Browsing by Author "Sreedevi, P"

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Effect of shade on nutrient uptake and dry matter accumulation in Ginger
(Kerala Agricultural University, 1998) Beena Elizebeth George; Sreedevi, P; Vikraman Nair, R
Effect of shade on plant characters and net assimilation rate of ginger cultivars
(Kerala Agricultural University, 1998) Beena Elizabeth George; Sreedevi, P; Vikraman Nair, R
Evaluation of turmeric cultivars for shade tolerance
(Department of Agronomy, College of Horticulture, Vellanikkara, 1992) Sheela Paul; Sreedevi, P
An experiment, 'Evaluation of turmeric cultivars for shade tolerance' was conducted during May 1990 to February 1991 at the College of Horticulture, Vellanikkara, Thrissur, Kerala, India. Two separate trials were carried out one under artificial shade and the other under natural shade in coconut garden. The trial under artificial shade was to assess the performance of turmeric cultivars under different shade levels, whereas that under natural shade was to test the fitness of these cultivars as intercrops in coconut garden. Trial under artificial shade was laid out in split plot design with four shade levels, 0, 25, 50 and 75 per cent in the main plots and six cultivars PCT-5, BSR-1, Ethamukulam, PTS-9, PCT-8 and PTS-38 in the subplots. For providing shade, pandals were erected on wooden frames and covered with unplaited coconut fronds to provide desired levels of shade. LI-COR integrating quantum radiometer with line quantum sensor was used for adjusting the shade intensities. Though no . significant difference was observed between cultivars at different shade levels, all cultivars gave highest rhizome yield at 50 per cent shade. Hence turmeric may be calssified as a shade tolerant/shade loving crop. Yield parameters such as drymatter production and harvest index were also more at 50 and 75 per cent shade, respectively. Among the cultivars P C T -8 , the highest yielder gave higher values for drymatter production, harvest index, chlorophyll content and percentage dryage. On analysing the performance of different cultivars at varying shade intensities; all the cultivars i were found to be better at 50 per cent shade, above which there was a declining trend in yield. The treatment differences were, however, not significant. In general, PCT-8 and PTS-9 performed better both under shade and in the open. Though different prediction models were tried, no model was found to be a good fit for the cultivars. Under natural shade, similar performance was exhibited by all the five cultivars tested with respect to rhizome yield, growth and yield attributes. However, BSR-1 outyielded the other cultivars. The same cultivar recorded more, content of chlorophyll, curcumin and oleoresin. In general, the performance of all the cultivars was poor under intercropping in coconut garden
Evaluation of ginger cultivars for shade tolerance
(Department of Agronomy, College of Horticulture, Vellanikkara, 1992) Beena Elizabeth George; Sreedevi, P
A study entitled 'Screening of ginger cultivars for shade tolerance' was conducted during May 1990 to February 1991 at the College of Horticulture, Vellanikkara, Thrissur, Kerala, India. Two separate trials were carried out, one under artificial shade and the other under natural shade in coconut gardens. The trial under artificial shade was intended to assess the performance of ginger cultivars under different levels of shade, while that under natural shade was taken up to test the fitness of these cultivars under intercropped situation in coconut garden. Trial under artificial shade was laid out in split plot design with four shade levels (0, 25, 50 and 75 per cent shade) as main plot treatments and six cultivars (Maran, Kuruppampadi, Himachal, Rio-de-jeneiro, Nudumangad and Amballore local) as subplot treatments with four replications. The trial under natural shade was laid out in randomised block design with five cultivars (Maran, Kuruppampadi, Himachal, Nedumangad and Amballore local) and four replications. For providing shade under artificial shade trial, pandals were erected on wooden frames and covered with unplaited coconut fronds to provide required levels of shade. LI-90 A Quantum sensor and LI-191 SA Line Quantum sensor were used for adjusting the shade intensities to the desired levels. As the overall performance of the crop was better under shade than in the open, ginger may be classified as a shade loving crop. Rhizome yields at 25, 50 and 75 per cent shade levels were comparable and significantly higher than that under direct sun with 25 per cent shade recording the highest value. Yield parameters such as harvest index and total- dry weight were also highest at 25 per cent shade. Significant interaction was noticed between shade levels and ginger cultivars on rhizome yield. Himachal was found to- be adapated to all situations. Quality of ginger rhizomes was found to be improved when grown under shade. Nutrient uptake was also higher under shaded situation. Based on the rhizome yield the cultivars adapted to each of the shade levels are as follows. 0 per cent shade - Kuruppampadi, Himachal 25 per cent shade- Nedumangad, Himachal, Maran, Kuruppampadi 50 per cent shade - Himachal, Kuruppampadi, Maran, Nedumangad and Amballore local 75 per cent shade - Himachal, Kuruppampadi The logarithmic model, log y = a+b(log x)+c(log x ) 2+d 3 (log x) was found to be a good fit for all the cultivars except Amballore local, for which the yield prediction could be well effected using the quadratic model (y = a+bx+cx2) . All the cultivars tested under natural shade, revealed no significant difference with respect to rhizome yield and most of the growth and yield attributes. Among the cultivars, Amballore local fared comparitively better under natural shade, where the percentage illumination was about 50 per cent. However, the performance of all the cultivars was poor in terms of rhizome yield under natural shade in coconut garden.
