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2018 - 201912020 - 20211
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Subject: Agronomy × Author: Dey, Prithwiraj × End date: 2021 × Type: Thesis ×
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    ThesisItemOpen Access
    Optimization of fibre flax production technology through agronomic management
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-07) Dey, Prithwiraj; Mahapatra, B.S.
    A field experiment was conducted during rabi season of 2019-20 and 2020-21 in E-5 block of the N.E.B.C.R.C. of G.B. Pant University of Agriculture and Technology, Pantnagar (Uttarakhand) with objectives to optimize seed rate, nutrient doses and harvesting time for fibre flax based on growth, yield, quality and profitability parameters, to find out the extent of lodging and assess the effectiveness of different treatments for the reduction of lodging, to find out the optimum water retting duration for fibre flax and to correlate several growth, yield and quality parameters of fibre flax to uncover the existing interrelations. The soil on the experimental site was sandy loam, neutral in pH with medium organic carbon (0.71%), low available nitrogen (196.9 kg/ha), medium available phosphorus (21.9 kg/ha) and potassium (210.1 kg/ha). The experiment was laid out in a split-plot design with three replications consisting of three levels of main plot factor (seed rate of 60, 80 and 100 kg/ha) and six levels of sub-plot factor (0:30:30, 60:30:30, 90:30:30, 120:30:30, 90:30:45 and 120:30:45 kg/ha N:P2O5:K2O). Time of harvest was taken as an additional factor with two levels (harvesting at 110 DAS and 135 DAS). Another side-by-side experiment was conducted in a completely randomized design with seven treatments (unretted, 1, 2, 4, 6, 8, 10 days retting duration) to find out the optimum retting duration of fibre flax. Use of 100 kg/ha seed rate resulted in about 27.9 and 26.1% higher scutched fibre yield than a seed rate of 60 kg/ha when harvested at 110 DAS and 135 DAS, respectively. Among the nutrient management levels, application of 90:30:45 kg/ha N:P2O5:K2O was found to have at par fibre yields with the best performing treatment. Late harvest at 135 DAS was recorded to have an 18.2% higher total fibre yield than early harvest. However, late harvest resulted in a significant decrement in the fibre quality and about 22.4% decrement in the superior quality heckled long fibre yield than early harvest. Long fibre yield, otherwise, was found to follow similar trends with the scutched fibre yield. Lodging in crop increased with the increasing seed rate, nitrogen dose and delay in harvest. However, the supply of additional potassium can mitigate lodging problems even in high seed rate conditions when harvested at 110 DAS. Several parameters such as plant height, long fibre yield, breaking tenacity, cellulose content was found to be positively correlated with the final plant population. Lodging in flax was positively correlated with nitrogen uptake and plant populations and negatively correlated with the potassium uptake and basal stem diameter. Potassium was found to increase the yield and quality of the fibre while reducing the occurrence of lodging through secondary stem strengthening. Based on the current study, a seed rate of 100 kg/ha and the application of 90:30:45 kg/ha N:P2O5:K2O were found optimum with respect to the growth attributes, fibre yield, quality and profitability for fibre flax cultivation. Harvesting at 110 DAS was found to result in a 23.7% more net returns on an average than late harvesting of the crop. Such treatments were also found to have positive or near positive available nitrogen, phosphorus and potassium balance in the soil after harvesting of the crop. Among the durations of water retting, 4-6 days retting duration was found to be optimum with respect to fibre quality parameters.
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    ThesisItemOpen Access
    Weed management options for spring sweet corn (Zea mays L. var. Saccharata)
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2018-05) Dey, Prithwiraj; Tej Pratap
    A field experiment was conducted during spring season of 2017 in D6 block of the N.E.B.C.R.C. of G.B. Pant University of Agriculture and Technology, Pantnagar (Uttarakhand) with objectives to study the bioefficacy of new generation herbicides against complex weed flora and phytotoxicity on crop if any, to study the effects of different cultural and chemical control measures alone and their combinations on weeds, crop growth and yield, to study the impact of weed management practices on the soil microbial activity and to find out the best method of weed management in spring sweet corn on the basis of crop yield and economic parameters. The soil on the experimental site was sandy loam, neutral in pH with high organic carbon (0.79%), medium available nitrogen (314.3 kg/ha), phosphorus (19.8 kg/ha) and potassium (220.3 kg/ha). Sweet corn variety “Sugar 75” was sown on 21st February, 2017 and harvested on 2nd June, 2017. The experiment was laid out in a randomized block design with three replications and twelve treatments viz. intercropping with mung bean, paddy straw mulching at 5 t/ha, atrazine at 1000 g/ha, halosulfuron-methyl at 90 g/ha, tembotrione at 120 g/ha, atrazine at 1000 g/ha with paddy straw mulching, atrazine at 1000 g/ha fb halosulfuron-methyl at 90 g/ha, atrazine at 1000 g/ha fb tembotrione at 120 g/ha, atrazine at 1000 g/ha fb one hand weeding at 40 DAS, twice hand weeding at 20 and 40 DAS, weed free and weedy check. The major weeds infesting the experimental field were Cynodon dactylon, Echinochloa colona among grasses, Alternanthera sessilis, Celosia argentea among broad-leaf weeds and Cyperus rotundus among sedges. Pre-emergence application of atrazine at 1000 g/ha fb postemergence application of halosulfuron-methyl at 90 g/ha was the most effective treatment in reducing weed density and twice hand weeding at 20 and 40 DAS was found most effective in reducing weed dry matter accumulation as compared to other treatments. All the weed control treatments significantly influenced the yield and yield attributing characters. Highest green cob yield was obtained with twice hand weeding at 20 and 40 DAS (15.46 t/ha) which was at par with pre-emergence application of atrazine at 1000 g/ha fb postemergence application of tembotrione at 120 g/ha (15.31 t/ha) among the weed control treatments. The highest net return and B:C ratio was recoded with pre-emergence application of atrazine at 1000 g/ha fb post-emergence application of tembotrione at 120 g/ha which was followed by twice hand weeding at 20 and 40 DAS. Pre-emergence application of atrazine at 1000 g/ha fb application of tembotrione at 120 g/ha was found best among the herbicidal treatments in all respect. Twice hand weeding at 20 and 40 DAS was found comparable with pre-emergence application of atrazine at 1000 g/ha fb post-emergence application of tembotrione at 120 g/ha and can be used as an alternative subjected to availability of labourers.