1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Integrated weed management in sorghum (Sorghum bicolor (L.) Moench)(Department of Agronomy, College of Agriculture, Vellayani, 2025-03-05) Gloria Raphael.; Renjan, BThe study entitled “Integrated weed management in sorghum (Sorghum bicolor (L.) Moench)” was undertaken at the College of Agriculture, Vellayani during 2022-2024. The objectives were to formulate an integrated weed management (IWM) strategy for sorghum and to assess the effect of IWM on growth, yield and economics of sorghum. The field experiment was conducted from November 2023 to February 2024 at the Farming Systems Research Station (FSRS), Sadanandapuram. The experiment was laid out in a randomised block design with ten treatments, replicated thrice. The treatments comprised T1: broadcasting cowpea seeds @ 15 kg ha -1, T2: broadcasting cowpea seeds @ 30 kg ha -1, T3:T1 + brown manuring with 2,4-D @1 kg ha-1at 20 days after sowing (DAS), T4:T2 + brown manuring with 2,4-D @1 kg ha-1at 20 DAS, T5: pre-emergence (PE) pretilachlor @ 0.75 kg ha-1fb one hand weeding (HW) at 25 DAS, T6: post directed application (PDA) of fenoxaprop-p-ethyl @ 0.06 kg ha-1 at 20 DAS, T7: post emergence (PoE) 2,4-D @ 1 kg ha-1 at 20 DAS, T8:HW at 20 DAS, T9: weed free control and T10: weedy check. In T1 and T2, cowpea seeds were broadcast on the same day of sowing and maintained as live mulch until 20 DAS, after which the cowpea plants and weeds were uprooted and retained as mulch. The sorghum variety CO-32 was raised and managed as per the recommendations of the KAU Package of Practices. The study revealed that weed management practices had a significant effect on the growth parameters of sorghum. The treatment T2 resulted in significantly taller plants (155.17cm and 219.67cm at 45 DAS and at harvest respectively), leaf area per plant (681.68 cm2 and 4693.01cm2 at 30 and 45 DAS respectively), leaf area index (LAI) (1.01 and 6.95 at 30 and 45 DAS respectively) and dry matter production (DMP) (25.87 g per plant and 71.49 g per plant at 45 DAS and at harvest respectively) and was comparable to T4, T5 and T6. The results indicated that the yield attributes of sorghum were significantly influenced by the weed management practices. T2 resulted in a higher number of grains per panicle (2991.3) and grain weight per panicle (64.30 g) which was comparable with T6, T5 and T4. Grain yield (2679 kg ha-1) and stover yield (9896 kg ha-1) of sorghum were higher in T2 and were comparable with T6 (grain yield of 2567 kg ha-1and stover yield of 9561 kg ha-1) and T4 (grain yield of 2462 kg ha-1 and stover yield of 9387 kg ha-1). The weed index was found to be the lowest in T2 (-2.97 %) and was comparable with T6 (1.36 %), T5 (2.78 %) and T4 (5.38%). In the experimental field, grasses were the most dominant weed flora. The total weed count was notably influenced by weed management practices. Among the treatments, T5 and T9 consistently resulted in the lowest absolute frequency of grasses, sedges, and BLW at all stages. IWM integrating pretilachlor application and cowpea mulching effectively reduced the relative frequency of grasses, sedges, and BLW in sorghum. Notably, T2 (00.30 g m-2and 10.22 %), T5 (00.06 g m-2 and 10.22 %) and T6 (0.00 g m-2 and 0.00 %) exhibited comparable lower dry weight and importance value (IV) of grasses at 30 DAS. T9 demonstrated the highest weed control efficiency (WCE) (100.00%) at all stages. At 30 and 45 DAS, it was comparable to T5 (99.93 % and 94.84 % respectively) and T2 (99.65% and 98.73% respectively). Integrated weed management practices influenced the dehydrogenase enzyme activity in the soil at 15, 30 and 45 DAS. Among the treatments, T5 exhibited the highest enzyme activity at 15 DAS (83.33 μg TPF g⁻¹ soil d⁻¹). T2 resulted in higher total carbohydrate (72.50 %), crude protein (13.69 %) and crude fiber content (5.86 %) and was comparable with T4 and T5 on a dry weight basis. Higher organic carbon content was recorded in T2 which was significantly higher than the weed-free control. T2 resulted in higher available soil N (187.35 kg ha⁻¹), T5 registered higher available P (61.19 kg ha⁻¹) and T9 had the higher available K (185.35 kg ha⁻¹). The economic analysis indicated that T6 resulted in higher net return (₹33,395 ha⁻¹) and benefit-cost ratio (BCR) (1.50), followed by treatments involving brown manuring and live mulch. The study has identified broadcasting cowpea seeds at 30 kg ha⁻¹ followed by uprooting and retaining as mulch at 20 DAS as the most effective weed management strategy in terms of yield, weed control efficiency and gross return in sorghum. However, post-directed application of fenoxaprop-p-ethyl at 0.06 kg ha⁻¹ at 20 DAS turned out to be the most economical in terms of net return and BCR. Broadcasting cowpea seeds at 30 kg ha⁻¹ followed by brown manuring with 2,4-D at 1 kg ha⁻¹ at 20 DAS could be identified as the most effective IWM method for achieving higher grain and stover yields in sorghum.Item Integrated weed management in cowpea (Vigna unguiculata L.)