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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 Herbicide mixtures for weed management(Department of Agronomy,College of Agriculture, Vellayani, 2016) Sheeja, K Raj; KAU; Elizabeth, K SyriacThe experiment entitled "Herbicide mixtures for weed management in direct seeded puddled rice Oryza saliva L." was carried out at College of Agriculture, Vellayani, during the period from 2013 - 2016, to assess the bioefficacy of two post emergence herbicide mixtures viz., bispyribac sodium + metamifop and penoxsulam + cyhalofop butyl in direct seeded rice; to study the residual effect in soil; to investigate the impact on microbial and earth worm population, soil enzyme activity and weed seed bank and also to assess the in vitro sensitivity to soil borne pathogen, Rhizoctonia solani, bio control agents and bio fertilizer organisms. Field experiment was undertaken during first and second crop seasons of 2014-15 at Nemom block at farmer's field. The experiment was laid out in RED with 12 treatments and three replications. Bispyribac sodium + metamifop @ 60, 70, 80 and 90 g ha"*,penoxsulam + cyhalofop butyl @ 120, 125, 130 and 135 g ha"*, bispyribac sodium @ 25 g ha"', penoxsulam @ 22.5 g ha"', hand weeding twice and weedy check constituted the treatments. The higher three tested doses of penoxsulam + cyhalofop butyl v/z.,125, 130 and 135 g ha ' and the highest tested dose of bispyribac sodium + metamifop viz., 90 g ha"' were better than other weed management treatments in improving the growth and yield attributes of rice. Pooled analysis indicated the superiority of penoxsulam + cyhalofop butyl @ 135 g ha"' which recorded the highest grain yield (8463 kg ha ' ) and it was statistically on par with its lower doses (130 and 125 g ha*'). Straw yield was not significantly influenced by the weed control treatments. Penoxsulam + c^lofop butyl @ 135 g ha"' recorded the highest net returns (93744 ha *) and B: C ratio (2.43), which was on par with its lower dose (130 g ha"'). Penoxsulam + cyhalofop butyl @ 135 g ha"' was more effective in reducing the total density of weeds. With regard to the control of sedges and BLW, penoxsulam + cyhalofop butyl was more effective, but with respect to grasses, both the herbicide mixtures were more or less similar in effectiveness. Penoxsulam + cyhalofop butyl @ 135 and 136 registered higher weed control efficiency and lower weed index than other treatments. Uncontrolled weed growth caused a yield reduction of 50.38 per cent. Herbicide treatments significantly reduced the nutrient uptake by weeds and enhanced the nutrient uptake by crop over weedy check. The higher doses of penoxsulam + cyhalofop butyl (125,130 and 135 g ha"') and bispyribac sodium + metamifop (70, 80 and 90 g ha*') were more effective in maintaining higher nutrient content in soil. Dynamics of soil microbial population, earthworm population, soil enzyme status and organic carbon content of soil consequent to the application of herbicide mixtures revealed that, both penoxsulam + cyhalofop butyl and bispyribac sodium + metamifop at their tested doses did not have any inhibitory effect. Results of screening trial revealed that maize was the most sensitive indicator plant for both the herbicide mixtures. Dry weight and fresh weight of maize shoot were adjudged as the best parameters for assessing the residual effect of bispyribac sodium + metamifop and penoxsulam + c>^Iofop butyl in soil respectively. Pot culture bioassay studies revealed that the tested herbicide mixtures and their doses did not have any residual effect. In vitro sensitivity studies of bispyribac sodium + metamifop and penoxsulam + cyhalofop butyl to Rhizoctonia solani pointed out that both the herbicide mixtures inhibit the growth of Rhizoctonia solani. Studies on the in vitro effect of herbicide mixtures to Trichoderma viride indicated that bispyribac sodium + metamifop was safe to the fungus, whereas penoxsulam + cyhalofop butyl was moderately toxic. Compatibility studies revealed that both the herbicide mixtures were highly compatible with Psetidomonas fluorescenSy Azospirillum lipoferum and Azotobacter chroococciim. Weed seed bank assay results indicated the effectiveness of the higher doses of penoxsulam + cylialofop butyl (135, 130 and 125 g ha'') in depleting the seed bank compared to other treatments. The present study revealed the superiority of heibicide mixtures over individual herbicides in the management of weeds in wet seeded rice. Application of penoxsulam + cyhalofop butyl @ 135 or 130 g ha*', at 15 DAS could be adjudged as the most economic and ecofriendly weed management practice for wet seeded rice as evidenced by high weed control efficiency, net returns and B: C ratio; environmental safety, high inhibitory effect to Rhizoctonia solani and good compatibility with bio control agents and bio fertilizer organisms.ThesisItem Open Access Integrated weed management under system of rice intensification (SRI)(Department of Agronomy, College of Horticulture, Vellanikkara, 2011) Musthafa, Kunnathadi; KAU; Abraham, C TAn experiment was conducted to assess the performance of system of rice intensification (SRI) vis-à-vis conventional system with special emphasis on weed problems under SRI and to develop an economic weed management strategy. Aiming at reducing drudgery while using manual cono weeder, it was also envisaged to develop the prototype of a self propelled cono weeder. The field studies laid out in randomized block design with 16 treatments in three replications were conducted at RARS, Pattambi in Palakkad district and in farmers’ fields at Alappad Kole in Thrissur district, during the Mundakan seasons of 2007 and 2008. The soil at Pattambi was