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Kerala Agricultural University, Thrissur
The history of agricultural education in Kerala can be traced back to the year 1896 when a scheme was evolved in the erstwhile Travancore State to train a few young men in scientific agriculture at the Demonstration Farm, Karamana, Thiruvananthapuram, presently, the Cropping Systems Research Centre under Kerala Agricultural University. Agriculture was introduced as an optional subject in the middle school classes in the State in 1922 when an Agricultural Middle School was started at Aluva, Ernakulam District. The popularity and usefulness of this school led to the starting of similar institutions at Kottarakkara and Konni in 1928 and 1931 respectively.
Agriculture was later introduced as an optional subject for Intermediate Course in 1953. In 1955, the erstwhile Government of Travancore-Cochin started the Agricultural College and Research Institute at Vellayani, Thiruvananthapuram and the College of Veterinary and Animal Sciences at Mannuthy, Thrissur for imparting higher education in agricultural and veterinary sciences, respectively. These institutions were brought under the direct administrative control of the Department of Agriculture and the Department of Animal Husbandry, respectively. With the formation of Kerala State in 1956, these two colleges were affiliated to the University of Kerala. The post-graduate programmes leading to M.Sc. (Ag), M.V.Sc. and Ph.D. degrees were started in 1961, 1962 and 1965 respectively.
On the recommendation of the Second National Education Commission (1964-66) headed by Dr. D.S. Kothari, the then Chairman of the University Grants Commission, one Agricultural University in each State was established. The State Agricultural Universities (SAUs) were established in India as an integral part of the National Agricultural Research System to give the much needed impetus to Agriculture Education and Research in the Country. As a result the Kerala Agricultural University (KAU) was established on 24th February 1971 by virtue of the Act 33 of 1971 and started functioning on 1st February 1972. The Kerala Agricultural University is the 15th in the series of the SAUs.
In accordance with the provisions of KAU Act of 1971, the Agricultural College and Research Institute at Vellayani, and the College of Veterinary and Animal Sciences, Mannuthy, were brought under the Kerala Agricultural University. In addition, twenty one agricultural and animal husbandry research stations were also transferred to the KAU for taking up research and extension programmes on various crops, animals, birds, etc.
During 2011, Kerala Agricultural University was trifurcated into Kerala Veterinary and Animal Sciences University (KVASU), Kerala University of Fisheries and Ocean Studies (KUFOS) and Kerala Agricultural University (KAU).
Now the University has seven colleges (four Agriculture, one Agricultural Engineering, one Forestry, one Co-operation Banking & Management), six RARSs, seven KVKs, 15 Research Stations and 16 Research and Extension Units under the faculties of Agriculture, Agricultural Engineering and Forestry. In addition, one Academy on Climate Change Adaptation and one Institute of Agricultural Technology offering M.Sc. (Integrated) Climate Change Adaptation and Diploma in Agricultural Sciences respectively are also functioning in Kerala Agricultural University.
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ThesisItem Open Access Standardisation of spacing and nutrient levels for fodder rice bean [Vigna umbellata (Thunb.)].(Department of Agronomy, College of Agriculture, Vellayani, 2018) Ajmal Fayique, C; KAU; Usha C, ThomasThe study entitled “Standardization of spacing and nutrient levels for fodder rice bean [Vigna umbellata (Thunb.)]” was conducted at College of Agriculture, Vellayani, Kerala during Kharif 2017 to standardize the spacing and nutrient requirement of fodder rice bean and to study its impact on growth, yield and quality of the crop. The experiment was laid out in Randomised Block Design (33 confounded factorial) with three replications.The treatments consisted of three spacings (s1 - 30 cm x 10 cm, s2 - 30 cm x 20 cm and s3 - 30 cm x 30 cm), three levels of nitrogen (n0 - 0 kg ha-1, n1 - 20 kg ha-1 and n2 - 30 kg ha-1) and three levels of phosphorous (p0 - 0 kg P2O5 ha-1, p1 - 20 kg P2O5 ha-1 and p2 - 40 kg P2O5 ha-1) . FYM @ 5 t ha-1 and K2O @ 30 kg ha-1 were applied uniformly to all treatments as basal. The treatment s1 resulted in the highest plant height at 30 DAS and leaf: stem ratio at harvest. Application of N @ 20 kg ha-1 registered the highest plant height and was on par with 30 kg N (n2) while leaf stem ratio was the highest at n2. Levels of P had no significant impact on growth characters. The treatment combination s2n2p1 produced the tallest plants (173.17 cm) at harvest and treatments s1n0p1 and s1n2p2 recorded the highest leaf: stem ratio (0.82) but were on par with s1n0p0, s2n0p0, s n0p2, s1n1p0, s2n0p2 and s3n0p1. At 30 DAS, s1 produced the highest LAI (2.27) while at harvest, s2 was found superior. The highest NAR was observed at s1 and was on par with s3. Closer spacing (s1) enhanced the CGR at 30 DAS and harvest. Application of 30 kg N ha-1 (n2) enhanced LAI at both stages. At 30 DAS and at harvest, higher NAR were observed at n1 and n2. At 30 DAS, n2 and p1 registered the highest chlorophyll contents. The treatment s1 n2 p1 (30 cm x 10 cm spacing + 30 kg N ha-1 + 20 kg P2O5 ha-1) resulted in the highest LAI, CGR and chlorophyll content at 30 DAS. Spacing and N levels had significant impact on green fodder yield (GFY) and dry fodder yield (DFY). The highest GFY (12.95 t ha-1) and DFY (2.59 t ha-1) were produced at s1 (30 cm x 10 cm) and was on par with s2. The highest GFY (13.66 t ha-1) and DFY (2.73 t ha-1) were produced at n2 (30 kg N ha-1) and was on par with n1. The S x N x P interaction s1 n2 p1 (30 cm x 10 cm + 30 kg N ha-1 + 20 kg P2O5 ha-1) recorded highest GFY (17.29 t ha-1) and DFY (3.46 t ha-1). The different spacing had no impact on crude protein (CP) but the lowest crude fibre (CF) was observed at s1. Application of 30 kg N ha-1 (n2) resulted in the highest CP content and the lowest CF content was estimated at 0 kg N ha-1. Among P levels, p2 recorded the highest CP (17.69%) and was on par with p1. The lowest CF (16.43 %) was observed at s2n0p1 (30 cm x 20 cm spacing + 20 kg P205 ha-1) and was on par with s1n0p0, s1n0p1, s1n2p0, s2n0p0, s2n0p2, s3n0p0 and s3n0p1. No variation in N uptake was observed due to treatments. Uptake of