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Assam Agricultural University, Jorhat

Assam Agricultural University is the first institution of its kind in the whole of North-Eastern Region of India. The main goal of this institution is to produce globally competitive human resources in farm sectorand to carry out research in both conventional and frontier areas for production optimization as well as to disseminate the generated technologies as public good for benefitting the food growers/produces and traders involved in the sector while emphasizing on sustainability, equity and overall food security at household level. Genesis of AAU - The embryo of the agricultural research in the state of Assam was formed as early as 1897 with the establishment of the Upper Shillong Experimental Farm (now in Meghalaya) just after about a decade of creation of the agricultural department in 1882. However, the seeds of agricultural research in today’s Assam were sown in the dawn of the twentieth century with the establishment of two Rice Experimental Stations, one at Karimganj in Barak valley in 1913 and the other at Titabor in Brahmaputra valley in 1923. Subsequent to these research stations, a number of research stations were established to conduct research on important crops, more specifically, jute, pulses, oilseeds etc. The Assam Agricultural University was established on April 1, 1969 under The Assam Agricultural University Act, 1968’ with the mandate of imparting farm education, conduct research in agriculture and allied sciences and to effectively disseminate technologies so generated. Before establishment of the University, there were altogether 17 research schemes/projects in the state under the Department of Agriculture. By July 1973, all the research projects and 10 experimental farms were transferred by the Government of Assam to the AAU which already inherited the College of Agriculture and its farm at Barbheta, Jorhat and College of Veterinary Sciences at Khanapara, Guwahati. Subsequently, College of Community Science at Jorhat (1969), College of Fisheries at Raha (1988), Biswanath College of Agriculture at Biswanath Chariali (1988) and Lakhimpur College of Veterinary Science at Joyhing, North Lakhimpur (1988) were established. Presently, the University has three more colleges under its jurisdiction, viz., Sarat Chandra Singha College of Agriculture, Chapar, College of Horticulture, Nalbari & College of Sericulture, Titabar. Similarly, few more regional research stations at Shillongani, Diphu, Gossaigaon, Lakhimpur; and commodity research stations at Kahikuchi, Buralikson, Tinsukia, Kharua, Burnihat and Mandira were added to generate location and crop specific agricultural production packages.

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  • ThesisItemOpen Access
    RELATIVE PERFORMANCE OF NIGER VARIETIES TO DIFFERENT MICROCLIMATIC REGIMES UNDER RAINFED SITUATION
    (2023) Gogoi, Vaishali; Ojha, N. J.
    A field experiment entitled “Relative performance of niger varieties to different microclimatic regimes under rainfed situation” was conducted at Instructional-cum- Research (ICR) farm, AAU, Jorhat during rabi season of 2022-23. The experiment was laid out in split plot design with three replications. The treatments consisted of five sowing dates viz., 20th October, 5th November, 20th November, 5th December and 20th December in main plots and three varieties viz., NG-1, GA-10 and JNS-9 in sub- plots. The experimental site was sandy loam in texture with pH 5.43, medium in available N (283.14 kg/ha), available K2O (156.55 kg/ha), organic carbon (0.56%) and low in available P2O5 (18.67 kg/ha). Different growth and yield attributing characters of niger were influenced significantly due to different dates of sowing. The growth characters viz., plant height, number of leaves per plant, number of branches per plant, leaf area index, plant dry weight, crop growth rate, relative growth rate, yield attributing characters viz., number of capitula per plant (16), number of seeds per capitulum (34.66) were significantly higher in the crop sown on 20th October (D1). The nutrient content and uptake (N, P and K) was also the highest in case of D1. Significantly higher seed yield (468.33 kg/ha) and stover yield (1935.22 kg/ha) were recorded when the crop was sown on 20th October. Among the varieties, growth parameters such as plant height, number of leaves per plant, number of branches per plant, leaf area index, plant dry weight, crop growth rate, relative growth rate, yield attributing characters such as number of capitula per plant (14.46), number of seeds per capitulum (32.06) and test weight (3.35g), seed yield (457.46 kg/ha), stover yield (1967.40 kg/ha) and oil yield (164.75 kg/ha) were significantly higher in the variety NG-1 (V1) over the other two varieties viz., GA-10 (V2) and JNS-9 (V3). However, significantly higher oil content was obtained in the variety GA-10 (37.61 %). Treatment combination of sowing of variety NG-1 on 20th October (D1V1) recorded the highest interaction effect in case of number of capitula per plant (17.66), seed yield (511.33 kg/ha), oil yield (164.75 kg/ha) and N- uptake by seeds (14.50 kg/ha). In terms of economics, the highest gross return (₹ 31138/ha), net return (₹ 18999/ha) and B-C ratio (1.57) were recorded when the variety NG-1 was sown on 20th October (D1V1). This was followed by sowing of variety JNS-9 on 20th October (D1V3) with gross return (Rs. 29030/ha), net return (₹ 16891/ha) and B-C ratio (1.39).