lateritic sandy clay loam with pH 4.96 and medium fertility, and that at Alappad Kole was clayey in texture with pH 5.0 and of high fertility. At both locations, the density and dry weight of weeds at 45 and 60 days after transplanting (DAT) were higher in all the SRI treatments especially when weed control was done through repeated cono weeding. At Pattambi, weed density and weed dry weight were the lowest in conventional system with post emergence herbicides, which recorded lower nutrient removal by the weeds and the lowest weed index and also higher gross return, net return and B:C ratio. The weed density and dry weight in the SRI fields were the lowest with pre emergence herbicide followed by hand weeding at 30 DAT, but the use of post emergence herbicides showed higher B:C ratio. At Alappad Kole, the weed density and dry weight, both at 45 and 60 DAT, were the lowest in conventional system with cono weeding at 10 DAT followed by post emergence herbicides. Cono weeding followed by hand weeding, pre emergence herbicides followed by hand weeding as well as the use of post emergence herbicides were also equally effective in controlling the weeds 233 in the conventional system, and were on par in the B:C ratios. In the SRI plots cono weeding at 10 DAT followed by post emergence herbicides recorded the lowest weed density and dry weight, however, use of post emergence herbicides recorded the highest net return and B:C ratio among the SRI treatments. Thus, considering the acute shortage and high wages for the labourers in Kerala, weed management through post emergence herbicides will be the preferable option for the farmers in both conventional and SRI systems of rice cultivation. Comparison between the two systems of rice cultivation at two different rice growing ecosystems showed that SRI improved the performance of individual hills through higher number of tillers hill-1, root length and root dry weight hill-1. On the other hand, the tiller number, dry matter production, root dry weight and productive tillers per unit area were higher in the conventional treatments. Owing to higher number of productive tillers per unit area the grain yield of conventional treatments was significantly higher than that of the typical SRI. At Pattambi, conventional system with post emergence herbicides recorded higher number of productive tillers m-2, panicle length, number of filled grains panicle-1, 1000 grain weight and grain yield (2877 kg ha-1), which was 33 per cent higher than the grain yield in the typical SRI. This treatment also recorded significantly higher B:C ratio (1.27) compared to that (0.91) of the typical SRI. However, the highest straw yield (2510 kg ha-1) at Pattambi was observed in ‘SRI with cono weeding at 10 DAT followed by post emergence herbicides’, which was on par with the typical SRI treatment. At Alappad Kole, higher number of productive tillers m-2, more filled grain percentage, highest 1000 grain weight, highest grain yield (6073 kg ha-1) and highest straw yield (5109 kg ha-1) were recorded by conventional system with cono weeding followed by hand weeding, which showed an increase of 93 per 234 cent in grain yield, with an additional yield of 2934 kg ha-1, and 109 per cent in straw yield over the typical SRI and recorded the highest gross return, net return and B:C ratio (2.46). Thus, the study showed the superiority of conventional system of rice cultivation at a spacing of 20 cm x 10 cm over the SRI system at a spacing of 30 cm x 30 cm at both the two different rice growing ecosystems studied viz., the sandy loam soils at Pattambi and the clayey soils at Alappad Kole. Prototype of the self propelled cono weeder was developed and field tested. It works satisfactorily in a single forward pass, and covers an area of 0.1 ha h-1. The field study showed that the self propelled cono weeder is effective for inter row weeding in rice, however, further refinement is needed to improve its weeding efficiency.ThesisItem Open Access Input optimization for medicinal rice (Oryza sativa L.) cv. Njavara.(Department of Agronomy, College of Agriculture, Vellayani, 2011) Sriramkumar, N; KAU; Geethakumari, V LThe investigation entitled “Input optimization for medicinal rice (Oryza sativa L.) cv. Njavara” was conducted at Instructional Farm, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala, during the summer seasons of 2007 and 2008 (January to April) to standardize an ideal nutrient schedule under two moisture regimes for sustaining Njavara production in lowlands, to investigate the soil physical, chemical and biological properties as influenced by regimes and sources of nutrients and to work out the economics of Njavara cultivation. Both the experiments (submerged and saturated situations) were laid out in randomised block design with ten treatments each and three replications. The treatments comprised four nutrient regimes viz., N1 - 30:15:15, N2 - 30:30:30, N3 - 40:20:20 and N4 - 40:40:40 kg NPK ha-1, two nutrient sources viz., organic nutrient source (S1) and integrated nutrient source (S2) and two controls viz., absolute control (no nutrient was applied) (C1) and POP for local rice variety (C2). Growth components like plant height, leaf number plant-1, leaf area index (LAI), number of tillers m-2, culm strength and flag leaf area, yield and yield attributes like number of productive tillers m-2, panicle length, number of grains panicle-1, number of filled grains panicle-1, 1000 grain weight, harvest index, sterility percentage, dry matter partitioning, paddy grain ratio and grain husk ratio were recorded. Leaf chlorophyll content was also estimated. Uptake of nutrients (N, P, K, S, Fe, Mn and Zn) and economics of cultivation were computed. Biochemical components