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Open Access
Combined application of granular preparations of pre-emergent herbicides and fertilizers in rice
(Department of Agronomy, College of Horticulture, Vellanikkara, 1995) Bindu, N K; KAU; John, P S
A field experiment was conducted at the Agricultural Research Station, Mannuthy under the Kerala Agricultural University during the first crop season of 1994 to find out the effect of pre-emergent herbicides and fertilizers in rice. The experiment was laid out in a randomized block design and consisted of fourteen treatments with three replications. Broadleaved weeds and sedges dominated the field. Among broadleaved weeds, Mono choria vaginalis and sphenocleazeylanica were predomint. Shoenoplectus lateriflorus and Cyperus difformis were the prominent sedges present in the field and Echinochloa colonum,saccolepis interrrupta and Isachne miliacea were the important grasses present. Butachlor, anilofos and oxyflourfen under different methods of application reduced the weed Population. Though oxyflourfen recorded high weed control efficiency, it was highly phytotoxic to the rice crop and resulted in poor crop stand. Butachlor and anilofos applied as homemade granular (GP) preparation or as spray alone, or in combination with fertilizer was safe to the crop. The available nutrient in the soil was not affected by the different methods of application of butachlor and anilofos, alone or when combined with fertilizer. Butachlor and anilofos as spray or as GP applied alone, or in combination with fertilizer recorded similar crop growth characteristics, yield and yield attributes. Nutrient up taken by weeds was lower in butachlor and anilofos treatment. Lower weed index values were recorded in butachlor and anilofos treatment. The highest return per rupee was obtained from anilofos treatments. The highest return per rupees was obtained from anilofos treatments. In general, combined application of anilofos or butachlor GP with fertilizer gave efficient control of weed, produced higher grain yields and high return per rupee invested. It also reduced cost, energy and time of weed control operation.
Open Access
Qualitative and quantitative changes in stored rice
(Department of Home Science, College of Agriculture, Vellayani, 1995) Geetha, Roy; KAU; Prema, L
Qualitative and quantitative changes in stored rice varieties viz. PTB – 10 and Red Thriveni were determined by assuming the changes in their grain constituents, physical characteristics, insect infestation, cooking characteristics and organoleptic qualities. After six months storage effect of different storage containers such as gunny bag, pathayam and metal bin on these qualities were taken into consideration. The grain constituents like protein, nonprotein nitrogen, calcium , iron and phosphorous were found to decrease at a greater rate in PTB – 10 stored in gunny bag when compared to red thriveni. Similarly constituents like moisture, uric acid and freefatty acids were found to increase in PTB-10 than in red thriveni. Chnages in grain constituents, reducing sugars, nonreducing sugars, starch and amylose were observed both in raw as well as in cooked rice samples after storage. Increase in reducing sugar and amylose was at a greater rate in PTB-10 stored in gunny bag especially when cooked while nonreducing sugars and starch level were found to decrease in a similar order. Compared to PTB – 10 in gunny bag after storage, red Thriveni obtained lower values for thousand grain weight and total solid level, when stored in all the storage containers tried. Head rice yield and gelatinization temperature of rice samples increased in red thriveni after storage, the rate being higher in gunny bag when compared to other two storage structures. Viscosity was found to increase greatly in red thriveni stored in metal bin. Insect infestation was found to be greater in gunny bags while metal bin was found to be insect proof. PTB – 10 was affected by insects more when compared to Red thriveni. PTB-10 obtained higher values for cooking characteristics such as volume expansion and gruel loss than red thriveni, when stored in gunny bag. As as result of storage water uptake level and swelling index increased at a greater rate in red thriveni in all the storage containers tried. The rate of decrease in optimum cooking time was greater in PTB-10 stored in gunny bag while stickness was greatly reduced in red thriveni when compared to PTB-10. Raw rice samples were more acceptable before storage as quality parameter hardness increased after storage. Storage provided low scores for colour and odour which had a negative influence on consumer acceptance. Red Thriveni was more acceptable for all the quality attributes than PTB-10. The quality attributes colour and appearance obtained low scores in the two rice varieties the decrease being greater in PTB-10 than Red Thriveni. Taste, flavor and doneness was found to decrease in the two rice samples. The rate of decrease in taste. Flavor and doneness was lower in red thriveni when compared to PTB-10. Among the storage containers, metal bin was found to be a better storage structure than pathayam and gunny bag. The experiment threw light on the significant of metal bin as a storage structure and favourable facts in the shelf life qualities of evolved varieties like red thriveni.