Evaluation of joint formulation of anilofos and 2,4-dee for the control of weeds in dry -Sown rice
(Department of Agronomy, College of Horticulture, Vellanikkara, 1995) Jijimol Kurian, P; Sreedevi, P
An experiment was conducted at the Agricultural Research Station, Mannuthy during the crop season of 1993 and 1994 to evaluate the joint formulation of anilofos (aniloguard) and 2,4-DEE for the control of weeds in dry-sown rice. The treatments included joint formulation of anilofos and 2,4-DEE (0.3 and 0.45 kg a.i./ha), anilofos (0.3 and 0.45 kg a.i./ha), 2,4 DEE (0.4 and 0.6kg a.i./ha), butachlor (1.25 kg a.i./ha). Unweeded and hand weeded control were included weeded control were included for comparison. The experiment was laid out in split splot desigh, replicated thrice. The main weed species found during the first year were Cynodon dactylon, Digitaris sanguinalis, Eleusine indica, Cyperus rotundus, Cyperus iria, Cleome viscosa and Ageratum conyzoides. In the second year Isachne miliaceae, Saccolepis interrupta, Echinochloa colona, Fimbrystylis miliaceae and Cyperus iria predominated. The population of grasses were reduced by the application of butachlor @ 1.25 kg a.i./ha at 3 DAS and joint formulation of anilofos and 2,4-DEE @ 0.45 kg a.i./ha at 9 DAS. The same treatments were equally effective in loweing the number of sedges and broadleaved weeds. With respect to weed control efficiency hand weeding was superior to the herbicides during the first year. However during the second year joint formulation of anilofos and 2,4-DEE recorded the highest weed control efficiency followed by hand weeding. No severe phytotoxic symptoms and loss were observed consequent to the application of the herbicides. Tank mix application of anilofos and 2,4-DEE recorded the highest number of tillers/m2. Joint formulation of anilofos and 2,4-DEE @ 0.45 kg a.i./ha recorded the highest dry matter production by the crop. Yield attributing characters and yield were higher in plots with joint formulation of anilofos and 2,4-DEE @ 0.45 kg a.i./ha at 9 DAS. The same treatment was more economical over other hericides in terms of total returns and benefit cost ratio.
