Browsing by Author "Padmaja, P"

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Effect of calcium magnesium and silicon on the uptake of plant nutrients and quality of straw and grain of paddy
(Kerala Agricultural University, 1972) Padmaja, P; Varghese, E J
Effect of Calcium, Magnesium and Silicon on productive factors and quality of Rice
(Division of Agricultural Chemistry, Agricultural College and Research Institute, Vellayani, 1964) Padmaja, P; Verghese, E J
Effect of calcium, magnesium and silicon on soil reaction and nitrogen and phosphorus status of the red loam soils of Kerala
(Kerala Agricultural University, 1972) Padmaja, P; Varghesa, E J
Effect of calcium, magnesium and silicon on the productive factors and yield of rice
(Kerala Agricultural University, Vellanikara, 1966) Padmaja, P; Verghese, E J
Effect of increasing levels of nitrogen on growth pattern, yield components and yield of high yielding dwarf indica rice -Ratna
(Kerala Agricultural University, 1976) Padmaja, P
Efficiency of primed rock phosphate for grain production in rice
(Kerala Agricultural University, 1982) Madhusoodhanan Nair, K; Padmaja, P
Potted plant studies were conducted in five major rice soils of Kerala namely karappadom, laterite, kayal, coastal sandy and kole soils to evaluate the efficiency of primed rock phosphate in moist aerobic soil with superphospate applied at flooding. Fractionation studies on the fate of applied phosphate revealed that priming of rock phosphate in moist aerobic soil resulted insubstantial conversion of phosphate to iron phosphate and aluminium phosphate and these products increased availability of phosphorus to rice on submergence. Primed rock phosphate was found to be as efficient as superphosphate in karappadom, kayal and coastal sandy soil in yield and uptake of phosphorus. But in laterite soil it was found to be significantly superior to superphosphate.
Efficiency of vermicompost on growth and yield of summer crop Okra (Abelmoschus esculentus moench)
(Kerala Agricultural University, 1999) Ushakumari, K; Prabhakumari, P; Padmaja, P
Increasing nitrogen use efficiency in upland soils
(Department of soil science and agricultural chemistry, College of Agriculture, Vellayani, 1982) Sathianathan, K M; Padmaja, P
An investigation was carried out at the College of Agriculture, Vellayani, during the year 1980-81 to study the efficacy of the use of some of the commonly available non-edible oilcakes as nitrification inhibitors to increase the nitrogen use efficiency in rainfed upland soils of Kerala. Urea was mixed with neem, mahua, maroti, rubber or karinja cakes at 5:1, 5:2 and 5:3 ratios (urea : oil -cake) to obtain a blend. The mineralisation pattern of those blends were studied along with untreated urea in an incubation study in a typical red loam upland soil kept at 60 per cent field moisture capacity to screen them for nitrification inhibitory properties. Selected blends at the most efficient ratio of mixing were tried in the field at 3 levels of nitrogen supply with cassava as the test crop. The experiment was laid out in randomised block design in factorial structure.
Kinetics of available silica of submerged acid soils
(Kerala Agricultural University, 1987) Kabeerathumma, S; Padmaja, P; Patnaik, S
Low cost technology for the collection of vermiwash in homesteads
(Kerala Agricultural University, 1998) Padmaja, P; Ushakumari, K; Prabhakumari, P
Note on the run off losses of major plant nutrients in water-logged rice soils
(Kerala Agricultural University, 1978) Padmaja, P; Koshy, M M
Occurrence of an abnormal earhead in paddy-short note
(Kerala Agricultural University, Vellanikara, 1968) Padmaja, P; Ramankutty, N N; Rerna Devi, L
On increasing the efficiency of superphosphate in slightly acid submerged soils
(Kerala Agricultural University, 1979) Kabeerathumma, S; Padmaja, P; Koshy, M M
Partial substitution of muriate of potash by common salt for cassava (Manihot esculenta crantz) in oxisols of Kerala
(Department of Soil Science & Agricultural Chemistry, College of Agriculture, Vellayani, 1995) Sudharmai Devi, C R; Padmaja, P
Field experiments were carried out in the College of Agriculture, Vellayani during 1991 to 1994 to study the possibility and extent of substitution of K of Muriate of Potash with the Na of common salt in Cassava variety M4 used as the test crop. Substitution of K was tried at 4 levels viz. 25, 50, 75 and 100 per cent of the recommended dose. Muriate of potash, replaced by wood ash and a combination of KHCO3 and NaHCO3 (eliminating chlorine source) also were included in the experiment. Plant growth characteristics like plant height and number of leaves did not vary significantly as a result of substitution. The maximum LAI was observed in the case of 50% K as MOP + 50% Na as CS treatment at all the growth stages. An increase in chlorophyll content was observed with NaCl substitution. In the early growth stages there was no significant variation in the production of roots, but