Open Access
Optimum plot size for inter croping experiments
(Department of Agricultural Statistics, College of Horticulture, Vellanikkara, 1995) Reji, K; KAU; Sunny, K L
A uniformity trial was conducted in bhindi intercropped with cowpea at the experimental field of College of Horticulture, Kerala Agricultural University, Vellanikkara during July 1993 to December 1993 to assess the nature and magnitude of soil heterogeneity, and to determine the optimum size of plot for increasing the efficiency of experiment with intercropping. Three different approaches have been attempted in the statistical analysis. At the time of harvest, the yield data from 320 plots each of size 0.60m x 0.45m were recorded separately after discarding the border rows. It was observed that the index of soil heterogeneity was very high in all these approaches indicating that the contiguous plots are not correlated and the fertile spots are distributed randomly or in patches. It was also observed that an increase in the plot size in either direction decreased the coefficient of variation but the decrease was not proportional in all these approaches. The empirical law suggested by smith gave a satisfactory fit to the data. All the other non- linear models tried also gave a satisfactory fit to the data in all these approaches. The optimum plot size obtained by following different approaches indicated that 10 basic units plots(2.7m2) are optimum for conducting the intercropping experiment with bhindi and cowpea. Comparison of the LER and the bivariate analysis method showed that for the same level of precision the LER method gives a smaller plot size implying that per unit cost of experimentation will be higher in bivariate analysis. For any choosen plot size the precision attained through LER analysis is larger than that through bivariate analysis. However, when the multivariate approach is adopted the optimum plot size was obtained as 10 basic units (2.7m2) as in the case of LER.
Open Access
Development of subsurface pad irrigation system for tomato
(Department of Agronomy, College of Agriculture, Vellayani, 1995) Abdul Nassar, K; KAU; Jaikumaran, U
An experiment was conducted in the summer rice fallows of the Agricultural Research Station, Mannuthy during 1995 to develop and test subsurface pad irrigation system for tomato and to compare it with surface irrigation. The soil was sandy clay loam, medium in organic carbon and available potassium and high in available phosphorus. The eight treatments comprised of combination of four frequencies of irrigation (IW/CPE ratios of 1.2, 0.9, 0.6 and 0.3) and two irrigation systems (subsurface pad irrigation and surface irrigation). The experiment was laid out in randomized block design with three replications. Poly bags filled with saw dust placed 45 cm beneath the surface at the frequency of one pad for every four plants formed SSPI. Water was supplied to pads by laterals supplying 40 mm of water per irrigation. The study revealed that tomato responded very well to irrigation. Biometric characters like plant height, number of leaves and leaf area index and yield attributing characters like number of flowers, number of fruits and total weight of fruits per plant were favourably influenced by frequent irrigation under both the systems of irrigation. The fruit yield increased with frequency of irrigation and maximum at the IW/CPE ratio of 1.2. The plants irrigated by surface method grew taller, had more leaf area index, produced more number of green leaves, flowers, fruits and total fruit weight per plant compared to the plants irrigated under SSPI system at the irrigation frequencies of IW/CPE ratios 1.2, 0.9, and 0.6. But at the IW/CPE ratio of 0.3, the subsurface irrigated plants performed better than the surface irrigated plants both in terms of growth and yield attributing characters. The crop receiving irrigations through SSPI systems consumed lesser amount of water at all the frequencies of irrigation compared to surface method. This decline at the IW/CPE ratios of 1.2, 0.9, 0.6 and 0.3 were to the tune of 22,30,40 and 18 per cent respectively. The soil moisture extraction from 0-15, 15-30 and 30-60 cm layers in SSPI was 62-70, 24-29 and 6-12 per cent respectively whereas in surface irrigation the respective values were 62-64, 22-23 and 13-15 per cent. The soil moisture redistribution was rapid in the case of surface irrigation whereas it was gradual in the case of SSPI. Moisture content in the case of SSPI was maximum at the radial distance of 15 cm from the pad on either sides whereas in surface irrigation there was no remarkable difference in the moisture content with respect to radial distance from the plant.
