Browsing by Author "Purushothaman Nair, N"

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Effect of graded levels of phosphorus and potassium on nodulation of two varieties of groundnut (Arachis hypogaea L.)
(Kerala Agricultural University, 1980) Purushothaman Nair, N; Sadanandan, N; Nair, K P M; Mohamed Kunju, U
Fodder production potential of five cultivars of bajra (Pennisetum Typhoides.Stapf) in coconut garden lands of Kerala
(Kerala Agricultural University, 1981) Raghavan Pillai, G; Purushothaman Nair, N; Sreedharan, C
Nutrient Status of the soil and plant as influenced by spacing and continued manuring in Coconut
(Department of Agronomy, College of Agriculture, Vellayani, 1998) Pratheep, M S; Purushothaman Nair, N
A study was conducted during 1995-96 at Coconut Research Station, Balaramapuram of Kerala Agricultural University to asses the nutrient status of . the soil and plant in West Coast Tall coconuts planted at three different spacings and manured with three levels of macro nutrients. The treatments were three spacings (5 m x 5 m, 7.5 m x 7.5 m and 10 m x 10 m) and three fertilizer levels (control i.e., zero NPK, the lower level i.e., 340 g N + 225 g P205 + 450 g K20 per palm per year and the higher level i.e., 680 g N + 450 g P205 + 900 g K20 per palm per year). The basic experiment was started in 1964 and being continued. The data collected during the study (1995-96) was statistically analysed and the results are presented here under. Closer spacing increased height of palms. The spacings of7.5 m x 7.5 m was statistically superior since it gave the highest nut yield per palm per year. Manuring increased height of palms, girth and leaf production. At the highest level of NPK closer spacing of 5 m x 5 m could give the highest yield per unit area. Female flower production was higher under 7.5 m x 7.5 m spacing. Fertilizer application also increased flower production. Fruit setting was not influenced by palm density and fertilizer application significantly increased fruit setting. Number of nuts per bunch was higher at the spacing of 7.5 m x 7.5 m and progressively increased with manuring. The weight and volume of unhusked nut was the lowest at the closest spacing and in unfertilized palms. There was increase in weight of husk with increase in spacing. Similarly there was an increase in the ratio of weight of husk to unhusked nut with increasing spacing. Maximum thickness and weight of kernal was recorded at the spacing of 7.5 m x 7.5 m. Copra out turn was more at the spacing of 7.5 m x 7.5 m. In manured palms there was a higher copra out turn per hectare contributed by the higher yield. The oil content of copra was negatively correlated with per palm yield. Available NPK of soil decrease with wider spacing. The soil nutrient status increased with application of macronutrients and the accumulation of fertilizer was more in the upper layer of 0 to 25 cm. There was decline in NPK status with increase in depth. The Ca and Mg content of soil decreased with increase in spacing up to 7.5 m x 7.5 m. Both Ca and Mg content of soil decreased with increase in macro nutrient application. Ca content of soil decreased with increase in depth. However, the decrease of Mg content was seen only up to 50 cm depth. Available micro nutrients (Fe, Cu, Mn and Zn) decreased with increase in spacing and application of fertilizers. Available Fe, Cu and Mn content of soil decreased with increase in depth. Nand P content of leaf of coconut increased with wider spacing. However K content decreased with spacing. All the three macro nutrients increased with increase in fertilizer application. Ca and Mg content of leaf also increased with increase in spacing and fertilizer application. By fertilizer application Fe, Mn and Cu content of leaf increased whereas Zn and Na decreased.
