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Subject: Seed Science and Technology × Author: KAU × End date: 2016 × Start date: 2011 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Effect of seed protectants against pulse beetle on viability, vigour and health of cowpea seeds
    (Department of Seed Science and Technology,College of Horticulture, Vellanikkara, 2016) Libi, Antony A; KAU; Rose, Mary Francies
    Experiments to assess the effectiveness of seed protectants against cowpea pulse beetle (Callosobruchus spp.)and their impact on seed quality and seedling vigour of selected cowpea varieties were conducted at College of Horticulture, Vellanikkara during 2014-2016. Separate experiments were conducted for both Lola and Kanakamony varieties following a completely randomized design with 13 treatments and three replications. Seeds were treated with seed protectants viz. neem oil, castor oil, coconut oil, sweet flag rhizome powder, neem leaf powder, paanal leaf powder, karinotchi leaf powder, neem kernel powder, diatomaceous earth, rice husk ash, Beauveria bassiana and spinosad. Untreated seeds served as control. Both treated and untreated seeds were dried to nine per cent moisture content were stored under ambient conditions for a period of 13 months. The seed quality parameters like germination, speed of germination, seedling vigour indices, electrical conductivity of seed leachate, mortality of adult pulse beetles, number of eggs laid by beetle, egg hatchability and seed infestation were recorded at monthly intervals. Seed microflora infection per cent were recorded at start and end of storage period.The results revealed that germination and other seed quality parameters in both treated and untreated seeds decreased progressively over the storage period.However, irrespective of the variety, the seed protectants significantly enhanced the viability and quality of treated seeds. The quality of treated seeds was higher than that of untreated seeds for most part of the storage period. The germination in untreated seeds was retained above 75 per cent (the minimum seed certification standards (MSCS) required for cowpea) for eight months while it was retained for nine months in all treated seeds. The rate of decrease in seed germination and quality was slower in semitrailing variety Kanakamony compared to trailing variety Lola. In both the varieties, the germination was lower in untreated seeds in comparison to the treated seeds. Germination, speed of germination, seedling growth parameters and vigour indices were invariably high in seeds treated with neem based seed protectants viz., neem kernel powder, neem leaf powder and neem oil. Among the neem based botanicals used, seed treatment with neem kernel powder maintained higher germination and seed quality parameters viz., seedling shoot length, seedling root length, seedling dry weight and seedling vigour index I and II during storage. Similarly, the electrical conductivity of seed leachate and per cent infection by seed microflora was found to be consistently low in seeds treated with neem based botanicals, vegetable oils and spinosad.The efficacy of seed protectants against pulse beetle was evaluated at monthly intervals by recording weight of infested seed, seed infestation, mortality, fecundity and egg hatchability in twenty five seeds drawn randomly from each replication. The results revealed that all the seed protectants used were effective against pulse beetle during the initial period of storage and were significantly superior to control over the period of storage.Among the seed protectants evaluated, highest mortality of adult beetles,lowest fecundity, egg hatchability and seed infestation were recorded in seeds treated with spinosad followed by oils viz., neem oil, coconut oil and castor oil as well as other neem based botanicals. Seed treated with spinosad offered protection against pulse beetle for up to seven months of storage as evident from the cent per cent mortality of adult beetles, complete suppression of egg hatchability as well as low seed infestation in both varieties. Seeds treated with neem oil, castor oil, coconut oil, neem kernel powder and neem leaf powder recorded cent per cent mortality of adult beetles for five months of storage in both varieties. No seed infestation was recorded in seeds treated with neem oil, castor oil and coconut oil for up to five months of storage while a similar protection was offered by neem leaf powder and neem kernel powder for up to four months of storage. Spinosad was found to be the most effective in controlling pulse beetle infestation throughout the storage period. Based on the impact of seed protectants on seed viability, seedling performance as well as protection against pulse beetle infestation in cowpea, seed treatment with seed protectants viz., spinosad or neem based products (neem kernel powder, neem leaf powder and neem oil) or as oils (coconut oil and castor oil) can be recommended to be most effective in enhancing seed viability (by a period of one month over control), higher seed and seedling performance and protection from pulse beetle infestation and infection by microflora in cowpea. Among the above Spinosad can be recommended as the best seed treatment for cowpea if it can ensured that the treated seeds would be used only for seed purpose. However, in case the stored pulse seeds are meant for use as food, feed and seed, treatment with coconut oil could be recommended in place of neem based products since neem based botanicals are reported to cause sterility in humans and animals.