P varied with N levels only and n1 and n2 recorded the highest P uptake. Spacing and P levels influenced K uptake by the crop and the highest uptake was observed at s1 and p2 but p2 was on par with p1. The three factor interaction s1n2p1 registered the highest P and K uptake. However, it was on par with s1n1p2, s1n1p0, s2n1p1 and s3n0p2 in P uptake and with s1n2p2 in K uptake. Increasing N levels increased pH and EC of soil after the experiment. Soil available N after the experiment was the highest at s3 (on par with s2) and n2 (on par with n1). At wider spacing, application of N enhanced the availability of N in the soil after the experiment. Available P in the soil varied with S x P interaction but all treatment combinations were on par except s2p0 and s3p2. The highest soil available K was observed at n0 among N levels and at p1 among P levels. The interactions S x N, S x P and N x P significantly influenced available K in the soil. Economic analysis revealed the highest net income (₹ 35762) and BC ratio (3.22) at s1n2p1 (30 cm x 10 cm spacing + 30 kg N ha-1 + 20 kg P2O5 ha-1). From the study, it can be concluded that fodder rice bean can be profitably cultivated at a spacing of 30 cm x 10 cm with application of 30 kg N ha -1 in two splits at 15 and 30 DAS and basal application of 20 kg P2O5 ha-1, 5 t ha-1 of FYM and 30 kg K2O ha-1.ThesisItem Open Access Customized fertilizer and nutrient scheduling for okra (abelmoschus esculentus (L.) moench)(Department of Agronomy, College of Horticulture, Vellanikkara, 2016) Yansin, Luikham; KAU; Anitha, SMultinutrient deficiencies in soil are common nowadays due to imbalanced use and extensive mining of nutrients, which have also led to the decline of soil and crop productivity over time. Customized fertilizers (CF), which are multinutrient carriers facilitating the supply of complete range of nutrients in right proportion for the crop grown in a particular soil, have come up as an alternative to tide over these problems. Scheduling of nutrients by split application promotes efficient utilization of nutrients in a need based manner and helps to reduce nutrient losses from the soil. An investigation entitled “customized fertilizer and nutrient scheduling for okra (Abelmoschus esculentus (L.) Moench)” was carried out at the Water Management Research Unit, Vellanikkara, Thrissur from May to September, 2015 with the objective of developing a customized fertilizer and studying its techno- economic feasibility and nutrient scheduling in okra. The investigation consisted of 12 treatments viz., FYM + 75% CF (2 splits at 30 days interval), FYM + 75% CF (4 splits at 15 days interval), FYM + 100% CF (2 splits at 30 days interval), FYM + 100% CF (4 splits at 15 days interval), FYM + 125% CF (2 splits at 30 days interval), FYM + 125% CF (4 splits at 15 days interval), FYM + soil test based NPK application (N & K as 2 splits at 30 days interval), FYM + soil test based NPK application (N & K as 4 splits at 15 days interval), FYM + NPK as per POP (N & K as 2 splits at 30 days interval), FYM + NPK as per POP (N & K as 4 splits at 15 days interval), FYM alone based on N recommendation of POP (2 splits at 30 days interval) and absolute control. Biometric observations were recorded and nutrient contents and uptake were estimated at 30 DAS, 60 DAS and 90 DAS. A customized fertilizer grade was developed based on the initial analysis of macro and micronutrient contents of soil and nutrient requirement of okra. Water soluble fertilizers and straight fertilizers were used for the preparation of CF. Based on the soil fertility rating and nutrient recommendation for okra, the actual nutrients needed for the experimental site was worked out in kg ha-1 as 59N: 9P: 34K: 16Mg: 1B. Based on this, CF grade 22.01N: 3.35 P: 12.68K: 5.97Mg: 0.37B was developed. The study revealed that application of 125 per cent CF either as two or four splits was equally effective and recorded the highest yield compared to lower doses of CF and other nutrient management practices. Application of 125 per cent CF resulted in a yield increase of 32.11 per cent, 35.16 per cent and 49.84 per cent compared to soil test based application, application of nutrients at recommended dose and application of FYM alone respectively. Application of 100 per cent CF recorded higher yield compared to nutrient application based on soil test based NPK and NPK as per POP. The yield increase in 125 per cent CF was due to the better development of growth and yield parameters and higher nutrient uptake including that of Mg and B in customized fertilizer doses. The lower doses of CF (75%) performed equally well as soil test based NPK and NPK as per POP with respect to yield. The combined application of fertilizers along with FYM gave better yield than application of FYM alone as a source of nutrients. Faster delivery of nutrients could be achieved through fertilizers since FYM alone could not meet the huge requirement of nutrients by okra. In this study, application of CF and other fertilizers in more splits did not show significant increase in yield of okra. Application of CF showed a positive effect on the soil fertility status except for nitrogen. The improvement in nutrient status could be attributed to application of optimum dose of CF along with FYM to maintain adequate supply of nutrients. The application of higher levels of CF was cost effective and economically beneficial due to higher yield despite increased cost of cultivation owing to higher cost of inputs. Nutrient application in lower splits was more economical due to reduced labour. The study indicated that application of multinutrient carriers such as customized fertilizers are a technologically and economically viable practice for increasing soil and crop productivity. The quantities of NPK required as CF are much lower than the POP recommendations, and therefore fertilizer doses can be reduced substantially.ThesisItem Open Access High density planting and seed tuber size on productivity enhancement of Lesser Yam[Dioscorea esculenta (Lour.) Burkill)(Department of Agronomy, College of Horticulture, Vellanikkara, 2019) Anasooya, Sebastian; KAU; Prameela, PThe experiment was conducted during the period from May 2018 to December 2018 at Agronomy Farm, College of Horticulture, Vellanikkara, Thrissur to study the effect of planting density and seed tuber size on productivity of lesser yam. Seed tubers of 50 g, 100 g, and 150 g were planted at spacings of 50 x 50 cm (high density planting), 75 x 50 cm (medium density planting) and 75 x 75 cm (low density