Open Access
Response of Gladiolus to Rapid Cloning Through in Vitro Techniques
(Department of pomology and floriculture, College of horticulture,Vellanikkara, 1995) Sakkeer Hussain, C T; KAU; Geetha, C K
Investigations were carried out to study the response of gladiolus to rapid cloning through in vitro techniques at the Department of Pomology and Floriculture and Plant Tissue Culture Laboratory of All India Co-ordinated Floriculture Improvement Project, College of Horticulture, Vellanikkara, during 1992-94. The main objective was to identify the most suitable explant and media combination for in vitro cloning. The explants used were corm axillary buds, cormel tips, inflorescence nodal segments (for enhanced release of axillary buds), inflorescence internodal segments, flower buds, flower bud bracts, root segments (for somatic organogenesis) and leaf segments (for somatic embryogenesis). The best season for the collection of corm axillary buds and cormel tips was from September to May. Surface sterilization of the explants could be effectively done with 0.1 or o.2 per cent mercuric chloride and the duration of treatment varied from I to25 minutes. Culture establishment of the corm axillary bud, cormel tip explants were better in MS medium supplemented with BAP ranging from 1.0 mg 1 -1 to 4.0 mg 1-1. The concentration of BAP required varied according to the stage of development of corms and cormels. Higher levels of BAP was ideal during early stages of development of corm and cormels. Of the different media (White’s, SH and MS) tried, MS medium was found to be the best culture establishment (Stage 1) when supplemented with 3.0 mg 1-1 BAP. Elongated shoots of Stage I were subjected to shoot proliferation (Stage 2). Multiple axillary bud production was very high when the MS medium was supplemented with BAP 1.0 mg 1-1 and NAA 0.5 mg 1-1 or BAP 2.0 mg 1-1 and NAA 0.5 mg 1-1. Callus production from the base of the elongated shoots were observed when the concentration of NAA increased in the medium. Of the different cytokinins (BAP, kinetin and 2ip) tried, BAP was found to be the best in Stage 2. Frequent subculturing onto the MS medium containing BAP 2.0 mg 1-1 and NAA 0.5 mg 1-1 increased the production of multiple axillary buds. These when transferred to the MS medium devoid of growth regulators resulted in elongation of shoots. The elongated shoots produced maximum number of roots in the MS medium containing 1.0 mg 1-1 IBA under the exclusion of light. However, early rooting was obtained in MS liquid medium devoid of growth regulators. Plantlet survival was maximum when treated with 0.2 per cent Bavistin immediately after removing from the culture vessels, followed by treatment with 0.2 per cent mancozeb and norfloxacin at the time of transplanting and post planting treatment with 1/10 MS solution and drenching with triadimefon 20.0 mg 1-1 at three days interval inside improvised mist chamber. Direct organogenesis could be obtained from immature inflorescence segments in modified MS medium supplemented with 15.0 mg 1-1 NAA and 3.0 mg 1-1 BAP. Among the various explants tried for callus mediated organogenesis, callus index was the maximum (400) when immature inflorescence segments were inoculated to the modified MS medium supplemented with NAA 15.0 mg 1-1 in 16 h photoperiod and also in the medium supplemented with 15.0 mg 1-1 NAA + 2.0 mg 1-1 BAP and kept under exclusion of light. The callus derived from inflorescence segments differentiated into shoots in the MS medium supplemented with 3.0 mg 1-1 BAP and also in the