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Open Access
Response of tomato to varying levels of fertigation
(Department of Agronomy, College of Horticulture, Vellanikkara, 2002) Rajaseelan Kingsly, D; KAU; Jaikumaran, U
A field experiment was conducted during 2000-2001 at the Agricultural Research Station, Mannuthy, Thrissur to find out growth and yield as well as water use and nutrient relations of tomato, as influenced by different levels of fertigation i.e. continuous nutrition through drip irrigation. The experiment consisted of combinations of three levels of irrigation (0.3,0.6 and 0.9 PE) through drip system and three levels of fertilizer (100, 50 and 150% recommended dose) supplied through drip irrigation. The fertilizer nutrients were supplied in progressive increments for sixty days and the fertigated treatments were mulched using black HDPE sheet. A control treatment, which received 20 mm surface irrigation through furrow method once in three days along with normal soil application of fertilizer without mulch cover was also included to compare with fertigation treatments. The experiment was laid out at randomised block design with three replications. The tomato CV Shakthi was tried in the experiment. The results revealed that the growth parameters viz., plant height, Leaf Area Index (LAI) and ~eaf Area Duration (LAD) were higher in the fertigated treatments than in the control crop. The respective values were 50.48 cm, 5.60 and 113.4 in case offertigated crops and 48.52 cm, 5.46 and 110.9 for the control crop, when observed at final growth stage. The control crop had a significant rooting pattern with higher vertical length (26.8 cm), lateral length (15 cm) and root dry weight of (8.2 g) than the fertigated treatments which had the respective values of 18.65 cm, 11.00 cm and 3.9 g. The ferigated crop produced maximum fruit set of 56.5 per cent and 36 numbers of fruits plant" with mean yield of 31.51 t ha-I. The respective values for the control crop were 42.6 per cent, 22 and 19.31 t ha" only. The treatment which received 150 per cent fertilizer dose with 0.6 PE irrigation gave a maximum yield of37.3 t ha-I which was 93 per cent more than the control crop. This level of production was comparable with that of the crop receiving 100 or 150 per cent recommended dose of fertilizers with irrigation at 0.9 PE through drip. The TSS content was not influenced by different treatments, but higher acidic fruits were produced by the control crop. The fertigated crops in general contained more nutrients in their biomass compared to control crop. The highest NPK content in plant was recorded at 60 DAP and at the stage these nutrient contents were 4.9,0.285 and 3.13 per cent in case offertigated crops and the respective values in control crop were 4.0, 0.245 and 3.07 per cent. The fruit cracking and bacterial wilt incidence were not affected by various treatments. But 72 per cent of control crop suffered by leaf curl virus disease but only 40 per cent, in case of fertigated plants. The mean soil temperature upto 30 cm depth increased "<-;- under mulched conditions over control treatment during morning (7.;3<) 1ST) and 'L.C;;- evening (2.:Mt 1ST) by 3.3°C and 2.6°C respectively. While control crop received 700 mm of water, the crop irrigated through the drip at 0.9, 0.6, 0.3 PE received 506, 358 and 210 mm of water. Field water use efficiency was the highest in the treatment which received 100% fertilizer with 0.3 PE irrigation (14.62 kg fruit per m-3 of water). As the irrigation levels reduced and fertilizer application increased FWUE was increased. The moisture content of the soil was more at 15 cm depth both at 15 and 30 cm radial distances, in all irrigation levels. The economic analysis indicated that the crop under recommended dose of fertilizer with 0.9 PE irrigation gave a maximum BC ratio of 1.92 followed by the crop raised under 150 per cent fertilizer dose with 0.6 PE irrigation (1.91). The saving of water through respective treatments, when compared to control enabled 0.38 and 0.95 ha to be additionally brought under irrigated tomato, if respective treatments were employed. The investigation led to the conclusion that fertigation is a sound technology and produceshigh yields in tomato. If water is not a limiting factor, adopt irrigation at 0.9 PE using 100 per cent recommended dose of fertilizer and if water availability is - constrained, adopt irrigation at 0.6 PE using 150 per cent recommended dose of fertilizer to reap rich harvest.