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    ThesisItemOpen Access
    Halogenation for improvement of storage Life of chilli (Capsicum annuum L.) seeds
    (Department of Seed Science and Technology,College of Horticulture, Vellanikkara, 2016) Navya, P; KAU; Dijee, Bastian
    An experiment ‘Halogenation for improvement of storage life in chilli (Capsicum annuum L.) seeds’ to standardise the optimum dose and mode of halogenation of chilli seeds and to evaluate the storage potential of halogenated seeds under ambient storage condition was conducted in Department of Seed Science and Technology, College of Horticulture, Vellanikkara during 2014-16.Seeds of two chilli varieties Ujwala and Anugraha were utilized for the study. Calcium oxy chloride (CaOCl2), iodine crystal (I2) and potassium iodide (KI) were the halogens used. Seeds were treated with halogens either alone or in combination with a carrier (CaCO3). Performance of treated seeds was compared to untreated control (T1). The halogen treatments comprised of each halogen at two doses viz.CaOCl2 @ 2g per kg of seeds (T2), CaOCl2 @ 4g per kg of seeds (T3), Iodine crystal @ 50mg per kg of seeds (T4), Iodine crystal @ 100mg per kg of seeds (T5), KI @ 50mg per kg of seeds (T6) and KI @100mg per kg of seeds (T7). In addition, seeds were also treated with a combination of halogen and carrier (CaCO3) in equal proportions (T8 to T13). After dry dressing the seeds with halogen or halogen carrier combination it was packed in 400G polyethylene bag and stored under ambient conditions. Seed quality parameters were recorded at monthly intervals for a period of 14 months. With the advancement of storage period, germination (%) declined irrespective of the treatments in both the varieties. Irrespective of the varieties throughout the storage period, performance of treated seeds was found to be superior over control irrespective of the varieties. In var. Ujwala, at the end of storage (14th month) high germination per cent was recorded in seeds treated with iodine crystal + CaCO3 @ 50mg each per kg of seeds followed by CaOCl2 +CaCO3 @ 4g each per kg of seeds. Seed treatment with CaOCl2 @ 2g per kg of seeds and CaOCl2@ 4g per kg of seeds were found to be the lower.Combination treatments such as iodine crystal + CaCO3 @ 50mg per kg of seeds , CaOCl2 + CaCO3 @ 2g each per kg of seeds, CaOCl2 + CaCO3 @ 4g each per kg of seeds and KI+ CaCO3 @ 50mg each per kg of seeds retained germination per cent above Minimum seed certification standards(MSCS) till 9th month of storage while in untreated seeds viability was retained only upto 5th month. Similarly in the case of parameters like vigour indices and dehydrogenase activity, seed treatment with iodine crystal + CaCO3 @50mg each per kg of seeds and CaOCl2 +CaCO3 @ 4g each per kg of seeds were found to be superior. In case of electrical conductivity of seed lechate a higher value was observed in untreated control while the least was recorded in seed treatment with Iodine crystal + CaCO3 @ 50mg each per kg of seeds. In var. Anugraha, high germination per cent was recorded in seeds treated with CaOCl2 + CaCO3 @ 2g each per kg of seeds, iodine crystal + CaCO3 @100mg each per kg seed and iodine crystal + CaCO3 @50mg each per kg of seeds. These treatments retained germination per cent above MSCS till 12th month of storage where as untreated seeds were viable only upto 9 months. Electrical conductivity of seed lechate was least in seeds treated with CaOCl2 + CaCO3 @ 2g each /kg of seeds compared to the highest value in untreated control. Microflora infection was found to be lower in halogenated seeds when compared to control in both the varieties. The major organisms observed were Aspergillus niger, Aspergillus flavus, Pencillium sp. The results indicated that seed treatment with halogens was highly beneficial in enhancing the storage life of chilli. Iodine crystal with carrier @50mg each per kg of seeds and CaOCl2 with carrier @ 2g each per kg of seeds may be recommended. Seed treatment with halogens therefore provides a cheaper method to enhance seed viability and seedling performance under ambient storage condition.
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    ThesisItemOpen Access
    Seed treatment with botanicals to enhance seedling vigour in Chilli (Capsicum annuum L.)