medium supplemented with 1.0 mg 1-1 BAP and 0.5 mg 1-1 NAA. Callus also could be obtained from flower buds and flower bud bracts. The callus derived from the corm axillary buds and cormel tip explants in Stage 2, differentiated in the basal MS medium devoid of growth regulators or supplemented with 20.0 ml 1-1 coconut water and also in the medium with 0.5 mg 1-1 BAP. The root segments (both in vitro and in vivo) produced callus in MS medium supplemented with 1.0 mg 1-1 NAA and the differentiation was obtained in the medium containing 3.0 mg 1-1 BAP an 1.0mg 1-1 NAA. Leaf segments failed to develop callus. However, the explants collected from the leaf covering the inflorescence boot leaf) when cultured in modified MS medium supplemented with 15.0 mg 1-1 NAA and 1.0 mg 1-1 BAP and incubated under darkness for three months developed somatic embryos. In vitro corm production was noticed in the cultures, if planting out was delayed. Earliest and large sized corm induction was made possible in elongated shoots of gladiolus from Stage 2 in Ms medium containing 5.0 per cent sucrose, 0.5 mg 1-1 NAA and 5.0 mg 1-1 triadimefon kept under etiolated condition. The size of the in vitro produced corms enlarged from 0.2 cm to 2.3 cm in the MS liquid medium containing 5.0 per cent sucrose and 3.0 mg 1-1 triadimefon.
Open Access
Effectiveness and crop seletivity of pre-emergence herbicides under different methods of application in puddled rice
(Department of Agronomy, College of Horticulture, Vellanikkara, 1995) Mohan Kumar, P D; KAU; Savithri, K E
A field experiment was conducted at the Agricultural Research Station, Mannuthy under the Kerala Agricultural University during the second crop season of 1992-93 to find out the effectiveness and crop selectivity of pre-emergence herbicides under different methods of application in puddled rice. Twelve treatments were com- pared with two controls (hand weeded and unweeded). The experiment was laid out in Randomised Block Design with three replications. Sedges and broadleaved weeds dominated the weed flora. Among the sedges, Schoenoplectus lateriflorus, Cyperus iria, C. difformis and Fimbristylis miliacea were the prominent species, and the broadleaved weeds included Mono- choria vaginalis, Marsilia quadrifoliata, Sphenochlea zeylanica and Nymphaea nouchali. The broad leaved weeds were effectively controlled by pretilachlor + safener, oxyflourfen and pendimethalin, besides butachlor and thiobencarb. All the herbicides except pendimethalin and anilofos gave good control of sedges. Oxyflour- fen spray showed the highest weed control efficiency among the herbicides tested. Sand mixed broadcasting of herbicides was found to be lesser toxic than spray in all the herbicides except pretilachlor + safener, where the safener present protected the crop completely from phytotoxicity. Crop growth characteristics were highly influenced by the herbicide and method of application. Pretilachlor + safener, oxyflourfen and thiobencarb were found superior. Yield attributes were relatively unaffected by the different treatments. Pretilachlor + safener spray recorded the highest yield, among herbicides. Sand mixed broadcasting of all other herbicides produced a slightly higher grain yield compared to spray. Nutrient uptake by crop was directly related to the dry matter accumula- tion. The lowest weed index value was registered by pretilachlor + safener spray. Pretilachlor + safener spray recorded the highest total returns and its sand mixed broadcast realised the highest return per rupee invested on weed control.