Evaluation of lowcost agronomic techniques for sustained rice production
(Department of Agronomy, College of Horticulture, Vellenikkara, 1985) Sreedevi, P; Sreedharan, C
Three field experiments were conducted at the Regional Agricultural Research Station, Pattambi, Kerala to evaluate some of the low cost agronomic techniques for sustained rice production during the period from 1982 to 1985. In the first experiment the performance of IR 42, a rice variety suited to low fertility conditions was assessed under varying levels of nutrition and spacing. Fertilizer, age of seedlings and planting density, for IR 42 were the experimental variables for the second experiment. In the third trial, azolla was evaluated as a low cost biofertilizer for IR 42. The first and third trials were laid out in split plot design while the second trial in factorial RBD. The rice cultivar IR 42 proved its mettle under the low fertility conditions. In fact, it gave an average yield of 2.78 t ha-1 in virippu and 2.32 t ha-1 in mundakan without any fertilizer application. A plant population of 33 hills m-2 (spacing 20 x 15 cm) in conjunction with full dose of fertilizer of 90 : 45 :45 kg NPK ha-1 recorded substantially more grain yield of 4.24 and 3.20 t ha-1 in virippu and mundakan seasons, respectively. Relatively lower grain and straw yields were registered by the treatment 100 hills m-2 (spacing 20 x 5 cm) at all levels of fertilizer application. The net return and benefit cost ratio were more in the former combination. Increasing the seedling number hill-1 from two to four or six was also found to be beneficial for this variety. At lower levels of fertilizer six seedlings hill-1 recorded higher grain yields. However, at higher levels four seedlings hill-1 was found to be superior. During virippu season planting of 35 days old seedlings was found to perform better compared to 30 and 25 days old seedlings whereas in mundakan season, 30 days old seedlings were found preferable in terms of grain yield. Recommended dose of fertilizers (90 : 45 : 45 kg NPK ha-1) with azolla @ 10 t ha-1 and 75 per cent of the same with azolla @ 15 t ha-1 recorded similar grain yields indicating that an extra dose of 5 t of azolla ha-1 could substantially reduce the chemical fertilizer requirement and save as much as 25 per cent of the fertilizer. The benefit cost ratios were almost equal in both the combinations while the return per rupee invested was more in the latter combination. The finding appears to caution against excessive use of azolla expecting better exploitation of all the benefits attributed to it. Nevertheless, data on the residual fertility of the soil after each crop indicate that residual fertility was higher in the plots receiving full dose of fertilizer along with the highest level of azolla, 20 t ha-1
Functional efficiency of pre-emergence herbicides in wet seeded rice
(Kerala Agricultural University, 1996) Mohankumar, P D; Savithri, K; Sreedevi, P
Influence of phosphorus on absorption and dynamics of nutrients in rice
(Department of Agronomy, College of Horticulture, Vellenikkara, 2003) Ponnaiyan, C; Sreedevi, P
Performance of fodder cowpea varieties at graded levels of phosphorus and potassium
(Kerala Agricultural University, 1981) Nair, M S; Sreedevi, P; Nair, R V
Performance of medium duration rice as influenced by plant population and fertilizer levels
(Kerala Agricultural University, 1991) Sreedevi, P; Sreedharan, C
In a few trials conducted at the Regional Agricultural Research Station, Pattambi, Kerala to assess the performance of IR 42 - a low fertilizer responsive rice variety - under different plant population and fertilizer management situations, it was found that the variety has the built-in ability to tolerate low fertility and at the same time respond to higher fertilizer doses than the recommended dose of 90 kg N, 45 kg P2Os and 45 kg K.iO/ha. The optimum plant population was found to be 33 hills/m . The highest net return and benefit cost ratio were associated with a plant population of 33 hills/m at full dose of fertilizer. But the return per rupee invested on fertilizer was more with 33 hills/m in the first crop season and with 25 hills/m in the second crop season at 50 per cent of the recommended dose of fertilizer.
