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Open Access
Cytogenetic studies on intervarietal hybrids of sesamum (Sesamum indicum L.)
(Department of Agricultural Botany, College of Agriculture Vellayani, Trivandrum., 1984) Chandramony, D; KAU; Krishnan Nair, N
Open Access
Enhancement of propagation efficiency in exotic varities of heliconia
(Department of Pomology and Floriculture, College of Agriculture, Vellayani, 2008) Reshmi, C R; KAU; Sheela, V L
Heliconias are among the most popular garden plants, both for the ease with which they can be grown and the sheer magnificence of the blooms. Studies were conducted to standardize rapid propagation techniques under in vitro and in vivo conditions. Three heliconia varieties belonging to three distinct groups viz., St. Vincent Red (small erect type), Golden Torch Adrian (hybrid) and Sexy Pink (large pendent type) were selected for the study. For in vitro culture establishment, shoot tip explants were effective. The treatment of shoot tips with 0.10 per cent mercuric chloride for ten minutes followed by dipping in 0.05 per cent mercuric chloride for five minutes (after trimming) resulted in better surface sterilization. Longitudinal cutting of the in vitro established shoot tip with apical dome into two halves and culturing them separately produced the highest number of axillary buds. Addition of 0.05 per cent activated charcoal to the establishment media reduced the media browning and hastened shoot initiation. For culture establishment of all the three varieties, MS medium supplemented with BA 5.00 mg l-1 was found to be the best. Murashige and Skoog medium supplemented with BA 2.00 mg l-1 resulted in the highest shoot proliferation in the variety St. Vincent Red. In Golden Torch Adrian, BA 2.00 mg l-1 + NAA 0.20 mg l-1 gave better results. In the variety Sexy Pink, Kinetin 5.00 mg l-1 + NAA 0.20 mg l-1 was the best. For further multiplication in Sexy Pink, BA 1.00 mg l-1 was sufficient. Solid culture medium was better for shoot proliferation in the variety Sexy Pink. Higher sucrose concentration (40.00 g l-1) increased the multiplication rate, but reduced the length of shoots as well as the number of leaves. Addition of activated charcoal to the media as well as exposure of cultures to light had negative effect on shoot proliferation. Full MS medium was found to be the best for in vitro rooting of the variety Sexy Pink. Addition of NAA 0.50 mg l-1 to the MS medium gave better results for in vitro rooting in Golden Torch Adrian and Sexy Pink. Sucrose @ 30.00 g l-1 was sufficient for in vitro rooting in the variety Sexy Pink. Activated charcoal delayed root initiation and reduced the number of roots in the variety Sexy Pink. Sand recorded 90.00 per cent survival in all the three varieties after two months of planting out. At varietal level, significant difference was evident in the total number of suckers. In the first experiment, the variety St. Vincent Red (3.82) was significantly superior in terms of total number of suckers. However, in the second experiment, St. Vincent Red (4.06) was on par with Golden Torch Adrian (4.10). The variety Sexy Pink produced comparatively taller suckers in both the trials. Varietal variation in the number of leaves was observed only in the earlier stages. During the preliminary field experiment, the variety Sexy Pink excelled in leaf area at almost all stages of observation. Among the three varieties, highest collar girth was recorded by suckers of Sexy Pink variety during the first two stages of observation. However, towards the later stages, it was statistically on par with St. Vincent Red. Foliar spray was superior to rhizome dip in terms of total number of suckers, height of suckers and the number of leaves. In the case of leaf area, both the treatments were more or less on par. Application of growth regulators had pronounced effect on sucker production at all the stages during the first experiment when BA 750 mg l-1 produced the highest number (4.19) of total suckers. In the second experiment, variation was evident only in the total number of suckers. Here, BA 850 mg l-1 produced the highest number (4.33) of