Browsing by Author "Oommen, M"

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Control of phanerogamic parasites infesting mango
(Department of Agronomy, College of Agriculture, Vellayani, 1993) Rashmi, C R; Oommen, M
To study the intensity of infestation of Loranthus and to suggest its control measures in mango orchard, survey and field experiments were conducted during 1992 – 93. The survey was carried out in three D.A.F. viz., Peringamala, Anchal, Mavelikkara and Instructional Farm, attached to the College of Agriculture, Vellayani. It was revealed from the survey that the Loranthus species Helicanthes elastic was attacking the mango orchards in all the locations of southern Kerala. It was also noticed that the rate of infestation of the parasitic weed was greater in older orchards than in younger ones. Out of the eight common varieties cultivated in all the locations, Bangalora variety recorded relatively lesser infestation than others. The field experiments were confined to Instructional Farm College of Agriculture, Vellayani. The experiment pertaining to the cultural control measures had three treatments viz., clearing of the parasite once in three months (T1) clearing of the parasite once in six months (T2) and unweeded control (T3), with six replications tested in a Randomized Block Design. Frequent lopping of the parasite as administrated in T1 recorded the least number of the infestations, biomass and carbohydrate uptake compared to T2. The number of haustoria spread of infestation, nutrient uptake and protein uptake were found to be comparable between T1 and T2. T2 was found to be more economical than T1. The chemical control experiments comprised of four herbicides viz., Simazine 10 mg a.i per litre (C1), atrazine 10 mg a.i per litre (C2), glyphosate 10 mg a.i per litre (C3) and dalapon 10 mg a.i per litre (C4) with two methods of application viz., padding and infusion with three replication in a Randomized Block Design. Infusion of all the herbicides invariably recorded its superiority in controlling the parasite than by padding. Among the four herbicides tried atrazine and glyphosate appreciably controlled the number of infestations, spread of infestation and biomass of the parasite. The uptake of nutrient, carbohydrate and protein by the parasite was also reduced by the application of atrazine and glyphosate. Infusion of atrazine and glyphosate was found to be the best treatment in controlling parasite growth and development. No visual symptoms of toxicity was found on the host after the application of any of the herbicides. Residual content of atrazine in the mango fruits was found to be below the toxicity level.
Cultural, manurial and water requirements for sweet potato (Iponoea batatas (L) Lam.)
(Department of Agronomy, College of Agriculture, Vellayani, 1989) Oommen, M; Sadanandan, N
Three field experiments were conducted in the wet lands and garden lands of Instructional farm of College of Agriculture, Vellayani to work out cultural, manurial and water requirements for sweet potato. The treatments in the first experiment – Nutritional requirements of sweet potato – consisted of three level of nitrogen (50, 70 and 100kg N/ha), three levels of phosphorus (25, 50 and 75kg P2O5/ha) and three levels of potassium (50, 75 and 100kg K2O/ha). The experiment was laid out in a 33 partially confounded factorial design with two replications. The second experiment – spacing cum depth of application of fertilizers – consisted of three spacing (40cm x 20cm, 60cm x 20cm and 80cm x 20cm) and three depths of application of fertilizers (10cm, 20cm and 30cm). The experiment was laid out in a 32 factorial design in RBD with four replications. The third experiment – Irrigation requirement – consisted of four levels of irrigation (IW/CPE ratios 0.25, 0.50, 0.75 and 1.00) and four levels of fertilizers (50:25:50, 75:50:75, 100:75:100 and 125:100:125 kg N,P and k/ha). The experiment was laid out in a split plot design with five replications. In the experiment to study the nutritional requirement of sweet potato growth attributes like length of vine, number of branches and leaf area index were maximum at higher levels of nitrogen and potassium. The highest values of tuber number, tuber weight, length of tuber and girth of tuber were obtained