at the later stages there was significant difference in this aspect. The root volume at 2 MAP varied significantly between treatments. In general, there was an increase in total weight of plant with NaCI substitution upto 50% and thereafter a decrease with higher levels of substitution, at all growth stages. Significant treatment difference could be observed in tuber yield in both the years of the experiment. T3 (50% MOP +50% CS) registered the highest tuber yield and T5 the lowest. The bulking rate and Utilisation Index also differed significantly among treatments. The cooking quality of the tubers from T3 was as good as that of T1. Significant differences could be observed in total sugars, reducing sugars and sucrose content of fresh tubers under different treatments. With increasing levels of substitution, the content of total sugars increased. Sucrose content was found to increase with Na application upto 75% substitution of K by Na. Significant variation was observed in the crude protein, total amino acid and free amino acid content of tubers. Hydrocyanic acid, total phenols and crude fibre also differed significantly between treatments. The keeping quality studies revealed that tubers from T3 could be stored fresh up to 35th day in moist soil, whereas tubers from T1 could be stored only upto 12th day, without deterioration. Enzyme studies revealed significant difference in the activity of starch synthesising enzymes, but NRA at 6 MAP was not affected by different treatments. The uptake of N was highest in T1 and P and K in T3. Na uptake by T1 which received no Na was generally higher than other treatments receiving Na. Ca and Mg uptake also differed significantly between treatments. Changes in soil organic carbon, available P, available K and available Mg were statistically significant between treatments but that of Ca was significant only from 4 MAP onwards. Yield of tubers was positively and significantly correlated to the uptake of N, P, K, Na, Ca and Mg. Yield at harvest was positively and significantly correlated to the root weight and root volume and also to the bulking rate at 2 MAP. Path coefficient Analysis revealed that the maximum direct effect on yield was contributed by the drymatter of roots at 2 MAP. From the results, it can be concluded that in soils having low to medium status of K, the K of MOP can be substituted up to 50% by Na of commonsalt in cassava without affecting the quality and quantity of tubers.
Phosphorus fixing capacity of major rice soils of Kerala
(Kerala Agricultural University, 1983) Madhusoodhanan Nair, K; Padmaja, P
Potassium utilization in cassava (Manihot utilissina pohl) as influenced by neem cake - urea blend
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1985) Manorama Thampatti, K C; Padmaja, P
Potassium utilization in cassava (manihot utilissima pohl.) as influenced by neem cake – urea blend. An investigation was carried out at the College of Horticulture, Vellanikkara, during the year 1983-84, which include a soil column study to understand the dynamics of NH4+- N and K+ ions when applied as urea or urea-neem cake blend either alone or along with muriate of potash. The columns were filled with soil collected from the field surface upto 60 cm depth. Each 15 cm was taken as a separate layer maintaining the same bulk density as observed in the field. Fertilizer treatments comprising, no fertilizer, urea or urea-neem cake blend to supply 100 ppm N and muriate of potash to supply 100 ppm K either alone or in combination were applied to the surface 15 cm soil and mixed thoroughly. The study indicated that under natural conditions NH4+ - N was concentrated more in the lower layers of soil beyond the root zone of cassava whereas potassium was concentrated more in the surface layers of 0-30 cm depth. Application of muriate of potash either alone or in combination with urea-neem cake blend increased potassium in the surface layer within eight hours after fertilizer application. When untreated urea granules were applied along with potassic fertilizer, a major part NH4+ - N was found either concentrated in lower layers, or nitrified and lost. But when urea-neem cake blend was applied along with potassic fertilizer a major part of nitrogen was retained as NH4+ - N in the surface layers upto two weeks and later it moved downwards. There was a drastic reduction of NH4+ - N status in the surface layers upto 45 cm after one week in untreated urea, whereas urea-neem cake blend maintained much of NH4+ - N in the surface 30 cm upto three weeks. Application of muriate of potash maintained highest potassium status followed by urea-neem cake blend along with muriate of potash. The maximum leaching loss of potassium was observed from untreated urea when applied along with muriate of potash. The loss was reduced considerably when potassic fertilizer was applied along with urea-neem cake blend. A field experiment was conducted as a continuation of the study carried out at the