1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Biology of Aceria sp. (Acari:ERIOPHYIDAE) in Amaranthus tricolor L.and its management(Department of Agricultural Entomology, College of Agriculture, Padannakkad, 2024-07-05) Krishna Keerthi, K P; Sreekumar,K MThe study entitled ‘Biology of Aceria sp. (Acari: Eriophyidae) in Amaranthus tricolor L. and its management’ was carried out at Department of Agricultural Entomology, College of Agriculture, Padannakkad and farmer’s field at Thaikkadappuram, Nileshwar during 2019 – 2023, with an objective to elucidate the biology and life cycle of Aceria sp. (Acari: Eriophyidae) and interpret the nature and extent of damage caused by Aceria sp. on Amaranthus tricolor L. and to develop its management strategy. The life cycle of Aceria sp. included egg, larva, first inactive stage, nymph, second inactive stage and adult. The developmental cycle lasted for an average of 11.83 days. Egg, larva, first inactive stage, nymph, second inactive stage and adult took an average of 2.94, 1.99, 1.11, 2.69, 1.09 and 4.89 days respectively and measured an average length of 46.78, 74.54, 117.58, 153.82, 189.46 and 229.37 µm respectively. The pre – oviposition and post – oviposition was recorded as an average of 1.80 and 2.92 days respectively. The major symptoms were stunted growth, leaf crinkling and malformation, petiole elongation and fibrous shoots. Population assessment during the early season (December to mid – February) showed a gradual increase in mean population of mites from 16 in December to 73.56 in February. The late cropping season (March to May) observed its highest population mean in May (174.44). Predatory mite population gradually decreased over time. The height of the plants reduced to an average 67.38 per cent and the petiole elongated to a mean of 184.72 per cent. Leaf area reduced to 18.08 cm2, in relation to healthy leaves (25.70 cm2). The stray population of amaranthus plants grown in and around the farmers’ fields and the backyards of their houses, served as off – season host for the mite. The mites were highly host – specific, as it was not sighted in any of the collateral as well as weeds collected from the infested area. Field evaluation of different botanicals and acaricides were conducted in farmer’s field in Thaikkadappuarm. A day after the first spray, no mites were seen in plots sprayed with acaricides. Fenpyroximate (T2) sprayed plots observed a significant reduction in average population in the third (0.223), fifth (2.557), seventh (6.000) and fourteenth (13.553) days after spray. The second application of treatments observed a variable result, in which spiromesifen was superior to the others in the third (1.443) and fourteenth days (11.890). On the fifth day, wettable sulphur (4.333) and on the seventh day, fenpyroximate (7.113) recorded the least population mean. The analysis of pesticide residue conducted on samples sprayed with spiromesifen and fenpyroximate, on the fifth, seventh and tenth days after spray, resulted in detection of fenpyroximate at the rate of 0.29 mg per kg, 0.30 mg per kg and 0.29 mg per kg, respectively. Spiromesifen residues were not detected in the analysis.Item Floral induction and seed yield in amaranthus (Amaranthus tricolor L.) as influenced by plant growth regulators(Department of Vegetable Science, College of Agriculture ,Vellayani, 2023-03-20) Sreelakshmi, S; Sarada, SThe project entitled "Floral induction and seed yield in amaranthus (Amaranthus tricolor L.) as influenced by plant growth regulators" was carried out at the Department of Vegetable Science, College of Agriculture, Vellayani, during 2020–2022, to study the effect of different plant growth regulators on floral induction in the amaranthus variety KAU Vaika, a short day cultivar, during non-inductive period, for seed production. The experiment was laid out in split plot design with three replications. Treatments consisted of three foliar spray intervals (10 days after transplanting, 20 days after transplanting, and 30 days after transplanting) in the main plot and four growth regulators in two different concentrations consisting of eight treatments (BA at 50 and 100 ppm, GA3 at 50 and 100 ppm, TIBA at 100 and 200 ppm and Triacontanol at 50 and 100 ppm) in the subplot. Observations on vegetative, flowering, yield and seed quality characters were recorded. Foliar spray application interval at 10 days after transplanting resulted in the highest growth characters in amaranthus, such as stem girth (6.40 cm), internodal length (5.16 cm) and number of braches per plant (11.44) whereas at 20 days after transplanting the total leaf weight (493.52 g) and total stem weight (334.10 g) were highest. The foliar spray application interval at 20 days after transplanting resulted in the earliest days to first flowering (114.72 days), earliest seed maturity (161.07 days), and longest terminal panicle (24.92 cm). The yield characters like seed yield per plant of 6.65 g was highest for foliar spray at 30 days after transplanting. Significant difference could not be recorded in