oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Fertilizer Placement Affects Weed Growth and Grain Yield in Dry-Seeded Rice (Oryza sativa L.) Systems  [PDF]
Bhagirath S. Chauhan, Seth B. Abugho
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.46155
Abstract:

A study was conducted in a split-plot design to evaluate the effect of fertilizer placement method on weed growth and grain yield in a dry-seeded rice (DSR) system. Main-plot treatments were four fertilizer placement methods: between narrow rows (between 15-cm-wide rows of the pattern 25-15-25 cm), between uniform rows (between 20-cm-wide rows), within uniform rows, and surface broadcast. Subplot treatments were three weed control methods: herbicide-treated, nontreated, and weed-free. Weed biomass was greater in the nontreated plots than in the herbicide-treated plots. Herbicide application reduced weed biomass by 89% to 99% compared with the nontreated control. Fertilizer placement did not influence weed biomass in the herbicide-treated plots; however, it greatly influenced biomass in the nontreated plots. Fertilizer placement on the surface increased weed biomass (69 -71 g·m2) compared with the placement of fertilizer below the soil surface (37 -57 g·m–2). Fertilizer placement did not influence weed density and biomass at 60 days after planting. Nontreated plots yielded 700 to 2080 kg·ha–1. Grain yield was similar between the herbicide-treated (2660-3250 kg

Weed Vegetation of Direct Seeded Ricefields in Muda Rice Granary Areas of Peninsular Malaysia  [PDF]
M. Begum,A.S. Juraimi,M. Azmi,A. Rajan
Pakistan Journal of Biological Sciences , 2005,
Abstract: A survey was carried out at heading stage of direct seeded rice to determine the major weed flora in Muda area, Kedah, Peninsular Malaysia. Thirty five weed species belonging to 17 families were identified in this area. Of these, 15 species were broadleaves, 10 sedges, 6 grasses and 4 aquatics. According to % field infestation and infestation rating score the six most widespread and abundant species were Oryza sativa complex (weedy rice), Leptochloa chinensis, Echinochloa crus-galli, Ischaemum rugosum, Fimbristylis miliacea and Ludwigia hyssopifolia. The hierarchy of weed type according to % field infested ratio was in the order of grasses (G)> broadleaved weeds (BL)> sedges (SG)> aquatics.
Impact of Manual and Chemical Control Over Weeds in the Direct Wet-seeded Rice (Oryza sativa L.)  [PDF]
Inayatullah Awan,Mohammad Amjad Nadeem,Mohammad Qazafi
Asian Journal of Plant Sciences , 2002,
Abstract: Study on rice (Oryza sativa L.) trial on cultural and chemical weed control was carried out during Kharif 2000. Different weeds under the direct wet-seeded rice crop were controlled by using cultural techniques as well as by the use of chemicals (rice herbicides). Weedy check was also kept in both the factors. Weeds were effectively controlled with herbicides and culturing method. Maximum tillers per m2 (928.10), 1000-grains weight (27.67 g) and highest paddy yield (8.89 t ha -1) were recorded from Rifit. The said herbicide also controlled the weed and gave minimum dry weed biomass (9.58 g). While in the other case, hand weeding after 6 weeks of seeding showed the best results.
Effect of integrated weed management practices on performance of dry direct seeded rice (Oryza sativa L.)  [PDF]
KP Bhurer, DN Yadav, JK Ladha, RB Thapa, K Pandey
Agronomy Journal of Nepal , 2013, DOI: 10.3126/ajn.v3i0.9006
Abstract: Weeds are serious problem in dry direct seeded rice (DDSR). A field experiment was conducted during rainy seasons of 2010 and 2011 at research farm of the Regional Agricultural Research Station (RARS) Parwanipur, to study the effect of integrated weed management practices on the performance of dry direct seeded rice. Ten treatment combinations viz; weedy, weed free (weekly), Pendimethalin fb (followed by) Bispyribac, Pendimethalin fb two hand weeding, Stale seedbed fb Bispyribac, Stale seedbed fb Pendimethalin fb Bispyribac, Mulch 4 t/ha fb Bispyribac fb one hand weeding, Stale seedbed fb mulch 4 t/ha fb Bispyribac, Pendimethalin and Sesbania co-culture fb 2,4-D Na salt fb one hand weeding and Pendimethalin fb 2,4-D fb one hand weeding were tested in a randomized complete block design and replicated thrice. Observations were taken on weed, plant growth and yield attributes, yield, and socio-economic parameters. All weed control