College of Agriculture, Vellayani, when urea-neem cake blend at 5:3 ratio increased nitrogen availability, nitrogen uptake and yield. But it had an adverse effect on potassium utilization of the crop resulting in poor quality tubers and the yield increase observed was not significant. The present experiment was planned to tide over this difficulty either by changing the time of application or increasing the rate of potassic fertilizer. Results of the experiment clearly showed that urea-neem cake blend increased nitrogen use efficiency of cassava as evident in higher soil available nitrogen and higher nitrogen uptake by the crop. When muriate of potash was applied one month after application of urea-neem cake blend, the uptake of potassium was not reduced considerably in the initial stages and at the same time uptake was comparatively higher at the sixth month and harvest stages. Potassium at 75 kg K2O ha-1 increased uptake of all nutrients and also produced maximum tuber yield of 21.39 tonnes ha-1, whereas application of potassium one month after application of urea-neem cake blend recorded 19.76 tonnes ha-1 of tuber yield which was on par with the former treatment. Potassium uptake at all major growth stages were significantly correlated with plant dry weight and tuber yield. Maximum benefit per rupee invested was obtained when the rate of potassium was raised from 50 kg K2O ha-1 to 75 kg K2O ha-1 along with 50 kg N as urea-neem cake blend. Changing the time of application of potassic fertilizers to one month and three months after planting also increased the benefit obtained. Both three treatments were on par with each other and significantly superior to others.
Relative efficency of rice varieties for absorption and utilization of soil and fertilizer phosphorus
(Department of soil science and agricultural chemistry, College of Horticulture, Vellanikkara, 1986) Mashar Velapurath; Padmaja, P
Relative efficiency of rice varieties for absorption and utilization of soil and fertilizer phosphorus An investigation was carried out at the college of Horticulture, Vellanikkara, Trichur, during the year 1984-’85 to study the efficiency of popular modern rice varieties of Kerala for absorption and utilization of soil and fertilizer P as well as for their capacity to P deficiency tolerance. A series of pot culture experiments was conducted using five short duration (Rohini, Jyothi, Annapoorna, Triveni and IR-36) and eleven medium duration (Jaya, IR-8, Sabari, Bharathi, Mashuri, IR-20, M0-4, M0-6, M0-7, H-4 and IR-42) rice varieties in karappadam soil of Kuttanad region of Kerala. The first pot culture trial involves evaluation of the above varieties for their capacity to utilize soil and applied fertilizer P using 32P labeled superphosphate. The experiment was carried out in CRD. The relative performance of all the varieties as well as their root distribution pattern were compared from another pot culture trial under identical fertility conditions. Fertilizers and lime were applied as per the package of practices recommendations of the Kerala Agricultural University. The experiment was designed in CRD. An attempt was also made to study the P requirement of each variety for the expression of maximum grain and straw yield from a solution culture trial. Solution containing all the macro and micronutrients was used for the experiment. The treatments consisted of combinations of different varieties and different levels of P supply. The various levels of P used were 0, 1, 2, 4, 5, and 10 ppm. The experiment was conducted in CRD factorial design. The results indicated that cv, IR-36 was having a very low P requirement for the expression of maximum yield potential among short duration varieties and that it responded well to applied fertilizer P, indicating its fertilizer responsive nature as well as tolerance to P deficiency. Triveni and Rohini were also having low requirements, but they differed in their dependence on the source of P to meet the requirement. Rohini was capable of utilizing native soil P efficiently while a good response to applied P was observed in the cv. Triveni. Jyothi utilized both the sources of P viz. soil and fertilizer; efficiently but was found to have a higher requirement for giving maximum grain yield. Among the medium duration varieties cv. Mashuri has the lowest requirement and majority of its requirement was met from the fertilizer revealing its P deficiency tolerance nature and responsiveness to applied fertilizer P. Cv. IR-42 and Bharathi were found to be tolerant to P deficiency due to their capacity to utilize native soil P efficiently and low requirements of P. Cv. H-4 was also having low requirement and it utilized both the sources efficiently. But this was not very much reflected on the grain yield. Cv. IR-8 and Jaya had comparatively higher requirements and it reflected well on the grain yield. But these varieties yielded poor at lower levels indicating its susceptibility to P deficiency.
