Browsing by Author "Johnkutty, I"

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Changes in nutrient availability and uptake in transplanted rice under shallow and deep submergence
(Kerala Agricultural University, 1994) Anilakumar, K; Johnkutty, I; Menon, P K G; Sivakumar, C
Field experiments were conducted to study the changes in electro-chemical properties and nutrient availability in soil and soil solution in transplanted rice during kharif and rabi season under deep (20 cm) and shallow (10 cm) submergence, respectively. The pH of soil and soil solution increased up to 30 days after transplanting (DAT), then decreased and again increased slightly at 50% flowering stage. Redox potential of soil decreased rapidly during kharif season while during rabi season, the values increased up to 30 DAT and thereafter stable values were recorded. Concentration of nutrients in soil and soil solution decreased with crop growth except in the case of soil P during kharif season and soil solution Ca during both the seasons. Availabilit y of nutrients in soil and soil solution except for P and Mg was more during kharif season, while the nutrient uptake was higher during rabi season. Application of P and K during rabi season was effective in areas where P and K were applied once in two seasons. Significant difference in yield was obtained only during rabi season.
Comparison between transplanting and direct-seeding methods for crop establishment in rice
(Kerala Agricultural University, Vellanikara, 2002) Johnkutty, I; Gracy, Mathew; Jose, Mathew
Effect of forms of urea on the yield of rice
(Kerala Agricultural University, 1993) Johnkutty, I; Mathew, P B; Kumar, V R
Field trials conducted in the farmers' fields at eight different farming situations for four seasons proved that large granule urea (LGU) is an economic and efficient source of N for low land rice, especially in areas with heavy rnonsoonic rains . LGU having no extra cost either in production or application over the ordinary prilled urea (PU) offers greater potential for efficient N nutrition in rice. The results also reveal that the entire quantity of LGU can be broadcast as a single basal dose.
Effect of minimum tillage system on productivity of rice
(Kerala Agricultural University, Vellanikara, 2003) Gracy, Mathew; Johnkutty, I
Effect of NPK fertilizers on the availability of micronutrients in submerged laterite rice soils of Kerala
(Kerala Agricultural University, 1992) Anilakumar, K; Hassan, M A; Johnkutty, I; Menon, P K G
Effect of organic sources on nitrogen availability in flooded rice soils
(Kerala Agricultural University, 1989) Anilakumar, K; Johnkutty, I; Hassan, M A; Menon, P K G
A study was conducted during the rabi season of 1982 to study the changes of N in the lateritic rice soil as well as in the rice plant as influenced by flooding in the presence of various organic and inorganic sources of nitrogen. The results revealed that daincha treated plots were able to liberate more nitrogen in the soil as well as in the solution than farm yard manure or azolla treated or urea alone treated plots. In general the NH4-N content in the soil showed a progressive decrease from tillering to harvest (11.13 - 1.99 ppm). The chemical kinetics of NOj-N, hydrolysable-N, non-hydrolysable N, organic carbon and total N were not influenced by the various treatments. Urea applied alone or in combination with daincha was found better for increased N uptake by the rice plant.
Influence of biostimulants on rice productivity
(Kerala Agricultural University, 1995) Johnkutty, I; Palaniappan, S P
Kinetics of silicon in relation to different levels of major nutrients in the lateritic flooded rice soils
(Kerala Agricultural University, 1990) Anilakumar, K; Johnkutty, I; Hassan, M A; Menon, P K G
Kole lands of Kerala
(Kerala Agricultural University, 1993) Johnkutty, I; Venugopal, V K
Long term effect of continuous fertilization by organic and inorganic sources on rice productivity
(Kerala Agricultural University, 1993) Anilakumar, K; Johnkutty, I; Kamalam Joseph
Pooled analysis of grain yield data for25 years (1961 to 1985) generated from a permanent manurial experiment with tall indica rice varieties revealed that during the first crop season (kharif), the treatment receiving combined application of cattle manure and NPK was significantly superior to others. The above treatment was on par with combined application of cattle manure, green leaves and NPK during the second crop season (rabi). The increases in yield by the former treatment over NPK alone were 7.6 and 5.6 per cent respectively during kharif and rabi seasons.
Mineralisation pattern of applied urea in rice soils
(Kerala Agricultural University, 1993) Anilakumar, K; Rajaram, K P; Johnkutty, I; Jose Mathew
A laboratory incubation study was conducted to find out the pattern of transformation and mineralisation of applied urea under submerged condition in the three major rice soils of Kerala. The hydrolysis of urea to ammonium was influenced by the soil reaction and organic matter content. The formation of oxidised N products like nitrate and nitrite was meagre due to lack of adequate oxygen to carry out the process of nitrification. This avoided the chances of N loss through denitrificalion in the waterlogged rice soils.