(Department of Agronomy, College of Agriculture,Pdanakkad, 19-04-04) Amaya, C P; Gayathri Karthikeyan, PItem Integrated weed management in cowpea (Vigna unguiculata L.)(Department of Agronomy, College of Agriculture, Padanakkad, 2022) Amaya, C P; Gayathri Karthikeyan, PAn experiment entitled ‘Integrated weed management in cowpea (Vigna unguiculata L.) was conducted at Instructional farm II of College of Agriculture, Padannakkad located at Karuvacheri, from December 2020 to March 2021 with the objectives of evaluating the efficacy of different weed management practices and to find out the economics of weed management in cowpea. The experimental design was Randomized Block Design (RBD) with 11 treatments replicated thrice. The short duration cowpea variety namely PGCP 6 was used for the study. The treatments consisted of T1 (pre-emergence application of pendimethalin @ 0.75 kg ha-1 at 0-3 DAS), T2 (T1 + hand weeding at 20-25 DAS), T3 (T1 + mulching @ 7 t ha-1 ), T4 (postemergence application of imazethapyr @ 75 g ha-1 at 20 DAS), T5 (T5 + hand weeding at 35 DAS), T6 (mulching @ 7 t ha-1 + T5), T7 (mulching @ 7t ha-1 + hand weeding at 20 DAS), T8 (hand weeding alone at 15 and 30 DAS), T9 (mulching alone @ 7 t ha-1 ), T10 (weedy check/control) and T11 (weed free). Weed density, dry matter and weed control efficiency (WCE) was lowest in weed free plots throughout the observation period and weedy check (control) recorded highest density dry matter and WCE among all other treatments. At 15 DAS, pre-emergent herbicide treated plots recorded lowest density of weeds in the order T3 >T1 >T2. At 30 DAS, T2 and T7 recorded lowest density of weeds. At 45 DAS, T5, T3, T8 and T7 were recorded with lowest density of weeds and which were on par to each other. At 60 DAS, T8, T3, T7 and T6 were recorded lowest density of weeds and which were on par to each other. In the case of weed dry weight at 15 DAS, T3 recorded the lowest value for dry weight compared to all other treatments except for T11. At 30 DAS, significantly lower value for dry weight was recorded in T2, which was on par with T7 and T3. At 45 DAS, significantly lower value for weed dry weight was recorded in T8 among all the treatments which were on par with T5 and T7. At 60 DAS, dry weight recorded by the treatment T2 was significantly lower among all the weed control treatments except for T3, T5, T7 and T8 which were on par to each other. Lowest WCE was observed in control plot or weedy check (T10). At 15 DAS, the treatments T3, T2 and T1 recorded the highest WCE. At 30 DAS, T2 was recorded with significantly higher WCE. At 45 DAS, WCE was significantly higher in T8 and was on par to T5, T7 T2 and T3. At harvesting stage (60 DAS), the treatment T2 recorded significantly higher value for WCE which was on par to T3. Significantly lower value for weed index (WI) was recorded in weed free plots and T7. Plant height, number of branches per plant (harvesting stage) and leaf area index was highest in weed free plot compared to that of all other treatments. Number of nodules per plant was recorded significantly superior in T7 at flowering stage and T2 at harvesting stage. Total dry matter production was highest in T7 which was on par with T3 at flowering and harvesting stages. Number of pods per plant, pod yield and seed yield were highest in weed free plots compare to that of all other treatments. Treatment T7 recorded significantly superior results in the case of number of seeds per pod, pod weight per plant and test weight and which was on par with that of pre-emergent application of T3 and T11. Among the available soil nutrients, depletion of available N was highest in T10 and treatment T8 recorded highest soil N content. Gross returns and net returns were highest in weed free plots compare to all other treatments which was followed by T3. Similar trend was shown in the case of net return also. The highest B:C ratio of 2.45 was obtained for T7 and T3 which were on par with T11 (2.42). The overall results indicated that weed infestation significantly affected yield in cowpea and integrated weed management (IWM) especially during the critical period of crop weed competition in cowpea is inevitable for getting an economic yield and could reduce yield loss even upto 67 per cent. Even though the cost of cultivation was highest in the weed free plots, the B:C was on par with that of the best IWM practices