planting- recommended spacing), adopting factorial RBD. The treatments consisted of nine combinations of seed tuber size and spacing. Growth characteristics like emergence percentage, number of sprouts per tuber, length of vine, number of tuber forming roots, number of leaves, leaf area, and total drymatter accumulation per plant were significantly influenced by seed tuber size. Large sized seed tubers (150 g) showed higher values for these parameters compared to that of medium or small sized tubers. In the initial growth stage of 45 days after planting (DAP), length of vine was significantly higher for large seed tubers. However by 90 DAP, all vines exhibited comparable length irrespective of seed size or spacing. Spacing significantly influenced the leaf area index (LAI) as well as number of leaves per vine, and at peak vegetative growth (135 DAP), the highest leaf count of 591 leaves per vine was noticed in 150 g tubers planted at wider spacing of 75 x 75 cm. Total dry matter accumulation per plant was not significantly influenced by spacing. Tuber forming roots could be observed even at 45 days after planting indicating early tuber initiation in lesser yam. The number of tuber forming roots increased upto 180 DAP, after which tuber bulking was noticed. Plants that emerged from large seed tubers produced more number of tuberous roots in the initial growth stage of upto 90 DAP. However at 135 DAP, plants from both 100 g and 150 g tubers were on par with respect to number of tuber forming roots. Plants at closer spacing of 50 x 50 cm produced higher number of tuber forming roots compared to wider spacing at 180 DAP. The crop growth rate (CGR), relative growth rate (RGR) as well as net assimilation rate (NAR) were influenced by seed tuber size and spacing. Plants from larger seed tubers and closer spacing had higher CGR, RGR and NAR. Higher RGR was observed during the period from 135 to 180 DAP. Spacing had no influence on NAR at initial growth phase. However at later stages of observations, high density planting resulted in higher NAR. The highest NAR was observed at 45-90 DAP, after which a declining trend was observed. The highest tuber yield was recorded from larger seed tubers of 150 g size (1270 g/vine), followed by 100 g (1053 g/ vine) and 50g seed tubers (929 g/vine), which differed significantly from each other. Spacing also had influence on tuber yield per plant and wider spacing resulted in significantly higher yield (1217 g), compared to 75 x 50 cm (1062 g) and 50 x 50 cm (972 g) spacings. Interaction effect also could be observed and performance of 150 g seed tuber at 75 x 75 cm was superior to others. It was also clear that neither the seed tuber size nor the spacing had influence on the number of small, medium or large sized tubers per plant or the length and girth of individual tubers. The trend in tuber yield per hectare was different as the yield is a function of number of plants per unit area. The highest productivity of 44.20 t/ha was realized when 150 g seed tubers were planted at a closer spacing of 50 x 50 cm. The combination of small seed tuber and wider spacing led to lower productivity in lesser yam (17.66 t/ha).Closer spacing resulted in higher cost of cultivation, but correspondingly yield per hectare was also high. The highest net profit of 5.31 lakhs per ha was realized when 150 g seed tubers were planted at 50 x 50 cm spacing, compared to 4.70 lakhs in the case of 50 g seed tubers and 4.34 lakhs from 100 g seed tubers at 50 x 50 cm. Considering the easy availability of small seed tubers and higher net profit and B:C ratio, for realizing maximum productivity per unit area, it is advisable to go for high density planting in lesser yam with seed tubers of about 50 g or 100 g weight. This is especially important in a state like Kerala where availability of land is a major constraint in crop production.ThesisItem Open Access Regulation of plant na/k ratio for productivity enhancement in pokkali rice(Department of Agronomy, College of Horticulture, Vellanikkara, 2019) Emily, Alias; KAU; Deepa, ThomasPokkali is a sustainable and unique rice farming system in coastal saline soils of Kerala. Salinity, submergence and high inherent acidity are the major issues underlying this special system of rice cultivation. In saline soils, higher Na content and the resultant high ratio between Na and other cations like K, Ca and Mg within the plant becomes detrimental for crop. Maintaining a low ratio of Na with other cations especially with K, is considered to be an yield determining and salt tolerance criterion in crops. Ameliorants containing sufficient amount of calcium inhibits the effect of soil acidity as well as soil salinity. As no response to soil application of nutrients is observed in Pokkali rice, foliar nutrition of K is expected to maintain nutritional balance within the plant. Hence the study was conducted with the objective to study the effect of the narrowing down of Na/K ratio in Pokkali rice by liming and foliar application of K. The study entitled “Regulation of plant Na/K ratio for productivity enhancement in Pokkali rice” was conducted at Rice Research Station, Vyttila. VTL8 was the variety used for the field experiment. Treatments included soil application of different levels of lime (500, 1000 kg ha-1) or dolomite (800, 1600 kg ha-1) alone and these treatments followed by foliar spray of sulphate of potash (2% SOP at 20 and 40 DAT). These treatments were compared with foliar spray of SOP alone and a control (no amelioration, no foliar spray). Various biometric observations, soil chemical characteristics and plant nutrient content were assessed during and after the field experiment. Crop duration was 137 days. Both growth and yield parameters exhibited significant variation among treatments. Number of tillers per sq. m, number of panicles per sq. m, percentage of filled grains and grain yield (2975 kg ha-1) were found to be higher for soil application of lime along with foliar spray of SOP at 20 and 40 DAT. Effect of dolomite @1600 kg ha-1 on yield was higher than the effect of lime @ 500 or 1000 kg ha-1. Foliar spray of K resulted in comparable yield to that of lime @ 1000 kg ha-1. Amelioration with dolomite @1600 kg ha-1 with or without foliar spray could significantly enhance the dry matter production and leaf area index and could result in a yield next to the best treatment. Liming influenced the plant nutrient content in Pokkali rice at various stages. Higher potassium, phosphorus and magnesium content were observed when applied with lime @1000 kg ha-1+ K (2% spray) at 20 and 40 DAT. Higher calcium content was observed in plots treated with dolomite @ 1600 kg ha-1. In acid saline soils, higher Na/K ratio is considered as the major yield limiting factor. Treatments significantly influenced the plant Na/K ratio at different stages of crop growth. Control treatment recorded highest Na/K ratio at all the stages. This indicated that amelioration and foliar spray of SOP had significant influence in reducing the plant Na/ K ratio. Correlation analysis also showed that grain yield had significant negative correlation with Na/K ratio at 90 days after transplanting. This indicates that Na/K ratio at flowering stage is most critical. Application of lime @1000 kg ha-1 or dolomite @ 1600 kg ha-1 along with SOP (2% spray) at 20 and 40 DAT could narrow down the Na/K ratio at flowering stage and thereby increase the yield significantly. A reduction in soil pH was observed in these treatments at flowering stage. In addition to the correction of soil acidity, application of lime and dolomite could improve the availability of calcium and magnesium content in soil as well as enhance their uptake by the crop. Economic returns were also found to be higher on application of lime @1000 kg ha-1 and 2% foliar spray of SOP. Hence application of lime @1000kg ha-1 and 2% foliar spray of SOP at 20 and 40 DAT can be recommended to increase the yield of Pokkali rice.ThesisItem Open Access Crop-weather relations on yield and quality of iruveli [Plectranthus vettiveroides (K.C.Jacob) N.P. Singh and B D Sharma](Department of Agronomy, College of Horticulture, Vellanikkara, 2019) Sabika, K P; KAU; Sindhu, P VIn India, about 7500 species of medicinal plants are being used in different traditional systems of medicines like Ayurveda, Siddha, Unani, Homeopathy, folklore etc. In medicinal plant cultivation, both yield and quality are equally important, and therefore, it is necessary to identify optimum growth factors that can ensure high yield and quality. Plectranthus vettiveroides (K. C. Jacob) N. P. Singh and B. D. Sharma (Syn. Coleus vettiveroides) is an important herbaceous medicinal plant belonging to the family Lamiaceae, where the root is the major economic part. The present study was conducted in the Department of Agronomy, College of Horticulture, Vellanikkara to assess the effect of variations in intensity of light, time of planting and mulching on yield and quality of Plectranthus vettiveroides known as Iruveli in Malayalam. The trial was laid out in randomized block design, replicated thrice. The treatments consisted of two growing conditions viz., open and 50 per cent shade, four dates of planting viz., May 15, June 15, July 15, and August 15 and three mulching treatments, viz., black polythene mulching, organic mulching, and no mulching. Growing condition, date of planting and mulching had significant influence on plant characters such as height, number of branches, total biomass yield and total root yield. The highest biomass yield and root yield were obtained from open condition (10382 kg/ha biomass and 1216 kg/ha root), May planting (15694 kg/ha biomass and 2508 kg/ha root) and black polythene mulching (16235 kg/ha biomass and 1786 kg/ha root). Interaction between growing conditions, date of planting and mulching was also significant with the highest biomass yield in the treatment combination of May planting under open condition with black polythene mulching (34715 kg/ha). The management methods also influenced the soil chemical properties. Available N and P were higher in 50 per cent shaded condition. Among mulching, available N and K were higher under organic mulching. Higher available N was found in July planting, whereas available P and K were higher in August planting. Among different micro climatic factors studied, soil temperature and soil moisture were significantly influenced by growing condition and mulching. Higher soil temperature was observed under open condition and black polythene mulching. However, higher soil moisture was under shaded condition and black polythene mulching Physiological, chemical and biochemical parameters were significantly influenced by growing condition, date of planting and mulching. Higher CGR and RGR values were observed under May planting, open condition and with black polythene mulching. Total chlorophyll content at the time of harvest was higher under shade (2.26 mg/g) and May planting (2.16mg/g). Higher essential oil content was recorded from open condition (1.77%), May planting (1.73%) and with black polythene mulch (1.81%). Combination of May planting, black polythene mulching and open condition resulted in the higher essential oil content of 2.35 %. Weed count and weed dry weights were significantly influenced by the treatments. Lower weed count and weed dry weight were observed under shade and black polythene mulching whereas higher growth was observed in open condition and no mulching. Correlation studies showed a positive correlation of total biomass, root yield and essential oil content with maximum temperature, relative humidity, rainfall and soil temperature. Essential oil content had significant positive correlation with light intensity, soil temperature, and soil moisture at initial stages of growth. There was also a positive correlation between biomass yield, total root yield and essential oil content. A higher B: C ratio was obtained from May planting with black polythene mulching under open condition. Planting in August with organic mulch under shaded condition recorded lowest B: C ratio. From the experiment it can be concluded that planting on 15th May in open condition under black polythene mulch as the optimum requirement for Iruveli.ThesisItem Open Access Weed management in upland rice (Oryza sativa L.) intercropped in coconut(Department of Agronomy, College of Agriculture, Vellayani, 2018) Ravikiran; KAU; Elizebeth Syriac, KThe investigation entitled “Weed management in upland rice (Oryza sativa L.) intercropped in coconut” was undertaken during the period, 2017 - 2018 at College of Agriculture, Vellayani, Thiruvananthapuram to standardise an eco-friendly and economic weed management strategy for upland rice intercropped in coconut. The field experiment was carried out at Coconut Research Station, Balaramapuram, Thiruvananthapuram district during the period from June to October 2017. The variety used was Prathyasa (MO-21) released from Rice Research Station, Moncompu. The experiment was laid out in randomized block design (factorial) with sixteen treatment combinations and three replications. The