Open Access
Integrated nutrient management in hedge lucerne (Desmanthus virgatus(L.)willed) under rainfed condition
(Department of Agronomy, College of Agriculture, Vellayani, 2001) Kavitha, G V; KAU; Lakshmi, S
A field experiment was conducted at the Instructional Farm, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala State to find out an integrated nutrient management technique for Desmanthus virgatus (L.) Willd. under rainfed condition. The influence of chemical fertilizers and biofertilizers on growth parameters, fodder yield, quality of produce, uptake of nutrients, chemical properties of soil and economics was investigated. Three levels of nitrogen (0, 15, 30 kg N ha"), three levels of potassium (0, 20, 40 kg ha") and biofertilizers (Rhizobium, AMF and Rhizobium + AMF) were combined to form twenty seven treatment combinations. The experiment was laid out in split plot design with three replications. Results of the experiment revealed that the chemical fertilizers as well as bioinoculants had significant positive influence on improving the fodder production potential of Desmanthus virgatus. Application of inorganic fertilizers and eo- inoculation of hedge lucerne with Rhizobium and AMF significantly increased the growth parameters namely plant height, length of branches, number of branches and leaf: stem ratio. Highest dose of chemical fertilizers and dual inoculation with biofertilizers registered maximum green fodder yield in all four harvests. Similar results were obtained in the case of dry fodder yield also. Quality parameters of the forage significantly improved as a result of dual inoculation with biofertilizers. Maximum crude protein content was realized with application of highest dose of nitrogen and potassium. The nutrient uptake showed a significant increase with increase in doses of chemical fertilizers. Dual inoculation of biofertilizers significantly increased the uptake of nitrogen, phosphorus and potassium. Combined application of biofertilizers improved the nitrogen and phosphorus status of the soil after the experiment. Highest dose of nitrogen gave the highest soil nitrogen content. Similarly highest dose of potassium recorded highest soil potassium content after the experiment. The physical and economic optimum dose of nitrogen for Desmanthus virgatus was 32 kg ha-I and 31 kg ha-I respectively while that of potassium was 22 kg ha-I, The use of chemical fertilizers and dual inoculation with biofertilizers recorded highest net returns and benefit: cost ratio, emphasizing the need for an integrated approach in nutrient management.
Open Access
Nutrient management for basmati rice (oryza sativa L) in wetlands
(Department of Agronomy, College of Agriculture, Vellayani, 2002) Sindu, M S; KAU; Annamma, George
A field experiment was conducted at the Instructional Farm, College of Agriculture, Vellayani from September 2001 to January 2002 to derive an optimum package for nutrient management for basmati rice in wetland condition. The experiment was laid out in factorial RBD with three replications. The treatments consisted of three levels of N (60, 90 and 120 kg N ha"), two sources of N (SI: SO per cent N as FYM and SO per cent N as chemical fertilizer and S2 : SO per cent N as vermicompost and SO per cent N as chemical fertilizer), two NPK ratios (2 : 1 : 1 and 2 : 1 : I.S) and an absolute control thereby forming 13 treatment combinations. Results of the experiment revealed that the effect of both N levels and NPK ratios had significant influence on most of the biometric and yield attributing characters and yield of basmati rice. Nitrogen @ 120 kg ha-I and NPK ratio of 2 : 1 : I.S were found significantly superior to lower levels. Eventhough the effect of sources of N was significant on plant height and dry matter production, the effect was not visible on the yield attributing characters and yield of the crop. A significant linear increase in grain yield was recorded upto 90 kg N ha-I , and thereafter the increase in grain yield was marginal. But the straw yield increased linearly with increase in N level and was also significantly influenced by the sources of nitrogen. NPK ratio of 2 : 1 : I.S recorded higher grain and straw yield. Nitrogen @ 120 kg ha-I and NPK ratio of 2 : I : I.S produced the highest grain protein content. The cooking time of