main plot treatments for growth characters like plant height, fresh yield, leaf to stem ratio, leaf node to first inflorescence and height at first flowering and seed quality characters like seed recovery percent, percent of chaffy seeds, percent of bold seeds, 1000 seed weight and germination percent except for the chaffy weight per plant (30.77 g), which was lowest for foliar spray at 10 days after transplanting. The highest plant height (86.27 cm), internodal length (6.44 cm) and stem weight (384.09 g) were recorded in plants treated with GA3 at 50 ppm, while the longest 128 terminal panicle (28.09 cm) was recorded with the application of GA3 at 100 ppm. Plants treated with BA at 50 ppm and 100 ppm recorded the highest leaf weight (533.61 g) and stem girth (6.84 cm), respectively. The highest number of branches per plant (13.78), earliest emergence of the first flower (70.57 days) and earliest seed maturity (116.68 days) were recorded with the application of TIBA at 100 ppm. Yield characters like yield per plant (982.26 g) were highest for plants treated with BA at 100 ppm, while the highest seed yield per plant (8.91 g) and lowest chaffy weight per plant (34.41 g) were recorded for the foliar spray treatment of triacontanol at 50 ppm. On analysing the interaction between foliar spray application interval and concentrations of growth regulators, the highest growth characters were observed on plants treated with BA or GA3, 10 days after transplanting. Growth characters like internodal length and plant height were observed the highest with the application of GA3 at 50 ppm and 100 ppm respectively at 10 days after transplanting, while the longest terminal panicle (29.50 cm) was recorded for GA3 at 100 ppm at 30 days after transplanting. The highest stem girth of 8.44 cm was recorded for BA 100 ppm, 10 days after transplanting whereas the highest leaf weight of 693.30 g was recorded for BA 100 ppm, 20 days after transplanting. TIBA at 100 ppm, 20 days after transplanting recorded the earliest flowering (52.60 days) and seed maturity (97.94 days) while TIBA 100 ppm, 10 days after transplanting recorded the highest number of branches per plant (17.60). Yield characters like yield per plant (1115.22 g) was recorded the highest for BA 100 ppm, 20 days after transplanting while seed yield per plant (10.54 g) was the highest for triacontanol 50 ppm, 30 days after transplanting. Significant interaction could not be observed for seed quality characters except for the chaffy weight per plant (28.60 g), which was the lowest for TIBA 200 ppm, 10 days after transplanting. The results of this experiment suggested that tri-iodobenzoic acid (TIBA), gibberellic acid (GA3) and triacontanol have the capacity to trigger off-season flowering in the amaranthus variety KAU Vaika. Application of TIBA and GA3 at 100 ppm, 20 days after transplanting could potentially cause early flowering, whereas the application of Triacontanol at 50 ppm, 30 days after transplanting resulted in the highest seed yield per plant.Item Influence of soil characteristics and fertility management practices on nutrient and antinutrient accumulation in amaranth (Amaranthus tricolor L.)(Department of Soil Science and Agricultural Chemistry, College of Agriculture ,Vellanikkara, 2024-05-18) Dharmendranaik, E.; Beena, V IThe research programme entitled “Influence of soil characteristics and fertility management practices on nutrient and antinutrient accumulation in amaranth (Amaranthus tricolor L.)” was carried out at the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellanikkara, Kerala Agricultural University during 2017-2023. The study was programmed to determine the extent of accumulation of antinutrients viz., nitrate and oxalate in vegetable amaranth under different fertility management practices and to elucidate the relationship between soil characteristics and antinutrient accumulation. The investigation was carried out in three phases viz., (i) pot culture experiment with nine fertility management practices and two soil types, (ii) field experiment involving the best three fertility management practices selected from pot culture study and two varieties of amaranth viz., red (Arun) and green (CO-1) (iii) an evaluation of antinutrient status in the amaranth samples collected from farmer’s field. Initial steps included the characterization of electrochemical properties and nutrient status of soils collected from two different locations: (i) Chittur, Palakkad (Vertisol - alkaline soil: Typic Haplusterts) and (ii) Vellanikkara lateritic soil (Instructional Farm, Vellanikkara,very strongly acidic soil: Kandic Paleustalfs). A pot culture experiment was conducted from January to May 2019 in CRD with red amaranth variety “Arun” and 18 treatment combinations viz., nine fertility management practices and two soil types. The nine fertility management practices included in the experiment were: T1: Organic manure alone (Organic KAU-POP: FYM @ 25t ha-1); T2: KAU-POP (N: P: K -100:50:50 kg ha-1 + FYM + foliar spray of 1% urea); T3: T2 with foliar spray of amino