of grains such as total, free and sulphur containing amino acids, phenols, starch, amylose, amylopectin and protein content were estimated. Data on weed biomass, weed flora and crop duration were also recorded. Soil enzymes (urease, phosphatase and dehydrogenase), soil microbial population (bacteria, fungi and actinomycetes population) and soil fertility status (available nitrogen, phosphorus, potassium, sulphur, iron, zinc and manganese) were assessed before and after the crop. Effect of nutrient regimes Effect of nutrient regimes on all growth parameters was significant. Growth parameters like plant height, leaf number plant-1, leaf area index (LAI), number of tillers m-2, culm strength and flag leaf area were significantly higher in N2. N2 recorded leaf chlorophyll content which was significantly higher than N3 and N1 and was on par with N4. All yield attributes except 1000 grain weight were significantly influenced by nutrient regimes resulting in significant variation in the crop yield (grain and straw). Maximum grain yield was recorded in N2 (30:30:30 kg NPK ha-1) (2.78 and 2.66 t ha-1) which was on par with N4 (40:40:40 kg NPK ha-1) (2.67 and 2.58 t ha-1) and was significantly superior to N1 and N3 under submerged and saturated situations respectively. Duration of the crop did not show significant variation due to nutrient regimes. Total amino acid and protein content of grain were significantly influenced by nutrient regimes and were maximum in N2. Nutrient regimes significantly influenced N, P and K uptake. Uptake of N, P and K in N2 was significantly higher than that in the other three nutrient regimes. Nutrient regimes did not significantly influence uptake of S, Fe, Mn and Zn. Results of the study also revealed that Echinochloa colona (L.) Link, Isachne miliacea Roth ex Roem. et Schult; Cyperus iria L., Cyperus difformis L. Fimbristylis miliacea (L.) Vahl.; Marsilea quadrifoliata Linn., Monochoria vaginalis (Burm. f.) Presl. ex Kunth and Ludwigia perennis L were the most predominant weed species in the experimental field under both situations. Weed biomass at 20 and 40 DAS were not significantly influenced by nutrient regimes during both the years of experimentation. Nutrient regimes showed significant influence on available nitrogen, phosphorus and potassium status of the soil after the investigation. Available sulphur, iron, zinc and manganese status of the soil after the experiment revealed non-significant effect of nutrient regimes in both the years of study. Among the soil enzymes, urease activity was influenced significantly by the nutrient regimes and it was in the order N4 > N3 > N2 > N1. Bacterial population was influenced significantly by the nutrient regimes and it was in the order N4 > N3 > N2 > N1. Effect of nutrient sources Nutrient sources had significant influence on all the growth characters, yield attributing characters like number of grains panicle-1, number of filled grains panicle-1, harvest index as well as crop yield (grain and straw). Highest number of grains panicle-1, filled grains panicle-1 and crop yield (grain and straw) were realized in integrated nutrient source and they were significantly higher than that realized from organic source. Duration of crop did not differ significantly between the nutrient sources. Integrated nutrient source registered significantly higher nitrate reductase activity and root weight compared to organic source. Biochemical components such as total, free and sulphur containing amino acids, phenols, starch, amylose, amylopectin and protein content of grain did not differ significantly between nutrient sources. Highest uptake of N, P and K was in integrated nutrient source. Sources of nutrients did not influence uptake of S, Fe, Mn and Zn during both the years of experimentation. Weed biomass under different nutrient sources at both 20 DAS and 40 DAS differed significantly from one another. Weed biomass during both stages and both the years of experimentation was more in organic source compared to integrated nutrient source. Highest weed biomass was recorded in absolute control at both stages during both the years. Available nitrogen, available phosphorus and available potassium status of the soil after the experiment in the plots receiving integrated nutrient source and organic nutrient source differed significantly from each other. Available N, P and K status of the soil were higher in integrated nutrient source. Organic carbon, available sulphur, iron, zinc and manganese status of the soil after the experiment were not significantly influenced by nutrient sources. Urease activity and bacterial population in the soil were influenced significantly by nutrient sources. Highest activity of urease and bacterial population in the soil were recorded in organic source compared to integrated nutrient source. Phosphatase and dehydrogenase activity as well as fungal and actinomycetes population in the soil were not influenced by nutrient sources. Economics of crop production Gross income, net income and BCR were highest in N2S2. Application of FYM @ 5 t ha-1 along with 30:30:30 kg NPK ha-1 (50 % N as organic + 50 % N as chemical fertilizer) (N2S2) recorded a net profit of Rs 57,586 ha-1 and Rs 53,546 ha-1 under submerged and saturated situations respectively. The lowest gross income, net income and BCR were recorded in N1S1 (FYM @ 5 t ha-1 along with 30:15:15 kg NPK ha-1 as organic source). The ideal nutrient schedule for sustaining Njavara production in lowlands under both submerged and saturated situations is N2S2 - FYM @ 5 t ha-1 + 30:30:30 kg NPK ha-1 (50 % N as organic + 50 % N as chemical fertilizer). This nutrient system realised highest grain yield, straw yield and net income.ThesisItem Open