Organic nutrition in amarantus
(Department of Agronomy, College of Agriculture, Vellayani, 2000) Arun Kumar, K R; Purushothaman Nair, N
An experiment was conducted 'at the Instructional Farm attached to the College of Agriculture, Vellayani, during November 1998 to February 1999 with objectives to find out the effect of different sources and levels of organic manures on the yield and quality of amaranthus and to assess the optimum quantity of these sources in sustaining the productivity of amaranthus. The experiment consisted of twenty six treatments and three replications laid out in RBD. The organic manures used were coir pith compost, FYM, neem cake, poultry manure and vermicompost. Five levels of these organic manures (50, 75, 100, 125 and 150 per cent of POP) were tried on nitrogen equivalent basis. The results of the study revealed that the growth characters as well as yield were significantly influenced by different levels and sources of organic manures. Regarding growth characters vermicompost, FYM and poultry manure performed well throughout the growth period. Highest level of FYM and vermicompost (150 per cent POP) maintained their superiority at all growth stages regarding plant height, number of leaves, number of branches and LAI. Maximum plant height of 67.22 cm was recorded at 45 DAP by highest level of FYM. Vermicompost @, 25 t ha" (150 per cent of POP) recorded maximum number of leaves (100.78) at 45 DAP but it was on par with highest dose ofFYM. Maximum LA! was noted in the highest dose of FYM and no other treatment was on par with it. High yield was obtained from 100, 125 and 150 per cent levels of FYM, vermicompost, poultry manure and neem cake. All the coir pith compost treatments recorded lower yield than POP. The lowest yield was recorded by lowest dose of coirpith compost. The same trend was obtained in the case of marketable yield also. Higher levels gave better yield in general. Total dry matter production showed an increasing trend with increasing dose of manure. Highest dose of FYM recorded maximum DMP of 11.41, 25.7 and 28.27 g respectively at 15, 30 and 45 DAP. Variation among different organic manures was significant in the case of biomass production also. Through out the growth stages 125 and 150 per cent levels of all manures except coir pith compost recorded superior biomass compared to POP. Vermicompost at highest level (25 t ha-I) recorded maximum biomass during three harvests. Variation was less in the case of NAR and dry matter partitioning at different stages. Quality of amaranthus improved with varIOUS organic manures. Maximum vitamin C content was recorded by highest level of vermicompost. Maximum fibre content was registered by neemcake at 100 per cent level of POP (4.8 t ha-I). Highest dose of poultry manure (25 t ha") gave highest protein content. Vitamin C and protein contents increased with increasing doses of manure. Highest moisture content was noted by highest dose of FYM. In the case of residual nutrients high soil NPK values were registered by higher levels of organic manures irrespective of source. No treatment was inferior to POP with respect to nitrogen content. Uptake of nutrient was poor from all coir pith compost treatments. Uptake of N increased with increasing levels of manures. P uptake was more for FYM treatments. Vermicompost at highest dose (17 5 I ha-I) gave maximum n C ratio
Quality of kernel in groundnut varieties TMV-2 and TMV-9 As influenced by phosphorus and potassium fertilization
(Kerala Agricultural University, 1981) Purushothaman Nair, N; Sadanandan, N
Status and availability of sulphur in the major paddy soils of Kerala and the response of rice to sulphatic fertilizers
(Department of Agronomy, College of Horticulture, Vellanikkara, 1995) Purushothaman Nair, N; Thajuddin, E
A series of investigations were undertaken entitled “ Status and availability of sulphor in the major paddy soils of Kerala and the response of rice to sulphatic fertilizers” at College, of Hortculture, Kerala Agricultural University, Vellanikkara from 1990 to 1994 with the objectives: (i) to assess the sulphor status of major paddy soils of Kerala (viz. alluvial and brown hydromorphic) (ii) to identify and appropriate soil test procedure for estimation of available sulphor in these soils (iii) to determine the critical levels of sulphor in the soils and plant (iv) to study the response of rice to two popular sulphatic fertilizers of Kerala (viz. ammonium sulphate and ammonium phosphate sulphate) and (v) to assess the sulphur use efficiency of 35S labelled ammonium sulphate and ammonium phosphate sulphate. The studies were conducted in four parts. In Part 1 of the studies, 105 samples each from alluvial and brown hydromorphic soils were collected from 10 rice growing districts of Kerala based on area under rice crop, estimated soluble SO4-S, adsorbed SO4-S, total sulphur content and organic + non sulphate sulphur contents. The soils were