Natural and predicted time course behaviour of ammonium nitrogen release in lowland rice soils
(Kerala Agricultural University, 2000) Johnkutty, I; Kandasamy, O S; Palaniappan, S P
An experiment was conducted on Typic Haplustall" soil at the Tamil Nadu Agricultural University, Coimbatore to study the effects of green manuring and N timings on soil ammonium-N release pattern under lowland flooded rice soils. The main-plot treatments consisted of three green manures viz., sesbania (Sesbania rostrata), cowpea (Vigna imguiciilnta) and parthenium (Parthenium hysterophoms L.) to supply 54 kg N ha"1 and one non-green-manure treatment. Application of 150 kg N ha"' as urea at varying quantities, at different growth stages of the crop along with one control formed the sub-plot treatments. Incorporation of green manures increased soil ammonium-N content. The effect was more pronounced during the peak period of soil ammonium-N release, which occurred between the second and fourth week after transplanting rice. Application of N fertilizer resulted in an immediate spurt in soil ammonium-N, but it declined within a few days. Due to faster N uptake by the crop, the decline was rapid during late growth stages. Continued splits (150 kg N ha'1 in six equal splits) ensured a steady ammonium-N supply throughout the growth period. Similarly, skipping of basal N and application of 150 kg N in three equal splits starting from early tillering stage onwards also adequately met the crop N demand for high yield. Mathematical models were developed on the ammonium-N release pattern from green manures and they predicted similar ammonium-N release pattern as observed in the experiments.
Relationship among leaf nitrogen content, SPAD and LCC values in rice
(Kerala Agricultural University, 2000) Johnkutty, I; Gracy Mathew; Thiyagarajan, T M; Balasubramanian, V
Response of ragi (Eleusine coracana Gaertn,) to different levels of nitrogen, phosphorus and potassium under rainfed conditions
(Department of Agronomy, College of Agriculture, Vellayani, 1981) Johnkutty, I; Chandrasekharan, P
Time course leaf n concentration in rice under different nitrogen application strategies and development of simulation models
(Kerala Agricultural University, 1999) Johnkutty, I; Kandasamy, O S
An experiment was conducted at the Tamil Nadu Agricultural University. Coimbalore dunn£ the kharif and rahi seasons of l'J'M-"96. lu study the time CIHIISC leaf N cmicetnraiion in lowland ria under diilercntN timings. Application of I 50 kg N ha"1 m six staggered sPllts/rom planting to heading or m tnree splits Irom early tillering Ul heading suslamed the leal'N eoncenlration at increased levels for higher grain yields. Early N application and limitation of N supply at later stages decreased the plant N con contrail on during grain filling stages and reduced the grain yield. Continued application ol Fertilizer N until heading stage favoured maintenance of N concentration in leaves during ilic posl-anlnests period, resulting in high grain yields. Based on the natural behaviour of time course leat'N concentration, simulation models «cre evolved based on the prediction ability and test of significance
Weed management in sugarcane (Saccharum officinarum L.) through herbicides and intercrops
(Department of Agronomy, College of Horticulture, Vellanikkara, 2003) Mahadev Sarashetti, S; Johnkutty, I
The present study was conducted to understand the effect of different weed management techniques i.e., hoeing, h~rbicides and intercropping systems on weed control, yield and quality of sugarcane. The field experiment was conducted at Anjanile, Chittur taluk of Palakkad district during 2002-03. Herbicide treatments were atrazine 2 kg ha-I as pre-ernergence (PE) fb hoeing and earthing up at 90 DAP, oxyfluorfen 0.20 kg ha' as pre-emergence (PE) fb 2,4-0, ametryn 2.0 kg ha' as PE fb 2,4-0 and' glyphosate I kg ha-I at 20 OAP fb 2,4-0 at 60 OAP. The intercropping treatments consisted of blackgram incorporation at 45 DAP, sunhemp incorporation at 45 OAP and its bhusa incorporation, daincha desiccation by 2,4-D, and sunhemp desiccation by 2,4-0. . . The major weed species in this experiment were Portulaca oleracea. Mollugo pentaphylla. Trianthema portulacastrum and Ageratum conyzoides. The population as well as dry matter production of weeds could be effectively controlled by the pre-emergence application of atrazine, ox.yfluorfen or ametryn fb 2,4-0 and also by growing sunhemp or daincha as intercrops. Higher weed . control efficiency and lower weed indices could be observed for herbicides, the atrazine and oxyfloufen; and for incorporation of balackgram, daincha or sunhernp. Pro-emergence herbicides and sunhcmp incorporation treatments gave better growth and yield parameters. In terms of cane production, oxyfluorfen 0.20 kg ha-I as pre-emergence fb 2,4-0 at 45 OAP and atrazine 2.0 kg ha-I fb hoeing and earthing up at 90 OAP werefound better. The overall results indicates that the weed problem in sugarcane could be effectively controlled by growing sunhernp as intercrop and incorporating it at 45 OAP or by spraying pre-ernergence herbicides viz., oxyfluorfen 0.20 kg ha-I as pre-ernergence (PE) fb 2,4-D. Among the intercrops, sunhemp incorporation at 45 DAP was found to be the best one. In terms of B:C ratio, sunhemp incorporation gave the highest value fb oxyfluorfen and 2,4-0. The results of 121 the study throws light. on the effective and economic weed control in sugarcanc by herbicides or .intercrops, which could replace hand hoeing, which is a costly affair. Considering the green matter addition and eco-safe weed control, growing sun hemp would be more preferable,