by the application of 75kg N, 50kg P2O5 and 100kg K2O/ha. Application of nitrogen, phosphorus and potassium at the rate of 75:50:100 kg/ha was found to be optimum for higher tuber yield. While nitrogen nutrition increased the protein content of tuber, potassium application enhanced the starch content. Highest levels of nitrogen, phosphorus and potassium increased the leaf, stem and tuber dry matter production and tuber bulking rate. Potassium only did influence the net assimilation rate. Crop growth rate was maximum at higher levels of nitrogen, phosphorus and potassium. The plant uptake of nitrogen, phosphorus and potassium was maximum at the highest level of these nutrients. The NPK combination of 75kg N, 50kg P2O5 and 100kg K2O/ha resulted in the maximum net return. Experiment on spacing cum depth of application of fertilizers revealed that wider spacing of 80cm x 20cm enhanced the growth characters such as length of vine, number of branches and LAI. Depth of application was not influential on this aspect. Yield attributes like tuber number, tuber weight and girth of tuber were higher at the spacing of 40cm x 20cm but length of tuber was maximum under wider spacing. Application of fertilizers at 20cm depth recorded maximum values for the aforesaid characters. Closer spacing of 40cm x 20cm and 20cm deep placement of fertilizers recorded higher tuber yield. Among the quality attributes protein content alone was influenced by wiser spacing, but protein and starch contents were increased when fertilizers were applied at 20cm depth. Wider spacing increased leaf and stem dry matter and CGR while closer spacing recorded higher tuber dry matter, tuber bulking rate and net assimilation rate. Depth of application of fertilizers did not influence the dry matter production. Plant uptake of nitrogen, phosphorus and potassium was increased by wider spacing and by the application of fertilizers at a depth of 20cm. A combination of 40cm x 20cm spacing and 20cm deep fertilizer placement resulted in maximum net return. Experiment on irrigation requirements divulged that highest IW/CPE ratio and higher fertilizer combinations recorded maximum length of vine and LAI, but number of branches was not influenced by them. Number of tubers, weight of tubers, length of tubers and girth of tubers were not influenced by irrigation, while levels of fertilizers increased the length of tubers. Tuber yield was higher at IW/CPE ratio of 0.75. Fertilizer combination of 100:75:100 kg of N, P and k/ha produced the maximum yield. Starch and protein contents were increased at higher levels of irrigation and fertilizer application. Total dry matter production and bulking rate increased upto an IW/CPE ratio of 0.75 and upto a fertilizer lever of 100:75:100 kg N, P and k/ha. Plant uptake of nitrogen, phosphorus and potassium at harvest was maximum at higher levels of irrigation and fertilizer application. Irrigating the field when the IW/CPE ratio becomes 0.75 and application of fertilizers at a ratio of 100:75:100 kg N, P and k/ha recorded maximum net returns.
Effect of salt solution spray on paddy grain maturity and yield
(Kerala Agricultural University, 1979) Oommen, M; Chandrasekharan, P; Sadanandan, N
Effect of slow release nitrogenous sources on growth and yield of rice variety: jaya
(Kerala Agricultural University, 1977) Oommen, M; Sadanandan, N; Mohammed Kunju, U; Sasidhar, V K
An investigation was carried out at the Model Agronomic Research Station, Karamana during the second crop season 1975 to study the comparative efficiency of different slow release nitrogen sources on growth, yield and yield contributing attributes of rice variety Jaya. All the slow release nitrogen sources were superior to ordinary untreated urea. Highest percentage of productive tillers was recorded by neem cake blended urea followed by AM treated urea. The weight of panicle was maximum in AM treated urea followed by neem cake blended urea. AM treated urea also gave the highest number of spikelets per panicle. Thousand grain weight, yield of grain and straw were maximum in AM treated urea followed by neem cake blended urea. AM treated urea gave an average yield of 4687kg/ha followed by neem cake blended urea which gave 4296kg/ha. The minimum grain yield of 2688kg/ha was given by untreated urea.