  • ThesisItemOpen Access
    INTEGRATED WEED MANAGEMENT IN SUMMER MAIZE (Zea mays L.)
    (2023) Narah, Tulika; Kurmi, K.
    A field experiment on “Integrated weed management in summer maize (Zea mays L.)” was carried out during summer, 2022 at the Instructional-cum-Research (ICR) farm, AAU, Jorhat, with the objectives of identifying the weed flora during the crop growth period; the best weed management practice in the crop and to understand the effect of the weed management practices on the soil physical, chemical and microbial population. A total of ten treatments were taken for the research which included - T1:Farmers practice i.e. manual weeding, T2: Recommended practice (Atrazine 1kg ha-1 PE), T3:Weedy fallow, T4: PE application of atrazine 0.5 kg ha-1 followed by PoE application of tembotrione 120 g ha-1, T5: Live mulching with cowpea, T6:Live mulching with greengram, T7: Mulching with lemongrass, T8:Mulching with biodegradable polythene, T9:Weedy Check and T10:Weed free check.The experiment was laid down in Randomized Block Design (RBD) with three replications. The soil of the experimental plot was of sandy loam texture with a pH of 5.1, available N in the medium range (286.54 kg ha-1), available P2O5 and K2O in low range with 24.37 kg ha-1 and 158.82 kg ha-1, respectively. The results of the experiment revealed that the PE application of atrazine 0.5 kg ha-1 followed by PoE application of tembotrione 120 g ha-1 (T4) has been able to control the weeds more effectively than the other treatments at the early stage of crop growth. However, during the later stage of crop growth more effective management of weeds was seen under mulching with lemongrass (T7). Mulching with lemongrass (T7) showed higher result with regards to crop growth parameters viz., Plant height, dry matter accumulation,crop growth rate, number of leaves plant-1 and leaf area index at all the stages as compared to rest of weed management treatments. Mulching with lemongrass(T7) also showed higher result in terms of yield attributing characters viz., number of cobs plant-1, cob length, cob girth, 1000 grain weight. Grain yield (69.15 q ha-1) was found to be significantly higher in mulching with lemongrass(T7). Significantly higher cob yield with husk(93.34 q ha-1) and cob yield without husk (90.68 q ha-1) was recorded in mulching with lemongrass(T7). Similarly straw yield (95.97 q ha-1) was found to be highest in mulching with lemongrass(T7). The NPK content and uptake by grain and stover of the crop was highest in mulching with lemongrass(T7).Mulching with lemongrass also recorded higher values of the soil available N, P2O5, K2O. The microbial population after harvest showed significantly higher population of microbes in mulching with lemongrass, as compared to the other treatments with a value of 6.77 log cfu g-1 soil for bacterial population and 4.74 log cfu g-1 soil for fungal population. The highest gross and net returns (Rs 168615 ha-1 and Rs 115308 ha-1, respectively ) were noted in mulching with lemongrass(T7) along with highest B:C (2.16) closely followed by PE application of atrazine 0.5 kg ha-1 followed by PoE application of tembotrione 120g ha-1 (T4).
  • ThesisItemOpen Access
    EFFICACY OF HERBICIDE COMBINATIONS FOR WEED MANAGEMENT IN DIRECT SEEDED KHARIF RICE
    (2023) Beypi, Mirdan; Kalita, Sontara
    A field experiment entitled “Efficacy of herbicide combinations for weed management in direct seeded kharif rice” was carried out in Instructional-cum-Research farm, Assam Agricultural University, Jorhat during kharif, 2022.The Randomized Block Design was used to arrange 12 weed management treatments in 3 replications. The treatments were weed free (T1), weedy check (T2), bispyribac-sodium 25g/ha + pyrazosulfuron 20g/ha 20 days after sowing (DAS) as check (T3), pretilachlor 750g/ha pre-emergence followed by fenoxaprop-p-ethyl 50 g/ha + ethoxysulfuron 15g/ha 20 DAS (T4), pretilachlor 750g/ha pre-emergence followed by triafamone + ethoxysulfuron 60g/ha 20 DAS (T5), pretilachlor 750g/ha pre-emergence followed by penoxsulam 30 g/ha + bentazone 1080 g/ha 20 DAS (T6), glyphosate 1000 g/ha followed by one mechanical weeding 30 DAS (T7), glyphosate 1000 g/ha followed by fenoxaprop-p-ethly 50g/ha + ethoxysulfuron 15g/ha 20 DAS (T8), glyphosate 1000 g/ha followed by triafamone + ethoxysulfuron 60g/ha at 20 DAS (T9), glyphosate 1000g/ha followed by penoxsulam 30g/ha + bentazone 1080g/ha 20 DAS (T10), hand weeding at 20 DAS and weeding with grubber at 40 DAS (T11) and two mechanical weeding at 20 and 40 DAS (T12). The texture of the soil was sandy loam with pH of 5.5, bulk density of 1.40 Mg/m3, organic carbon of 0.67% and available N, P2O5 and K2O of 289.93, 19.69 and 114.11 kg/ha, respectively. All treatments significantly lowered the weed density as well as dry matter in terms of broad-leaved, sedge and grassy weeds at 60, 90 and 120 DAS and at harvest as compared to weedy check. Significant reduction (75.59, 56.97, 44.77 and 30.44 %, respectively) in density of total weeds was observed in treatment (T5) pretilachlor 750g/ha pre-emergence followed by triafamone + ethoxysulfuron 60g/ha 20 DAS at 60, 90 and 120 DAS as well as at harvest over weedy check. The same treatment recorded significantly lower dry matter of total weeds at 60, 90 and 120 DAS and at harvest to the tune of 73.39, 52.71, 37.76 and 27.46 %, respectively over weedy check. Pretilachlor 750g/ha pre-emergence followed by triafamone + ethoxysulfuron 60g/ha 20 DAS (T5) showed higher result with regards to crop growth parameters viz., plant height, number of tillers/m2, leaf area index, dry matter accumulation/m2 and crop growth rate at all the stages as compared to rest of weed management treatments except for plant height which was found to be not significant at 30, 120 DAS and at harvest. The above-mentioned treatment also showed higher result in terms of yield attributing characters viz., number of panicles/m2 and number of grains/panicle with 77.60 and 40.97 % increase over weedy check. In case of panicle length and test weight, the result was found to be not significant among all the treatments. Grain yield was found to be significantly higher in pretilachlor 750g/ha pre-emergence followed by triafamone + ethoxysulfuron 60g/ha 20 DAS (T5) with 175.16 % higher over weedy check and was at par with pretilachlor 750g/ha pre-emergence followed by fenoxaprop-p-ethyl 50 g/ha + ethoxysulfuron 15g/ha 20 DAS (T4). Similar result was observed in terms of straw and biological yield with 137.38 and 152.37 %, respectively increase over control. In case of straw yield (50.68 kg/ha) T5 was at par with T4 (46.65 kg/ha) and T6 (44.85 kg/ha). Weed management treatment did not significantly affect harvest index of direct seeded kharif rice. The lower weed index was recorded in pretilachlor 750g/ha pre-emergence followed by triafamone + ethoxysulfuron 60g/ha 20 DAS (T5) (5.84 %) followed by pretilachlor 750g/ha pre-emergence followed by fenoxaprop-p-ethyl 50 g/ha + ethoxysulfuron 15g/ha 20 DAS (T4) (13.30 %) and pretilachlor 750g/ha pre-emergence followed by penoxsulam 30 g/ha + bentazone 1080 g/ha 20 DAS (T6) (17.49%). No significant change in N, P and K content was recorded in grain and stover whereas N, P and K uptake by the crop was significantly higher in pretilachlor 750g/ha pre-emergence followed by triafamone + ethoxysulfuron 60g/ha 20 DAS (T5). The mentioned treatment decreased N, P and K content in weeds and their uptake as compared to weedy check by 5.18, 22.08 and 6.78, and 50.18, 59.02 and 50.76 %, respectively over weedy check. The same treatment recorded higher available N, P2O5 and K2O by 7.55, 19.57 and 3.96 %, respectively over weedy check. Weed management treatment did not significantly affect soil organic carbon of direct seeded kharif rice. The highest gross and net returns (103541 and 62751 ₹ /ha, respectively) were noted by pretilachlor 750g/ha pre-emergence followed by triafamone + ethoxysulfuron 60g/ha 20 DAS (T5) along with the highest B-C ratio (1.54) closely followed by pretilachlor 750g/ha pre-emergence followed by fenoxaprop-p-ethyl 50 g/ha + ethoxysulfuron 15g/ha 20 DAS (T4) (1.36).