owing to the superior yield in these plots. Pre-emergence application of pendimethalin along with mulching; and mulching along with hand weeding could effectively keep the field weed free for the critical period of crop weed competition and this treatment resulted in highest B:C ratio and highest on par yields.Item Enhancing morpho-physiological vigour of sesame seedlings for improving productivity and weed competitiveness(Department of Plant Physiology, College of Horticulture, Vellanikkara, 2017) Sreepriya, S; Girija, TSesame is one of the oldest oilseed crops grown in summer rice fallows of Kerala. Weed infestation is a major biotic stress affecting the yield of sesame. Seedling growth of sesame is slow during the first four weeks, making it a poor competitor during this period. Weed suppression during the early stages of crop establishment (10 to 30 DAS) is important for improving the productivity of the crop. The present study was initiated to enhance the early vigour of sesame plants by suitable seed priming treatments and also to assess the effect of early vigour on weed competitiveness and analyse the carry over effect of these treatments on the productivity of the crop. The variation in varietal response to these priming treatments were also studied. A laboratory study was conducted with five popular varieties of sesame viz., Surya, Thilak, Kayamkulam 1, Thilarani and Thilathara, released from Kerala Agricultural University. Ten priming treatments with plant growth regulators (IAA, GA), micronutrients (MnSO4, borax), mixture of MnSO4 and borax with GA (Tank mix), biofertilizers (phosphobacteria, azospirillum, PGPR mix-1) and water were tried. Results on observations showed that seed priming improved the germination and vigour of all the five varieties tested. Among the treatments, priming with micronutrients and hormones gave the best results. Based on the vigour index, five priming treatments were selected for the field trial and the variety Thilak, which gave maximum response to these treatments, was used as the test variety in the field. The experiment was laid out in split plot design at ORARS, Kayamkulam. Weeded and unweeded treatments formed the main plots and five selected treatments along with control (unprimed seeds) were the sub-plot treatments. Observations on morphological characters were studied at 20 days interval and yield characters were recorded at the time of harvest. Physiological and biochemical effects of the priming treatments were studied at vegetative and reproductive stages of the crop. Weed count and weed dry matter were recorded at 10 DAS and at the time of harvest in the unweeded plots. Weed control efficiency of the priming treatments was computed at the time of harvest. The biochemical parameters such as contents of chlorophyll, total soluble protein and GA were higher during the reproductive phase as compared to the vegetative phase. Chlorophyll including chlorophyll a and chlorophyll b, and soluble protein content showed greatest improvement in MnSO4 primed plants. The nitrate reductase enzyme plays a major role in nitrogen metabolism of the plant. In the present study, the nitrate reductase enzyme activity was found to be higher during the reproductive phase of the crop in all the treatments except for control (unprimed seeds) and water priming. The IAA content was also higher in the reproductive phase in all the treatments. Major improvement in IAA content was observed with borax priming. The growth indices such as crop growth rate, relative growth rate, net assimilation rate and leaf area index were improved with priming treatments in both unweeded and weeded plots. Yield and yield attributes such as number of branches, number of capsules and seeds per capsule improved significantly with MnSO4 and tank mix treatments, which contributed to higher yield. The improvement in vigour of sesame plants with seed priming treatments reduced the weed count and weed dry matter production in the unweeded plots as compared to the control (unprimed seeds) due to the higher competitiveness of the primed seeds. The study revealed that seed priming with MnSO4 or Tank mix of GA, borax and MnSO4 can be an effective component in the integrated management of weeds in sesame as it can contribute to 30 per cent control of weed growth.Item Standardisation of nutrient and weed management techniques for organic rice(Department of Agronomy, College of Agriculture, Vellayani, 2013) Murugesh, M S; Girija Devi, LThe present investigation on “Standardisation of nutrient and weed management techniques for organic rice” was conducted at the Department of Agronomy, College of Agriculture, Vellayani, during 2012-2013. The objectives were to standardise