Note on the effect of salt solution spray on the germination of seed in rice
(Kerala Agricultural University, 1979) Oommen, M; Chandrasekharan, P; Sadanadan, N
Nutrient management for intercropped colocasia esculenta var thamarakannan
(Department of Agronomy, College of Agriculture, Vellayani, 1993) Rajasree, J; Oommen, M
Field experiments were conducted at the Instructional Farm, College of Agriculture, Vellayani to study the effect of nitrogen and potassium on growth and yield of Colocasia and uptake pattern of major nutrients under open and intercropped situations in coconut gardens. The treatments in the experiment consisted of a combination of three levels of N) 40, 60 and 80 kg/ha) and three levels of K (80, 120 and 160 kg/ha). The experiment was laid out in 32 factorial RBD. Different growth attributes like plant height, number of leaves plant-1and LAI were maximum when N @ 60 kg/ha and K @ 160 kg/ha were applied under open condition. Under intecropped situations N @ 40 kg/ha and K @ 160 kg/ha recorded the maximum values for these characters. The yield attributes viz., number of cormels/plant, mean weight of cormels, cormel and corm yield/plant, and harvest index gave maximum values when N @ 60 kg/ha and K @ 160 kg/ha were applied under open condition. In the intercropped situation, the highest values were obtained when N and K were applied @ 40 and 160 kg/ha. Nitrogen @ 60 kg/ha and K @ 160 kg/ha gave the highest yield of marketable tubers under open condition while K @ 160 kg/ha gave the maximum yield under intercropped situation. Nitrogen had no influence on yield of marketable tubers under intercropped situations. Pottasium application increased the starch percentage of tubers and 160 kg K/ha resulted in the maximum value under open and intercropped situations. Plant uptake of N, P and K were influenced by increasing levels of K and was highest at the highest level of K in both open and intercropped situations. Available N and P content of the soil was not influenced by N and K levels under open condition, while the available K was maximum when 160 kg/ha was applied in both open and intercropped situations. Maximum benefit cost ratio and net returns were obtaining by the application of N and K @ 60 kg/ha and 160 kg/ha respectively under open conditions and 40kg/ha and 160 kg/ha respectively under intercropped situation with coconut.
Nutritional requirement of arrow root as pure crop
(Department of Agronomy, College of Agriculture, Vellayani, 1991) Remesan, K K; Oommen, M
A field experiment was conducted in garden lands of Instructional Farm of College of Agriculture, Vellayani, to study the effect of N, P and K on growth, yield and quality of arrow root and uptake pattern of major nutrients. The treatments in the experiment consisted of four levels of nitrogen (0, 50,100 and 150 kg/ha N). Four levels of phosphorus (0, 25, 50 and 75 kg/ha P2O5) and four levels of potassium (0, 50, 100 and 150 kg/ha K2O). The experiment was laid out in 43 partially confounded factorial in RBD with two replications. Different growth attributes like height of plants, number of leaves, number of suckers per plant, leaf area index were maximum at higher levels of nitrogen and potassium. The total drymatter production was highest by the application of 150 kg N. 75 kg P2O5 and 150 kg K2O per hectare. The highest value of rhizome number, length of rhizome and girth of rhizome were obtained by the application of 100 kg/N, 75 kg P2O5 and 150 kg/ha K2O. Maximum mean rhizome weight was with 150 kg n/ha, 75 kg P2O5 and 150 kg K2O per hectare. Fresh weight of plants was maximum with highest levels of nitrogen, phosphorus and potassium. Rhizome yield was maximum when nitrogen, phosphorus and potassium were applied at the rate of 150, 75 and 150 kg/ha respectively. Highest levels of nitrogen, phosphorus and potassium increased the starch, yield and protein content of rhizome. Nitrogen nutrition increased the crude fibre content of rhizome, but potassium application decrease the fibre content. The plant uptake of nitrogen, phosphorus and potassium was maximum at highest level of these nutrients. Maximum benefits cost ratio and net return were obtained by the application of 150 kg/ha N, 75 kg/ha P2O5 and 150 kg/ha K2O.
Nutritional requirement of green gram (Vigna Radiata (L.) Wilczek) grown in rice fallows
(Kerala Agricultural University, 1981) Savithri, K E; Nair, K P M; Oommen, M; Abdul Salam, M
A field experiment to study the effect of three graded levels each of nitrogen (20, 30 and 40 kg/ha), phosphorus (30, 45 and 60 kg Pa05/ha) and potash (10, 20 and 30 kg K20/ha) on the yield and quality of green gram variety, Pusa Baisakhi grown in rice fallows of the Instructional Farm, College of Agriculture, Vellayani, Trivandrum has shown that the grain yield was significantly increased by highest level of potash over the lowest level and bhusa yield by highest level of nitrogen over the lower levels. Levels of nutrients had no significant influence on grain protein content, but highest level of potash significantly increased the grain protein yield over the lowest level. In the case of protein content of bhusa, higher levels of potash showed an adverse effect whereas fodder protein yield was not significantly affected by the treatments.
Protein content of paddy grains as influenced by slow release nitrogen fertilisers
(Kerala Agricultural University, 1977) Oommen, M; Sadanandan, N; Mohamed Kunju, U