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  • ThesisItemOpen Access
    Evaluation of hybrids for yield and quality in chilli (Capsicum annuum L.)
    (Department of Olericulture, College of Agriculture,Vellayani, 2016) Aiswarya, C S; KAU; Sreelathakumary, I
    The research projec t entitled “Evaluation of hybrids for yield and quality in chilli ( Capsicum annuumL.)” was conducted at Department of Olericulture, College of Agriculture, Vellayani during 2015-16. The objective of the study was to evaluate the yield and quality characters of F1 hybrids of chilli. The experimental material consisted of five parents viz., CA 3 (P1), CA 5 (P2), CA 6 (P3), CA 8 (P4) and CA 32 (P5) and 10 F1s produced in diallel mating design excluding reciprocals. The hybrid Arka Harita and variety Vellayani Athulya were used as checks for the estimation of standard heterosis. The experiment was laid out in Randomized Block Design (RBD) with 17 treatments and three replications for two seasons viz., May 2015 to September 2015 and October 2015 to February 2016. Analysis of variance showed significant differences among the treatments for almost all characters studied. Among the hybrids P4 x P5 recorded the highest fruit weight (9.66 g), flesh thickness (2.81 mm), green fruit yield plant-1 (962.93 g), dry fruit yield plant-1 (144.05 g) and yield plot-1 (27.72 kg). Maximum fruits plant-1 was recorded in the hybrid P3 x P4(148.76), fruit length in P1 x P5(12.61 cm) and fruit girth in P3 x P5 (4.43 cm). Among the parents P5 recorded highest fruit weight (6.73 g), flesh thickness (2.61 111m), green fruit yield plant-1 (448.70 g), dry fruit yield plant-1 (79.98 g) and yield plot-1 (12.91 kg). The hybrid P2 x P5 had high quality parameters like oleoresin (18.90 %), ascorbic acid (122.66 mg/lOOg) and colour value (195.39 ASTA units). The check variety Vellayani Athulya was superior for characters such as days to first flower (23. 83 days), days to first harvest (42.96 days), fruit length (12.66 cm), fruit girth (6.27 cm), fruit weight (17.36 g) and flesh thickness (3.31 mm). No incidence of white fly, bacterial wilt, leaf curl, fruit rot and mosaic were observed in the field. The incidence of thrips and mites were less in the parents and hybrid combinations. The highest standard heterosis for green fruit yield plant'1 among the hybrids was recorded in P4 x P5 (177.23 %) followed by P3 x P5 (147.35 %), and P2 x P5 (127.24 %). For fruit weight highest standard heterosis was observed in P4 x P5 (191.09 %) followed by P3 x P5 (188.12 %) and P2 x P5 (170.30 %). Maximum standard heterosis for yield plot'1 was recorded in P4 x P5 (177.34 %), P3 x P5 (147.35 %) and P2 x P5 (127.31 %). Among the hybrids the highest standard heterosis for the quality characters such as oleoresin (36.59 %), ascorbic acid (6.05 %), and colour value (8.17 %) were recorded in P2 x P5. Correlation for different characters showed that green fruit yield plant"1 had positive correlation with the primary branches plant'1, fruits plant"1, fruit length, fruit weight, flesh thickness and seeds fruit'1. On the basis of the present study the hybrids CA 8 x CA 32 (P4 x P5), CA 6 x CA 32 (P3 x P5) and CA 5 x CA 32 (P2 x P5) were found promising for yield characters such as fruit weight, green fruit yield plant'1, yield plot'1 and quality. Among the parents CA 32 (P5) was found superior. The superior hybrids identified viz., CA 8 x CA 32 (P4 x P5), CA 6 x CA 32 (P3 x Ps) and CA 5 x CA 32 (P2 x Ps) can be subjected to multilocational trials and if found superior can be recommended for variety release.