Role of tillage agrochemical use on vam in cowpea in rice fallow
(Department of Agronomy, College of Horticulture, Vellenikkara, 1998) Duethi, P P; Sreedevi, P
A field experiment was conducted at the Agricultural Research Station, Mannuthy in summer rice fallow during January-April, 1997. The study was to assess the effect of tillage practices and use of agrochemicals on soil V AM and to analyse the possibility of any saving in inorganic fertilizer use. Effect of summer cropping on improvement of soil health was also aimed at. The experiment was laid out in strip plot design with 24 treatment combinations replicated thrice. Combination of tillage and herbicide levels were tried in parallel strips. Fertilizer levels were given across these strips. Tillage levels included minimum and normal tillage. Fertilizer levels consisted of control, full recommended doze of fertilizer i.e., inorganics and organics, half the recommended doze of fertilizer i.e., inorganics and organics, half the recommended doze of fertilizer i.e., inorganics and organics along with VAM, full recommended dose of inorganics alone and full recommended doze of organics alone. Results revealed that most of the growth characters were not significantly influenced by tillage treatments. However, with respect to plant height and drymatter production higher values were observed in minimum tilled plots. Yield attributing characters favourably influenced by minimum tillage were number of pods per plant, weight of pods per plant, test weight, pod yield per ha, grain yield per ha and stover yield per ha. Nitrogen and phosphorus uptake were favoured by minimum tillage. Organic carbon status, available nitrogen and available zinc were higher in minimum tilled plots. Most of the growth and yield attributing characters were not affected by herbicide application. Soil studies revealed slightly lower values for organic carbon, available nitrogen and available phosphorus content in herbicide applied plants. Fertilizer levels had more significant influence on yield attributes and soil nutrient levels. In all the growth characters half of the recommended doze of fertilizer along with V AM was superior or equally well as that of full recommended doze of fertilizer and full organics alone. The same combination fared well with most of the yield characters also. Among the interaction effects tillage x fertilizer interactions were significant in percentage nitrogen in plant, protein content of grain, organic carbon status and available potassium in soil. Herbicide-fertilizer interactions were significant in the case of percentage nitrogen, uptake of nitrogen, percentage phosphorus in plant, organic carbon status of soil and available potassium of soil. Tillage and herbicide interactions significantly influenced only on organic carbon status of soil. To conclude, minimum soil disturbance was prefered in summer cropping. The use of agrochemicals especially herbicide (Alachlor) in the normal recommended doze of 2.5 kg ai/ha was rather safe on V AM population in soil. Integrated nutrient management comprising of the use of organics, inorganics and bioinoculant was more cost effective and desirable in terms of crop performance and improvement in soil health.
Studies on the performance of rice variety 'Aswathy' under different methods of direct seeding and weed control
(Department of Agronomy, College of Horticulture, Vellanikkara, 1979) Sreedevi, P; Balakrishna Pillai, P
An experiment was conducted in the Rice Research Station and Instrumentation farm, Mannuthy, Kerala Agricultural University during the first crop season of 1978 to study the performance of a rice variety 'Aswathy' under different methods of direct seeding and weed control.
Time of application of pre-emergence herbicides on phytotoxicity and weed control in semi-dry rice
(Department of Agronomy, College of Horticulture, Vellenikkara, 1994) Susan Lee Thomas; Sreedevi, P
A field experiment entitled 'Time of application of pre-emergence herbicides on phytotoxicity and weed control in semi-dry rice' was conducted during first crop season (Virippu) of 1933 i.e., from May to September at Agricultural Research Station, Mannuthy under the Kerala Agricultural University, Vellanikkara, Thrissur. The objective of the trail was to find out the best time of application of pre-emergence herbicided on phytotoxicity and weed control in semi-dry rice. The experiment was laid out in split plot design with three replications. Treatments included in the trail were pre-emergence application of herbicides such as pendimethalin, thiobencarb, butachlor and oxyfluorfen at 0, 3, 6 and 9 days after sowing with handweeded and unweeded plots as the controls. The dominant weeds found in the experiment field were Digitaria sanguinalis and Cynodon dactylon among grasses, Cyperus rotundus and Cyperus iria among sedges and Cleome viscosa and Ageratum conyzoides among broadleaved weeds. The population of grasses was reduced by the application of oxyfluorfen at 6 DAS and pendimethalin upto 6 DAS. Hanweeding was significantly superior than the herbicides in lowering the number of sedges and broadleaved weeds. At 30 DAS the highest weed control efficiency was recorded by oxyfluorfen. Though phytotoxic symptoms were developed in rice seedling where oxyfluorfen was applied at 6 and 9 DAS, it later recovered by about two weeks. Pendimethalin and oxyfluorfen treated plots gave the highest number of tiller/m2. Chlorophyll content of leaves and dry matter production of rice were more in pendimethalin treated plots. Yield attributing characters and yield were higher in plots treated with pendimethalin at 3 DAS. Total returns and return per rupee invested were higher in the case of pendimethalin at 3 DAS and oxyfluorfen at 9 DAS.
Weed flora and their relative dominance in semi-dry rice culture
(Kerala Agricultural University, 1997) George Thomas, C; Abraham, C T; Sreedevi, P