  • ThesisItemOpen Access
    CONSERVATION AGRICULTURE PRACTICES IN RICE-LINSEED CROPPING SEQUENCE
    (2023) Maurya, Manish Kumar; Rafique, Nawab Tayab
    A field experiment entitled “Conservation agriculture practices in rice-linseed cropping sequence” was conducted at Instructional cum Research (ICR) farm, AAU, Jorhat during kharif, 2022 and rabi season, 2022-2023. The experiment consisted of three objective viz. (i) to study the effect of rice establishment methods on growth and productivity of rice and on succeeding linseed crop, (ii) to examine the effect of kharif rice stubble managements on performance of linseed crop and (iii) to assess the economics of the rice based double cropping system as influenced by rice establishment methods and stubble management practices. The experiment consisted of three rice establishment methods viz. transplanting (M1), wet-DSR (M2) and dry-DSR (M3) in main-plot and four stubble management practices viz. no residue (S1), 15 cm tall stubble chopped (S2), 15 cm tall stubble unchopped (S3) and 30 cm tall stubble chopped (S4) in sub-plot. The experiment was laid out in split-plot design with three replications. The soil at experimental site was sandy loam in texture with a pH of 5.1 and 5.26, medium in availability of nutrients including N (282.4 and 279.09 kg ha-1), P2O5 (23.86 and 24.79 kg ha-1), K2O (128.4 and 126.5 kg ha-1) and organic carbon content (0.51 and 0.53%) in Kharif and rabi season, respectively. The total rainfall received during kharif and rabi season was 1267.9 and 278.5 mm, respectively. The mean maximum and minimum temperature during kharif season ranged from 28.2 to 34.90C and 10.9 to 25.60C, respectively while during rabi season, they ranged from 21.4 to 31.90C and 7.9 to 20.50C, respectively. Different growth and yield attributing characters, as well as the yield of rice, were significantly influenced by rice establishment methods. All the growth and yield attributing characters were significantly higher in transplanting (M1) over wet-DSR and dry-DSR. The highest grain yield (5.17 t ha-1) and straw yield (7.04 t ha-1) were also recorded with transplanting (M1). Similarly, different growth and yield attributing characters, as well as the seed yield of linseed were significantly influenced by rice establishment methods and stubble management practices. All the growth and yield attributing characters were significantly higher where linseed was grown following the dry-direct-seeded rice (M3). The highest seed yield (5.28 q ha-1) and stover yield (11.29 q ha-1) were also recorded where linseed was grown following the dry-direct-seeded rice (M3). Similarly, among the stubble management practices, growth and yield attributes were significantly higher where linseed was grown following 30 cm tall rice stubble chopped (S4). The highest seed yield (5.72 q ha-1) and stover yield (11.53 q ha-1) were also recorded where linseed was grown following 30 cm tall rice stubble chopped (S4). The highest cost of cultivation (₹ ha-1 76169.46) in the rice-linseed cropping system was incurred where linseed was grown after transplanted rice with 30 cm tall stubble chopped (M1S4). The highest gross return (₹ ha-1 137376.7) and net return (₹ ha-1 61207.21) were obtained by the treatment combination of linseed grown after transplanted rice with 30 cm tall stubble chopped (M1S4). However, the maximum benefit-cost ratio was recorded where linseed succeeded wet-direct-seeded rice with 30 cm tall rice stubble unchopped (2.02:1) followed by linseed grown after wet-direct-seeded rice with 30 cm tall stubble chopped (1.95:1). From the point of view of the rice-linseed cropping system, the best combination in terms of rice equivalent yield (6668.77 kg ha-1) was obtained by linseed following transplanted rice with 30 cm rice stubble chopped (M1S4).
  • ThesisItemOpen Access
    EVALUATION OF ORGANIC AND NATURAL FARMING PRACTICES ON CROP PRODUCTIVITY AND SOIL IN KHARIF RICE
    (2023) Dutta, Saurav Kumar; Saud, Ranjit Kumar
    A field experiment entitled “Evaluation of organic and natural farming practices on crop productivity and soil in kharif rice” was conducted in research farm of AAU-ARRI, Titabar during the sali season of 2022-23 with a view to study the growth, yield behaviour, soil conditions of scented rice (variety: Bokul joha) under different organic and natural farming treatments. The experiment was laid out in randomized block design with three replications. The treatments consisted of eight in total viz. absolute control(T1), complete natural farming (beejamrit + ghanajeevamrit + jeevamrit mixture at 300 litres/ha at 30, 60 and 90 DAT) (T2), enriched compost 5 t/ha + biofertilizer (Azospirillum, PSB 4 kg/ha as seedling root dip (T3), enriched compost 5 t/ha (T4), vermicompost 5 t/ha (T5), enriched compost 2.5 t/ha + vermicompost 2.5 t/ha (T6) , fresh azolla at 400 kg/ha as dual crop + biofertilizers (Azospirillum, PSB and KSB mix at 4 kg/ha as seedling root dip) (T7), vermicompost at 1 t/ha mixed inocula of Azospirillum amazonense A-10 and Bacillus megaterium P-5 4 kg/ha and rock phosphate 10 kg/ha P2O5 (T8). The treatments brought significant influences on the various growth and yield attributing characters. Among the different treatments, the highest plant height, dry