suckers and it was on par with BA 700 mg l-1 (4.00) and GA3 650 mg l-1 (3.79). Irrespective of the stage of plant growth, gibberellic acid produced taller suckers and BA 500 mg l-1 resulted in the shortest suckers. BA treatments recorded comparatively higher number of leaves. Growth regulator application had remarkably influenced the leaf area of suckers also. Application of BA 1000 mg l-1 (3.53 cm) and GA3 800 mg l-1 (3.33 cm) recorded higher collar girth in suckers. VG interaction exerted significant variation in the number of suckers. At varietal level, BA 750 mg l-1 produced the highest number of suckers in St. Vincent Red (4.75), GA3 500 mg l-1 in Golden Torch Adrian (4.63) and GA3 750 mg l-1 in Sexy Pink (4.00). Among VG treatment combinations in the second experiment, the highest number of suckers (4.75) in the variety St. Vincent Red was produced by BA 700 mg l-1. The varieties Golden Torch Adrian (4.88) and Sexy Pink (3.75) recorded the highest with BA 850 mg l-1. Gibberellic acid produced taller suckers. In the second experiment, VG interaction had no significant effect on the height of suckers. Regarding the number of leaves, BA resulted in comparatively higher number of leaves in both the experiments. In all the three varieties, BA 850 mg l-1 produced the highest number of leaves. Collar girth was found to increase with increase in the concentrations of BA and GA3 in all the three varieties. The economics of foliar application of growth regulators revealed that BA 850 mg l-1 significantly enhanced the profit in the varieties Golden Torch Adrian and Sexy Pink. Although negligible, BA 700 mg l-1 recorded slight positive response in the variety St. Vincent Red with respect to profit.
Open Access
Development of F1 hybrids of indeterminate tomato (Solanum lycopersicum L.) for protected cultivation
(Department of Olericulture, College of Agriculture, Vellayani, 2015) Lekshmi, S L; KAU; Celine, V A
The present investigation entitled “Development of F1 hybrids of indeterminate tomato (Solanum lycopersicum L.) for protected cultivation” was conducted at the Department of Olericulture, College of Agriculture, Vellayani, from 2013 to 2015 with the objectives of identifying superior varieties and developing F1 hybrids of indeterminate tomato suited for protected cultivation. The study consisted of two experiments conducted in the naturally ventilated polyhouse of size 50 m x 20 m located at the Instructional Farm, Vellayani. In the first part of the first experiment, 40 tomato genotypes were evaluated for two consecutive years in an RBD with three replications. As the second part, 12 commercial hybrids were evaluated. The second experiment consisted of a 9 x 9 half diallel analysis laid out in an RBD with three replications. Analysis of variance showed significant differences between the genotypes for all the characters for two crops. Pooled analysis revealed that, LE 1 recorded the highest yield (2443.43 g) and fruit weight (108.13 g) followed by LE 7. LE 53 had maximum number of fruits per plant (65.00). In the present study, genotypes had wide variation for quality parameters. Fruits of LE 14 recorded highest TSS with a mean of 5.74 ºBrix. LE 7 had maximum ascorbic acid (30.13 mg/100g) and lycopene content (13.09 mg/100g). Beta carotene value was maximum in LE 16 (184.15 mg/100g). There was minimum incidence of pests, diseases and physiological disorders under protected conditions. Among the 12 hybrids evaluated, INDAM 9802 was the highest yielder (1444.40 g) followed by F1 T 30 (1412.22 g). F1 T 30 recorded maximum fruits per plant (35.66) which was on par with F1 Queen (35.55). Genetic parameters like phenotypic and genotypic coefficients of variation, heritability and genetic advance were studied to assess the genetic variability among the genotypes. High heritability coupled with high genetic advance were observed for characters like truss per plant, fruits per truss, fruit weight, fruits per plant, yield per plant and yield per plot. Path analysis revealed highest positive direct effect for fruit weight (0.3956), truss per plant (0.3558) and fruits per plant (0.3381). Based on D2 analysis