MSc

The study “Seed invigoration with nanoparticles for seed yield and quality in chilli” was conducted in the Department of Seed Science and Technology, College of Horticulture, Vellanikkara during May 2019 with the objective of standardizing the optimum seed treatment dose required for increasing yield, improving quality and prolonging seed longevity. Normal grade and nano grade zinc oxide (ZnO) and titanium dioxide (TiO2) were used for seed treatment on chilli variety Anugraha.
The study consisted of two experiments. In the first experiment, chilli seeds dry dressed with 500, 900 and 1300 mg kg-1 of normal and nano grade ZnO and TiO2 along with control (thirteen treatments) were raised in a Randomized block design with three replications. While all treated seeds performed better than control (untreated seeds) treatments with nanoparticles performed better than the normal grade particles. Highly significant variations was observed for traits such as plant spread, plant height, days to harvest, fruit length, number of fruits per plant, fruit weight at maturity, fruit yield, number of seeds per fruit, seed yield per plant and 100 seed weight.
Seed treatments with nano ZnO @ 1300 mg kg-1 of seed (T4) performed superior for plant spread (60.1 cm), plant height (67.30 cm), number of fruits per plant (122), fruit length (7.40cm), fruit weight (3.46g), fruit yield (422.70 g) and seed yield per plant (41.14 g). Normal grade ZnO treatments was effective in improving number of seeds per fruit (62) (ZnO @ 900 mg kg-1 of seed). Significant effects were recorded when seeds were treated with normal grade TiO2 @ 500 mg kg-1 of seed (T11) for fruit weight at maturity (3.53 g).
In the second experiment the effect of wet seed treatment with nanoparticles on seed storability was assessed. The experiment was laid out in Completely Randomized Design with thirteen treatments in three replications. Treatments include nano ZnO and TiO2 at 100,250,500 and 100 mg kg-1. Seed quality parameters like germination, seedling length, dry weight and vigour indices showed a declining trend throughout the storage period while electrical conductivity and seed infection increased. Treatments ZnO@100 mg kg-1 of seed (T2), ZnO@250 mg kg-1 of seed (T3 ), ZnO@500 mg kg-1 of seed (T4 ), ZnO@1000 mg kg-1 of seed (T6), TiO2@500 mg kg-1 of seed (T10),
TiO2@750 mg kg-1 of seed (T11) and TiO2@1000 mg kg-1 of seed (T12) retained germination above 60 % (IMSCS) at the end of seven months of storage. ZnO @ 250 mg kg-1 of seed (T3) retained the highest germination per cent of 65.66 %.
Vigour index-I was found to be high in ZnO @ 1000mg kg-1 of seeds (T6) (925.88) and vigour index II in TiO2 @1000 mg kg-1 of seed (T12) (1471.81) at the end of storage.The electrical conductivity of seed leachate obtained from nano ZnO @ 250 mg kg-1 of seed and nano TiO2 @ 750 mg kg-1 of seed recorded the lowest values (295μScm-1and 290.33 μScm-1).Pathogen infection in seeds were found to be lower in treated seeds than in untreated control. Infection was recorded in nano ZnO @ 100 mg kg-1 of seeds (T2) (13.3%) and nano TiO2 @ 250 mg kg-1 of seeds (T9) (10%) treatments. The seed storage fungi observed were Aspergillus niger and Aspergillus flavus.
Seed treatments with inorganic nanoparticles are effective in improving field performance and as well as retaining seed quality in storage. Nano ZnO at 1300 mg kg-1 of seeds was the best treatment followed by nano TiO2 at 900mg kg-1 of seeds in improving yield in chilli. Treatments nano ZnO at 250 and 1000 mg kg-1 of seed may be used as seed treatments to enhance seed longevity in chilli.