  • ThesisItemOpen Access
    Efficiency of vermiconversion and decomposition of farm residues on soil health, yield and quality of banana (Musa spp.)
    (Department of Science and Agricultural Chemistry, College of Horticulture,Vellanikkara, 2016) Mayadevi, M R; KAU; Sushama
    An investigation entitled “Efficiency of vermiconversion and decomposition of farm residues on soil health, yield and quality of banana (Musa spp.)” was undertaken at College of Horticulture and Banana Research Station, Kannara during 2013-2015. The objectives of the study were to compare the efficiency of native and exotic earthworms on vermiconversion of farm residues and the effects of different modes of vermicomposting on soil health, yield and quality of banana and to evaluate the in situ decomposition of banana crop residues An experiment with seven treatments and three replications was laid out in randomized block design to assess the composting efficiency of native and exotic earthworms. Seven treatments included absolute control as soil (S), ex-situ compost in silpaulin vermibed without earthworms (Ex-C), ex-situ vermicompost in silpaulin vermibed using Perionyx excavatus (Ex-P), ex-situ vermicompost in silpaulin vermibed using Eisenia foetida (Ex-E), in-situ vermicompost in banana planting pits using Perionyx excavatus (In-P), in-situ vermicompost in banana planting pits using Eisenia foetida (In-E), in-situ compost in banana planting pits without earthworms (In-C). In the next study, the prepared composts were tested along with recommended doses of fertilizers and FYM to assess their effects on growth, yield and crop quality of banana var. Nendran in RBD with seven treatments replicated thrice. The treatments were absolute control (S), 300:115:450g N:P2O5:K2O plant-1 + FYM at the rate of 20 kg plant-1 (POP) , exsitu vermicompost in silpaulin vermibeds with Perionyx excavatus at the rate of 20 kg plant -1 (Ex–P), ex-situ vermicompost in silpaulin vermibeds with Eisenia foetida at the rate of 20 kg plant -1 (Ex–E) , in-situ vermicompost in crop pits with Perionyx excavatus at the rate of 20 kg plant -1 (In-P), in-situ vermicompost in crop pits with Eisenia foetida at the rate of 20 kg plant -1 (In-E), in -situ compost at the rate of 20 kg plant -1 (In-C). After the harvest of the crop, the entire residues from each plant was incorporated in the respective crop pits and the insitu degradation of the banana residues was monitored. The salient findings are summarized as follows In the first trial, the composting efficiency of native and exotic earthworms under different modes of composting was compared. Chemical properties of compost like pH, electrical conductivity, and content of primary nutrients were significantly affected by modes of composting. Exotic earthworms like Eisenia foetida produced higher auxin content in the compost whereas Perionyx excavatus registered higher dehydrogenase activity under ex-situ mode of composting. The total microbial load was recorded in the compost prepared without earthworms under both modes of composting. Compost yield was more in ex-situ composting methods and Eisenia foetida was more efficient in composting as compared to Perionyx excavatus. Humic acid characterization by Fourier Transform Infra-Red spectroscopy revealed a similar spectra from different treatments and were found to be characterized by aromatic rings and triple bonded skeleton. Presence of relatively higher quantity of polysaccharide like substances was observed in insitu mode of composting. The spectra of humic acids for ex-situ composts prepared using Perionyx excavatus revealed a nitrate band of characteristic shape appearing prominently. Perionyx excavatus produced humic acids with high aromaticity both under ex-situ and in-situ mode of composting. Scanning electron microscopy revealed neo-formed CaCO3 nodules embedded in humic acids in the ex-situ vermicompost produced by Eisenia foetida. Transmission Electron Microscopy of humic acids indicated a globular structure for vermicompost prepared by Perionyx excavatus and a lamellar structure with voids for vermicompost prepared using Eisenia foetida. On field experimentation with different treatments using Nendran banana as the test crop, the highest yield was obtained for combined application of fertilizers and farm yard manure as per POP. Number of fingers per hand and number of functional leaves were found to influence the yield, irrespective of treatments. The number of days to bunching and harvest was significantly reduced for banana under in-situ composting. Higher content of total, reducing and non-reducing sugars were observed for in-situ composting treatments. On the contrary, higher titratable acidity was recorded for the control treatment. Both vitamin C content and sensory parameters were complimentary for POP treatment. Increased absorption and translocation of nutrients such as N, P, K and Mg in fruits were observed under organic nutrition using Perionyx excavatus. For the next study, the residues of banana were added to the respective pits for monitoring the carbon and nitrogen mineralization. The carbon mineralization with respect to time was fitted to single pool exponential model to derive the rate of mineralization and half-life. It revealed crop residues pre-treated with vermicompost using exotic earthworms had a higher rate of C cumulative mineralization. Nitrogen addition by both exotic and native species of earthworms were almost similar under in-situ conditions. The banana residue decomposition by Eisenia foetida was about 3.5 times higher than that of Perionyx excavatus. Calcium content of Perionyx excavatus pre-treated residues added the maximum calcium to the soil.