acid-methionine 200 mg L-1 (instead of urea spray); T4: N: P: K - 100:75:75 + FYM + foliar spray of 1 % urea + lime as per soil test; T5: T4 with foliar spray of amino acid-Methionine 200 mg L-1 (instead of urea spray) + lime as per soil test based recommendation; T6: N: P: K -100:50:50 kg ha-1 in the form of Factamfos (basal), urea (top dress) and MOP +FYM +foliar spray of 1% urea; T7: T6 with foliar spray of amino acid -methionine 200 mg L-1(instead of urea spray); T8: Soil test based application of nutrients + foliar spray of 1%urea; T9: T8 with foliar spray of amino acid-methionine 200 mg L-1 (instead of urea spray). In all the treatments except T6 and T7, N and P were applied in the form of urea and superphosphate. In the treatments, T6 and T7, basal dose of 50: 50 kg ha-1 N and P were applied as Factamfos and the remaining 50 kg N as top dress in the form of urea. Potassium was applied in the form of MOP in all the treatments. In all the treatments,FYM was applied @ 25t ha-1 as per POP. The top-performing three fertility management practices were selected from the pot culture experiment based on two criteria viz., yield and antinutrient content (nitrate and oxalate). The field experiment was carried out in RBD with six treatment combinations from January to May 2022 at Agronomy Farm, College of Agriculture, Vellanikkara. For the evaluation of antinutrient status in the samples from farmers’ fields, fifteen amaranth samples each from two locations namely, Chittur and Madakkathara panchayat were collected. Fifteen soil samples pertaining to the sampled area were also collected. Soil and plant analysis for macro and micronutrients as well as antinutrients were also carried out. The data revealed that amaranth yield is comparatively lower in the first harvest. The second and third cuttings gave comparable yields. The total yield data from the three cuttings showed that the plant yield of amaranth did not differ significantly with soil type for the first and second harvests. However, Chittur soil exhibited a significantly higher yield than Vellanikkara soil for the third harvest. The total amaranth yield from the three harvests was significantly lower in organic manure alone treatment (109.16 g plant-1) and KAU POP (167.89 g plant-1) compared to the other treatments irrespective of the stage of harvest. Methionine spray gave a comparatively lower yield than urea spray. Soil test based application of nutrients performed better than KAU POP treatment. The treatments T4 and T6 (100: 75: 75 NPK and Factamphos treatments with urea spray) showed superiority over the other treatments in producing higher amaranth yield. Nitrate and oxalate contents in amaranth were significantly lower in Vellanikkara soil as compared to Chittur soil at all the three stages of harvest. Organic manure alone treatment registered the lowest value for nitrate as well as oxalate in both soils. Methionine treatments exhibited nitrate and oxalate levels similar to that of urea spray. While examining the nitrate and oxalate levels across the different harvest stages and treatments, it was found that nitrate and oxalate concentration in amaranth ranged from 953.58 (T1 second cut) to 4486.66 mg kg-1 (T8 third cut) and 2791.24 (T1 and T6 second cut) to 3843.66 mg kg-1 (T2 first cut) respectively. In order to understand the extent of reduction in nitrate and oxalate concentrations due to cooking, fresh amaranth samples from the first cut were steamed for 3-4 min., air dried and the analysis of nitrate and oxalate was carried out. It was found that the cooked amaranth samples had nitrate levels in the range of 931.33 (Organic KAU POP) to 1793.66 mg kg-1 (KAU POP) and oxalate levels in the range of 2301.00 (Organic KAU POP) to 3211.42 mg kg-1 (Factamphos treatment) across the different fertility management treatments. However, in the raw amaranth samples from the first cut, nitrate content ranged from 1202.66 (T9) to 2044.00 mg kg-1 (T3) and that of oxalate ranged from 2881.28 (T1) to 3843.36 mg kg-1 (T2). Higher values of antinutrients were observed in KAU POP treatment even after cooking. Among the integrated nutrient management practices, significantly lower values of nitrate and oxalate were recorded in soil test-based nutrient (T8 and T9) treatments. The percentage reduction in nitrate and oxalate due to cooking ranged from 9.59 to 21.67 % and 15.50 to 36.05 % Total antioxidant activity was higher in Vellanikkara soil at the second and third harvest stages and its content decreased with advancement of harvest time. Higher values were observed in the first cutting and the values ranged from 3570.50 mg kg-1 (T1 – OM alone) to 3146.39 mg kg-1 (T5 - high P and K). However, all the treatments were on par. The same trend was obtained for the second and third harvests. Beta carotene content was lower in Vellanikkara soil as compared to Chittur soil and its content also decreased with harvest time. Organic manure alone treatment was significantly inferior to INM treatments, especially soil test-based application of nutrients at first and third harvest. The