INFLUENCE OF NITROGEN AND WEED MANAGEMENT ON GROWTH AND YIELD OF AEROBIC RICE (Oryza sativa L.)
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Title |
INFLUENCE OF NITROGEN AND WEED MANAGEMENT ON GROWTH AND YIELD OF AEROBIC RICE (Oryza sativa L.)
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Creator |
SANDYA RANI, K
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Contributor |
MALLA REDDY, M
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Subject |
NITROGEN, WEED, MANAGEMENT,GROWTH, YIELD, AEROBIC, RICE
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Description |
An experiment entitled “Influence of nitrogen and weed management on growth and yield of aerobic rice (Oryza sativa L.)” was carried out during kharif, 2011 at Regional Agricultural Research Station, Warangal. The soil of the experimental site was sandy loam in texture, slightly alkaline in reaction, medium in available nitrogen, low in available phosphorus and medium in available potassium. The experiment was laid out in randomized block design (factorial concept) with three nitrogen levels viz., 120, 180 and 240 kg ha-1 and four weed management practices, viz., pre-emergence application of pendimethalin @ 1.2 kg a.i. ha-1 + post-emergence application of pyrazosulfuron ethyl @ 30 g a.i. ha-1 at 25 DAS, mechanical weeding at 20 and 45 DAS, weed free check and weedy check replicated thrice. The weed spectrum of the experimental field consisted of three groups of weeds like grasses, sedges and broad leaved weeds. The observed sedges were Cyperus rotundus, Fimbristylis argentea; grasses were Cynodon dactylon, Echinochloa colona, Dinebra retroflexa, Panicum javanicum and broad leaved weeds were Corchorus olitorius, Eclipta alba, Digera arvensis, Cyanotis axillaris, Psoralea corylifolia, Ammannia baccifera, Euphorbia geniculata, Phyllanthus niruri, Portulaca oleracea, Abutilon indicum, Celosia argentia, Commelina benghalensis, Merremia emarginata, Gynandropsis pentaphylla and Parthenium hysterophorus. Among these, broad leaved weeds were dominant followed by grasses and sedges in aerobic rice. Pre-emergence application of pendimethalin @ 1.2 kg a.i. ha-1 + post-emergence application of pyrazosulfuron ethyl @ 30 g a.i. ha-1 at 25 DAS registered significantly lower density and dry weight of weeds; higher weed control efficiency and lower nitrogen uptake by weeds at harvest and weed index over mechanical weeding. The growth parameters such as plant height, number of tillers m-2, drymatter production and leaf area index at all growth stages, yield attributes such as panicle number, panicle length, filled grains per panicle; grain and straw yield were significantly higher with 240 kg N ha-1 than 120 kg N ha-1 but it was at par with 180 kg N ha-1. The nitrogen uptake by the rice crop increased significantly with increase in N level from 120 to 240 kg N ha-1. The highest gross returns, net returns and returns per rupee invested were obtained at 240 kg N ha-1 followed by 180 kg ha-1. Significantly higher plant height, number of tillers m-2, leaf area index, dry matter production at all growth stages, panicle number, panicle length, filled grains per panicle, grain and straw yield and nitrogen uptake at different growth stages were recorded with pre-emergence application of pendimethalin @ 1.2 kg a.i. ha-1 + post- emergence application of pyrazosulfuron ethyl @ 30 g a.i. ha-1 at 25 DAS over mechanical weeding. The highest gross returns, net returns and returns per rupee invested were obtained with pre-emergence application of pendimethalin @ 1.2 kg a.i. ha-1 + post-emergence application of pyrazosulfuron ethyl @ 30 g a.i. ha-1 at 25 DAS and it was comparable with weed free condition. From this study, it can be concluded that application of 180 kg N ha-1 was found to be optimum for aerobic rice in sandy loam soils of Telangana region and pre- emergence application of pendimethalin @ 1.2 kg a.i. ha-1 + post-emergence application of pyrazosulfuron ethyl @ 30 g a.i. ha-1 at 25 DAS was found to be effective and economical weed management practice in aerobic rice during kharif seas |
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Date |
2016-06-29T10:56:40Z
2016-06-29T10:56:40Z 2012 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/68199
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Language |
en
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Relation |
D9174;
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Format |
application/pdf
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Publisher |
ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY RAJENDRANAGAR, HYDERABAD
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