chemicals. Performance of treated seeds was compared with untreated control. The polymer treatments comprised of both polymers at two doses Viz. Polykote @ 5 ml per kg of seed, Polykote @ 10 ml per kg of seed, Hitron @ 5 ml per kg of seed and Hitron @ 10 ml per kg of seed. A combination of plant protection chemicals such as fungicides, carbendazim-mancozeb (2g per kg of seed), insecticide- bifenthrin (0.1%) and biocontrol agent – Trichoderma viride (4g) were used. Polymer coated seeds were packed in 700 G polyethylene bag and stored under ambient conditions. Seed quality parameters were recorded at bimonthly intervals for a period of sixteen months.
With the advancement of storage period, germination declined irrespective of the treatments in both the seeds. Throughout the storage period, performance of treated seeds was found to be superior over control. In okra, at the end of the storage period of sixteen month , higher germination per cent (60.67 %) was recorded in seeds treated with Polykote (10ml) +carbendazim- mancozeb (2g) + bifenthrin (0.1%) followed by Hitron (5ml) + carbendazim-mancozeb (2g) + bifenthrin (0.1%) (54.00%), while lower values were recorded in untreated control (28.67%).
All the treatments except untreated control maintained MSCS (Minimum Seed Certification Standards) of 65 per cent germination up to ten months of storage. The seeds treated with Polykote (5ml) + carbendazim-mancozeb (2g) + bifenthrin (0.1%) per kg seed, Polykote (10ml/kg seed), Polykote (10ml) + carbendazim-mancozeb (2g) + bifenthrin (0.1%) per kg seed, Hitron (5ml/kg seed), Hitron (10ml) + carbendazim-mancozeb (2g) + bifenthrin (0.1%) per kg seed retained germination per cent above MSCS up to twelve months of storage whereas, the best treatment Polykote (10ml) +carbendazim- mancozeb (2g) + bifenthrin (0.1%) maintained MSCS up to fourteen months of storage. Similarly in the case of quality parameters like vigour indices and dehydrogenase activity, seed treatment with polykote (10ml) +carbendazim- mancozeb (2g) + bifenthrin (0.1%) found to be superior. In case of electrical conductivity of seed leachate a higher value was observed in untreated control while the least was recorded in seed treatment with polykote (10ml) +carbendazim- mancozeb (2g) + bifenthrin (0.1%) per kg of seed.
In OP melon, the effect of polymer film coating on seed quality parameters followed the same trend as that of okra. Higher per cent of germination noticed in seed treated with polykote (10ml) +carbendazim- mancozeb (2g) + bifenthrin (0.1%). These treatments retained germination per cent above MSCS till fourteenth month. Electrical conductivity of seed leachate was least in seeds treated with polykote (10ml) +carbendazim- mancozeb (2g) + bifenthrin (0.1%) per kg of seed compared to untreated control.
Microflora infection was found to be lower in polymer treated seeds when compared to control in both the crops. The major microorganisms observed were Aspergillus niger, Aspergillus flavus.
The results indicated that seed treatment with polymers was highly effective for enhancing the storage life of okra and OP melon. The polymers along with plant protection chemicals help to retain viability and storability of seeds. Among the treatments, polykote (10ml) +carbendazim- mancozeb (2g) + bifenthrin (0.1%) showed best results which may be recommended for pre storage seed treatment. Seed treatment with polymers therefore provides a cheaper and safe method to enhance seed viability and seedling performance under ambient storage condition.