data on soil nutrients indicated that ammoniacal nitrogen decreased with harvest stages in both soils. Even though nitrate nitrogen decreased with the advancement of crop growth in lateritic soil, it showed an increasing trend in Chittur soil indicating no leaching loss of this nutrient in this soil type. Both the soils were inherently rich in nutrients and cattle manure is a source of key nutrients including N, P, K, S, Mg, and Ca as well as certain micronutrients. This would have been the reason for the lack of significant variation among the fertility management treatments.Based on the yield performance and antinutrient content (nitrate and oxalate) in amaranth the best three treatments were selected from the pot culture study so as to assess their performance under field condition. The field experiment was conducted at Agronomy Farm, College of Agriculture, Vellanikkara with two varieties of amaranth viz., Arun (red amaranth) and Co-1 (green amaranth) and the three treatments selected from the pot culture study. . The selected treatments were : T1 - N: P: K - 100:75:75 kg ha-1 + FYM+ foliar spray of 1% urea + lime as per soil test-based recommendation, T2 - N: P: K -100:50:50 kg ha-1 in the form of Factamfos (basal), urea (top dress) and MOP +FYM + foliar spray of 1% urea and T3 - Soil test based application of nutrients + foliar spray of 1% urea. Data on the effect of treatments on amaranth yield indicated that the varieties differed significantly. At the first and third harvests amaranth var: Co-1 had a significantly higher yield (9.19 and 8.43 t ha-1 respectively) than Arun (4.98 and 5.73 t ha- 1 respectively). However, there was no significant difference in yield between the varieties at the second harvest (9.20 and 8.08 t ha-1 respectively). The impact of various fertility management practices on amaranth yield was not significant. However, there were significant differences in nitrate and oxalate levels between the varieties . Red amaranth variety Arun registered higher levels of nitrate as well as oxalate. Analysis of nitrate and oxalate contents after cooking showed lower values. Nitrate and oxalate concentrations recorded in cooked amaranth var: Arun were 3190 .00 mg kg-1 and 3331.48 mg kg-1 respectively. Corresponding values noticed in Co-1 were 861.66 and 2783.73 respectively. The magnitude of reduction in nitrate and oxalate contents after cooking were in the range of 58.02 to 68.14 % and 10.38 to 12.19 % respectively. The potential toxic concentration of nitrate nitrogen in amaranth is 2100 mg kg -1 and that of oxalate is 2-5 g day-1. Therefore, it may be concluded that nitrate and oxalate concentration in cooked amaranth is not a serious issue if the fertilizers are applied along with organic manure as per the recommendations of Kerala Agricultural University Analysis of amaranth samples collected from farmer’s fields of Chittur taluk and Madakkathara panchayat revealed significant differences in nitrate and oxalate contents among the plant samples. The mean nitrate content in Chittur plant samples was 29148.94 mg kg-1, while in Madakkathara plant samples, it was notably higher at 39112.20 mg kg-1 indicating a significant variation in nitrate content between the two locations at a 0.05 % significance level. Similarly, the oxalate content (3595.95 mg kg-1) in plant samples from Chittur was found to be significantly higher than that of Madakkathara panchayat (2911.29 mg kg-1). Application of high doses of nitrogenous fertilizers without appropriate levels of organic matter, phosphorus and potassium would have been the reason for the accumulation of nitrate to extremely high level in amaranth cultivated by farmers. Considering the harmful effects of nitrate and oxalate and the benefits of the major nutrient potassium for human health, it was found that indicators viz., potassium nitrate ratio and potassium oxalate ratio in amaranth leaves may be used to assess amaranth nutritional quality. Among the two varieties tested, var. Arun displayed K/NO3 -and K/oxalate ratios of 5.24 and 9.54, respectively. Corresponding ratios for the Co-1 variety were 11.27 and 12.09, respectively. The present investigation revealed that Amaranthus dubius (Green amaranth var. Co-1 ) has higher nutritional value and lower levels of antinutrients viz., nitrate and oxalate as compared to Amaranthus tricolor L.( Red amaranth var. Arun ). Organic POP recommended by Kerala Agricultural University is a good practice to reduce antinutrients in amaranth. However, the yield and nutritional value of amaranth were higher under integrated nutrient management than in KAU organic POP in both the soils under study. Nitrate accumulation in both red and green amaranth could be reduced to a certain degree by the adoption of appropriate fertility management practices.Item Evaluation of STCR based targeted yield equations of amaranthus (Amaranthus tricolor L.) in southern laterite soils of (AEU-8) of Kerala(Department of Soil Science and Agricultural Chemistry, College of Agriculture,Vellayani, 2023-05-06) Dara Hadassah Eunice; Visveswaran, S