Access Floristic diversity, autecology and competitive behaviour of weed flora in wetland rice ecosystem(Department of Agronomy, College of Agriculture, Vellayani, 2010) Sajith Babu, D; KAU; Sansamma GeorgeFloristic diversity, autecology and competitive behaviour of weed flora in the wetland rice ecosystem were studied by conducting a field survey and two field experiments. The field survey was conducted during the first and second crop seasons of 2003 in the rice fields of 30 panchayaths in Thiruvananthapuram district having more than 50 hectares of net sown area, covering all the four thaluks of the district. Weed flora was surveyed from both cultivated and fallow fields. The design adopted for conducting the floristic survey was Stratified Multistage Random Sampling and the methodology was Census Quadrate Method. The field experiments were conducted during the first crop seasons of 2003 and 2004 at College of Agriculture, Vellayani. The design adopted was Strip plot. The treatments included four levels of nutrient management and three levels of crop spacing and the number of replications was five. Part III of the investigation was an autecological study wherein the growth and development pattern of two of the major weed flora observed in the experimental area was studied by keeping an area of 1.2 X 4.2 m2 on the same side of all the plots in Part II. Perusal of the results of the field survey indicated that substantial diversity of weed flora existed in the wetland rice ecosystem in Thiruvananthapuram district of Kerala. In the cultivated rice fields, there were 46 weed specii during the first crop season and 49 species during the second crop season. In the rice fallows during the first crop season there were 43 specii while during the second crop season there were 54 specii. In the cultivated fields during both seasons, the most prominent species among the different classes of weeds (grasses, sedges and broad leaved weeds) were Isachne miliacea Roth ex Roem et Schult, Cyperus iria L. and Monochoria vaginalis (Burm.f.) Presl. Ex Kunth respectively. Isachne miliacea Roth ex Roem et Schult was the dominant grass weed in the fallows as well. However the dominant sedge weed in the fallows was Cyperus distans L.f. during the first crop season while it was Fimbristylis miliacea. during the second crop season. Monochoria vaginalis (Burm.f.) Presl. Ex Kunth and Ludwigia perennis topped the list of broad leaved weeds in the rice fallows during first and second crop seasons respectively. Results of the field experiment showed that weed growth in the rice field was influenced significantly by the sources and levels of nutrients as well as by crop spacing. During both the years at 20 and 40 DAT the weed density and dry weight were the lowest when the rice crop was treated with NPK @ 90:45:45 kg ha-1 applied with 25 per cent N as organic (N2) while at 60 DAT enhanced nutrient level (NPK @ 112.5:56:25:56.25 kg ha-1) applied with 25 per cent N as organic (N4) recorded the lowest value. During both the years, at all growth stages the weed density and dry weight were the lowest under the closer spacing of 15 X 15 cm (P1) The grain and straw yield were maximum under NPK @ 112.5:56:25:56.25 kg ha-1 applied with 25 per cent N as organic in combination with widest spacing (n4p3). Dead heart occurrence was minimum under the widest crop spacing The net income and Benefit : Cost ratio were the highest when rice crop was treated with 125 per cent of the recommended NPK with 25 per cent organic substitution in combination with widest spacing (n4p3) Autecological studies showed that the growth and development of Isachne miliacea Roth ex Roem et Schult. was significantly influenced by the management practices for the associated rice crop. The higher dose of NPK applied as chemical fertilizers only (N3) along with widest spacing (P3) stimulated all the vegetative parameters (shoot / root length and plant spread) of the weed. During both the years plants growing in rice fields treated with recommended dose of NPK with 25 per cent organic substitution (N2) and rice crop planted at wider spacing (P3) recorded delayed flowering but produced more seeds per panicle The root and shoot length of Cyperus iria L growing in rice fields treated with 100 per cent recommended NPK as chemical fertilizers (N1) with minimum spacing (P1) recorded the maximum value during the both years. Delayed flowering of the sedge was noticed under N2. The number of seeds produced per plant was significantly high under N4 and P3. The general trend was that addition of organic manures in rice delayed flowering but increased seed production in the associated sedge weed From the studies it may be concluded that by altering nutrient management and adjusting the plant population, the competitive ability and productivity of rice crop can be improved substantially. Though, closer spacing of 15 X 15 cm significantly reduced the density and dry weight of weeds, the wider spacing of 20 X 20 cm in conjunction with enhanced fertilizer dose of 112.5:56:25:56.25 kg NPK ha-1 applied with 25 per cent N as organic manures significantly enhanced the rice grain and straw yield. The treatment also resulted in significant enhancement in net income and B:C ratio in medium duration variety Aiswarya in first crop season.ThesisItem Open Access Geospatial analysis and soil nutrient dynamics of Rubber plantations in relation to growing environment(Department of Agronomy, College of Agriculture, Vellayani, 2013) Shankar, Meti; KAU; Meera Bai, MPara rubber (Hevea brasiliensis Muell. Arg.) grown in varied soil and climate condition in traditional rubber growing regions of India. Variability in soil and climate influences performance of rubber and for this site specific management helps to increase input use efficiency and enhance crop production. Geospatial analysis under GIS environment helps to integrate soil and climate variability and identify the limitations and potential areas for enhancing the rubber production without horizontal expansion of rubber cultivation. Hence the present study was undertaken with the following objectives 1. To develop soil, climate, rubber area and rubber yield database to understand the variability of rubber productivity. 