treatments consisted of two stale seedbed methods viz., stale seedbed with mechanical removal of weeds (s1) and no stale seedbed (s2) and eight weed management methods i.e., penoxsulam @ 20 g ha-1 at 10-15 days after sowing (DAS) fb hand weeding (HW) at 35-40 DAS (m1), penoxsulam @ 25 g ha-1 at 10-15 DAS fb HW at 35-40 DAS (m2), penoxsulam @ 30 g ha-1 at 10-15 DAS fb HW at 35-40 DAS (m3), penoxsulam @ 20 g ha-1 at 10-15 DAS fb metsulfuron methyl + chlorimuron ethyl (MM+CE) @ 4 g ha-1 at 35-40 DAS (m4), penoxsulam @ 25 g ha-1 at 10-15 DAS fb MM+CE @ 4 g ha-1 at 35-40 DAS (m5), penoxsulam @ 30 g ha-1 at 10-15 DAS fb MM+CE @ 4 g ha-1 at 35-40 DAS (m6), HW twice at 15 and 35 DAS (m7) and weedy check (m8). Study of the weed flora of experimental area indicated the dominance of broad leaved weeds (eight spp.) followed by grasses (six spp.) and sedges (two spp.). Stale seedbed method (s1) recorded significantly lower weed density at all stages of observations (15, 30 and 60 DAS), weed dry weight at 15 and 30 DAS and higher weed control efficiency (WCE) at 30 and 60 DAS compared to no stale seedbed. Among the weed management methods, at 60 DAS, all the penoxsulam doses i.e., 20, 25 and 30 g ha-1 at 10-15 DAS fb either HW at 35-40 DAS or MM+CE at 35-40 DAS (m 6, m4, m3, m5, m1 and m2) were on par in their effect on total weed dry weight and WCE. Stale seedbed method (s1) registered significantly higher plant height at 60 DAS, number of tillers m-2 at 30 DAS and at harvest, dry matter production at harvest and LAI at 60 DAS compared to no stale seedbed (s2). Penoxsulam at different doses fb HW treatments (m 1, m2 and m3) recorded higher plant height at 30 and 60 DAS and at harvest, number of tillers m-2 at 30 DAS, DMP at harvest and LAI at 30 DAS. None of the herbicide treated plots showed any phytotoxicity symptom on rice crop. The yield attributes viz., number of spikelets panicle-1, per cent filled grains and thousand grain weight were significantly higher for stale seedbed, compared to no stale seedbed (s2). Weed management methods also significantly improved yield attributes viz., panilces m-2, spikelets panicles-1, per cent filled grains and thousand grain weight compared to weedy check treatment. Penoxsulam @ 25 g ha-1 at 10-15 DAS fb HW at 35-40 DAS (m2) registered the highest values for per cent filled grains and thousand grain weight. Stale seedbed method (s1) recorded significantly higher grain yield, straw yield and lower weed index compared to no stale seedbed method (s 2). Though penoxsulam @ 25 g ha-1 at 10-15 DAS fb HW at 35-40 DAS (m2) registered the highest grain yield (3.23 t ha-1), it was on par with the other penoxsulam fb HW treatments viz., m1 and m3. None of the s x m interactions were found statistically significant. Regarding weed index also m2 registered the lowest value and it was significantly superior to all other weed management methods. Higher net income (₹ 27, 848/-) and B:C ratio (1.48) were obtained with stale seedbed method (s1), compared to no stale seedbed (s2). Application of penoxsulam @ 25 g ha-1 at 10-15 DAS fb HW at 35-40 DAS (m2) registered the highest net income (₹ 36,090/-) and B: C ratio (1.63). The s1m2 registered the highest net income (₹ 44,433/-) and B: C ratio (1.77), among the interactions. The results on soil microbial population revealed that population of fungi, bacteria and actinomycetes increased in all the herbicidal treatments compared to pre-treatment population. Activity of dehydrogenase enzyme also increased significantly in the herbicide applied plots implying the safety of the tested chemicals on soil health. Based on grain yield, weed index and economic analysis, integration of stale seedbed method with the broad spectrum herbicide penoxsulam @ 25 g ha-1 at 10-15 DAS fb HW at 35-40 DAS can be recommended as an eco-friendly and economic weed management practice in upland rice.ThesisItem Open Access Agrotechniques for enhancing root production in Desmodium gangeticum (L.) DC under partial shade(Department of Agronomy, College of Agriculture,Vellayani, 2019) Abhijith, S S; KAU; Anilkumar, A SThe study entitled “Agrotechniques for enhancing root production in Desmodium gangeticum (L.) DC. under partial shade” was undertaken during 2017-2019, in the Instructional farm, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala, with an objective to study the integrated effect of root endophyte fungus, planting density, source efficacy of nutrients, moisture stress and subsurface mulching on the growth, yield and quality constituents of Desmodium gangeticum (L.) DC. under partial shade. The field experiment was laid out in randomized block design with 12 treatments and three replications. The treatments were, T1 – Inoculation with Piriformospora indica (root endophyte) alone, T2 – T1 + Soil application of cow dung slurry (5% at monthly interval), T3 – T1 + Soil application of NPK (basal- @ 40:40:40 kg ha-1 year-1), T4 – T2 + Irrigation at 15 mm depth, T5 – T2 + Irrigation at 30 mm depth, T6 – T3 + Irrigation at 15 mm depth, T7 – T3 + Irrigation at 30 mm depth, T8 – T5 at high density planting (40 cm x 20 cm), T9 – T7 at high density planting, T10 – T8 under subsurface mulching with black polythene, T11 – T9 under subsurface mulching with black polythene and T12 – control at normal row planting (40 cm x 40 cm). Piriformospora indica was inoculated with the potting medium @ 10g fungal culture kg-1 of potting medium. Results of the experiment revealed that integrated management practices have significant effects on growth and yield attributes of D. gangeticum. The treatment T7 recorded the tallest plants at 3 and 4 months after transplanting (MAT) whereas, T9 was superior at 5, 6 and 7 MAT and at harvest. The treatment T7 registered the highest number of branches at all stages of growth. At 3 and 5 MAT, T6 recorded the highest leaf number whereas T7 was superior at 4, 6 and 7 MAT and at harvest. T5 registered the highest root number at 3 MAT but T10 was found superior at 5, 6 and 7 MAT and at harvest. At 2 MAT, T9 and at all other growth stages, T7 recorded the highest root spread. T5 at 3 MAT, T7 at 5 and 6 MAT and at harvest and T6 at 7 MAT registered the highest root volume. With respect to length of tap root, the treatments T9 at 3, 4, and 6 MAT and at harvest and T8 at 7 MAT were found superior. At 3 MAT, T5 revealed the highest girth of primary root but at 5, 6 and 7 MAT, T7 and at harvest T6 were found superior. The treatment, T7 registered the longest laterals at 5, 6 and 7 MAT and at harvest. The root fresh and dry weight showed a