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2017 - 201964
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Subject: Agronomy × Author: KAU × End date: 2019 × Start date: 2017 ×
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    ThesisItemOpen 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, Thomas
    The 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.
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    ThesisItemOpen 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, P
    The 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.
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    ThesisItemOpen 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, Thomas
    Pokkali 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.
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    ThesisItemOpen 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 V
    In 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.
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    ThesisItemOpen Access
    Weed management in upland rice (Oryza sativa L.) intercropped in coconut
    (Department of Agronomy, College of Agriculture, Vellayani, 2018) Ravikiran; KAU; Elizebeth Syriac, K
    The 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.
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    ThesisItemOpen Access
    Customized nutrient management for rice (Oryza sativa L.) in the Southern Laterites (AEU8)
    (Department of Agronomy, College of Agriculture,Vellayani, 2019) Sheeba, S S; KAU; Shalini Pillai, P
    The study entitled “Customized nutrient management for rice (Oryza sativa L.) in the Southern Laterites (AEU 8)” was undertaken at College of Agriculture, Vellayani during 2016 to 2019. The main objectives were to assess and rate the available nutrient status of rice soil in the Southern Laterites (AEU 8), to develop a Zn – B mix for rice and to evaluate the effect of the mix on rice, at different N/K ratios. The study was carried out in three parts. The first part was on assessment and rating of available nutrient status of rice soil in Southern Laterites (AEU 8). Southern Laterites is spread over five blocks (Athiyannoor, Parassala, Nemom, Perumkadavila and Vellanad). Parassala, Nemom and Perumkadavila were selected for the study since paddy cultivation was observed in comparatively larger area in these blocks. One hundred and fifty, geo-referenced soil samples were collected from the rice fields during April to May 2017, at random from the 11 panchayats spread over these three blocks. The soil samples were analysed and rated for 14 soil fertility parameters and block wise digital maps were prepared with ArcGIS 10.1. Based on the nutrient index, it was observed that organic carbon, available Ca, Mg, S, Cu, Zn and B recorded low nutrient indices (< 1.5) in all the three blocks. While available N was low in Nemom and Perumkadavila, it was medium (1.5 – 2.5) in Parassala block. Available P showed high index (> 2.5) in Parassala and Perumkadavila and medium index in Nemom. While Parassala and Nemom blocks could be rated as medium with respect to available K, Perumkadavila exhibited high index for K. Available Fe and Mn were high in all the blocks. The rice soils of Southern Laterites were observed to be strongly acidic with a mean pH of 5.27 ± 0.58, normal in electrical conductivity (0.77 ± 0.31) dS m-1, low in organic carbon (0.52 ± 0.23) % and available N (263.70 ± 49.32) kg ha-1, high in available P (90.40 ± 59.78) kg ha-1 and medium in available K (228.94 ± 87.84) kg ha-1. The soils were low in available Ca (15.78 ± 4.96) mg kg-1, available Mg (5.87 ± 1.85) mg kg-1 and available S (1.34 ± 0.83) mg kg-1. Among the micronutrients tested, the rice soils exhibited deficiency of available Cu (0.44 ± 0.22) mg kg-1, Zn (0.77 ± 0.19) mg kg-1 and B (0.315 ± 0.002) mg kg-1. The second part of the study comprised development of a Zn – B mix for rice. The Zn and B requirement was calculated based on the difference between the crop requirement and Zn and B status of the soil. Crop requirement of Zn and B was computed as the product of the potential yield and whole plant nutrient composition. Accordingly, the Zn and B requirement could be calculated as 4.088 kg ha-1 and 0.738 kg ha-1 respectively. The Zn – B mix for rice was formulated by mixing zinc sulphate heptahydrate (ZnSO4.7H2O) and boric acid (H3BO3) in the ratio 4 : 1. The third part of the study was a field experiment to assess the effect of the Zn – B mix on rice, at different N/K ratios. The experiment was conducted during the second crop season (September to January) of 2017 and 2018. The