the nutrient schedule, spacing and weed management techniques for organic rice and to assess the economic feasibility of the organic package. The experiment was laid out in the field in split plot design with combination of spacing, S (S1-20 cm x 15 cm and S2-15 cm x 15 cm) and weed management techniques, W (W1-stale seedbed and W2-hand weeding) as main plot treatments and nutrient schedule, N (N1-option-1 of the ad hoc recommendation of KAU: FYM 5 t + 800 kg oil cakes ha-1 (1/2 basal + 1/2 top dressing at active tillering stage), N2-option-2 of the ad hoc recommendation of KAU: FYM 1 t + green leaf manure 1t + dual culture of azolla + 2 kg Azospirillum + 2 kg P solubilizing bacteria + 1kg PGPR (mix 1) ha-1, N3-option-3 of the ad hoc recommendation of KAU: 1/3rd RDN as FYM, 1/3rd as vermicompost and 1/3rd as neem cake + 2 kg Azospirillum + 2 kg P solubilizing bacteria ha-1, N4-soil test based application–half as vermicompost and half as neem cake). The KAU Package of Practices Recommendation (FYM 5 t + 90:45:45 kg NPK ha -1) was taken as control. Closer spacing (S2-15cm x 15 cm), hand weeding (W2) and option-3 of the ad hoc recommendation of KAU (N3) significantly influenced plant height and DMP, while closer spacing (S2-15cm x 15 cm) and option-3 of the ad hoc recommendation of KAU (N3) only had significant influence on tiller production and LAI. Stale seedbed (W1) and closer spacing (S2-15 cm x 15 cm) had significant influence on most of the yield attributing characters, while, among nutrient schedule, N3 (option-3 of the ad hoc recommendation of KAU) attributed the maximum for yield contributing characters, but was on par with N4 (soil test based application) and also with N1 (option-1 of the ad hoc recommendation of KAU) for grain yield. The results on weed control revealed the superiority of closer spacing (S2-15 cm x 15 cm) and stale seedbed technique (W1) over others in controlling the weeds throughout the growth stages. However the weed control efficiency was the lowest in conventional (Control-KAU Package of Practices Recommendation) compared to the organic throughout the growth stages. The nutrient uptake was the highest in N3 (option-3 of the ad hoc recommendation of KAU) and the lowest in N2 (option-2 of the ad hoc recommendation of KAU). However, uptake study had also revealed the superiority of conventional (Control-KAU Package of Practices Recommendation) over organic in the uptake of nutrients. The net returns and B:C ratio were the highest in closely spaced plants (S2-15 cm x 15 cm) and in N3 (option-3 of the ad hoc recommendation of KAU). From the study it can be concluded that for realising higher grain yield in organic rice, a closer spacing of 15 cm x 15 cm (S2) is ideal. Any of the two weed management techniques, i.e., either stale seedbed (W1) or hand weeding (W2) can be practiced for controlling weeds. Option-3 of the ad hoc recommendation of KAU (N3-1/3rd RDN as FYM, 1/3rd as vermicompost and 1/3rd as neem cake + 2 kg Azospirillum + 2 kg P solubilizing bacteria ha-1) is the best nutrient schedule for realizing maximum yield from organic rice. The most economic package for organic rice production is the combination of closer spacing of 15 cm x 15 cm (S2), with stale seedbed technique (W1) of weed control and option-3 of the ad hoc recommendation of KAU (N3-1/3rd RDN as FYM, 1/3rd as vermicompost and1/3rd as neem cake + 2 Kg Azospirillum + 2 Kg P solubilizing bacteria ha-1) as nutrient schedule. The organic package was economically significantly superior to conventional package due to the premium price fetched by organic rice.Item Integrated weed management in upland rice(Department of Agronomy, College of Agriculture, Vellayani, 2001) Shyam Nair, S; Prathapan, KItem Integrated weed management in brinjal (Solanum melongena L.)(Department of Agronomy, College of Agriculture, Vellayani, 2000) Mandira Chakrabarti; Sansamma GeorgeA field experiment was conducted at the Instructional Farm, College of Agriculture, Vellayani, Thiruvanantbapuram to study the technical and economic feasibility of different weed management practices for brinjal. The study was carried out during the period from August to November, 1999. The experiment was laid out in Randornised Block Design with fourteen treatments and three replications. The treatments consisted of physical, cultural and chemical methods of weed control alone or in combination. Unweeded check and completely weed free check were included as control treatments. 