2. To prepare rubber distribution map and delineate productivity constraint area map of rubber in Kanaykumari and Kasargod. 3. To study the soil nutrient dynamics and phenology of rubber in different growing environments. Objectives of the present study were addressed by conducting two experiments. Under experiment I, two districts - Kanyakumari and Kasargod - were selected and identified 60 holdings in each district distributed over different Soil Management Unit (SMU). Recorded girth and Tapping Panel Dryness (TPD) observations and collected surface soil sample (0-30 cm) from identified holdings and analyzed for major nutrient and physical parameters. Using GPS reading developed holdings soil database and generated soil nutrient map and brought under GIS platform to identify the soil constraint areas. Water balance approach was followed to delineate climate constraint area in each district. Rubber distribution map was developed for each district using satellite image and overlayed with soil and climate constraint map to know the extent of rubber area under soil and climate constraint. Under experiment II, Kottayam district was selected for studying the soil nutrient dynamics of mature rubber plantation in relation to phenology and growing environment. Identified two holdings in each of three elevation classes; 0-100, 100-300 and > 300m. Collected surface soil samples and recorded rubber phenology at monthly interval. Soil samples were analyzed for pH, OC, nitrogen, exchangeable Al. Recorded annual litter fall and mineralization potential. Rainfall and temperature were recorded at one location in each of the three elevation classes. Mean soil OC, available P, K, Ca and Mg varied significantly between Kanyakumari and Kasargod district. Soil available P and K were significantly higher in Kanyakumari where as soil OC, available Ca and Mg were significantly higher in Kasargod. Within the district, soil OC, available P, K and Ca showed high spatial variability. Rainfall distribution was distinctly different in two districts. Well distributed rainfall with less dry period and long growing period was seen in Kanyakumari. In Kasargod rainfall was concentrated between June- September, as a result dry period was longer and growing period was shorter. During December to March period moisture stress level was more in Kasargod compared to Kanyakumari. Performance of rubber in terms of girth and rubber yield was better in Kanyakumari compared to Kasargod. Average per tree rubber yield (g/tree/tap) during dry period and annual yield per unit area (kg/ha/year) was significantly higher in Kanyakumari compared to Kasargod. Incidence of Tapping Panel Dryness (TPD) was significantly more in Kasargod compared to Kanyakumari. Leaf nutrient content showed balance level of N, P and K and deficiency of Ca and excess of Mg in Kanyakumari. In Kasargod leaf K was balanced, whereas Mg was in excess and deficiency of nutrient was in the order of P>Ca>N. Rubber showed a distinct signature compared to other vegetation. Satellite based rubber area was estimated with good accuracy and rubber area was comparable with ground statistics. Ovrelay analysis indicated that considerable extent of rubber area in Kanyakumari distributed over area without moisture stress but same was not seen in Kasargod. In general all rubber area in Kasargod comes under poor to very poor moisture adequacy during summer compared to only 48 per cent rubber area in Kanyakumari experienced poor moisture adequacy during summer. In Kanyakumari 28 per cent of rubber area distributed over low available P, medium in OC, K and high Ca and Mg followed by 18 per cent over area medium in OC, available P ,K and high in available Ca and Mg. In Kasargod, 61 per cent rubber area distributed over low available P, medium K and high in OC, available Ca and Mg. In Kanyakumari district soil cation (Ca and Mg), and soil OC factors showed significant relation with rubber growth and yield. In Kasargod only topography factor showed significant relation with rubber yield. In Experiment II rubber showed distinct phenological difference over elevation with rubber in high elevation showing early wintering compared to low elevation. Number of new leaf flushes was more in low elevation compared to high elevation. Annual litter addition did not vary along elevation; however rate of litter decomposition was slow at high elevation compared to low elevation. In general maximum and minimum temperature was low at high elevation where as no marked difference in quantity and distribution of rainfall was seen along elevation. Soil OC was significantly higher at high elevation compared to low elevation, but mineralization of soil OC and total N was significantly low at high elevation compared to low elevation. Peak soil total N was observed for short period at high elevation indicating the short growing period compared to low elevation. Wide gap between potential and actual NO3 and NH4 nitrogen at low elevation compared to high elevation indicated the loss at low elevation through leaching and denitrification. At low and medium elevation, rubber active growth stage coincided with peak N mineralization whereas peak rubber yield period coincided with low N