Open Access
Soil nutrirent dynamics in cocoa
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 1995) Smitha, B; KAU; Wahid, P A
An investigation on the dynamics of soil nutrients in the rootzone of cocoa (Theobroma cacao) was conducted during 1993 – 94 at the College of Horticulture, Vellanikkara. Soil and leaf samples were taken from cocoa trees under the Cadbury – KAU Co – operative Cocoa Research Project, Vellanikkara. Cocoa variety used for the study was forastero. The soil of the site was laterite (Oxisol). The treatments consisted of factorial combinations of N, P and K fertilizers each at two levels (with and without), two levels (with and without) of irrigation and shade and seven age groups namely 1, 3, 4, 5, 6, 9 and 12 years. Soil samples were also collected from an uncropped and unfertilized area nearby. The impact of long – term inorganic fertilization, irrigation and shade and age of the tree on soil chemical characteristics as well as foliar nutrition of cocoa influenced by long – term inorganic fertilization, irrigation and shade were assessed. Continuous application of urea for a period of nine years increased soil acidity and availability of P, S, Fe and Mn. It also increased total soil P and Fe. But it resulted in depletion of available K, Ca, Mg, Zn and Zn and Mn reserves of the soil. Long – term application of superphosphate resulted in the build – up of available and total P in soil. It also improved the status of soil available Ca, S and soil reserves of Ca and S. But it depleted soil available and total K, available and total Zn, available Mg and Cu and total Mn. Muriate of potash application increased the available and total K content of the soil. On the other hand it caused depletion of available P, Ca, S, Mn, Cu and soil Ca and Mg reserves. Interactions among urea, superphosphate and muriate of potash were also significant with regard to the fertility of the cocoa rootzone is concerned. Increasing soil acidity due to urea application, enrichment of S and Ca due to superphosphate application, and decrease in available P and S due to muriate of potash application were highly influenced by depth. Regular irrigation over a period of five years resulted in reducing the availability of P, Ca, Mn and Cu. It also reduced the total P and Mn in soil. But available K, Zn, S and total S tended to increase with irrigation. In the irrigated plots, total and available P were significantly lower in the surface layers compared to that in unirrigated plots. Provision of shade for a period of 13 years resulted in the build – up of soil organic carbon, available P, Fe and soil reserves of P, Ca, S, Fe, Zn and Mn. On the other hand it decreased the concentrations of available and total K, available S, and Zn and total Mg. Irrigation x shade interaction significantly influenced the available P content of soil. Urea application increased the foliar concentrations of N, Fe, Mn and Cu, but it decreased the leaf K content significantly. Long – term superphosphate application reduced Zn content of cocoa leaf. Application of muriate of potash increased leaf K content, but depressed foliar mg content significantly. Leaf N and K contents of cocoa were highly influenced by N x K interactions. N x P interaction significantly affected foliar Zn concentration of cocoa. Foliar Zn recorded higher values in plants receiving no nitrogen and phosphorus. Irrigation resulted in increased foliar concentrations of almost all nutrients except that of Ca and Mg. Foliar Ca content was higher in unirrigated plants. Effects of irrigation on leaf Mg was not significant. Cocoa trees under shade recorded higher concentrations of N, P, Mg, Fe and Mn and Cu in their foliage while K content was higher in open grown plants. Irrigation x shade interaction significantly influenced foliar N content. Shaded and irrigated conditions resulted in highest foliar N content. Nutrient dynamics in rootzone of cocoa over a period of 12 years of crop growth and fertilization could be described by linear or quadratic model. The linear model was found to be a better fit for available and total K, available and total Mg, available Cu and total Zn. In the case of available and total P, available and total Ca, available Zn, total S and total Cu the changes in concentrations with time could be described by a quadratic model. Available Mn content of the soil showed steady increase with age up to nine years followed by a sharp decrease.