grains increased with increase in N level. Nitrogen @ 120 kg ha-I and NPK ratio of 2 : I : I.S recorded the highest uptake of nutrients. Use of vermicompost for substituting 50 per 1'9 cent N resulted in the highest uptake of Nand P while the effect on K uptake was not significant. An increase in N application resulted in an increase in available N and P status of the soil after the experiment. Nitrogen @ 120 kg ha ", use of vermicompost for substituting 50 per cent Nand NPK ratio of 2 : 1 : 1.5 registered significantly superior available K status in the soil. The maximum NUE in terms of agronomic efficiency and apparent recovery was observed at 90 kg N ha-! and thereafter it decreased with the increase in N level. Application ofNPK in 2 :. 1 : 1.5 ratio also resulted in higher NUE. Sources of N were significant only with respect to apparent recovery and substituting 50 per cent N with vermicompost registered superior value. The physical optimum dose of N for grain yield and agronomic efficiency were worked out to be 109.24 and 94.67 kg N ha-! respectively. Straw yield exhibited a linear response to applied nitrogen. An increase in N level increased the disease incidence while a significant reduction in disease incidence was observed with the NPK ratio of 2 : 1 : 1.5 over 2 : 1 : 1. The highest net returns and BCR were recorded when FYM was used to substitute 50 per cent of nitrogen. Increase in N levels upto 90 kg ha-! and application of NPK in' 2 : 1 : 1.5 ratio was found profitable. So a fertilizer dose of 90 : 45 : 67.5 kg NPK ha-! with 50 per cent N as FYM and 50 per cent N as chemical fertilizer can be recommended for maximizing the yield and returns of basmati rice in wetlands.
Open Access
Effect of nutrient inter-relations on productivity of rice in lateritic soils
(Department of Agronomy, College of Horticulture, Vellanikkara, 2002) Sindhu, P V; KAU; Meera Menon, V
The effect of nutrient inter-relations on productivity of rice in latritic soils was investigated during the first crop season (Virippu) Or 1999-2000 at the Agricultural Research station, Mannuthy. The objective of the study was to arrive at the minimum level combination of applied elements for maximum productivity based on the interaction pattern between applied and native elements so as to develop a sustainable management system. Jyothi was used as the Fest variety to analyse the pattern of interacting influences of P, K, Ca and S at two levels each, among themselves as well as on the native elements. The results showed that treatments had significant beneficial influence on yield expression, causing 90 and 10% increases in yield over absolute control and the presently recommended package of practices. This indicated the necessity of including Ca and S in the nutrient management system. Decline in chlorophyll content and high levels of cell sap pH, together with excess contents of Fe and Zn appear to act as the supressors of yield expression. The latter influences are inherent in soil and are actually the net product of the balance between positive and negative effects of nutrients. A significant finding was that application of any element by itself was not a guarantee for its uptake, and was subject to the effect of other elements, and similarly, had direct or indirect influences on other elements. The positive influence of K and Ca at the maximum tillering and S at the panicle initiation stage, and negative influence of Fe and Mn at the panicle initiation stage pointed out to the need for phasic management of nutrients. The only element inhibiting Fe uptake had been Si, suggesting that the reversal of the process of laterisation holds the key to higher yields. Discriminatory transfer of individual elements between leaf blade and leaf sheath appeared to be an important regulatory factor in deciding yield expression. Highest yield resulted when blade-sheath ratio was maximum tillering and panicle initiation declined in respect of Ca, Fe and Mn and increased in respect of K and S. the study resulted in development of the broad base of a management technology for high productivity and sustainability. The components included keeping N at the present reconunended level, reducing P by 50%, increasing K by 100% and top dressing N using s containing fertilizers as well as moderate basal dressing with Ca.