mineralization. But at high elevation both active growth and peak yield coincided with peak N mineralization. At high elevation, climate factor showed significant positive relation with next month rubber yield indicating the climate limitation at high elevation. At low elevation, climate factor and soil reaction factor did not show significant relation with next month rubber yield indicating mineralization and climate are not limiting at low elevation.ThesisItem Open Access Fodder production technology under light and moisture stress situations(Department of Agronomy, College of Agriculture, Vellayani, 2014) Anita, M R; KAU; Lakshmi, SThe field experiment of the project entitled “Fodder production technology under light and moisture stress situations” was undertaken at the Instructional Farm, College of Agriculture, Vellayani, Thiruvananthapuram, during January 2012 to March 2014. The main objectives of the project were to identify drought tolerant varieties of fodder cowpea and their performance evaluation in varying proportions of grass legume mixtures under open and shaded conditions. The project comprised of two investigations. The Investigation-I entitled “Drought tolerance studies in fodder cowpea under open and shaded situations” was conducted during the summer season (January to March) of 2012. The Investigation-II on “Evaluation of grass-fodder cowpea mixtures under open and shaded situations” was conducted for two years from March 2012 to 2013 and from March 2013 to March 2014. In Investigation-I, five fodder cowpea varieties (V1-UPC-618, V2-UPC-622, V3-Bundel Lobia-1, V4-COFC-8 and V5-CO-5) were evaluated for their drought tolerance under four soil moisture stress levels (M1 - pre sowing irrigation + life saving irrigation; M2 - pre sowing irrigation + irrigation at IW/CPE ratio of 0.4; M3 - pre sowing irrigation + irrigation at IW/CPE ratio of 0.6 and M4 - pre sowing irrigation + irrigation at IW/CPE ratio of 0.8). The investigation was conducted as two separate experiments one in open and other in shade. Both the experiments were laid out in split plot design with four replication. Based on the results of this investigation, two drought tolerant fodder cowpea varieties were selected each under open and shaded situation, for conducting Investigation-II. The fodder cowpea varieties COFC-8 (V4) and UPC-622 (V2) which recorded significantly higher green fodder yield (24.21 t ha-1 & 21.36 t ha-1, respectively), crude protein yield (0.79 t ha-1 & 0.66 t ha-1, respectively) and net returns of Rs 44880 ha-1 and Rs 36011 ha-1, respectively were selected for open condition. The fodder cowpea varieties COFC-8 (V4) and UPC-618 (V1) which recorded significantly higher green fodder yield (11.50 t ha-1 and 11.00 t ha-1 respectively), crude protein yield of 0.41 t ha-1 & 0.34 t ha-1 respectively and net returns of Rs 13498 ha-1 and Rs 11873 ha-1 respectively were selected for shaded situation. Investigation-II on the evaluation of grass-fodder cowpea mixtures were also conducted as two separate experiments, one in open and the other in shade. The experiments were laid out in RBD with three replications, comprising of two grasses [G1-Hybrid napier (Suguna), G2-Guinea grass (Harithasree), two best fodder cowpea varieties from the first investigation (V1-COFC-8(open and shade), V2-UPC-622 (open), UPC-618 (shade) and three grass legume row ratios (R1-1:1, R2 -1:2, R3 -1:3). The results indicated the superiority of the grass legume mixture of hybrid napier cv. Suguna and with both the fodder cowpea varieties in the grass legume row ratio of 1:2 with respect to green fodder yield, crude protein yield and net returns. Based on the results, it can be concluded that hybrid napier cv. Suguna intercropped with fodder cowpea varieties COFC-8 and UPC-622 in open condition and with COFC-8 and UPC-618 in partial shade (30 per cent) in the row ratio of 1:2 is the best for obtaining maximum yield, quality and net returns.ThesisItem Open Access Productivity of rice in laterite soil in relation to nitrogen-sulphur interaction(Department of Agronomy, College of Horticulture, Vellanikkara, 2010) Rathish, S T; KAU; John, P SThe research programme entitled “Productivity of rice in laterite soil in relation to nitrogen - sulphur interaction” was conducted mainly to study the nitrogen and sulphur availability and their interaction as influenced by organic manure sources, particularly straw incorporation in rice cultivation. The “Mineralization pattern of nitrogen and sulphur” was studied in pot culture experiment at College of Horticulture, Vellanikkara during the rabi season (Mundakan) Sep 2007 – Feb 08. “Response of rice to nitrogen and sulphur mineralization from organic matter with varying C:N ratios” was studied in farmers field, Pudhunagaram, Palakkad during the rabi seasons (Mundakan) Sep 2006 – Feb 07 and Sep 2007 – Feb 08. The mineralization of nitrogen and sulphur from the organic materials was influenced by time after application. The straw incorporated treatment released noticeably lower amount of nitrogen and sulphur in the initial stages than no manure application. The early growth characters of rice such as plant height, tiller production and dry matter production were significantly lower in straw incorporated treatments. Straw incorporation followed by application of nitrogen and sulphur or both, did not make any significant change in growth pattern probably due to inadequacy or improper timing. Increasing levels of nitrogen and sulphur positively influenced the vegetative growth and yield. The interactive effects of manures × N/S were significant for several characters. Beneficial effects of higher nitrogen and sulphur with straw incorporation were less evident in the early