matter, leaf area index and number of tillers at different intervals were found in the vermicompost @ 1t/ha mixed inocula of Azospirillum amazonense A-10 and Bacillus megaterium P-5 4 kg/ha and rock phosphate 10 kg P2O5. The highest grain (34.62 q/ha) and straw yield (15.50 q/ha) were also obtained from application of vermicompost 1t/ha (on dry weight basis) mixed inocula of Azospirillum amazonense A-10 and Bacillus megaterium P-54 kg/ha rock phosphate @ 10 kg/ha P2O5 (T8) followed by the treatment including fresh azolla @ 400 kg/ha as dual crop + biofertilizers (Azospirillum, PSB and KSB mix @ 4 kg/ha as seedling root dip) (T7). In case of the soil, residual N (272.09 kg/ha) was found to be significantly high in fresh azolla at 400 kg/ha as dual crop + biofertilizers (Azospirillum, PSB and KSB mix at 4 kg/ha as seedling root dip) (T7) whereas P2O5 (22.8 kg/ha) and K2O (123.17 kg/ha) were found to be highest in vermicompost 1t/ha (on dry weight basis) mixed inocula of Azospirillum amazonense A-10 and Bacillus megaterium P-54 kg/ha rock phosphate @ 10 kg/ha P2O5 (T8). An economic analysis showed that the highest net return (₹ 1,40,779/ha), gross return (₹ 1,60,305 /ha) and highest B:C ratio of 1.95 was recorded in the treatment comprising of vermicompost application of 1t/ha and mixed inocula of Azospirillum amazonense A-10 and Bacillus megaterium P-5 at 4 kg/ha and rock phosphate 10 kg/ha P2O5.
  • ThesisItemOpen Access
    SMART NUTRIENT MANAGEMENT WITH NANO UREA ON RABI MAIZE (Zea mays L.) UNDER RAINFED SITUATION
    (2023) Singh, Rajib; Kalita, R.
    A field experiment was carried out during rabi, 2022-23 at the experimental plot of the Department of Agronomy, B. N. College of Agriculture, Assam Agricultural University, Biswanath Chariali to assess “Smart nutrient management using nano urea on rabi maize (Zea mays L.) under rainfed situation” with two objectives viz. studying the effect of foliar application of nano-urea on growth and yield of rabi maize and to find out the optimum combination of nano-urea and with conventional urea. The experiment consisted of 11 treatments in randomized block design viz. T1: Recommended Dose of Fertilizer (RDF) T2: 100% P & K + Spray of Nano urea @ 6 ml l-1 at knee high and tasseling stage, T3: 100% P & K + Spray of Nano urea @ 8 ml l-1 at knee high and tasseling stage, T4: 100% P & K + Spray of Nano urea @ 10 ml l-1 at knee high and tasseling stage, T5: 25% N + 100% P & K + Spray of Nano urea @ 6ml l-1 at knee high and tasseling stage, T6: :25% N + 100% P & K + Spray of Nano urea @ 8ml l-1 at knee high and tasseling stage, T7: 25% N + 100% P & K + Spray of Nano urea @ 10ml l-1 at knee high and tasseling stage, T8: 50 % N + 100% P & K + Spray of Nano urea @ 6 ml l- 1 at knee high and tasseling stage, T9: 50 % N + 100% P & K + Spray of Nano urea @ 8 ml l-1 at knee high and tasseling stage, T10: 50 % N + 100% P & K + Spray of Nano urea @ 10 ml l-1 at knee high and tasseling stage, T11: 100% P & K. The results of the investigation revealed that the treatment T1 (RDF) resulted in relatively taller plant height (103.20 cm) at knee high stage which is statistically at par with T8, T9 and T10. However, the highest plant height during tasseling (245.20 cm) and physiological maturity (243.80 cm) was observed in T8 (50% of recommended dose of N from conventional urea + spraying Nano urea @ 6 ml l-1 at knee high and tasseling stage). T1 also registered the significantly higher number of green leaves (8.73) plant-1, dry matter accumulation (138.83 g) and leaf area index (1.84) at knee high stage. Conversely, in later stage of growth, effect of nano urea was found to be significant with notably higher value of number of green leaves plant-1 (11.67 and 9.60); leaf area index (4.63 and 3.10 plant-1) and dry matter accumulation (214.76 and 645.26 g plant-1) recorded at tasseling and physiological maturity, respectively under T8. The crops under this treatment also showed the significantly thicker stem (7.53 cm). Crops receiving 50 % N from conventional urea and 6 ml l-1 of nano urea recorded greater crop growth rate (CGR) between knee high and tasseling (209.79 g m-² day-1) and between tasseling and physiological maturity (638.10 g m-² day-1). In case of, relative growth rate (RGR), higher value (0.32 g g-1 d-1) was recorded under T6 that receiving 25% recommended N from conventional source and 6ml l-1 of nano urea in between knee high to tasseling; whereas between tasseling to physiological maturity stage the highest value (0.47 g g-1d-1) was found in T8. The effect of nano urea was also observed with respect to leaf chlorophyll content and relative water content (RWC) of leaf as the highest being 1.37 mg g-1 fw. and 91.23 %, respectively recorded under T8 . Effect on yield parameters revealed significantly influence of nano urea with respect to increased length (35.88 cm), weight (368 g) and girth (20.29 cm) of cob together with more number of seeds per cob (615.93) and test weight (247.54 g) which were recorded under T8. The improvement of these yield parameters was reflected in grain yield (72.25 q ha-1), stover yield (110.67 q ha-1) and harvest index (39.50 %) and production efficiency (120.42 %) as well. The soil available nitrogen was highest (268.75 kg ha-1) in T10 (50 % N + 100% P & K + spray of Nano urea @ 10 ml l-1), however T1 (RDF), T8 (50 % N + 100% P & K + Spray of Nano urea @ 6 ml l-1) and T9 (50 % N + 100% P & K + Spray of Nano urea @ 10 ml l-1) showed comparable value and the lowest value (241.19 Kg ha-1) was recorded in T11 i.e. 100% P & K. Among all the treatments, T1 (RDF) recorded the highest cost of cultivation (􀀀 80,650 ha-1) followed by T8 and, the lowest (􀀀 75000 ha-1) was incurred in T11 i.e.100% P & K. The highest gross return (Rs. 1,50,569 ha-1), net return (Rs. 72,069 ha-1) and benefit-cost ratio (1.91) was obtained in T8 whereas, T11 i.e. 100% P & K recorded the lowest gross return (􀀀. 