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ThesisItem Open Access Shade response of common rainfed intercrops of coconut(Department of Agronomy, College of Horticulture, Vellanikkara, 1981) Lalitha Bai, E K; KAU; Vikraman, RAn experiment was conducted at the College of Horticulture, Vellanikkara during 1980-81 to study the shade response of five common rainfed intercrop of coconut garden. The experiment was laid out in randomised block design with four levels of shade and five replications. The study revealed that sweet potato cannot be cultivated under shade as it is a ‘shade –sensitive’ crop,while coleus is suitable only where light infiltration is high. Colocasia, turmeric and ginger were found suitable for intercropped situations. Colocasia appears to be shade – tolerant while ginger and turmeric are indicated as ; shade – loving’. These two shade – loving crops are best suited under shaded situations up to 25 and 50 per cent shade, respectively . Photosynthetic mechanism appears to have a decisive role on the shade response of all these crops expecting sweet potato. Excepting colocasia, plant height (length of vine) in all the crops increased with increasing shade intensities. Number of branches (tillers) in all the crops significantly decreased with increasing intensities of shade. The content of total chlorophyll and its components were significantly influenced by shading in all the crop. The contents of nitrogen, phosphorus and potassium in all the plant components of all crops increased because of shading. The uptake of all the nutrients followed an identical pattern as that of dry matter accumulation in all the crops.ThesisItem Open Access Effect of shade and moisture regimes on the growth of cocoa seedlings(Department of Agronomy, College of Horticulture, Vellanikkara, 1981) Gopinathan, R; KAU; Vikraman Nair, RAn experiment was conducted at the College of Horticulture, Vellanikkara during 1979-80 on the effect of shade and moisture regimes on the growth of cocoa Theobroma cacao L.) seedlings. The investigations were carried out to arrive at the optimum shade and moisture requirement for the growth of cocoa seedlings. The experiment was laid out in a completely randomised design with four levels of shade and three levels of moisture with four replications. The study revealed that cocoa seedlings must be shaded and well watered for their better growth. 50 – 55% shade and irrigation at 75% available moisture was found best. Death of all the seedlings in the open by the third month of observation stresses that, cocoa seedlings cannot be grown without any shade irrespective of the frequency of irrigation. Expect net assimilation rate (NAR) and leaf area ratio (LAR) all the growth characters were increasing with increasing shade (up to 50 – 55%) and increasing frequencies of irrigation.ThesisItem Open Access Influence of crop geometry on the growth and yield of rice variety jaya(Department of Agronomy, College of Horticulture, Vellanikkara, 1985) Usha, K E; KAU; Balakrishnapillai, PInfluence of crop geometry on the growth and yield of rice variety 'Jaya'. An experiment was conducted in the Regional Agricultural Research Station, Pattambi during the second crop season of 1983 to study the influence of crop geometry on the growth and yield of rice variety 'Jaya'. The experiment was laid out in split plot with three replications. The treatments consisted of six treatment combinations of two levels of spacing between plants (20 x 15 cm, 20 x 10 cm) and three levels of spacing between alleys (80 cm, 160 cm and 240 cm apart) in the main plot and four levels of crop orientation (north-South, East-West, diagonal planting North East-South West and diagonal planting North West-South East) in the sub plot. Observations on weather factors such as temperature, relative humidity, rainfall, sunshine hours, wind velocity and evaporation were recorded daily. Crop growth characters like height, number of tillers, leaf area index were recorded at different stages of development of the crop and yield components like number of productive tillers, length of panicle, and yield of girth and straw were noted during the harvest. The day time variation of albedo was also measured at frequent intervals. N-S oriented crop was significantly superior to others with regard to crop growth characters as well as yield components. Height, number of tillers, number of productive tillers, length of panicle and number of grain per panicle were influenced by the 20 x 15 cm spacing while the 20 x 10 cm spacing showed the maximum drymatter production, maximum