Open Access
Performance of basmati rice varieties as influenced by date of planting
(Department of Agronomy, College of Agriculture, Vellayani, 2002) Sheena, S L; KAU; GirijaDevi, L
A field experiment was conducted at the Instructional Farm of the College of Agriculture, Vellayani during the second crop season of 2001 to study the performance of basmati rice varieties under different dates of planting. The experiment was laid out in strip plot design with three replications. The treatments included four varieties (Pusa basmati-l, Haryana basmati, Kasturi and Basmati-370) and four dates of planting (October 10, October 23, November 5 and November 18). The results of the experiment revealed that varieties and different planting dates had significant influence on most of ~e qjometric and yield attributing characters of basmati rice. Among the varieties Pusa basmati -1 recorded the lowest height and possess good cooking qualities but it was highly susceptible to sheath blight disease. Among the varieties Kasturi matured early and was resistant to sheath blight disease, Grain yield was also higher for Kasturi as it has more panicle weight and thousand grain weight and also possess excellent cooking qualities as that of Pusa basmati-l. Eventhough basmati-370 recorded maximum height, LAI and DMP, this variety was susceptible to lodging which decreased the grain yield while Haryana basmati was inferior in all quality aspects. Earlier planting (lOth October) increased the grain yield and yield attributing characters and quality aspects. Agrometeorological studies revealed that early planted crop took more number of growing degree days, HTU and PTU Eventhough the growth duration was more for early planted crop, it produced the highest grain yield. Correlation 2 studies indicated that earlier planted crop received sufficient rams which positively influenced all the yield attributing characters resulting in higher yield while late planted crop experienced a high maximum temperature and wind which was negatively correlated with yield. There was a positive correlation between duration, minimum temperature, relative humidity, sunshine hours and heat units and a negative correlation with maximum temperature and wind. Correlation between weather parameters and sheath blight intensity also revealed a positive correlation between disease incidence and maximum temperature, relative humidity and rainfall. ,. Economic analysis showed that planting of Kasturi on to" October gave maximum net returns and BCR.
Open Access
Effect of seed hardening on establishment, growth and productivity of semi-dry rice
(Department of Agronomy, College of Horticulture, Vellanikkara, 2001) Mohanasarida, K; KAU; Jose Mathew
Studies involving laboratory and field experiments were conducted during kharif 2000 at the College of Horticulture, Vellanikkara to investigate the effect of seed hardening treatments on imparting moisture stress tolerance in semi-dry rice and its subsequent effect on germination, establishment, seedling vigour, growth, yield attributes and yield of the crop. The treatments, thirteen in number, consisted of hardening the seeds with aqueous solutions/slurries or combination of both, of different materials such as salts, plant protection chemicals, botanicals, organic manures, biofertilizers etc. The effect of the treatments was more conspicuous in the laboratory study, showing significant variation in respect of most of the parameters studied. Hardening with imidacloprid (0.05%), Azospirillum (2.0%) and leaf extract of Ungu (l.0%) generally recorded the best results in respect of germination percentage and seedling parameters. In the field ,study hardening with imidacloprid (0.05%) and Azospirillum (2.0%) were found to be consistently superior in hastening germination, maintaining adequate seedling population, reducing seedling mortality and producing healthy seedlings. Growth components and root characters showed significant improvement due to seed hardening, with imidacloprid and Azosprillum recording the best results. The yield increase due to seed hardening, over control, ranged from 0.6 to 2.1 t ha". Imidaclopridand Azosprillum continued to record superior performance in respect of yield and yield attributes, also. KCl, KH2P04 and Ungu recorded significantly higher grain yield, over control, but was inferior to imidacloprid. The NPK uptake by the crop was significantly influenced by seed hardening treatments at almost all the growth stages, with imidacloprid and Azosprillum recording highest values in most of the cases. The study clearly revealed the effectiveness of seed hardening in realizing high yields in rainfed semi-dry rice through amelioration of moisture stress during the early growth stages.