86,305 ha-1), net return (􀀀 11,305 ha-1) and benefit-cost ratio (1.15). Results showed that spraying of nano urea @ 6ml/L at knee high and tasseling stage with basal application of 50% of recommended N from conventional urea with 100 % P & K was superior in terms of noticeably enhanced and economically efficient corn yield which was resulted from significantly improved growth and yield parameters. Therefore, it could be inferred that spraying of nano-urea @ 6ml l-1 at knee high and tasseling stage coupled with basal application of 50% of recommended N from conventional urea with 100 % P & K could be a promising and smart option as nutrient management strategy to harvest higher and economically efficient rabi corn yield under rainfed upland situation in Assam.
  • ThesisItemOpen Access
    PERFORMANCE OF AROMATIC RICE (Oryza sativa L.) UNDER NATURAL FARMING PRACTICES
    (2023) Bhuyan, Kishor Jyoti; Goswami, Jogesh
    A field experiment entitled "Performance of aromatic rice (Oryza sativa L.) under natural farming practices" was conducted at the organic block of the Instructional-cum-Research Farm, Assam Agricultural University, Jorhat, during kharif, 2022–23, with a view to studying the growth, yield, quality and economics of joha rice (variety: Tulasi joha) as well as its impact on overall soil health under natural farming practices. The experiment was laid out in a Randomized Block Design (RBD) with three replications. The experiment consisted of eight different treatments of natural farming practices, viz., T1: control (no nutrient input), T2: vermicompost (*RD of N), T3: panchagavya as foliar application @ 1.5% each at 30, 60 and 90 DAT, T4: enriched panchagavya as foliar application @ 1.5% each at 30, 60, and 90 DAT, T5: jeevamrutha as foliar application @ 1.5% each at 30, 60, and 90 DAT, T6: beejamrutha as root dip treatment @ 3%, T7: vermiwash as foliar application @5% each at 30, 60, and 90 DAT, T8: green leaf manuring (5t/ha). The soil of the experimental site was sandy loam in texture, acidic (pH 5.25), medium in organic carbon (0.76%), low in available N (270.89 kg/ha) and K2O (134.76 kg/ha), and medium in P2O5 (23.90 kg/ha). The total rainfall received during the crop period was 935.9 mm. The treatments had a significant influence on the various growth, yield and quality parameters, while, a few parameters like leaf chlorophyll content, relative growth rate and L-B ratio were found to be non-significant. Among the different treatments, enriched panchagavya as foliar application @ 1.5% each at 30, 60, and 90 DAT (T4) showed significantly higher crop growth and physiological parameters such as plant height, number of tillers/m2, number of leaves/ plant, root length, root volume, root dry weight, leaf area index, leaf area duration, plant dry weight and Crop Growth Rate (CGR) at different crop growth stages, followed by vermicompost (T2) and panchagavya as foliar application @ 1.5% each at 30, 60 and 90 DAT (T3). The yield attributing characters such as number of panicles/m2, length of panicle, weight of panicle, number of filled grains/panicle and quality parameters such as length, breadth and amylose content of grains were found to be highest under the treatment enriched panchagavya as foliar application @ 1.5% each at 30, 60, and 90 DAT (T4) followed by vermicompost (*RD of N) (T2) and panchagavya as foliar application @ 1.5% each at 30, 60 and 90 DAT (T3). In the case of grain yield, enriched panchagavya as foliar application @ 1.5% each at 30, 60, and 90 DAT (T4) showed significantly higher (24.80 q/ha) results, which was at par with T2, T3, T5 and T6. However, the treatments did not have any significant variations on the straw yield or harvest index. Except for soil organic carbon, higher soil chemical properties such as available N, P2O5 and K2O at harvest were recorded in the treatment T8 consisting of green leaf manuring (5 t/ha), followed by vermiwash as foliar application @5% each at 30, 60, and 90 DAT (T7) and beejamrutha as root dip treatment @ 3% (T6), while, higher soil biological properties such as total microbial count, dehydrogenase activity and microbial biomass carbon were found in enriched panchagavya as foliar application @ 1.5% each at 30, 60, and 90 DAT, which were at par with panchagavya as foliar application @1.5% each at 30, 60, and 90 DAT (T3). An economic analysis showed that the highest net return (₹91133/ha), gross return (₹138072/ha) and highest B:C (1.94) were recorded in the treatment enriched panchagavya as foliar application @ 1.5% each at 30, 60, and 90 DAT (T4) followed by panchagavya as foliar application @1.5% each at 30, 60, and 90 DAT (T3).