similar trend. The treatments T9 at 3 MAT, T6 at 5 and 7 MAT and T7 at 6 MAT and at harvest showed the highest fresh and dry root weight. The highest root yield at harvest was recorded by T8 which was on par with T9, T10 and T11. Chlorophyll content varied with different growth stages. T5 at 2 MAT, T6 at 5 MAT, T11 at 6 MAT and T9 at 4 and 7 MAT and at harvest registered the highest total chlorophyll content. Like chlorophyll content, RLWC also showed variations with respect to different growth stages. T2 at 3 and 4 MAT, T6 at 7 MAT and T7 at 5 and 6 MAT and at harvest recorded the highest values. At 5 and 7 MAT and at harvest T7, T5 and T6 respectively recorded the highest root-shoot ratio. The treatments T11 and T9 at 2 and 7 MAT and T8 at 3, 5 and 6 MAT and at harvest registered the highest leaf area index. Observations on crop growth rate showed the significance of T8 at 4 to 5 MAT, T6 at 6 to 7 MAT and T9 at 5 to 6 MAT and 7 MAT to harvest. With respect to relative growth rate, T4 at 2 to 3 MAT and T6 at 3 to 4, 4 to 5 and 6 to 7 MAT followed by T9 at 7 MAT to harvest were found superior. At 2 to 3 and 4 to 5 MAT, the treatments T11 and T10 respectively recorded the highest values for net assimilation rate. Ethanol extract of plant roots grown under control at normal row planting (40 cm x 40 cm) (T12) recorded the highest total alkaloids at harvest. Among seed parameters, only number of seeds per inflorescence was significantly influenced by the treatments at 6 MAT and it was the highest in T1. Soil moisture studies revealed the significance of T8 and T9 in enhancing soil moisture retention before and after irrigation. T4 on par with T6 registered the highest consumptive use, daily consumptive use and Kc. Crop water use efficiency was the highest for the treatment T8. T2 registered the highest field water use efficiency and water productivity. T9 recorded the highest up take of primary plant nutrients. After the experiment, organic carbon and available K status of soil were found superior in T3 and T10. Even though nursery seedlings exhibited P. indica root colonization at harvest, it was not clearly evident through microscopic investigation. Economic analysis of the system revealed the significance of T8 (₹ 47,902 ha-1) which was on par with T9 and T10 with respect to net income. The highest benefit-cost ratio was also registered by T8 which was significantly superior to all other treatments. It is concluded that high density planting of P. indica inoculated seedlings under partial shade followed by monthly application of cow dung slurry (5 %) and scheduling irrigation at 30 mm depth once in six days (T8) was found beneficial for enhancing leaf area index, root production, crop water use efficiency, net income (₹ 47,902 ha-1) and benefit-cost ratio (1.74).ThesisItem Open Access Fertigation and mulching in oriental pickling melon (Cucumis melo var. conomon (L.) Makino) under high density planting(Department of Agronomy,Vellanikkara, 2016) Ashly, P; KAU; Joseph, P AA field experiment was conducted to study the eficcts of 'Fertigation and mulching in oriental pickling melon {Cucumis melo vor.conomon (L.) Makino ) under high density planting and LDPF mulching in the summer rice fallow at the Agricultural Research Station (ARS) , Mannuthy from December 2014 to February 2015. High density planting of short duration less spreading high yielding variety of op melon at 33,333 plants per hectare was found to increase the yield of op melon more than double the yield at the recommended population of 10,000 plants per hectare. Under high density planting there is a proportionate increase in the demand of water and nutrients, which are crucial for the balanced growth, development and yield of the crop. The purpose of this experiment was to find out an optimum level of irrigation, fertilizer which will be supplied as drip fertigation for the highest yield and quality of fruits under polythene mulched condition. There were nine drip fertigation combinations with three levels of irrigation (75, 100 and 125 per cent Ep ) and 3 levels of fertilizers (200, 250 and 300 per cent of RDF), and one control which were laid out in Randomized Block Design with three replications. There was a significant increase in the characters like length of vine, number of leaves per vine, number of secondary branches per vine, leaf area index and shoot dry matter production at harvest with increase in irrigation levels from 75 per cent Ep to 125 percent Ep. At the same lime, other growth attributes such as number of primary branches per vine and days to fust male and female flower appearance didn't show any significant effect with various drip irrigation levels. Similarly, under high density planting and polythene mulching, the length of vine, number of leaves per vine, number of secondary branches per vine, LAI and shoot dry matter production at harvest increased linearly with increase in fertilizer levels from 200 per cent to 300 per cent of recommended dose. But increase in fertilizer level did not make any significant effect on the number of primary branches of OP melon. It remained constant around 2 in all levels of irrigation and fertilizer. The interaction between irrigation and fertilizer levels was not significant in any of the characters viz., length of vine, number of leaves per vine, number of primary and secondary branches per vine and LAI and shoot dry matter production at harvest. Per hectare yield of crc^ as well as various yield attributes like number of fruits per plant, average fruit weight, average volume of fruit and fruit yield per plant were not affected significantly by various irrigation levels. However, the average weight and volume of fruits increased slightly and non significantly with increase in irrigation levels from 75 per cent Ep to 125 per cent Ep. All other parameters like number of fruits per plant, yield of fruits per plant and fruit yield per ha recorded maximum value at 100 per cent Ep and the value declined gradually when irrigation level was increased to 125 percent Ep. Even though the weight and volume of individual fruits were maximum at 125 per cent Ep, the number of fruits per plant was less in this treatment, which ultimately resulted in a raluction in per ha yield of the crop. Number of fruits per plant, fruit yield per plajit and per hectare yield of fruit showed significant increase with increase in fertilizer level from 200 per cent to 250 per cent of recommended dose of fertilizer. But a further increase in fertilizer level affected the above characters negalively.So