stages and was pronounced in the later stages. Nitrogen application with cow dung showed better performance during vegetative stage, but declined towards harvest. The tiller decline was lower in the straw incorporated treatments than either cow dung applied or unmanured treatments. Yield attributing characters were significantly influenced by incorporation of straw and cow dung along with nitrogen and sulphur. Grain yield increased from 3432 kg ha-1 in the absolute control to 7085 kg in the straw + N90 + S30 treatment in first year and from 3657 kg to 7116 kg in the cow dung + N90 + S30 treatment in second year. The interaction effects of manures × N/S were more pronounced than N × S. Combined application of organic manures and nitrogen noticeably increased protein nitrogen and protein sulphur content. Most of the plant nutrients were positively correlated with each other and positively correlated with grain yield. N × Fe and S × Fe have showed significant negative correlation. Agronomic efficiency of nitrogen or sulphur (kg grain/kg nutrient applied) was not influenced by organic manure application. Apparent recovery of nitrogen as well as physiological efficiency of nitrogen was the highest in combination of organic manures with 45 kg nitrogen and 30 kg sulphur. The utilization or physiological efficiency was also highest (kg grain/kg nutrient taken up) for the above combination. Straw incorporation resulted in long term maintenance of soil fertility as evidenced by higher mineral nitrogen and sulphur in soil upto a period of 110 days. In sulphur deficient soil, sulphur fertilizers could increase the rice yield and the use efficiency of nitrogen. The finding of the study points to beneficial effects of rice straw left in the field after harvesting using combine harvesters. However 37 to 52 kg ha-1 less mineral N was observed in the straw incorporated soil during the 30 days after incorporation and 20 days after rice planting compared to cow dung, both incorporated at 10 t ha-1. If this deficit could be compensated by N added at appropriate time, the straw will be a better and cheaper source of organic matter than cow dung.ThesisItem Open Access Productivity analysis of aerobic rice (Oryza sativa L.) and its impact on green house gas emission(Department of Agronomy, College of Agriculture, Vellayani, 2014) Jinsy, V S; KAU; Shalini Pillai, PThe experiment entitled "Productivity analysis of aerobic rice (Oryza sativa L.) and its impact on green house gas emission" was undertaken at the Cropping Systems Research Centre, Karamana, Thiruvananthapuram, during January to May, 2011 and 2012. The main objectives of the-study were to standardise the production techniques for aerobic rice, to study its water productivity as against flooded rice and to assess the variation in green house gas emission under aerobic and flooded situations. The entire study comprised two field experiments. The first experiment (Part - I), entitled "Productivity analysis of aerobic rice against conventional rice" was conducted during the summer season (January to May) of 2010- '11 and 2011-' 12. The second experiment (Part - 11) on "Agro techniques for aerobic rice" was conducted during the summer season of 2011-' 12, to standardize the agro techniques for the aerobic rice variety from Part - I. Four rice varieties [VI: Aiswarya, V2: Uma, V3: MAS 946 - 1, V4: PMK (R) 3] were evaluated for their adaptabilityand performance both under flooded (W I) and aerobic (W2) conditions, asPart ~ 1o,'Ihe experiment was laid out in RBD with five replications (two separate layouts '(o~'flooded rice and aerobic rice). The agro techniques study for aerobic rice, comprised two spacings (S I: 20 cm x 10 cm, S2: 15 cm x 10 cm), two nutrient levels (NI: 90:45:45 kg NPK ha", N2: 90:45:67.5 kg NPK ha") and two methods of fertiliser application (AI: soil application, A2: soil application + foliar application of K), laid out in RBD, replicated thrice. The results of the study are as follows. The variety, MAS 946 - 1 (V3) proved significant with respect to growth and physiological parameters. The grain yield was maximum for MAS 946 - 1 (3.13 t ha-I under flooded, 2.85 t ha" under aerobic) accounting for about 10 per cent increase over the next best varieties, Aiswarya and Uma. Flooded rice, in general yielded more than aerobic rice. However, the results were significant only during the second year of experimentation, where the yield variation between flooded rice and aerobic rice was 15.63 per cent. The average water productivity of aerobic rice (0.75 kg m-3) was 70.4 per cent greater than that of flooded rice (0.44 kg m'), MAS 946 - 1 recorded the maximum water productivity of 0.48 kg m-3 and 0.80 kg m", under flooded and aerobic cultures respectively. The superiority of aerobic rice in mitigating green house gas (GHG) emission from rice fields was revealed from the significantly lower efflux of methane under aerobic (3.03 mg m-2 hr-I) compared to flooded rice (6.16 mg m-2 hr'). Though methane emission did not vary significantly among the varieties under flooded culture, MAS 946 - 1 recorded significantly the least methane efflux (14.08 mg m-2 hr') under aerobic system. The benefit cost ratio (BCR) of flooded rice was 1.39 and that of aerobic rice was 1.13 over the two years. MAS 946 - 1 recorded the highest BCR (1.40) and was on a par with Uma (1.33) during the second year. MAS 946 - 1 was selected as the best variety for Part - II of the study based on its growth, physiology, yield and methane emission. , The results of Part - II of the study revealed that wider spacing (S I: 20 cm x 10 cm), higher nutrient level (N2: 90:45:67.5 kg NPK ha-I) and combined method of nutrient application (A2: soil application + foliar