the 40 genotypes were grouped into eight clusters. Cluster I was the largest with twenty four genotypes followed by cluster II with ten genotypes. Diallel analysis was carried out using nine parents selected based on genetic divergence and per se performance. The parents were crossed in a diallel fashion excluding reciprocals to obtain 36 F1 hybrids. The study revealed that P5 x P9 had the highest yield (3114.03 g) which was on par with P6 x P8 (3074.37 g) and P1 x P5 (3077.58 g). P1 x P5 had the maximum fruits per plant (103.93). The magnitude of relative heterosis, heterobeltiosis and standard heterosis varied considerably. For yield, relative heterosis ranged from -32.40 to 92.72, heterobeltiosis from -47.14 to 89.54 and standard heterosis from 2.91 to 160.95. The σ2gca and σ2sca ratio indicated that non-additive gene action was predominant for all traits. Among the nine parents, P9 (LE 1), P5 (LE 20) P1 (LE 2), and P2 (LE 7) were superior for yield and yield attributes. The estimates of sca effects indicated that P5 x P9 (LE 20 x LE 1), P6 x P8 (LE 39 x LE 38) and P1 x P5 (LE 2 x LE 20) were the most promising hybrids for protected cultivation. The present study revealed that the genotypes LE 1 and LE 7 and the hybrids INDAM 9802 and F1 T 30 were superior for yield and yield attributes under protection. Based on the mean performance, standard heterosis and sca effects the three potential crosses viz., P5 x P9, P6 x P8 and P1 x P5 could be adjudged as suitable indeterminate tomato hybrids for protected cultivation.
Open Access
In vitro propagation and rapid analysis of selected varieties of papaya (carica papaya L)
(Department of Pomology and Floriculture, College of Agriculture, Vellayani, 2007) Bindhu, B; KAU; Jayachandran Nair, C S
A study was carried out at the Department of Pomology and Floriculture, College of Agriculture, Vellayani during 2003-2006 for refining existing tissue culture protocol with respect to selected varieties and hybrids of papaya. Molecular characterization of papaya hybrids was also carried out using Random Amplified Polymorphic DNA (RAPD) technique. Papaya varieties and hybrids selected for the study were Pusa Nanha, CO-5, Washington, Pusa Nanha x Coorg Honeydew, Pusa Dwarf x Coorg Honeydew, Solo x Coorg Honeydew and Pusa Nanha x Solo. Apical buds and lateral buds from seedlings and mature plants were used as explant for in vitro propagation. The present study revealed that full strength MS medium supplemented with sucrose 30.00 g l-1 and agar 6.00 g l-1 under light condition produced highest shoot number and longest shoot in papaya varieties and hybrids. Application of BA 0.50 mg l-1 along with NAA 0.10 mgl-1 was found to be better for initial culture establishment and proliferation of papaya varieties and hybrids. Application of amino acid, arginine 50.00 mg l-1 resulted in highest shoot proliferation rate, while highest shoot length was obtained from arginine 100.00 mg l-1. Addition of activated charcoal 0.05 per cent and Cobalt chloride 10.00 mg l-1 increased shoot proliferation rate and shoot length in papaya varieties and hybrids. In vitro rooting was best in full strength MS medium supplemented with IBA 3.00 mg l-1, sucrose 30.00 g l-1and activated charcoal 0.05 per cent. Earliest planting out of in vitro propagated plants in potting media was carried out in papaya variety Pusa Nanha and late planting out in papaya hybrid Pusa Nanha x Coorg Honeydew. Highest plant height of in vitro propagated plants, at time of planting out in potting media was recorded by papaya variety Washington and lowest by papaya hybrid Pusa Nanha x Coorg Honeydew, while hsighest leaf number was reported from papaya variety CO-5 and lowest from Pusa Nanha. But longest root was noticed in papaya hybrid Pusa Nanha x Coorg Honeydew and shortest root from CO-5. No significant difference was noticed in the number of roots produced at the time of planting out in potting media. In vitro propagated plants of papaya had better establishment in the potting mixture containing sand : soil : cowdung (1 : 1 : 1) + Mycorrhiza (1.00 g plant -1). After field establishment, highest plant height and