  • ThesisItemOpen Access
    Effect of weed management on growth and yield of summer baby corn (Zea mays L.)
    (2023) N, KAMAL; Sarmah, A.K.
    A field experiment entitled “Effect of weed management on growth and yield of summer baby corn (Zea mays L.)” was carried out at Instructional-Cum-Research farm Assam Agricultural University, Jorhat during summer 2023 to study the effects of different weed management practices on weeds and growth, yield and economics of baby corn. The treatments consisted of Earthing-up and weeding at 25 DAS (T1); Paddy straw mulching at 1 DAS 4 t/ ha (T2) ; Paddy straw mulching at 1 DAS 4 t/ ha followed by earthing-up and weeding at 25 DAS (T3); Atrazine 1.0 kg/ha as preemergence (T4) ; Metribuzin 2.0 kg /ha as pre-emergence (T5); Metribuzin 1.0 kg/ha as pre-emergence followed by hand weeding 25 DAS (T6); Metribuzin 1.0 kg/ha as pre-emergence followed by hand weeding at 40 DAS (T7); Metribuzin 1.0 kg/ha as pre-emergence followed by POE application of tembotrione 120 g/ha at 25 DAS (T8);The weedy check (T9) and Weed free (T10). The experiment was laid out in randomized block design with three replications. The soil texture of the experimental site was sandy loam which was low in available N (262.93kg/ha), medium in available P2O5 ( 27.48kg/ha ), medium in available K2O (147.94 kg/ha) and medium in organic carbon(0.52 %). The baby corn hybrid G-5414 was sown on 21.02.2023and first picking was done on 21.04.2023.The total rainfall received during the crop growing period was 263.80 mm In the experimental site, total 10 major weed species were recorded including grasses, sedges and broad leaved. Different weed management practices significantly influenced the density and dry matter of weeds at all the observations. At 40 DAS application of paddy straw mulching at 1 DAS (4t/ ha) followed by earthing-up and weeding at 25 DAS(T3) recorded the lowest weed density whereas the lowest dry matter was recorded with application of Metribuzin 1.0 kg /ha as pre-emergence followed by hand weeding 25 DAS(T6).Similarly, all the weed management treatments significantly influenced the growth, yield attributes and yield of baby corn. The highest plant height (146.50cm), number of leaves/plant(11.38), LAI(5.64) at 60 DAS and dry matter accumulation(60.26 g/ plant) at harvest was recorded with the T3treatment which was found at par with the T6 and T8 treatments. The highest number of baby corn/plant(2.78),corn weight with husk(53.64 g) ,corn weight without husk(13.74 g) and cob yield (9.45 t/ha ) and green fodder yield ( 29.32 t/ha) was recorded with the T3 treatment which was found at par with the T6(cob yield: 9.28 t/ha ) and T8(cob yield : 9.23 t/ha ) treatments. The content and uptake of N, P and K by plant as well as available N, P2O5 and K2O post harvest soil was also recorded highest with the T3treatment which was at par with T6 treatment. The highest gross return ₹ 220317.00 /ha was recorded with the T3 treatment. However, the highest B-C ratio of 3.32 and the highest net return of ₹ 164815.00/ha was recorded with treatment T6. The study revealed that the application of paddy straw mulching at 1 DAS @ 4t/ha followed by earthing-up and weeding at 25 DAS (T3) resulted in effective management of weeds as well as the highest cob yield (9.45t.ha) and green fodder yield (29.32t/ha) with a net return of ₹ 1,56,409.00/ha and B-C ratio 2.45. However, application of Metribuzin 1.0 kg/ha at as pre-emergence followed by hand weeding at 25 DAS (T6) recorded the next best cob yield (9.28t/ha) and green fodder yield (28.72 t/ha) with the highest net return of ₹ 1,64,815.00/ha and B-C ratio of 3.32 due to low cost of cultivation in T6 treatment compared to the T3 treatment
  • ThesisItemOpen Access
    PERFORMANCE OF DIRECT-SEEDED WINTER RICE (WET DSR) AS AFFECTED BY DIFFERENT WEED MANAGEMENT PRACTICES
    (2023) Sarma, Hridesh Harsha; Konwar, Milon Jyoti