    (College of horticulture, Vellanikara, 2016) Sandhya, R; KAU; Dijee, Bastian
    An experiment was undertaken at the Department of Seed Science and Technology, College of Horticulture, Kerala Agricultural University, Vellanikkara, Thrissur to elucidate the effects of botanicals and compare the efficacy of normal grade and nanopowder botanicals on seedling vigour in chilli. The study consisted of three experiments such as seed treatment with normal grade botanicals, seed treatment with nanopowder botanicals and field performance of seeds treated with botanicals in two varieties Anugraha and Ujwala. The study involved five commonly used botanicals namely viz., arappu (Albizia amara), fenugreek (Trigonella foenum-graecum), pungam (Pongamia glabra), custard apple (Anona squamosa) and neem (Azadirachta indica). Preparation of powders involved collection and shade drying of the above mentioned leaves followed by grinding in mixer grinder and sieving to get a uniform particle size. These normal grade powders were used in experiment one. These finely ground powders were further synthesized using High Energy Ball milling and characterized using Particle Size Analyser (PSA), Scanning Electron Microscope (SEM) to reduce the particle size to nano dimension. These nanopowders were used in experiment two. Chilli seeds were pre-treated with each of the normal grade and nanopowders mentioned above in each of the following three doses, 0.5 g kg-1, 1 g kg-1 and 2 g kg-1 of seeds. The treated seeds along with the untreated (control) were packed in 400 gauge polyethylene bags and stored in the ambient conditions. Observations on seed quality parameters were recorded as per ISTA standards at monthly intervals. In both the varieties tested, irrespective of the particle size of the botanicals used, seed treatments with botanicals had a favourable impact on seed viability and seedling vigour over the period of storage. In variety Anugraha, treated seeds enhanced the viability of seeds for twelve months compared to ten months in case of untreated seeds. However, viability in untreated and treated seeds of variety Ujwala was retained for six and nine months respectively. Seeds of variety Anugraha stored better than that of Ujwala. Considering the impact of seed treatment with normal grade botanicals, on seed quality parameters, arappu @ 2 g kg-1, fenugreek @ 2 g kg-1, and fenugreek @ 0.5 g kg-1 were superior to other treatments in variety Anugraha, whereas, arappu @ 0.5 g kg-1, fenugreek @ 2 g kg-1 and custard apple @ 0.5 g kg-1 were found to be superior in variety Ujwala. In case of seed treatment with nanopowder botanicals, it was evident that, in variety Anugraha, custard apple @ 0.5 g kg-1, fenugreek @ 1 g kg-1, and fenugreek @ 0.5 g kg-1, were superior, whereas, in variety Ujwala, fenugreek @ 0.5 g kg-1, custard apple @ 1 g kg-1, and fenugreek @ 1 g kg-1 were superior. Seeds treated with treatments mentioned above had registered high germination, seedling vigour, dehydrogenase activity and low electrical conductivity throughout the storage period. Microflora infection per cent was found to be lower in treated seeds than in untreated control. The seed storage fungi observed were Aspergillus niger, Aspergillus flavus, Pencillium sp and Alternaria sp. A similar trend was observed in the field performance of treated seeds. In variety Anugraha, fruit yield per plant was high when treated with nano powder treatments such as custard apple @ 0.5 g kg-1, fenugreek @ 1 g kg-1, and fenugreek @ 0.5 g kg-1. The fruit yield per plant in these treatments was 372 g, 362 g and 341 g, respectively. Treatments with normal grade botanical treatments such as arappu @ 2 g kg-1, fenugreek @ 2 g kg-1 and fenugreek @ 0.5 g kg-1 also resulted in higher fruit yield per plant. The fruit yield per plant of 315 g, 295.4 g and 269.9 g, were realised from these treatments respectively. In variety Ujwala, the fruit yield per plant was high when treated with nanopowder botanical treatments such as fenugreek @ 0.5 g kg-1, custard apple @ 1 g kg-1 and fenugreek @ 1 g kg-1. The fruit yield per plant in these treatments was 270 g, 267 g and 258 g, respectively. Treatments with normal grade botanical treatments such as arappu @ 0.5 g kg-1, fenugreek @ 2 g kg-1, custard apple @ 0.5 g kg-1 also resulted in higher fruit yield per plant. The fruit yield per plant of 253 g, 238 g and 237 g, were realised from these treatments respectively. It was observed that, treatments with nanopowders enhanced seed quality better than the normal grade powders. In general, seeds treated with botanicals such as fenugreek (Trigonella foenum-graecum), custard apple (Anona squamosa) and arappu (Albizia amara) performed better than the others. Among the normal grade powder treatments, arappu was found to be the best treatment, whereas, custard apple and fenugreek were found to be best among seeds treated with nanopowders. The storage life of treated seeds of variety Anugraha retained for twelve months compared to ten months in case of untreated control. In case of variety Ujwala, viability can be retained upto nine months compared to six months untreated control. Hence, the present study indicates that, viability and seedling performance can be enhanced by treating the chilli seeds with normal grade botanicals like arappu, fenugreek or nanopowders like custard apple and fenugreek.