experiment was located in the Chenkal panchayat of Parassala block, in a farmer’s field where Zn and B deficiency was identified from the first part of the study. The experiment was laid out in randomised block design with 13 treatments (12 + 1), replicated thrice. The treatments T1 to T4 were combinations of N/K (1.0 : 0.5) + foliar application of 0.5 % and 1.0 % Zn – B mix at maximum tillering (MT) and panicle initiation (PI) stages, T5 to T8 were N/K (1.0 : 1.0) + foliar application of 0.5 % and 1.0 % Zn – B mix at MT and PI stages, T9 to T12 were N/K (1.0 : 1.5) + foliar application of 0.5 % and 1.0 % Zn – B mix at MT and PI stages and T13 was control (KAU POP for rice). The variety used for the study was Uma (MO 16). The soil of the experimental site was sandy clay loam, strongly acidic in reaction, low in organic carbon, medium in available N and K, high in available P and deficient in available Ca, Mg, Zn and B. In all treatments except control, nutrients were applied on soil test basis. The results revealed that growth attributes were significantly influenced by N/K ratio and foliar application of Zn- B mix and the treatments were observed to be superior to control (KAU POP). Mean tiller count and leaf area index were significantly higher with N/K (1.0 : 1.5) + foliar application of 0.5 % Zn – B mix at PI stage (T10) at MT and PI stages. It was on a par with T9, T11 and T12. However, the mean total dry matter production (12356 kg ha-1) was significantly higher with T12 (N/K (1.0 : 1.5) + foliar application of 1.0 % Zn – B mix at PI stage) and was comparable with T10. Among the yield attributing characters, mean number of productive tillers m-2 (488.35) and grain weight per panicle (2.78 g) were significantly higher with T12 and were at par with T10. The treatments T10 and T12 were comparable with respect to the number of spikelets per panicle, filled grains per panicle and sterility percentage. The treatment T12 resulted in significantly higher mean grain yield (5.67 t ha-1) and was comparable with T10 (5.61 t ha-1). Straw yield was higher with T12 (6.89 t ha-1) and was on a par with T10 (6.83t ha-1). The treatments were superior to control (KAU POP), with T10 recording 43.9 per cent improvement in grain yield. Crude protein content of grain and uptake of major nutrients, Ca, Zn and B were significantly higher with T12 and was comparable with T10. Incidence of rice bug (at the milk stage) and false smut disease (at harvest) was observed during both the years. Mean benefit cost ratio was higher (1.72) with T10 and was comparable with T12 (1.69) as against a BCR of 1.16 for the KAU POP. The present study revealed that the fertility status of rice soils of the Southern Laterites (AEU 8) need to be addressed in terms of soil acidity, low organic carbon status, build-up of phosphorus and deficiency of secondary nutrients and micronutrients like Zn, B and Cu, on soil test basis. Based on the crop requirement and nutrient status of the soil, a Zn – B mix was formulated, as a mixture of zinc sulphate heptahydrate and boric acid in the ratio 4 : 1. Application of nitrogen and potassium in the ratio 1.0 : 1.5 along with foliar application of 0.5% Zn – B mix at panicle initiation stage was observed to be effective in enhancing the growth and yield attributes, yield and economics of rice in the Southern Laterites (AEU 8) of Kerala
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    ThesisItemOpen Access
    Vetiver based Organic Mediculture Technologies for the Sustainable development of Watersheds
    (Department of Agronomy, College of Agriculture,Vellayani, 2019) Ishrath, P K; KAU; Anilkumar, A S
    An investigation entitled “Vetiver based organic mediculture technologies for the sustainable development of watersheds” was carried out during 2016 to 2019 at the Instructional farm, College of Agriculture, Vellayani. The investigation comprised of three field experiments and one pot culture study. The objectives were to standardise nursery management practices for quality planting material production, develop vetiver based biological systems for soil and water conservation and to explore the phytoremediation potential of vetiver for waste water and degradable solid waste utilization. The vetiver variety “ODV-3”, turmeric variety “Varna”, cowpea variety “Bhagyalakshmi” and a local variety of greater galangal were used for the study. The techniques for quality planting material production were standardised by testing planting materials (a1- slips; a2- clumps), planting systems (b1- planting strips; b2- shallow basins), rooting medium (c1- coirpith compost: soil: cowdung (2:1:1) + inoculation