Open Access
Source-efficacy relations of Organics in Wetland rice culture
(Department of Agronomy, College of Horticulture, Vellenikkara, 2002) Rajagopal, Prashant; KAU; John, P S
Summary, etc. A field experiment was carried out during the Kharif season of 2000 at the Agricultural Research Station, Mannuthy to assess the efficacy of various sources of green leaf and organic manures in relation to nutrient accretion, rice growth and yield. The interactive effect of decomposition products on nutrient mineralization, chemical properties of the soil and subsequent elemental composition of the plant were studied in relation to rice growth. The changes in carbon: nitrogen relations in the soil and the pattern of nitrogen mineralization were monitored through an incubation study conducted at the College of Horticulture, Vellanikkara. The field experiment was laid out in randomized block design with three replications. The treatments consisted of twelve organic amendments of both plant and animal origin, three synthetic fertilizer combinations and an absolute control. All organic treatments were incorporated at 5tJha on dry weight basis. The short duration lNV, Matta Triveni was used in the experiment. Treatments had a significant effect on the content of major nutrients both in soil and plant. Micronutrients did not affect the yield by their inadequacy, however, Fe content in plants was found to be excess and may have negatively influenced the yield The growth characters of the plant like height of tillers, number of tillers, weight of roots, plant dry matter and total plant weight were largely affected by the . treatments. The height of tillers was highest in plots treated with poultry manure at all stages of the crop, while number of tillers especially after 25 DAT was maximum in FE treated plots and this was also the case in the number of productive tillers. Among the yield attributes, the number of spike lets per panicle and the length of panicle was maximum in poultry manure treated plots. The chaff percentage was highest in sesbania treated plots. The number of productive tillers was maximum in FE treated plots. The highest yield of grain (4.37 tIha) and straw (5.20 tJha) were from FE treated plots but the grain straw ratio (0.84) was the lowest in this treatment. In case of FE treatment, the high yield was as a result of increase in number of productive tillers, while in case of pongamia and gliricidia, it was due to reduced chaff percentage and enhanced test weight. A higher yield was obtained in case of poultry manure treatment due to enhancement of number of spikelets per panicle The treatments in the field experiment were replicated as an incubation study to understand the pattern of nitrogen mineralization and to observe the variations in carbon nitrogen relations. A measured quantity of soil (lOOg) was placed in glass conical flasks and corresponding quantity of organic manures so as to maintain a ratio of 5 tJha and the fertilizer treatments also in the same ratio were incorporated and incubated for a period of 100 days. The mineralization of nitrogen was studied and in case of organic manures cow dung, gliricidia and sesbania were the first to do so. Straw and acacia treatments were the slowest to mineralize achieving peak levels at 70 days after incubation that were due to the quantities of lignin carbon and fibre in the organic manures. In case of phosphorus mineralization, it was noticed that mineralization in all the treatments irrespective of it being organic or inorganic in nature, tended to decrease rapidly after incubation up to 40 days and then gradually increase to levels higher than the initial level and in case of potassium mineralization, a slow and gradual increase in the levels ofK were observed which was noticed even after 70 days with a slight decrease being noticed towards the end in some treatments. The rate of decomposition and mineralization was affected by the CIN ratio, ligninIN ratio and also moisture content, content of fibre and nutrients 'present in the organic material. Substitution of a major quantity of inorganic fertilizers is possible by the use of organic manures. However, considering the mineralization patterns, a better option would be the combined use of inorganic and organic manures whereby the synthetic fertilizers would meet the initial nutrient need of the crop as they are readily available to the crop during the initial exponential growth phase and in the later stages the organic manures would provide the required nutrients.