    A field experiment was conducted at the research farm of AAU-ARRI, Titabar during the sali season (2022) with a view to study the growth and yield behavior of wet direct-seeded sali rice under different crop establishment techniques as well as to find out the best weed management practices for direct-seeded sali rice. The treatments consisted of three establishment techniques viz., broadcasting (M1), drum seeding (M2), line sowing (M3) and six different weed management practices viz., hand weeding at 20, 40 and 60 DAS (W1), pyrazosulfuron-ethyl @ 30 g/ha at 2 DAS fb bispyribac-Na @ 25 g/ha at 25 DAS (W2), pyrazosulfuron-ethyl @ 30 g/ha at 2 DAS fb mechanical weeding at 40 and 60 DAS (W3), pyrazosulfuron-ethyl @ 30 g/ha at 2 DAS fb bispyribac-Na @ 25 g/ha at 25 and 45 DAS (W4), weed free check (W5), weedy check (W6). The experiment was laid out in split-plot design which was replicated thrice. The soil of the experimental site was clay loam in texture, acidic in reaction (pH 4.97), medium in organic carbon content (0.56 %), low in available N (242.41 kg/ha), medium in available P2O5 (24.16 kg/ha) and available K2O (154.23 kg/ha). The results revealed that establishment techniques brought significant influences on growth and yield attributing characters, yield, weed density and weed dry weight in all the growth stages. Drum seeding (M2) proved statistically superior in regards to growth attributes viz., plant height, number of tillers/m2, leaf area index and dry matter accumulation at all growth stages compared to line sowing (M3) and broadcasting (M1). Similarly, drum seeding recorded significantly the highest yield attributing characters such as number of panicles/m2, panicle length, panicle weight, number of filled grains/panicle followed by line sowing (M3) and broadcasting (M1). Drum seeding technique (M2) also recorded significantly highest grain yield (43.07 q/ha) and straw yield (68.79 q/ha). Moreover, higher uptake of nitrogen, phosphorus and potassium by grain, straw and total uptake were also recorded in the same treatment. Among the different weed management practices, weed free (W5) check recorded the lowest weed density, weed dry matter and weed index as well as highest weed control efficiency and weed control index at all the growth stages followed by pyrazosulfuron-ethyl @ 30 g/ha at 2 DAS fb bispyribac-Na @ 25 g/ha at 25 and 45 DAS (W4). Weed management practices also significantly recorded higher growth attributes viz., plant height, number of tillers/m2, leaf area index and dry matter accumulation, yield attributing characters viz., number of panicles/m2, panicle length, panicle weight, number of filled grains/panicle, grain and straw yield as well as uptake of nitrogen, phosphorus and potassium in grain, straw and total uptake. The highest grain (47.50 q/ha) and straw yield (75.11 q/ha) was recorded under weed free check (W5) which was followed by the treatment of pyrazosulfuron-ethyl @ 30 g/ha at 2 DAS fb bispyribac-Na @ 25 g/ha at 25 and 45 DAS (W4) (44.37 q/ha grain and 71.80 straw q/ha). In terms of treatment combinations, drum seeding along with weed free check (M2W5) recorded the highest interaction effect in respect to number of tillers/m2 at 90 DAS (393.67), number of filled grains/ panicle (130.00), grain yield (51.22 q/ha), straw yield (78.35 q/ha), nitrogen uptake by grain (55.57 kg/ha) and phosphorus uptake by straw (16.26 kg/ha) which was followed by drum seeding along with pyrazosulfuron-ethyl @ 30 g/ha at 2 DAS fb bispyribac-Na @ 25 g/ha at 25 and 45 DAS (M2W4) (49.23 q/ha grain and 75.84 q/ha straw yield) being statistically at par with line sowing along with weed free check (47.43 q/ha grain and 75.30 q/ha straw yield). In terms of economics, the treatment combination of drum seeding along with pyrazosulfuron-ethyl @ 30g/ha 2 DAS fb bispyribac-Na 10 % SC @ 25 g/ha at 25 and 45 DAS (M2W4) recorded the highest net return (Rs. 74,705/ha) and B:C (2.27).