Browsing by Author "Gracy Mathew"

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Correlation and yield component analysis in greengram (Vigna Radiata L.) in summer rice fallows
(Kerala Agricultural University, 1996) Kanakamany, M T; Gracy Mathew; Leenakumary Tessy Joseph, S; Tessy Joseph
Twelve genotypes of greengram were evaluated during summer 1995 in the rice fallows of tiie Regional Agricultural Research Station, Pattambi. WGG 62 was the highest yielder among the genotypes tested. Out of the ten characters studied the number of pods per plant, per day productivity, chlorophyll ' a' and total chlorophyll contents showed positive and significant association with grain yield. Duration of the crop was found to have no direct relation with yield.
Effect of phosphorus and sulphur on growth, yield and nutrient uptake of rainfed upland cowpea
(Kerala Agricultural University, 1998) Gracy Mathew; Sreenivasan, E; Anilakumar, K
A field experiment was conducted during kharif 1992-94 in a sandy loam acid laterite soil to study the effect of graded doses of phosphorus and sulphur on the yield and nutrient uptake of rainfed cowpea (Vigna unguiculata [L.j Walp). The different levels of phosphorus showed significant difference in the yield and nutrient uptake of cowpea. Maximum grain yield and nutrient uptake was obtained with application of 60 kg P3O5 ha'1. The net return was also highest with this level of phosphorus nutrition. Application of sulphur did not show any remarkable influence on growth, yield and nutrient uptake of cowpea.
Nitrification pattern in a laterite soil
(Kerala Agricultural University, 1991) Gracy Mathew; Vikraman Nair, R
An investigation was conducted at the College of Horticulture, Vellanikkara, Trichur during 1984-85 with typical laterite soil collected from Vellanikkara to study the nitrification pattern in the soil and to examine the effect of various factors on nitrification. The rate of nitrification in the soil was found to be naturally low. Attempts were made to locate the factors responsible for the low rate of nitrification. Factors like build up of ammoniacal nitrogen to values around 100 ppm, pH, organic matter content, cropping history, moisture level of incubation, source of fertiliser nitrogen and lack of microbial population were not indicated as responsible for the naturally low rate of nitrification.
Nutritional constraints of rice -legume system in laterite soils of humid tropics
(Department of Agronomy, College of Horticulture, Vellanikkara, 2002) Gracy Mathew; John, P S
A research programme entitled "Nutritional constraints of rice- legume system in laterite soils of humid tropics" was carried out from 1997-'98 to'1999- '00 at Regional Agricultural Research Station, Pattambi. The objectives of the programme were to study the effect of crop residue recycling, nutrient management practices and tillage and water management practices on soil and plant elemental status and productivity of rice- rice-legume cropping system There were two experiments in the programme. The first experiment entitled, "Soil- plant elemental status and productivity as influenced by crop residue recycling and nutrient supply in the rice-legume cropping system" was taken up to study the impact of nutrient management practices as well as crop residue recycling on soil productivity and crop growth. The crop residues added in the system involved harvested left overs of grain cowpea crop during summer as well as addition of two-third portion of straw of kharif crop to rabi season crop. Silica at 250 kg ha", higher K dose of 70 kg ha-I and soiVfoliar supply of Mg, Zn, Cu, B and Mo were also included in various treatment combinations. The treatments exhibited significant influence on grain and straw yield. The treatment which did not receive any inorganic fertilizers registered the lowest yield during all the seasons. Straw addition did not' bring about yield advantage in kharif, but in rabi there was steady and significant increase over the seasons. Silica application was not beneficial in initial seasons, but from fourth rice crop onwards, significant increase was noticed. Though there was an improvement in organic carbon of soil during some seasons, summer cowpea raising did not bring about specific yield improvement. The absence of response to addition of summer cowpea residues revealed that either lack of N or a lower level of organic carbon may not be the limiting factors for low yield in these laterite soils. Potassium application even at the higher dose of 70 kg ha-I was "found to have no appreciable effect on growth and yield of paddy. Foliar application of boron and molybdenum and soil as well as foliar spray of Mg, Zn and CLl continuously for five seasons did not bring about any significant influence on growth and yield of paddy The second experiment, " Effect of tillage and water management practices on soil-plant, elemental status and productivity of rice in rice- rice legume cropping system" was aimed to study the influence of deep ploughing and intermittent drainage. Deep ploughing during kharif season had no significant influence during the current season or for the following rabi crop indicating that in puddled soil condition deep ploughing will not be of much advantage. The two water management practices did not produce any appreciable difference in growth or yield of the crops during the kharif seasons; 'but it adversely affected the performance of rabi 1999-'00 crop which could be due to , the dry atmospheric condition during the season. During rabi 1998-'99, the desiccating effect was considerably low and hence the drainage did not affect the growth of the crop. Hence the effect of intermittent drainage depends on season as well as the current weather situation. The elemental composition of the plant showed that there was no deficiency of any of the elements analysed in the plant system and hence the general low yield obtained from these soils could be due to nutritional constraints owing to excesses, imbalances or metabolic unavailability of elements. The plant had high content of non-applied elements particularly Fe. This excess absorption -of iron might be due to the high content of available iron in the soil. The absorbed nutrients, particularly N was not effectively utilized for grain production as evidenced by the relatively high content of 0.9 per cent N in straw as against 1.1 per cent in grain. Management practices like addition of cowpea residues, supply of nutrients, adoption of deep tillage or intermittent drainage did not show any advantage. Recycling of paddy straw as well as continuous addition of silica were effective in improving yield.
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 rice to phosphorus solubilising bacterial culture for its P utilisation under waterlogged condition
(Kerala Agricultural University, 1996) Anilakumar, K; Gracy Mathew
The response of P solubilising bacterial culture to waterlogged rice was evaluated in a field experiment. The bacterial culture had no effect on P availability in soil and P uptake by plants at any stage of crop growth There was no marked advantage for the bacterial culture on yield or in reducing the recommended dose of P to waterlogged rice where there is little response to applied P.
Screening plant materials for nitrification inhibition properties and testing the field performance of promising materials
(Department of Agronomy, College of Horticulture, Vellanikkara, 1986) Gracy Mathew; Vikraman Nair, R
The present study ‘screening plant materials for nitrification inhibition properties and testing field performance of promising materials’ was conducted during May 1984 to November 1985 at the College of Horticulture, Vellanikkara, Trichur. A total of 17 materials were used for screening using already proved nitrification inhibition materials like N-Serve and neem cake as reference. Nitrification rate in the soil was found to be very low and there was no appreciable conversion of NH+4 form to NO 3. Since there was no significant difference in the NH+4 content between treatments due to the naturally low rate of nitrification, selection of promising materials possessing nitrification inhibition property could not be done. Attempts were made to locate the factors that resulted in the low rate of nitrification in the soil. Organic matter content, pH, cropping history, amount of NH+4– N build up in the soil, incubation conditions and low microbial population were not indicated as responsible for the noted low degree of nitrification. In red and black soils of Coimbatore, nitrification was appreciable and there was fast disappearance of NH+4–N. Data on various growth parameters like mean, height, LAI and dry matter production of the test crop. Fodder maize, did not show any treatment difference. The yield in the treatment which received no fertiliser nitrogen was significantly lower than in other treatments. Similar were the results on nitrogen content of plant parts at various stages and those on total nitrogen uptake. The addition of materials used as nitrification inhibitors did not show any added advantage over untreated urea since the degree of nitrification in the soil was not appreciable.