'Swetha' was the variety of brinjal used for the study. Results of the study revealed that grasses, broadleaved weeds and sedges competed with the brinjal crop. The weed intensity and distribution was found significantly influenced by the weed management practices included in the study. It was evident that weeds failed to emerge under the black polythene mulching and the few weeds recorded were those emerging from the planting hole. There was no distinguishable weed growth even from the planting hole beyond 30 days after transplanting (OAT). The farmers practice of giving two manual weeding at 15 and 30 OAT allowed unchecked weed growth upto 15 OAT, but had comparatively high weed control efficiency at later stages. Application of fluchloralin as pre-plant incorporation (PPI) was found to inhibit early emergence of grasses and broadleaved weeds, but gave poor control of sedges. Fluchloralin + one hand weeding at 20 OAT was found to give season long control of weeds and was a better option than fluchloralin alone and fluchloralin + smother cropping. The cultural practices of stale seed bed technique and smother cropping gave early season weed control but allowed weed emergence later and gave improved weed control efficiency when integrated with one hand weeding. The effect of glyphosate application also was found to respond in similar lines. The weed management practices were found to exert considerable influence on growth and yield characters of the crop. Under weed free situation the plant produced the highest number of branches and leaves and had the maximum number of flowers and fruit also. The crop yield was found to bear a direct positive correlation with the weed control efficiency of the management practices. Weedy check recorded the lowest yield and the yield losses worked out was 58.43 per cent. Excluding the weed free check, the yield loss was minimum under black polythene mulching followed by fluchloralin + one hand weeding. The most remunerative treatment was found to be fluchloralin + one hand weeding (T9) followed by two manual weeding (T3). The herbicides were found non persistent leaving little toxic residue in the soil after the experiment.Item Integrated weed management in okra (Abelmoschus esculentus (L.) Moench)(Department of Agronomy, College of Horticulture, Vellenikkara, 2000) Sainudheen, K; Abraham, C TField experiments were conducted during summer and kharif seasons of 1998 and 1999 at College of Horticulture, Kerala Agricultural University, Thrissur, with the objective of developing an integrated method for management of weeds, especially perennial weeds like Cynodon dactylon (L.) and Cyperus rotundus L. in okra. Broadspectrum herbicide glyphosate, solarization, smother croppmg with cowpea and monthly digging were compared with unweeded control in the summer season, for their effect on weeds. In the subsequent okra crop, during kharif season, different pre-emergence herbicides and farmer's practice of hand weeding were compared with black polyethylene mulching and unweeded control. The experiment was carried out in a split-plot design with three replications, taking summer season treatments as main plots and weed control methods in okra, as sub plots. Cynodon dactylon and Cyperus rotundus were the predominant perennial weeds in the field. Cyperus iria, Digitaria ciliaris, Dactyloctenium aegyptium, Eleusine indica and Ludwigia parviflora were the major annual weeds. In summer season.,) treatments solarization and glyphosate l.2 kg ha-1 were very effective in reducing the weed problems. They also resulted in reduction in the underground vegetative propagules of perennial weeds. Solarization resulted in increasing the soil temperature by 8.5 and 6. 7°C at 5 and 1 0 cm depths respectively, during April. In the subsequent okra crop, black polyethylene mulching gave complete prevention of any weed problems. Among the other combinations, glyphosate 1.2 kg ha" (twice at 45 days interval) during summer season followed by metolachlor l.0 kg ha-1 + HW at 45 DAS in okra crop (in 1998) as well as solarization followed by pendimethalin l.0 kg ha-1 + HW at 45 DAS (in 1999). The total returns was higher ill plots which received polyethylene mulching in the okra crop, irrespective of main plot treatments given in the summer season. Among them, highest total return was obtained from glyphosate 1.2 kg ha-I in the summer season followed by polyethylene mulching in okra crop (Rs.31,704 ha"), followed by solarization followed by black polyethylene mulching (Rs.30,594 ha"). However, the highest return per rupee invested on weed control was obtained from combinations of metolachlor 1.0 kg ha" (in okra) with glyphosate 1.2 kg ha" in summer season (Rs.2.41), solarization (Rs.2.28) and that of glyphosate 0.8 kg ha'. But all the combinations of weedy control in summer season, except that of polyethylene mulching resulted in loss as far as the cost of weed control and the total cost is concerned.