also, among the fertilizer levels, the average weight and volume of fruits were highest at 250 per cent RDF even though the effect was non- significant. The interaction between irrigation and fertilizer levels was not significant on the weight of fruits per plant and average weight and volume of fruits. But, there was significant elTect of interaction between irrigation and fertilizer levels on characters like ftuit yield per plant and per ha. Highest fruit yield per plant and highest per ha fruit yield were recorded at IiFi which was significantly superior to all the other combinations except I3F2,. So, there was positive interaction up to 100 per cent Ep and 250 per cent of recommended dose of fertilizer level when applied together as drip fertigation with LDPE mulching. Number of days taken for the appearance of flowers and the number of days taken for harvest did not show significant variation under various levels of drip fertigation. The interaction between irrigation and fertilizer levels was also non- significant on these characters. In general, days to first male flowering and female flowering were 21 and 26 respectively in drip fertigation treatments, while they were 25 and 29 respectively in control. Fruits were harvested 63 and 68 days after planting in drip fertigation treatments and control plots respectively. There was an increase in fruit dry weight with increase in irrigation levels from 75 per cent Ep to 100 per cent Ep and then it declined with further increase in irrigation level to 125 per cent Ep and the highest fruit dry matter production was recorded with 250 per cent of RDF compared to both 200 and 300 per cent of RDF. The interaction between irrigation and fertilizer levels also significantly influenced the fruit dry matter production. The maximum was observed at a combination of irrigation with 100 per cent EP and fertilizer with 250 per cent RDF. Both nitrogen and phosphorus content of leaves at 45 DAS increased significantly with increase in irrigation levels from 75 per cent to 125 per cent Ep under drip irrigation. But the increase in potassium content with increase in irrigation levels was non- significant. But the concentration of nitrogen, phosphorus and potassium in leaves of op melon increased significantly with increase in fertilizer levels from 200 per cent RDF to 300 per cent RDF. This shows the tendency of op melon to absorb and accumulate more and more NPK in their leaves with an increase in their availability in the root zone. The interaction between the tested irrigation and fertilizer levels did not show any significant effect on the content of primary nutrients in leaves of op melon at 45 DAS. Nitrogen content of shoot at harvest increased significantly with irrigation levels from 75 per cent Ep to 125 per cent Ep and fertilizer level from 200 per cent to 300 per cent of RDF. The fruit nitrogen level at harvest remained constant with slight variation, with the different levels of irrigation and fertilizers. At the same time, the interaction between any of the tested irrigation and fertilizer levels did not make any significant effect on shoot and fruit nitrogen content at harvest. Levels of irrigation significantly influenced the total N uptake by the crop at harvest. With increase in irrigation levels, N uptake increased significantly up to band then decreased, b and b were at par. The total nitrogen uptake by the crop at harvest increased with increase in fertilizer levels upto F2 and then decreased. F2 was significantly superior to F| and F3. The interaction between irrigation and fertilizer levels didn't make an\ significant effect on the character. Phosphorus content of shoot at harvest of op melon was found increasing significantly with increase in drip irrigation levels from 75 per cent Ep to 125 per cent Ep and fertilizer from Fi to F3 levels. At the same time, the fruit phosphorus content at harvest was not significantly affected by an increased application of phosphorus in soil.Fruit P content at harvest was not influenced by levels of irrigation and fertilizers. None of the combinations between irrigation and fertilizer levels showed significant superiority in increasing either shoot or fruit phosphorus content in OP melon. Levels of irrigation significantly influenced the P uptake by the crop. With increase in irrigation levels, P uptake increased up to b- But b and b were at par and significantly superior to b- With increase in fertilizer levels, the P uptake by the crop also increased up to F3. But F2 and F3 were at par and significantly superior to Fi. The Interaction between irrigation and fertilizer levels could not make any significant effect on P uptake by the crop. Irrigation and fertilizer levels significantly influenced the potassium content of shoot at harvest, but not the content of fruit. Significantly the highest potassium content in shoot was recorded at irrigation level of 125 per cent Ep and fertilizer level of 300 % RDFfFj). The fruit potassium content remained constant with different irrigation and fertilizer levels. Levels of irrigation significantly influenced the total K uptake by the crop. With increase in irrigation levels, K uptake increased significantly up to b (100 per cent Ep) and then decreased. Similarly, total K uptake also increased significantly upto 250 per cent RDF and then decreased. The interaction between irrigation ai^d fertilizer levels didn't show any significant influence on total K up lake. With increase in drip irrigation from 75 to 125 per cent Ep field water use efficiency decreased from 215.6 ( kg ha-mm ') to 145.8 ( kg ha-mm'') . Among the fertilizer levels, highest field water use efficiency was reported by 200 per cent RBF (181.9 kg ha-mm"') . However, the variation in FWUE among the fertilizer levels was not as significant as that observed in irrigation treatments. High level of irrigation in the control practice reduced FWUE in a significant way and was the lowest at 42.7 kg ha-mm"'. Soil chemical properties such as pH and Electrical Conductivity didn't show appreciable variation due to the various levels of irrigation and fertilizer. This indicates that chemical properties of soil are not likely to be influenced by short term management practices like irrigation and fertilizer application. In all the treatments and control, soil moisture content was the highest in the surface layer of 0-15 cm and the lowest in the bottom most layer of 30-45 cm. The decrease in soil moisture content from surface to the bottom most layer was gradual. In each layer, moisture content increased with