application of K) significantly increased productive tiller count (545.32 m"), grain weight per panicle (2.83 g) and grain yield (3.28 t ha-I) ofMAS 946 - 1. Aerobic nee culture is a prormsmg technology under water scarce situations. Compared to flooded rice, the water productivity of aerobic rice was 70.4 per cent higher, methane emission was 50.8 per cent lower with a slight yield reduction of 15.63 per cent. Among the four varieties tested, MAS 946 - 1, the first aerobic rice variety released from VAS, Bengaluru and Aiswarya and Uma, KAV rice varieties, proved superior for aerobic conditions under Kerala situations. It can be concluded that the performance of the variety, Uma is as good as MAS 946 - 1 for cultivation under aerobic condition in the lowlands of Kerala. A recommended spacing of 20 cm x 10 cm with a nutrient schedule of 90 kg N, 45 kg P20S and 60 kg K20 as soil application along with 7.5 kg K20 per hectare as foliar application was found as the best agronomic package for rice under aerobic situation.ThesisItem Open Access Biology and management of weedy rice (Oryza sativa f. spontanea)(College of Horticulture, Vellanikkara, 2015) Nimmy, Jose; KAU; Abraham, C TWeedy rice is the complex of morphotypes of Oryza species widely distributed in the commercial rice fields in more than 50 countries of Asia, Africa and Latin America, especially in areas where farmers have switched to direct seeding due to labour shortage and high cost. Taxonomically, Indian weedy rice is identified as Oryza sativa f. spontanea which belongs to the indica group. Invasion and spread of weedy rice in the cultivated rice fields have forced the farming community to abandon rice farming, leading to socio economic and ecological impacts in the rice bowls of Kerala. Management of weedy rice infestation is complex mainly because of its morphological similarities to cultivated rice and lack of herbicides for selective control of weedy rice in cropped fields. Hence, the present research programme was undertaken to estimate the extent of infestation of weedy rice in rice bowls of Kerala, to study the biology and ecology, and to chalk out strategies for integrated management of weedy rice. Survey conducted in the major rice belts of Kerala, viz., Kole, Kuttanad and Palakkad, revealed that more than 65 percent of the area has low to severe weedy rice infestation. In the major rice bowls of Kerala there was severe, moderate and low infestation of weedy rice in 26, 36 and 49 panchayaths, respectively,. The extent of infestation was more in Kuttanad in Alleppey, Kottayam and Pathanamthitta districts and Kole lands of Thrissur district. In Palakkad region, the infestation was more in panchayaths of Alathoor and Nemmara blocks. Survey revealed the presence of weedy rice variants with respect to morphological characters like number of tillers per plant, height of plant, length of ligule, panicle characters, colour of grains, and length and colour of awns. Studies conducted on the germination of weedy rice seeds revealed that there was no significant difference between the germination of weedy rice in the presence and absence of rice seeds in the soil. It was noticed that seed germination was higher at the surface and 2 cm depth of the soil and there was drastic reduction in the germination from deeper layers of 4-8 cm. Investigations on dormancy revealed that hull induced dormancy in weedy rice could be broken by exposing seeds to 20ºC for 48 hours, treating with 0.6% nitric acid for six hours, rupturing seed coat, or maintaining electrical conductivity of 5 dS m-1 for six hours in the growing media. Scanning electron microscope studies confirmed that lesser overlapping of lemma and palea contributed to quicker germination of half mature straw coloured weedy rice grains whereas, slow germination in black coloured mature seeds is due to the clear overlapping of lemma and palea. Presence of more number of stomata both on adaxial and abaxial surface, silica deposits and hairy out-growths on leaf, and high root volume in weedy rice contributed to its early vigour, growth and competitiveness. Management options found effective for the control of weedy rice in direct seeded puddled rice include (1) pre sowing surface application of oxyfluorfen @ 0.2 kg ha-1 three days before sowing in thin film of water (2) selective drying of weedy rice panicles with nonselective broadspectrum herbicides glufosinate ammonium or glyphosate @ 15 % - 20 % concentration at 60-65 DAS using specially designed wick applicator/wiper device (3) stale seed bed technique with (wet tillage in between two stales under heavy infestation) application of broad spectrum herbicide followed by flooding for exhausting soil seed bank (4) straw burning after harvest of infested fields followed by zero tillage in succeeding crop and (5) soil solarisation for more than 30 days during summer months using 100 micron transparent polythene sheets. A novel hand held wiper device was developed for the direct contact application of nonselective broadspectrum herbicides for selective drying of weedy rice panicles at 60-65 days after sowing, when rice and weedy rice plants maintain height difference of 20 cm. The device was filed for Indian Patent at Patent Office, Chennai (Application No. 1763/CHE/2014 dated 01.04.2014). Effective and economical management of weedy rice is possible by the integrated use of different options for management depending on the intensity of infestation. Various weedy rice management options standardized in the present study were demonstrated in farmers’ fields in a participatory mode. The demonstrations have given good results and many farmers have already adopted the package for the integrated management of weedy rice.