plant girth was noticed in papaya variety Washington and lowest in papaya hybrid Pusa Dwarf x Coorg Honeydew. While highest leaf number upto six weeks after planting was shown by papaya variety CO-5 and thereafter by papaya variety Washington. Lowest leaf number upto eight weeks after planting was noticed in papaya hybrid Solo x Coorg Honeydew and thereafter by papaya hybrid Pusa Dwarf x Coorg Honeydew. Early flowering was reported in papaya hybrid Pusa Dwarf x Coorg Honeydew and late flowering in papaya variety Washington. Most of the papaya varieties and hybrids selected for the present study exhibited only dioecious nature, but papaya hybrid Solo x Coorg Honeydew showed gynodioecious nature. Highest field establishment of in vitro propagated plants was shown by papaya varieties CO-5 and Washington and lowest by papaya hybrid Solo x Coorg Honeydew. Genomic DNA was successfully isolated from four papaya hybrids using CTAB method. All the ten primers (six primers from OPA and four primers from OPB series) yielded amplification products with isolated DNA. A total of 39 RAPDs were obtained from ten primers of which 36 bands were polymorphic. Primers OPA-03, OPA-04, OPA-12, OPB-04 and OPB-17 gave 40 scorable bands, with an average of 8.0 bands per primer. The largest cluster in dendrogram was formed by three hybrids - Pusa Nanha x Coorg Honeydew, Pusa Dwarf x Coorg Honeydew and Pusa Nanha x Solo. The second cluster contained only one hybrid - Solo x Coorg Honeydew. The minimum similarity coefficient detected in the present study was 0.389, suggesting a genetic differentiation among the papaya hybrids.
Open Access
Induced mutations in banana var. Nendran
(Department of Agricultural Botany, College of Agriculture, Vellayani, 1990) Radha Devi, D S; KAU; Krishnan Nair, N
The present investigations was carried out in the Department of Agricultural Botany, College of Agriculture, Vellayani during 1985-88 and in the plant tissue culture Laboratory attached to the Department of Plantation Crops, College of Horticulture, Vellanikkara, Thrissur during 1986-88. The project was taken up to standardise the techniques for induced mutagenesis in-vitro and in-vitro in banana (Musa paradiciaca L.) var. nendran and aslo to analyse the direct effect of 60 Co gamma rays on growth and bunch characters in the vM1 and vM3 generations. One, two and three months old suckers of various sizes (after removal of 25 to 75 per cent of the pseudostem) were exposed to 1.0, 1.5, 2.0, 2.5 and 3.0 kR gamma rays. For in-vitro mutagenesis, isolated shoot tips were exposed to 0.50, 0.75, 1.00, 1.25 and 1.50 kR gamma rays. Ex-vitro analysis of five plants per treatment per exposure was done in the vM1 generation for various growth, bunch and fruit characters.
Open Access
Studies on heterosis and combining abilities with respect to important economic traits in Capsicum annuum, L.
(Division of Agricultural Botany, College of Agriculture, Vellayani, 1981) Manikantan Nair, P; KAU; Mary, K George
Sixty three varieties of Capsicum annuum representing different agroclimatic regions of the country constituted the base material of the study. Based on yield potential , adaptability and tolerance to leaf curl complex disease, thirty varieties were selected for subsequent studies. Comprehensive genetic studies including estimation of genetic parameters, cause effect relationship by path coefficient analysis, genetic divergence by Mahalanoble D2 statistic and a nine parent diallel analysis to causes the combining ability, to unravel the pattern of inheritance and also to examine the level of heterosis manifested with respect to eighteen economic characters including four nutritiveand quality attributes namely Vitamin A, Vitamin C, Capsaicin and Oleoresin content were conducted during the year 1976-79. Analysis of plot means exhibited highly significant differences among varieties except for Capsaicin content. The high degres of variability in economic attributes offers scope for recombining desirable genes from different varieties.
Open Access
Biometric analysis of yield and certain yield attributes in the para rubber tree: Hevea Brasiliensis Muell. Arg.