  • ThesisItemOpen Access
    Trends in India summer monsoon distribution over the western ghats
    (Academy of Climate Change Education and Research Vellanikkara, 2016) Abhijit Asokan; KAU; Kurien, E K
    The Western Ghats with its strategic position plays a great role in channelling the summer monsoon rain into the mainland. The natural ecosystems and human livelihoods of this region are highly dependent on the Indian Summer Monsoon rainfall and even the slightest change can trigger a change in these systems. The global climate changing scenario is having its toll in the monsoonal system over this region. The extreme events in the region have been analysed for trends using Mann Kendall method and the return periods of the one day maximum rainfall has been modelled using Generalized Extreme Value (GEV) theory. The mean annual monsoonal rainfall over the region is 1616.15 mm and the standard deviation is 242.966.It was observed that the mean annual monsoonal rainfall varied from 231.4mm in grid 117 to 3416 mm in grid 253. The one day maximum rainfall extracted from the 32 constituent grids for the entire period showed a variation from 118.63 mm in 1981 to 316.63 mm in 2005. The temporal variation in one day maximum rainfall for the time series had a significant trend. The values were seen to increase steadily and a profound increase was observed in the recent decades. When the One day maximum rainfall was analysed for different latitudes, two latitudes (14°N and 21°N) had significant positive trends in One Day Maximum Rainfall in the whole region. Out of the 32 grids, 7 grids (186, 359, 394, 428, 429, 497 and 498) showed a significant rising trend in one day maximum rainfall. It was also observed that during the recent years, the occurrence of One day maximum Rainfall has shifted to the far end of the season. The number of grids getting heavy, very heavy and extreme rainfall events was found to have increased during the later years of the study. No significant trend in the instances of occurrence of heavy rainfall over the years was observed. But a significant trend was observed in the occurrences of rainfall events of very heavy and extreme magnitudes. When Split period analysis of the contribution of moderate and high intensity rainfalls was carried out, it was observed that the share of high intensity rainfalls had increased and a decrease was observed in the share of moderate events over the years. The return period analysis of the one day maximum rainfall events was done and it was observed that the 2 year, 5 year, 10 year, 25 year, 50 year and 100 year return levels of rainfall as 186.2mm, 224.3 mm, 250.2 mm, 283.8 mm, 309.3 mm and 335.1 mm for the complete region. The return levels for the two year return period were seen to be over 100 mm for the grids of 184 (118mm), 219 (114.9mm), 253 (145.8mm), 285 (104.5mm), 357 (147.6 mm), 392 (144.2mm), 427 (129.9mm) and 462 (122.4mm). A significant rising trend in the extreme events of summer monsoon rainfall over the Western Ghats was observed. This calls for better planning in all areas of livelihoods and management strategies to contain the disasters of a changing climate.