with Azospirillum and AM Fungi); c2- c1 + cowdung slurry at monthly interval) and moisture regimes (d1- irrigation at 8 mm CPE; d2- irrigation at 16 mm CPE) in a 24 factorial Randomised Block Design with three replications. Conclusions were drawn after two and four months of planting. Inoculation of vetiver clumps with biofertilizers and planting in shallow basins filled with enriched rooting medium and application of cowdung slurry at monthly interval with irrigation scheduling at 16 mm CPE resulted in the production of higher number of planting materials (10.67 tillers per plant) and the highest benefit cost ratio (2.83) after two months of planting. Considering the dual benefit of planting material production and root yield, inoculation of vetiver slips with biofertilizers and planting in polythene mulched trenches, filled with enriched rooting medium followed by application of cowdung slurry at monthly interval and irrigation scheduling at 8 mm CPE resulted in the highest net income (₹.5.84 lakhs ha-1) and benefit cost ratio (2.96) after four months of planting. The study on “Vetiver based alley cropping systems for soil and water conservation” was undertaken in 32 factorial Randomised Block Design with three replications. Combinations of vetiver vegetative barriers were developed in three different planting geometries, i.e., a1- normal row planting (50 cm x 50 cm), a2- paired row planting (25/75 cm x 50 cm); a3- high density planting (25/75 cm x 25 cm) with three different sequential intercropping systems, i.e., b1- turmeric- cowpea- turmeric, b2- greater galangal and b3- control (without intercropping). High density planting of vetiver followed by continuous alley cropping of greater galangal (a3b2) resulted in the highest vetiver equivalent yield (14.44 t ha-1), net income (₹.4.05 lakhs ha-1) and benefit cost ratio (2.27). Substantial reduction in runoff (95 %), soil loss (166 %) and nutrient erosion (76 %) could be achieved through a3b2 within a period of 18 months, extending from June 2017 to December 2018. Considerable improvement in soil health with respect to physical properties of soil, viz., bulk density (33 %), porosity (28 %), water holding capacity (47 %) and infiltration rate (72 %) and build-up of soil organic carbon (43 %) were also observed in a3b2 compared to initial soil status. To develop vetiver systems for waste water utilization in agriculture, an experiment was laid out in Completely Randomised Block Design with seven types of waste water in three replications. The treatments were, a1- waste water from coconut husk retting yards, a2- kitchen waste water, a3- waste water from fish market, a4- coirpith leachate, a5-sewage water, a6- Vellayani lake water and a7- nutrient solution. Vetiver was proved as a good phytoremediator with respect to decontamination and water purification properties (nutrient and heavy metal uptake). In general, the morphological characters (number of leaves and tillers) and root characters (root weight, spread, volume and drymatter) were significantly improved by growing vetiver in fish-waste water. To explore the phytoremediation potential of vetiver for degradable solid waste utilization, a study was conducted in 4 x 2 x 2 factorial Randomised Block Design with three replications. Four ratios of degradable land fill materials (sewage sludge) and virgin soil (a1- 1:0; a2- 1:1; a3- 1:3; a4- 1:5), two crop establishment techniques (nursery grown rooted slips with enriched rooting medium (b1) and without enriched rooting medium (b2)); foliar nutrition (c1-sequential application of cow‟s urine, vermiwash and fermented plant juice; c2- sequential application of NPK fertilizer grade of 19:19:19, KNO3 and Ca(NO3)2 at monthly interval) were tested in this study. It could be concluded that, production of vetiver slips inoculated with Azospirillum and AM Fungi in enriched rooting medium and transplanting in the main field with sewage sludge and virgin soil (1:5) followed by sequential application of foliar fertilizers @ 0.50 per cent (19:19:19, KNO3 and Ca(NO3)2 ) resulted in the highest root yield (4.11 t ha-1), net income (₹.1.01 lakhs ha-1) and benefit cost ratio (1.97). Vetiver based mediculture technologies in relation to cost effective quality planting material production, alley cropping systems for soil and water conservation and phytoremediation techniques for waste water and biosolid utilization were developed for the sustainable development of watersheds.
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    ThesisItemOpen Access
    Bioefficacy and soil health impact of flucetosulfuron in wet seeded rice (Oryza sativa L.)