increase in drip irrigation level from 75 % Ep to 125 % Ep. The moisture content in each layer was more in the control plot as it received more moisture through flood irrigation. In each layer the variation in moisture content was negligible within every level of drip irrigation due to the influence of varying levels of fertilizers. Keeping quality of the fruits was not affected by irrigation or fertilizer levels up to 45 days after harvest under high density planting with LDPE mulching. All the drip fertigation treatments were far superior to control on increasing the net profit per hectare and also the net income per rupee invested. In all the irrigation treatments F2 fertilizer level increased the net profit per hectare as well as net income per rupee invested in a significant way as the increase in fertilizer level above Ft had negative effect on crop yield. Among the treatment combinations I2F2 recorded the highest net return of Rs. 531581 per hectare followed by I3F2 of Rs 513651. Among the treatment combinations also I2F2 recorded the highest net income of Rs 2.06 per rupee invested followed by 1.95 by both I3F2 and I}F2. The study may be concluded by stating that for the most profitable production of op melon in the summer rice fallows of Kerala, high yielding less spreading varieties like Saunhagya should be planted at a high density of 33,333 plants per hectare and managed by drip fertigation at 1 GO per cent Ep and 250 per cent RDF with LDPE mulching. This has produced the highest net profit per hectare and net income per rupee invested.ThesisItem Open Access Characterization and management of weedy rice (Oryza sativa f spontanea)(Department of Agronomy, College of Agriculture, vellayani, 2016) Anjali, K; KAU; Ameena, MThe study entitled ‘Characterization and management of weedy rice (Oryza sativa f spontanea)’ was carried out as four separate experiments conducted at COA, Vellayani and farmers’ fields of Nemom block during 2014-16. The main objectives of the study were morpho-physiological and agronomic characterization of weedy rice morphotypes of Kerala; formulation of a management strategy and assessment of crop weed interference under elevated carbon dioxide concentration. Experiment I. ‘Morpho-physiological and agronomic characterization of weedy rice morphotypes’ was conducted as pot culture laid out in completely randomized design with eight weedy rice morphotypes collected from major rice tracts of Kerala (Trivandrum, Kuttanad, Kole lands, Palakkad, Kozhikode and Ezhome). Morphological characterization of weedy rice morphotypes using morphometric descriptors and its comparison with cultivated varieties revealed that during initial stages most of the weedy rice morphotype possess similar morphological characteristics as the cultivated varieties. Physiological characterization of weedy rice morphotypes revealed no significant variation in chlorophyll content, total soluble protein and stomatal characteristics with cultivated rice varieties. However, root growth in terms of volume and dry weight was significantly higher for most of the morphotypes collected from Trivandrum, Kuttanad, Palakkad, and Ezhome. Earliness in 50% flowering was observed in all the weedy rice morphotypes compared to cultivated rice. Sterility of weedy rice morphotypes were significantly higher (17.77 to 32.79%) compared to cultivated rice varieties (9.23 to 12.85%). All the weedy rice morphotypes collected showed a prominence in awn length ranging from 2.37 to 9.23 cm. An average grain and straw yield of 4.89 and 16.14 g plant-1 and 1000 grain weight of 20.42 g was recorded by weedy rice morphotypes. Shattering percentage expressed as grain threshebility was significantly high for weedy rice morphotypes ranging from 29.73 to 46.32%. The seeds of weedy rice recorded wide variation in longevity ranging from 4.96 to 15 months which is an indication of variable seed dormancy. Experiment II. ‘Management of weedy rice by enhancing rice competitiveness’ was undertaken as micro plot study by raising cultivated rice and most common weedy rice morphotype and maintaining a standard weedy rice population of 7 plants m-2. To enhance rice competitiveness, three levels of seed rates viz., 100,120 and 140 kg ha-1 in combination with three types of priming techniques, i.e., without priming, hydropriming and hardening (2.5 % KCl) were included.Among the treatments, seed rate of 100 kg ha-1 along with hydropriming(T2) recorded significantly higher number of grains per panicle (120.02), grain yield (4.44 t ha-1) and straw yield (6.71 t ha-1) which was on par with T5 (120 kg ha-1 + hydropriming). Confirmatory trial at farmers’ field revealed that seed rates of 100 kg ha-1 or 120 kg ha-1 along with hydropriming (T2& T5) resulted in superior yield attributes inrice viz., number of grains per panicle, grain and straw yield ha-1.Weedy rice count m-2 and dry weight were significantly lower under these treatments. T2 (100 kg+ hydropriming) along with T5 (120 kg+ hydropriming) turned out to be the most economic treatment with a B:C ratio of 1.68 and 1.64 respectively. Experiment III. ‘Effect of elevated CO2 concentration on growth of rice and weedy rice’, was undertaken as pot study under elevated CO2 concentration of 500 ppm in Open Top Chamber (Chamber A) and in ambient conditions (Chamber B and open field). The most common morphotype of weedy rice and two cultivated rice varieties (Jyothi and Uma) were selected for the study. Significant variations in vegetative (no of tillers, leaf area index and leaf area duration) as well as yield attributes and yield (no. of grain panicle-1, grain yield plant-1) were observed under elevated CO2 levels in all these three systems. Higher grain yield per plant was recorded by weedy rice in Chamber A with an elevated CO2 level (1.73 times higher than open condition), followed by Chamber B (recorded 1.19 times more than open condition). However, the extent of response varied among the cultivars under varying atmospheric situations with Uma showing a greater percentage increase in grain yield (51.4% in Chamber A and 40% in Chamber B) followed by weedy rice (42.3% in Chamber A and 16% in Chamber B). The study revealed significant variation among the weedy rice morphotypes. Cultivated rice and weedy rice exhibited morphological similarity during initial stages of growth. Seed rate of 100 kg ha-1 with hydropriming can be recommended as the most effective and economic management strategy for weedy rice. The response of weedy rice to elevated CO2 was more compared to cultivated rice varieties.