(Department of Agricultural Botany, College of Agriculture, Vellayani, 1984) Markose, V C; KAU; Mary, K George
The para rubber tree, Hevea brasiliensis, is the commercial source of natural rubber. Introduced into the Far East in 1876, from Brazil, commercial cultivation started in India during 1902. The tree has a gestation period of six to seven years. A large number of clones have been evolved through ortet selection and through hybridisation, which show variability for different characters. The present study was undertaken to estimate (1) productivity (2) yield pattern (3) variability (4) correlations (5) effect of yield attributes (6) genetic diversity of twenty clones, and (7) early growth vigour of open pollinated seedlings of selected clones.
Open Access
Calibration and validation of ceres rice crop simulation model
(Department of Agronomy College of Agriculture, Vellayani, 2018) Anju, V S; KAU; Girija Devi, L
The project entitled ‘Calibration and validation of CERES-Rice crop simulation model’ was conducted in the Department of Agronomy, College of Agriculture, Vellayani from 2016 to 2018 with the objectives to calibrate and validate CERES-Rice model to generate the genetic coefficients of the rice variety Prathyasa, to study the crop- weather relationship and to quantify the yield gap of the variety by running simulations. The field experiment was conducted at Upanniyoor Panchayat in farmer’s field for four seasons (Virippu 2016 and 2017 and Mundakan 2016 and 2017) and it was laid out in randomized block design. The treatments consisted of five dates of sowing each in Virippu (D1 - May 31, D2 –June 15, D3 –June 30, D4 –July 15 and D5 – July 30) and five dates of sowing each in Mundakan (D1 -Oct 14 / Sept 26, D2 – Oct 30 /Oct 10, D3 – Nov 14/ Oct 25, D4 –Nov 30/Nov 9 and D5 – Dec 14/Nov 24). The sowing dates in Mundakan seasons of 2016 and 2017 varied due to the delayed onset of rainfall in 2016. The plot size was 5 x 4 m2 with three replications. Routine observations on height, leaf area, dry matter production (DMP), number of tillers, panicles, spikelets per panicle, filled grains per panicle, 1000 grain weight, straw yield and grain yield were recorded apart from phenological observations. Soil analysis was conducted before and after the experiment. The soil and crop data collected from the experimental field and weather data from the Department of Agrometeorolgy were used as inputs for running the model. Study on phenology revealed that the crop duration decreased from 111 to 100 and 117 to 107 days respectively in Virippu 2016 and 2017. A similar decreasing trend was observed in Mundakan 2016, but in Mundakan 2017, it increased from 114 to 117 days in early sowing and decreased drastically from 117 to 105 days in delayed sowing. The height of the plant was found varying at different stages, D1 produced the tallest plants at harvest in Virippu seasons of both the years, while it was the highest in D3 in Mundakan 2016 at different stages and D5 in Mundakan 2017. The number of tillers was the highest in D2 and D1 respectively in Virippu in both the years and D2 and D1 respectively in Mundakan 2016 and 2017. The DMP was the highest in D2 and D1 respectively in Virippu and Mundakan 2016 and 2017. The grain yield was the highest in D2 in both the seasons in 2016 and D1 in both the seasons in 2017. The yield attributes such as productive tillers m-2 was the highest in D2 in both the seasons in 2016 and D1 in both seasons in 2017. The number of spikelets per panicle was the highest in D1 during Virippu 2016 and 2017 and Mundakan 2017 and D2 in Mundakan 2016. D1 in Virippu 2017 was on par with D2, and D2 in Mundakan 2016 was on par with D1. The number of filled grains per panicle was higher in D1 in Virippu 2016 and Mundakan 2017, while D2 recorded higher filled grains per panicle in Virippu 2017 and Mundakan 2016. D1 in Virippu 2016 was on par with D2 and D2 in Mundakan 2016 was on par with D1. The harvest index (HI) was higher in D1 in Virippu 2016 and 2017 and Mundakan 2017, while D2 recorded higher HI in Mundakan 2016. D1 in Virippu 2016 was on par with D2 and D5, and D1 in Virippu 2017 was on par with D2. In Mundakan season, D2 was on par with D1 and D5 in 2016 and D1 was on par with D2 in 2017. In Virippu and Mundakan 2016, N uptake was the highest in D1 while P and K uptake were the highest in D2, whereas in Virippu and Mundakan 2017, N, P and K uptake were the highest in D1. The organic carbon content of the soil was found influenced only