Thumbnail Image

Theses

Browse

20212
Reset filters
Subject: Seed Science and Technology × Author: KAU × End date: 2021 × Start date: 2021 × Type: Thesis × Thesis Type: M.Sc ×
Reset filters

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    ThesisItemOpen Access
    Impact of biopriming on seed quality and longevity in Rice (Oryza sativa L.)
    (Department of Seed Science And Technology, College of Agriculture,Vellanikkara, 2021) Ruth Olivya Sarella; KAU; Dijee Bastian
    The study "Impact of bio-priming on seed quality and longevity in rice" (Oryza sativa L.) was conducted at the Department of Seed Science and Technology, College of Agriculture, Vellanikkara to study the effect of different seed priming treatments on seed quality and seed longevity under natural as well as accelerated ageing. Pseudomonas fluorescens, Trichoderma viride, coconut water was used for seed priming rice variety Jyothy. Seeds of rice variety Jyothy were treated with the following treatments: -, Pseudomonas fluorescens @ 10g/kg (T1), Trichoderma viride @ 4g/kg (T2), Coconut water @ 75% (T3), P. fluorescens + T. viride (T4), P. fluorescens + coconut water (T5), T. viride + coconut water (T6), P. fluorescens + T. viride + coconut water (T7), Hydro priming (T8), Control (untreated) (T9). Both treated and untreated seeds were dried to <10 per cent moisture content and packed in Polyethylene bags (700 guage). The treated seeds were allowed to age both naturally and under accelerated ageing conditions. There were significant differences among the treatments on seed quality parameters. Irrespective of the treatment, germination, seedling growth (dry weight, length of root and shoot), vigour index- I (VI-I), vigour index- II (VI-II), speed of germination, SOD enzyme activity, dehydrogenase enzyme activity decreased significantly over the storage period. A significant increase in seed moisture content, electrical conductivity, Mean Germination Time (MGT), Time taken for 50% germination (T50) and seed microflora, was observed with increase in storage period. Seed treatment with P. fluorescens (10g/kg) + T. viride (4g/kg) + coconut water (75%) retained a germination per cent of (83.69%) and higher vigour indices among the treatments after nine months of storage followed by Pseudomonas fluorescens @ 10g/kg (T1) and P. fluorescens + T. viride (T4) while treatment hydropriming (T8) was found to be inferior in all quality parameters. Coconut water treatments were found to be superior in increasing root and shoot length of the seedlings across the storage period which was reflected in the vigour indices. Bio priming with P. fluorescens resulted in early emergence of seedlings. Seed microflora was found to increase significantly towards the end of storage period. This increase was least in P fluorescens @ 10g/kg (T1), Aspergillus spp., Pencillium spp. were observed in the primed seeds. In present study it was found that among bio primed treatments P fluorescens treated seeds performed better than T. viride treated seeds in all quality parameters. Accelerated aged seed samples were gathered and tested at daily intervals for 7 days to evaluate seed quality parameters. In general, dry priming performed better than wet primed seeds. Vigour indices was found to be highest in bio primed seeds (T2, T4 , T7) than othertreatments Seed longevity is found to be higher in bio primed seeds which can be evaluated from speed of germination (T1, T4, T7), electrical conductivity (T2, T4 ), dehydrogenase and SOD enzyme activities. Seed infection (%) increased towards the end of ageing period and recorded least in P. fluorescens treatments (T1, T7, T5) Seed treatments P. fluorescens (10g/kg) + T. viride (4g/kg) + coconut water (75%) was the best treatment followed by P fluorescens @ 10g/kg of seeds in improving seed quality as well as seed longevity. Treatments P fluorescens @ 10g/kg (T1), T. viride @ 4g/kg (T2), P. fluorescens + T. viride (T4), P. fluorescens + T. viride + coconut water (T7) of seed may be used as seed treatments to enhance seed longevity in rice.
  • Thumbnail Image
    ThesisItemOpen Access
    Impact of potassium and ABA application on vivipary and seed quality in oriental pickling melon (Cucumis melo var. conomon Mak.)
    (Department of Seed Science and Technology, College of Agriculture, Vellanikkara, 2021) Vaisakh, K; KAU; Dijee Bastian
    Oriental pickling melon is a crop with cultural and economic significance in Kerala. Vivipary has been observed in this crop which reduces the seed yield and quality. Adjusting the planting time and application of some chemicals were found effective in controlling vivipary. The study on ‘Impact of potassium and ABA application on vivipary and seed quality in oriental pickling melon (Cucumis melo var. conomon Mak.)’ was conducted at the Department of Seed Science and Technology, College of Agriculture, Kerala Agricultural University, Vellanikkara, Thrissur during the year 2019-2021 using the variety ‘Saubhagya’ to understand the effect of different levels of potassium and ABA on vivipary and the quality of seeds. The crop was sown during the month of February (2021) following randomised block design with eight treatments and three replications. The treatments consisted two foliar sprays of potassium (0.5% MOP, 1% MOP, 1.5% MOP) at 50 per cent flowering and at an interval of two weeks after flowering, one foliar spray of abscisic acid (100 mg/l ABA, 200 mg/l ABA and 300 mg/l ABA) at 50 per cent flowering and a basal application of recommended fertilizers with 50 percent additional potassium (POP + 50% K). The treatments had significant impact on fruit and seed quality parameters. The fruit length and yield were enhanced in the ABA treatments. The potassium treatment, POP + 50% K also gave significantly higher fruit yield which was on par with the ABA treatments. Higher content of potassium in fruit flesh and placenta was observed in 300 mg/l ABA treatment. The treatments were effective in controlling the vivipary. The abscisic acid treatment (300 mg/l ABA) was the most effective which reduced the vivipary up to 1.37 per cent followed by the treatment with potassium (1.5 per cent MOP) where the vivipary was 3.29 per cent. The number of seeds per fruit and the total seed yield was the highest in the treatment with 300 mg/l abscisic acid. The seeds extracted from fruits harvested from the field experiment were used for the seed longevity studies. The storage potential was assessed with the help of accelerated ageing test. The seeds were tested for different quality parameters after each day of accelerated ageing and the results showed that the seed quality deteriorated during the 7-days of ageing in all treatments. The seed quality parameters like vigour, germination, shoot and root length decreased whereas the electrical conductivity of seed leachate, mean germination time, seed moisture and seed infection per cent increased indicating a decline in seed quality over accelerated ageing. The highest germination and vigour throughout the accelerated ageing was observed in seeds collected from treatment 100 mg/l ABA and it maintained minimum germination for seed certification prescribed by IMSCS (60.00% for melon) till day 4 of accelerated ageing. The highest dry weight of seedling and lowest electrical conductivity of seed leachate were observed in seeds extracted from treatment 300 mg/l ABA. The seed infection did not vary among the treatments. Initially there was no incidence of any pathogens but as the ageing period advanced the seed infection per cent increased. The pathogens like Aspergillus sp. and Pencillium sp. were identified. The agar plate method showed higher infection per cent compared to blotter method. From the study it can be concluded that the overall performance of the seed was found to be higher in abscisic acid treatment (300 mg/l ABA) indicating that it is the best treatment among all the treatments given.