thousand grain weight and highest value of grain and straw yields. The grain yield was not significantly influenced by the alley treatments. It was found that proper spacing and orientation had significant effect on overall growth and yield of the crop. Highest grain yield was recorded in plots with N-S orientation and with 20 x 10 cm spacing. The best performance is attributed to more effective utilisation of solar radiation with the uniform exposure of plants to sunlight. The albedo measurements were also higher over the closely spaced and N-S oriented plots indicating the better growth and performance of the crop. Results of the present investigation indicate that rice in Kerala during the second crop season can be grown most successfully if planted at a spacing of 20 x 10 cm and oriented in N-S direction.ThesisItem Open Access Fertiliser management in cassava- groundnut intercropping system(Department of Agronomy, College of Horticulture, Vellanikkara, 1985) Bridgit, T K; KAU; Sreedharan, CAn experiment was conducted at Agricultural Research Station, Mannuthy, to study the effect of levels of N and time of application of N and K in a cassava- groundnut intercropping system. This 2x2x4 factorial experiment was laid out in randomized Block design with three replications under rainfed conditions. The study revealed that intercropping cassava with groundnut enhanced the growth parameters of cassava at all stages of growth. Yield attributes, yield and total drymatter production of cassava were also increased by intercropping. The quality characters like drymatter starch and crude protein content of tubers were improved by intercropping. Hundred percent recommended dose of N increased the growth, yield and quality over 75 percent of the recommended dose. Among the time of application T3 (15, 75 and 120 DAP) has given the highest tuber yield (21.92t ha-1) followed by T1 (15,60 and 90 DAP) of 21.65 t ha-1. T4 (basal, 60 and 90 DAP) which is the recommended dose recorded the lowest yield of 17.9 t ha-1. A comparatively higher utilization index was obtained with intercropping and higher level of N (75kg ha -1). T1 andT1 and T3 recorded more UI values than T2 and T4. The nutrient content as well as up take in cassava was increased by legume intercropping and higher levels of N. T1 and T3 recorded more nutrient content in different plant parts as compared to T2and T4. The fertility status of the soil was improved by intercropping and levels of N. Yield of ground nut was influenced by higher levels of N. Yield of groundnut was influenced by higher levels of N and time of application of N and K to cassava.T2 and T4 recorded more yield. Nutrient content and up take of bhusa was not influenced by levels of N and time of application of N and K. Maximum LER was seen in sole cassava plot when N and K was given at 15,75 and 120 DAP while in intercropped plot it was highest when N and K were given at 15,60 and 90DAP. Income from cassava cultivation was increased by intercropping with groundnut application of N and K at 15, 75 and 120DAP. Groundnut can be intercropped successfully with cassava under Kerala condition and a substantial quantity (25 per cent) of fertilizer nitrogen required by the main crop could be saved by this practice. For getting better fertilizer use efficiency of applied N and K fertilisers, 1st dose should be applied at 15 DAP of cassava instead of the now recommended basal Dose. Second dose can be extended up to 75 days of planting and the last dose up to 120 DAP so as to coincide with the harvest of the intercrop and the earthing up of cassava.ThesisItem Open Access Nitrogen management for grain cowpea (Vigna unguiculata (L.) Walp.) in summer rice fallows(Department of Agronomy, College of Agriculture, Vellayani, 1985) Sheela, P; KAU; Muraleedharan Nair, VA field experiment was conducted at the College of Agriculture, Vellayani during the summer season of 1983-84 to study the response of two varieties of cowpea to different nitrogen management conditions. Various combinations of 5,10,20 or 30 kg N/ha basal, 0,5 or 10 kg N/ha top dressing as foliar spray at flowering, immediately after fertilization of early flowers and mid pod-fill stage as major treatments and two varieties (Kanakamony and Krishnamony) as minor treatments were tried in a split plot design with three replications. The study revealed the favourable influence of higher amounts of nitrogen on growth characters lika plant height, leaf number, number of branches per plant and number of nodules at flowering. Yield components such as number of pods per