    (Department of Agronomy, College of Agriculture, Vellayani, 2018) Arya, S R; KAU; Elizabeth, K Syriac
    The investigation entitled "Bioefficacy and soil health impact of flucetosulfuron in wet seeded rice (Oryza sativa L.) was carried out at College of Agriculture, Vellayani, Thiruvananthapuram during the period of 2015-2018. The objectives were to evaluate the bioefficacy of flucetosulfuron in wet seeded rice; to assess its impact on soil health by determining the microbial count, earthworm population, enzyme status and herbicide residue in soil through bioassay using indicator plant as well as to assess the weed seed bank. It was also envisaged to study the in vitro sensitivity of biofertilizer organisms and biocontrol agents to flucetosulfuron. Field experiment was conducted during the I and II crop seasons of 2016- ’17, in a farmer’s field in Kalliyoor Panchayat, Nemom block, Thiruvananthapuram district, Kerala, with 12 treatments replicated thrice in Randomized Block Design. The treatments were: T1 : Flucetosulfuron @ 20 g ha-1 at 2-3 DAS, T2 : Flucetosulfuron @ 25 g ha-1 at 2-3 DAS, T3 : Flucetosulfuron @ 30 g ha-1 at 2-3 DAS, T4 : Flucetosulfuron @ 20 g ha-1 at 10-12 DAS, T5 : Flucetosulfuron @ 25 g ha-1 at 10-12 DAS, T6 : Flucetosulfuron @ 30 g ha-1 at 10-12 DAS, T7 : Flucetosulfuron @ 20 g ha-1 at 18-20 DAS , T8 : Flucetosulfuron @ 25 g ha-1 at 18- 20 DAS , T9 : Flucetosulfuron @ 30 g ha-1 at18-20 DAS, T10: Bispyribac sodium @ 25 g ha-1 at 15 DAS, T11: Hand weeding at 20 and 40 DAS and T12 : Weedy check. The short duration variety Kanchana was used for the trial. The weed flora in the experimental field comprised of four species of grasses, six species of broad leaved weeds and three species of sedges. Based on density and dry weight, sedges were the predominant group in the experimental field followed by broad leaved weeds and grasses. Application of flucetosulfuron @ 20, 25 and 30g ha-1 at 10-12 and 18-20 DAS (T4, T5, T6, T7, T8 and T9) recorded lower total weed density, total weed dry weight and nutrient removal by weeds and higher total weed control efficiency and were on par with the hand weeding treatment (T11). Yield reduction due to weeds was found to be 52.33 and 55.61 per cent during the I and II crop seasons respectively. The highest grain yield was recorded by the application of flucetosulfuron @ 25 g ha-1 at 10-12 DAS (T5) and flucetosulfuron @ 20 g ha-1 at 10-12 DAS (T4) during the first and second crop seasons respectively. The same trend was observed in the case of dry matter production also. Pooled analysis of the grain yield for the two seasons indicated the superiority of T5 which recorded the highest grain yield of 8.33 t ha-1. This treatment was on par with the other levels of flucetosulfuron viz., 20 and 30 g ha-1 at 10-12 DAS (T4 and T6) and hand weeding treatment (T11). Higher yield attributes, harvest index and nutrient uptake were also recorded for these treatments. However, net income and B:C ratio were significantly lower for hand weeding treatment. Herbicide application did not cause any significant inhibitory effect on the earthworm population and spider count. Application of herbicides increased the microbial population in herbicide treated plots. Flucetosulfuron, at the tested doses (20, 25 and 30 g ha-1) and time of application (2-3, 10-12 and 18-20 DAS), did not show any adverse impact on the activity of soil enzymes (dehydrogenase, acid phosphatase and urease) and soil organic carbon status. To identify the most suitable indicator plant for assessing flucetosulfuron residue in soil, four separate pot culture experiments were conducted using barnyard millet, cucumber, sunflower and maize. Sunflower was identified as the most sensitive indicator plant and shoot length of sunflower was adjudged as the best parameter to assess the flucetosulfuron residue in soil. Bioassay after each field experiment using sunflower revealed that there was no residual toxicity of flucetosulfuron in the post experiment soil. Pot culture experiments were carried out before and after each field experiment, to study the weed seed bank dynamics. Results revealed that non- herbicidal plots recorded higher weed count compared to herbicide applied plots. In all the herbicide treated plots, effective reduction in weed seed bank could be obtained irrespective of the dose of the herbicide. Regarding the time of application, application of flucetosulfuron at 10-12 and 18-20 DAS caused significant depletion of weed seed bank during both the seasons compared to its application at 2-3 DAS. In vitro sensitivity of biofertilizer organisms viz., Azospirillum lipoferum, Azotobacter chroococcum, Bacillus megaterium and Frateuria aurantia to flucetosulfuron indicated that growth of none of the organisms were significantly inhibited by the tested doses of flucetosulfuron. Similarly, in vitro sensitivity to biocontrol agent Trichoderma viride revealed that, at all the tested concentrations of flucetosulfuron, it showed a colony diameter of 9 mm uniformly with zero per cent inhibition indicating the compatibility of the herbicide. The compatibility studies with Pseudomonas fluorescens also revealed the safety of the herbicide. The present study revealed that application of flucetosulfuron @ 20, 25 and 30 g ha-1 at 10-12 DAS was very effective in controlling the weeds and recorded significantly higher grain yield and monetary benefits in wet seeded rice. Application of flucetosulfuron @ 20, 25 and 30 g ha-1 at 2-3/10-12/18-20 DAS had no adverse impact on soil health and was found compatible with the tested biofertilizer organisms (Azospirillum lipoferum, Azotobacter chroococcum, Bacillus megaterium and Frateuria aurantia) and biocontrol agents (Trichoderma viride and Pseudomonas fluorescens).
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    ThesisItemOpen 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 S
    The 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).