Open Access
Dynamics of the absorption of forms of N by crops plants
(Department of Agronomy, College of Horticulture, Vellanikkara, 1995) Retheesh, P K; KAU; Balachandran, P V
An investigation was conducted at the Radiotracer Laboratory, College of Horticulture, Vellanikkara in the year, 1993 which consisted of two parts. In the first part absorption of different forms of nitrogen relative to its concentrations at different growth stages of rice was studied using labelled and non-labelled fertilizers. To know the molecular absorption of urea 14C-labelled urea fertilizer was used and the presence of 14C in the plant was taken as an evidence for the absorption of molecular form of urea. In the case of ammoniacal and nitrate forms of N, 15N-labelled and non-labelled materials were used alternately to find out the preferential absorption. In the second part of the investigation an attempt was made to know the possibility of molecular absorption of urea by a few selected plantation crops. The uptake of N and dry matter production were higher when rice plants were supplied with a combination of ammonium and nitrate in equal proportions. Among the three forms of nitrogen supplied at different combinations, nitrate N recorded the highest uptake when present along with urea N or ammoniacal N or both. Though the presence of urea had a repressing effect on the uptake of nitrate, ammonium enhanced the nitrate uptake. The uptake of nitrate N was more in the presence of ammonium than in its absence. With respect to ammonium uptake it was found that urea and nitrate had more or less similar influence on it. It was seen that rice plants absorbed molecular form of urea even in the presence of other readily available forms of nitrogen. The molecular absorption of urea by rice plants was found to vary from 12-18 percentage of the total N uptake. When urea was supplied along with ammonium and or nitrate the uptake of urea was found reduced. The quantity of urea absorbed by the plantation crops was found negligible and ranged from 0.5-3.3 µg per g of the plant dry weight.
Open Access
Combining ability studies in tomato (lycopersicon esculentum mill)
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 1995) Seeja, G; KAU; Chandramony, D
An experiment in tomato (Lycopersicon esculentum Mill.) was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 1993-94, with the objective of estimating the combining ability of parents and gene action, involved in the inheritance of different yield attributes. The study was conducted in a line x tester model, using three bacterial wilt resistant varieties as lines and five popular varieties as testers. The three bacterial wilt resistant varieties (lines) were Arka Abha, Arka Alok and Sakthi. The five popular varieties (testers) were LE 312, LE 370, LE 373, RFH-1 and PKM-1. These eight parental varieties and 15 hybrids were planted in the field in RBD, with three replications. Observations recorded were plant height, number of branches/plant, growth habit, spread of the plant, period of harvest, individual fruit weight, number of fruits/plant, fruit yield/plant, number of leaves/plant, pericarp thickness, locules/fruit, size of fruit and pest and disease incidence. Analysis of variance revealed highly significant differences among the genotypes for all the characters. Gca alone was significant for number of branches/ plant while sca alone was significant for spread of the plant and pericarp thickness. Both gca and sca were significant for the remaining characters such as plant height, period of harvest, individual fruit weight, fruits/ plant, fruit yield/plant, leaves/plant, locules/fruit and size of fruit. The additive to dominance variance ratio indicated a preponderance for non additive gene action in the above characters. Combining ability analysis showed that all the three lines viz., Arka Abha, Arka Alok and Sakthi were good general combiners with respect to fruit yield and other yield attributes whereas the testers were good general combiners, for the different vegetative characters such as plant height, branches and leaves/plant. Among the 15 hybrids combinations, significant sca and heterosis were observed in the hybrids such as Arka Abha x LE 370, Arka Alok x PKM-1, Arka Alok x LE 312, Arka Abha x RFH-1 and Sakthi x RHF-1. Among these hybrids, Arka Abha x LE 370 showed significance for fruit yield, individual fruit weight, size of fruit, plant height, leaves/plant, branches/plant and also showed resistance to mosaic, leaf cur1 and fruit borer. This hybrid exhibited indeterminate growth habit. The hybrid Arka Alok x PKM-1 showed significance for fruits/plant, fruit yield/plant, plant height and leaves/plant. The combinations Arka Alok x LE 312 and Arka Alok x RFH-1 showed high sca and heterosis for individual fruit weight, fruit size and pericarp thickness, and also high heterosis for fruit yield/plant. Among these, Arka Aloka 312 showed indeterminated growth and Arka Alok x RFH-1 showed semi determinate growth habit. Sakthi x RFH-1 exhibited high sca for fruit yield/plant and heterosis for fruit number and individual fruit weight. This hybrid also showed resistance to leaf curl and mosaic. This hybrid showed determinate growth habit. Therefore these hybrids can be utilized for further crop improvement programme.

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