after Virippu 2016 with D5 recording the highest value. In the case of available N, P and K status of the soil, only the N status was found affected and that was only after Mundakan 2017 with D2 recording the highest value. Crop weather relationship was studied by computing the different heat units such as Growing degree days (GDD), Heliothermal units (HTU), Photothermal units (PTU) and Heat unit efficiency (HUE) at different stages such as sowing to active tillering (P1), active tillering to panicle initiation (P2), panicle initiation to booting (P3), booting to heading (P4), heading to 50% flowering (P5), 50% flowering to physiological maturity (P6), vegetative stage (P7), reproductive stage (P8) and ripening stage (P9). These heat units computed were the highest in D1 and showed positive correlation with yield for GDD at P1, HTU at P5 and P6, PTU at P1 in Virippu, while in Mundakan positive correlation was obtained with GDD at P1 and P7, HTU at P2, PTU at P1 and P7. Negative correlation was obtained with GDD at P3, P8 and P9 and PTU at P4, P8 and P9 in Virippu and with HTU at P2 and P3 and PTU at P6 and P9 in Mundakan. The correlation between yield and yield attributes with weather parameters revealed positive correlation for minimum temperature at P3, P4 and P8, RH I & RH II at P1 and P7, BSS at P2, P3, P4 and P6, rainfall and rainy days at P1 and P7, pan evaporation at P6, P8 and P9 and wind speed at P6 and P9 in Virippu season. Negative correlation was observed with minimum temperature, pan evaporation and wind velocity at P1, rainfall at P3, P4, P6, P8 and P9, rainy days at P6, P8 and P9, RH I at P6, P8 and P9, RHII at P5, P6 and P9 in Virippu season. In Mundakan season positive correlation was obtained with maximum temperature from P1 to P9 except P6, RH I at P2, P4, P5, P7, P8 and P9 and rainy days at P1 and negative correlation with maximum temperature at P1, P2 and P6, minimum temperature at P6, BSS at P2, rainfall at P6, pan evaporation at P3, P5, P6, P7, P8 and P9. The genetic coefficients for the variety Prathyasa was generated by calibrating the CERES-Rice model by using the data of Virippu rice 2016 and validated by using the data of Mundakan 2016, Virippu and Mundakan 2017 respectively and the genetic coefficients generated were P1-720, P2R-33.7, P5-21.3, P2O-12, G1-38.7, G2-0.028, G3-1, G4-1 respectively. Model simulated results showed that there was close association between observed and simulated yield and the error percentage varied from -16.90 to 16.55 for Virippu 2016 and from -1.26 to 64.77 in Virippu 2017. In Mundakan, error per cent ranged from -13.43 to 16.63 in 2016 and from -11.09 to 12.58 in 2017. The error percentage for panicle initiation day varied from 1.96 to 18.37 in Virippu 2016, while it varied from -5.88 to 10 in Virippu 2017 and for Mundakan it varied from -8.16 to 0 in 2016 and from -8 to 1.96 in 2017. Similarly the error percentage for anthesis day varied from 8.54 to 11.25 and 4.88 to 9.88 in Virippu 2016 and 2017 and from 4.88 to 9.88 and 3.66 to 8.43 in 2016 and Mundakan 2017. The error percentage of physiological maturity day varied from -1.96 to 18 in Virippu 2016, while it deviated from -7.84 to 0.99 in Virippu 2017. During Mundakan season, error percentage ranged from -1.98 to 6.54 in 2016 and from -2.91 to 4.81 in 2017. Regression equations for grain yield were developed for certain phenological stages in Virippu and Mundakan from highly correlated weather parameters. The yield gap quantification revealed that the highest total and sowing yield gaps were in delayed sowing (D5), management yield gap in early sowing(D1), and the lowest in D3 and D4 (delayed sowing) and D2 (early sowing) respectively for the same parameters. Thus, the study enabled to generate the genetic coefficients of variety ‘Prathyasa’ and simulated the grain yield and panicle initiation, anthesis and physiological maturity days with minimum error percentage. The study also helped to quantify various yield gaps such as total, management and sowing gaps due to different dates of sowing, from the potential yield generated by the model along with the attainable and actual yield data supplied from the field experiment and farmers’ field. The various correlations worked out between yield, weather parameters and heat units provided an insight into the crop weather relationship. Finally, and the foremost implication of the study is that delayed sowing reduces the yield considerably in rice crop in both the seasons irrespective of other factors.