Research notes on the effect of soluble iron and aluminium on rice seedlings
(Kerala Agricultural University, Vellanikara, 1969) Padmaja, P; Anandavalli Amma, P; Moni, N S
Residual effect of primed rockphosphate on succeeding pulse crop
(Kerala Agricultural University, 1985) Madhusoodhanan Nair, K; Padmaja, P
Standardisation of plant part as an index of potassium status in banana, musa (AAB Group) nendran
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 1994) Sumam George; Padmaja, P
A field experiment in Musa (AAB group) Nendran, the most popular commercial fruit crop of Kerala was undertaken from August, 1991 to May, 1992 with seven graded levels of K as treatments replicated thrice. The soil, medium in N and P and high in K status belonged to the taxonomic class ‘loamy kaolinitic isohyperthermic aeric tropic fluvaquents’. The effects of higher levels of K on all important growth characters of the crop like height of pseudostem, girth of pseudostem at different heights from the ground level, total number of leaves, number of functional leaves, total leaf area, leaf area index and total dry matter production were more pronounced from the shooting stage of the crop after the plants had received the full dose of K supply. Uptake of major nutrients N, P and K showed increasing trend with increase in K supply. Uptake of Ca showed a negative relationship with increasing K application while Mg uptake showed an inconsistent pattern. Uptake of micronutrients Fe, Mn, Cu and Zn were maximum at K3 level of application (225 g K2O plant-1). Soil content of available K increased while exchangeable Ca and Mg contents decreased at higher levels of K supply. The maximum bunch yield of 26.18 t ha 1-which was significantly higher than all other treatments was recorded at K3 level (225 g k2O plant-1) This level also resulted in maximum values for all the yield attributing characters like number of hands bunch-1, number of finger bunch-1, weight of hand, length of finger, girth of finger and weight of finger. By adopting this recommendation a net fertilizer saving of 75g K2O plant-1 Can be achieved which is equivalent to 312.5 kg of muriate of potash costing Rs. 2000 at the present market rate. Over and above this, increase in yield obtained by doing so is 4500 kg ha-1. Additional income that could be generated by the way of sale of this at the rate of Rs. 8 kg-1 works out to Rs. 36000. Thus a total saving of Rs. 38000 ha-1 can be achieved by following the suggested recommendation. Path coefficient analysis of yield attributes showed that the character number of finger bunch-1 is having the maximum direct effect on yield followed by girth of fruit and weight of fruit. Quality characters of the fruit namely total and non reducing sugars, shelf life and flesh peel ratio showed significant and positive trend towards K nutrition. Correlation coefficient were worked out between bunch yield and important crop characters. Balance sheet of nutrients in soil after harvest of the crop was worked out to assess the final soil status of nutrients in relation to the initial status. Petiole of the third leaf up to shooting stage of the crop and that of the flag leaf there after was selected as the index of K status of the plant as the K content of the same was found to hold the maximum relationship with bunch yield at all the growth stages. The critical K levels in the petiole for maximum yield as well as maximum response to fertilizer application at each stage were determined which were found to be 1.30 per cent and 1.02 per cent respectively at early vegetative stage, 1.28 per cent and 1.06 per cent respectively at late vegetative stage, 1.80 per cent and 1.36 per cent respectively at shooting stage, 2.43 per cent and 1.98 per cent respectively at post shooting stage, 2.50 per cent and 1.80 per cent respectively at bunch maturation stage and 2.47 per cent and 1.80 per cent respectively at harvest stage. The critical K content in soil for economic yield worked out to 286.5 kg K2O ha-1 at early vegetative stage, 276.5 kg K2O ha-1 at late vegetative stage, 271.o kg K2O ha-1 at shooting stage, 239.o kg K2O ha-1 at post shooting stage, 245.0 kg K2O ha-1 at bunch maturation stage and 236.0 kg K2O ha-1 at harvest stage. Graphs were plotted relating petiole K content to soil K content at important growth stages of the crop based on quadratic regression models to provide information on soil K content at a particular stage if the petiole K content at that stage is known. Linear regression models were developed relating soil K content to fertilizer dose to find out the quantity of fertilizer to be applied to bring the soil level to the critical level.