penduncle, pods per plant, seeds per plant and percentage of podset increased significantly by foliar application of nitrogen at different stages of the reproductive phase. The highest grain yield of 476 kg/ha was obtained from plants receiving 20 kg N/ha basal plus 10 kg N/ha applied to foliage at mid pod-fill stage. The number of seeds per pod and 100 seed weight were not influenced by the Various nitrogen levels tried. Harvest index and protein content of grain were enhanced by application of nitrogen as basal plus foliar sprays. The nitrogen content in plant parts were increased with increasing amounts of nitrogen. Foliar application of nitrogen at flowering or mid pod-fill stage increased the leaf nitrogen concentration The total nitrogen content available P2O5 and available K2O contents of soil influenced by the treatments. The higher level of nitrogen invariably led to higher values of total nitrogen in soil, available and available K2O after the crop harvest. The greatest profit of Rs 1661.85 was obtained from plants receiving 20 kg N/ha basal plus 10 kg N/ha as foliar spray at mid pod-fill stage (T12) The study indicated that application of 20 kg N/ha basal when supplemented v/ith 10 kg N/ha as foliar spray at mid pod-fill stage of the crop could give higher grain yields and profits.ThesisItem Open Access Spacing cum fertilizer investigation on rice variety, Mashuri, in the Onattukara tract(Department of Agronomy, College of Agriculture, Vellayani, 1983) Sobhana, S; KAU; Chandrasekharan, PWith a view to investigate the influence of different fertilizer levels, spacings and their combinations on the growth and yield of rice variety, Mashuri, in the sandy loam tracts of Onattukara, an experiment was conducted at the Rice Research Station, Kayamkulam, during the second crop season of the year, 1981-82. The response of the variety to four fertilizer levels (50 : 25 : 25, 60:30:30, 70:35:35 and 80:40:40 kg/ha NPK), four spacings (10cm X 5 cm, 10cm x 10 cm, 15 cm x 10 cm and 20 cm x 1o cm) and their combinations was studied. The experiment was laid out in randomised block design , as a 4 x 4 factorial experiment with three replications.ThesisItem Open Access Shade tolerance of guinea grass var. mackuenii under different levels of potassium(Department of Agronomy, College of Agriculture, Vellayani, 1982) Mullakoya, P; KAU; Raghavan Pillai, GAn investigation was carried out in the Instructional Farm attached to the College of Agriculture, Vellayani, during 1981-82 with the objective to assess the production potential of guinea grass var. Mackuenii under varying intensities of shade. It was also aimed to assess the potassium requirement was laid out in a 4 x 4 factorial randomised block design with 3 replications. The results of the study are summarised below: (1) Height of grass was positively influenced by both shade intensities and potash levels. (2) Leaf area of grass was increased with increase in shade intensities and potash levels. (3) Tiller production was adversely affected by shade, while potash application increased tiller number of grasses.ThesisItem Open Access Nutritional management in coleus (Coleus parviflorus Benth)(Department of Agronomy, College of Agriculture, Vellayani, 1983) Geetha, K; KAU; Madhavan Nair, K PAn experiment was conducted at the College of Agriculture, Vellayani with the objective of finding out the optimum doses of nitrogen and potash tried were 0, 30, 60,90 and 120 kg/ha each. The two timings tried were entire dose as basal, and half basal and half thirty days after planting. Nitrogen had significant effect on plant height, number of branches, number of functional leaves, plant spread and leaf area index whereas levels of potash had not much effect on these aspects except at early stage. Time of application of nutrients had no effect on these growth characters.ThesisItem Open Access Nutritional requirement of the sesamum variety thilothama in partially shaded uplands(Department of Agronomy, College of Agriculture, Vellayani, 1985) Girija, Devi L; KAU; Chandrasekharan, PAn experiment was conducted in the red loom soils of the Instructional Farm, College of Agriculture , Vellayani during 1983 to study the effects of three levels of nitrogen (0, 20 and 40 kg N/ha), three levels of phosphorus (0, 15 and 30 kg P2O5/ha) and three levels of potassium (0,20 and 40 kg K2O/ha) on the growth, yield, oil and protein content and chemical composition and uptake of mineral nutrients of sesamum. The field trial was laid out as a 3 factorial experiment confounding NPK in replication - 1 and NP2K2 in replication-2.