Open Access
Management and utilization of water hyacinth (Eichhornia crassipes ( Mart.) Solms)
(Department of Agronomy College of Horticulture, Vellanikkara, 2018) Indulekha, V P; KAU; George Thomas, C
Water hyacinth is one of the most productive plants on earth, but it is also considered as the world’s worst aquatic weed. The phytoremediation capacity of water hyacinth and its management through ecofriendly means like silage making, composting, and mulching were studied at the College of Horticulture, Vellanikkara. The phytoextraction capacity of water hyacinth was evaluated through a purposive sampling by collecting plant and water samples from 20 sites in central Kerala. These samples were analysed for various nutrients including heavy metals. To study the association of plant nutrients with water nutrients, cross tabulation was done and dependence of plant nutrient factor on water nutrient was measured through Chi-square. The Chi-square statistic was significant for N, P, Mg, and Ni indicating that the level of nutrients could be brought to a minimum through water hyacinth. The accumulation of heavy metals in water hyacinth was in the order Fe> Al> Mn> Zn> Cr> Ni> Co> Hg> Pb> As. Among them, Pb content in plant samples was within the permissible limit, but contents of Fe, Cu, Cr, Zn and Ni were beyond the safe limits. The quality and palatability of silage prepared with fresh and wilted water hyacinth with or without rice straw or guinea grass and using molasses, cassava flour, or rice bran as additives was investigated. Considering the quality parameters such as pH, odour, and palatability, wilted water hyacinth with molasses (5%) or cassava flour (10%) and wilted water hyacinth with cassava flour (10%) and rice straw (10%) or guinea grass (10%) are the best options for utilizing water hyacinth as silage. The composting experiment consisted of four methods viz., Bangalore method, Indore method, phospho-composting, and vermicomposting. All the prepared composts had neutral to slightly alkaline pH. The lowest C: N ratio was recorded with vermicompost (11.58) followed by Bangalore compost (12.68). Nitrogen content at 3 months after composting (MAC) was higher in vermicompost and Bangalore compost. The highest N content at 6 MAC was observed in vermicompost (1.75%). Phosphorus content was higher in phospho-compost at 3MAC and 6 MAC. There was no significant difference in K content of different composts at 3 MAC. Calcium, Mg and S contents were high in vermicompost. Micronutrients such as Zn, Cu, Co, and Ni were higher with Bangalore composting. Heavy metals such as As, Cd, and Pb were not detected in any of the composts. None of the composts contained heavy metals beyond safe limits. A field experiment involving three mulch materials–jack tree leaves, green water hyacinth, and coconut leaves–were compared with no mulching in turmeric for two years. All the mulch materials including water hyacinth had positive effects on most morphological and physiological parameters of turmeric such as plant height, number of leaves, leaf area index, leaf area ratio, and dry matter production. In both years, rhizome yield was also higher in plots mulched with organic debris compared to non-mulch control. Nutrient uptake by the crop was also higher with mulching compared to non-mulched plots. All the mulch materials substantially affected weed density and weed dry weight and reduced turmeric-weed competition for different growth factors.

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