Open Access
Impact of plant population and weed management practices on the performance of Basmati Rice
(Department of Agronomy, College of Agriculture, Vellayani, 2002) Jacob, D; KAU; Elizabeth K, Syriac
A field experiment was conducted at the Instructional Farm, College of Agriculture, Vellayani during the mundakan season of 200/-2002 in order to determine the effect of spacing and weed management practices on the yield of scented basmati rice cv. Pusa Basmati-I. The field experiment was laid out in Randomised Block Design with two factors, in fifteen treatment combinations and three replications. The factors included were spacings viz. 15 x ] 5 cm (S,). 20 x 10 cm (S2) and 15 x 10 cm (S3) and weed management practices viz. anilofos + 2,4-D EE at 6 OAT followed by hand weeding at 20 DAT (Wi), anilofos + 2,4-0 EE at 6 OAT followed by 2,4-D sodium salt at 20 DA T (W2), hand weeding twice at 20 and 40 DA T (Wl). weed free check 0N4) and unweeded control 0Ns). Transplanting basmati rice at 20 x 10 cm, which is the recommended spacing for medium duration rice in Kerala, enhanced the growth characters of rice such as plant height, tiller count and leaf area index. Dry matter production and nutrient uptake of rice were also enhanced by this spacing. The count of grasses, sedges and broad leaved weeds and the total weed population was reduced by this practice resulting in higher net income and benefit-cost ratio. The dry matter production of weeds and nutrient uptake by weeds were also significantly lower at this spacing compared to the other two spacings Adoption of pre-emergence application of anilofos + 2,4-D EE @ 0.4 + 0.53 kg ai ha" at 6 DAT followed by 2,4-D sodium salt @ ] kg ai ha-' at 20 DAT resulted in enhanced plant height. tiller count, leaf area index. dry matter production and nutrient uptake of rice. The yield attributes and grain yield were significantly increased by this practice and the weed index was significantly reduced. The total weed population, weed dry matter production and nutrient uptake were also reduced and weed control efficiency was increased by this treatment. The treatment combination involving recommended spacing of 20 x 10 cm and pre-ernergence application of anilofos + 2,4-D EE @ 0.4 + 0.53 kg ai ha" at 168 6DAT followed by 2,4-D sodium salt @ 1 kg ai ha" at 20 DAT, recorded higher dry matter production and nutrient uptake of rice. This resulted in higher grain yield and lower weed index than other interactions. The lowest total weed count, weed frequency and weed density at all stages of observation were registered for this interaction. Moreover it helped to reduce the weed dry matter production and nutrient uptake. Compared to the existing practice of hand weeding twice at 20 and 40 DAT, all weed management practices except unweeded control, showed their superiority in augmenting the grain yield and thus increased the net income and benefit cost ratio.
Open Access
Investigations on the allelopathic influence of eupatorium (Chromolaena odorata(L.) King and Robinson and utilization as organic manure
(Department of Agronomy, College of Agriculture, Vellayani, 2002) Navaz, M; KAU; Sansamma George
Lab and field experiments were conducted at the Instructional Farm, College of Agriculture, Vellayani during June 2001 to February 2002 to study the allelopathic influence of eupatorium (Chromolaena odorata (L.) King and Robinson) on important field crops and weed species and to investigate the potential of the weed biomass as organic manure. In Experiment I, allelopathic influence of eupatorium on three important field crops ie., rice (Oryza sativa L.), cowpea (Vigna unguiculata (L.) Walp.) and Bittergourd (Momordica charantia L.) and two weed species. ie ., Thatch grass (lmperata cylindrica (L.) Beauv.) and eupatorium (Chromofaena odorata (L.) King and Robinson) was studied. The treatments comprised of aqueous plant part leachates of fresh and decayed eupatorium at five and ten per cent co ncentr at io n. The results revealed that aqueous fresh plant part leachates inhibited germination and early seedling growth of rice, cowpea and bittergourd severely. Germination of thatch grass and eupatorium were also suppressed by the treatments. In general, the aqueous fresh plant part leachates showed greater effect than the decayed plant part leachates, and the effect was more -with leaf leachate. The inhibitory effect was more with the higher concentration of the leachate. Under Experiment II, field observations were made to study the biology of eupatorium under Kerala conditions. Composting of mature eupatorium was tried and the response of bhindi to eupatorium as compost and green leaf manure was observed in comparison with poultry manure, vermicompost, coirpith compost and farmyard manure. The results revealed that eupatorium took about 293 days from germination to seed maturity under Kerala conditions. The plant flowering was during December - January and seeds dispersed in the months of February - March. Each plant produced about 25,000 seeds on an average and had a germination percentage of about 30 per cent. When the mature and dried eupatorium weed biomass was composted, the C : N ratio came down from 62.72 to 18.88 in four months and was ready for use as organic manure. The NPK content of the composted material was 0.76, 0.58 and 0.81 per cent respectively. The yield response of bhindi to eupatorium as organic manure revealed that eupatorium compost was on par with poultry manure and farmyard manure treatments. However when the fresh weed biomass was used as green leaf manure, the yield was considerably lower. The results indicated the need and usefulness of composting the weed biomass before using it as sole source of organic manure in bhindi.

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