classified in to categories of low, medium and high based on the available SO4-S extracted by CaCl2. From this part of the study it was found out that 56 per cent of alluvial soils and 83 per cent of brown hydromorphic soils were deficient in sulphor. Sulphur deficient locations and sulphur sufficient locations were delineated. Sulphur status map for rice soils of Kerala was prepared. In Part II, representative soils belonging to three status categories (low, medium and high) were collected from 30 locations each of alluvial and brown hydromorphic types and conducted a pot culture with two treatments (S0 and S40 kg S ha-1) with two replications. These soils were analysed with 12 methods of sulphur estimation using different extractants. The relative yield of grain, straw and total biomass and relative uptake of nutrient S were estimated. Correlations between relative yields and sulphur extracted by different methods were studied. From this the suitability of the methods were evaluated. It was found that all the 12 methods studied could extract available SO4 – S satisfactorily. Scatter diagrams were drawn with relative yields of grain, straw, biomass and uptake of S against the sulphur extracted by different extractants. The critical levels were worked out following the Cate and Nelson procedure. The best suitable extractants for the estimation of sulphur in alluvial soil and brown hydromorphic soil were found out by assessing the responsiveness of rice in soils classified as deficient by each extractant. It was observed that in alluvial soil the critical levels varied between 5 to 22 ppm for different extractants. Monocalcium phosphate was to be the best extractant for alluvial soils. In brown hydromorphic soil the critical levels varied between 6 ppm to 20 ppm. Monocalcium phosphate + acetic acid was found to be the best extractant for brown hydromorphic soils. Relationship between plant content of S and relative yield of grain studied by Cate and Nelson procedure showed that in alluvial soil 0.075 per cent S and in brown hydromorphic soil 0.08 per cent S in plant at harvest were critical concentrations below which response to applied sulphur can be expected. In Part III of the studies, two locations having sulphur deficiency, one each falling under alluvial and brown hydromorphic soil, were selected for field experiments (CSRC, Karamana – alluvial and RARS, Pattambi –brown hydromorphic). Field experiments were conducted in these two locations for two seasons (Kharif and Rabi 1992-93) with nine treatments (control – S0, 4 levels of ammonium sulphate – S10, S20, S30, and S40 and 4 levels of ammonium phosphate sulphate - S10, S20, S30, and S40 kg S ha-1 in 2x4+1 factorial RBD with 3 replications). The results revealed that sulphur levels significantly increased yield of grain and straw and growth attributes like productive tillers. Sink capacity and dry matter production were increased by sulphur application. Among the two sources ammonium phosphate sulphate was found to be superior to the other. Agronomic efficiency, physiological efficiency and apparent recovery efficiency showed that the efficiencies were maximum at low level of sulphur (10 kg S ha-1). Sulphur levels increased, S, N and K uptake. The ratios of nutrients removed per ton showed that the ratios of these nutrients to sulphur narrowed down with sulphur application over control. The gross income, net income and B: C ratio were higher for sulphur application and the highest values were for 30 kg S ha-1. The physical optimum levels ranged between 25.34 to 31.47 and the economic optimum levels ranged between 23.06 and 28.73 for the sources in two locations at the two seasons. The economic optimum levels of AS and APS were 27 and 25 kg S ha-1 respectively. There was no residual effect in general, except that at brown hydromorphic soil sulphur @ 40 kg ha-1 could contribute to meet the requirement of sulphur for the succeeding crop in producing more grain yield. In Part IV of the studies, a pot culture experiment with 35 S labelled AS and APS was conducted at Radiotracer lab. The radioassay and chemical analysis were conducted. The soil and levels of S were same as that of field experiment. The specific activity of grain and straw increased with higher levels of 35 S application. The sulphur use efficiency in alluvial soil was highest at sulphur rate of 20 kg S ha-1. In brown hydromorphic soil sulphur use efficiency was highest at 30 kg S ha-1. Sulphur taken up from fertilizer significantly increased with sulphur levels in both the soils. A-values were on par for different levels in both the soils. Brown Bydromorphic soil showed higher A-value, sulphur use efficiency and total sulphur taken up from fertilizer.
Studies on the performance of two groundnut varieties, TMV-2 and TMV-9, under graded doses of phosphorus and potassium.
(Department of Agronomy, College of Agriculture, Vellayani, 1978) Purushothaman Nair, N; Sadanandan, N