treatments significantly reduced the weed density and dry weight of weed resulting significant increase in yield of DSR over weedy check in both years. Weed free treatment resulted the highest yield, however, it was not economical due to high cost of cultivation. The use of Pendimethalin fb 2,4-D fb one hand weeding produced yield (5161 in 2010 and 6160 kg/ha in 2011) which were statistically at par with yield (5305 in 2010 and 6319 kg/ha in 2011) obtained under the weed free treatment. Further, the highest benefit cost ratio (CBR) 1.77 and 2.22 and net return Rs 47700 and 75084/ha during 2010 and 2011, respectively, were obtained under this treatment indicating its superiority over other treatments. The grain yield, yield attributing characters viz. panicles per m2, panicle weight, filled grain per panicle, thousand grain weight as influenced by different weed management practices revealed that higher yield resulted from weed free plot followed by Pendimethalin followed by two hand weeding and Pendimethalin followed by 2,4-D followed by one hand weeding. However, the net return per unit investment resulted highest in Pendimethalin followed by 2,4-D followed by one hand weeding. This proved that amid increasing wage rate and labor scarcity integrated weed management through Pendimethalin 30 EC (stomp) @ 1 kg a. i./ha as pre- emergence herbicide application followed by 2,4-D sodium salt 80 WP @ 0.5 kg a.i./ha followed by one hand weeding or stale seed bed followed by Pendimethalin 30 EC (stomp) @ 1 kg a. i./ha followed by Bispyribac (nominee gold) @ 25 g a. i./ha 10 % @ 200 ml/ha at 20 days of seeding resulted best alternative for
Production Efficacy of Six Rice Cultivars Against Various Herbicides Applied for Weed Control in Direct Wet-Seeded Rice (Oryza sativa L.) Culture  [PDF]
Inayat Ullah Awan,Tufail Abbass,Mohammad Amjad Nadeem
Journal of Biological Sciences , 2001,
Abstract: Six varieties namely IR-6, IR-9, KS-282, Bas-370, Bas-198 and Bas-385 were sown at seed rate of 100 kg ha-1.Two herbicides viz. Acelor @ 250 ml ha-1 and Rifit @ 1 l ha-1 were applied as post emergence (30 days after seeding) to all plots except weedy check (control). Weeds were affectively controlled with herbicides application. Maximum number of tillers m-2 (340.2), number of panicles m-2 (329.8), 1000-grain weight (25.50 g), highest paddy yield (7.50 t ha-1) and straw yield (19.24 t ha-1) were observed in KS-282. Acelor @ 250 ml ha-1 controlled weeds more effectively and gave minimum weed population m-2 (15.28), maximum number of tillers m-2 (330.7), number of panicles m-2 (319.0), number of spikelets per panicle (139.2), 1000-grain weight (21.99 g), paddy yield (6.48 t ha-1) and harvest index (31.39 %)
Mungbean (Vigna radiata L.) Residue and Nitrogen Rate Affected Growth and Yield of Direct Seeded Rice (Oryza sativa L.) In Rainfed Riceland  [PDF]
P. Suriyakup,A. Polthanee,K. Pannangpetch,R. Katawatin
Asian Journal of Plant Sciences , 2007,
Abstract: An experiment was conducted in a farmer’s field in Ban Muong village, Muang district in Khon Kaen province in 2003. The objective of this study was to investigate the effect of mungbean (Vigna radiata L.) residue and nitrogen rates (0, 30 and 60 kg N ha-1) on growth and yield of direct seeded rice (Oryza sativa L.) in rainfed riceland. The results showed that mungbean residue had no effect on tiller number, leaf area index and total top dry weight of rice in rice-mungbean intercropping or sole rice cropping. Also, mungbean residue had no significant effect on panicle number m-2, spikelets number per panicle, 1,000 grain weight, percentage filled grain, harvest index or grain yield However, mungbean residue tendes to increase rice grain yield over sole rice by 0.33 t ha-1(13 %) with had no nitrogen application. Rice grain yield was significantly affected by nitrogen rates. The highest rice grain yield (2.7 t ha-1) was obtained with a nitrogen rate of 30 kg N ha-1. Nitrogen fertilizer application at a rate of 60 kg N ha-1 decreased grain yield, when compared with 30 kg N ha-1.
Influence of Integrated Weed Management Practices on Dynamics and Weed Control Efficiency in Dry Direct Seeded Rice  [PDF]
KP Bhurer,DN Yadav,JK Ladha,RB Thapa,KR Pandey
Nepal Journal of Science and Technology , 2013, DOI: 10.3126/njst.v14i2.10413
Abstract: Field experiment under dry direct seeded rice(O ryza sativa L.) was conducted during rainy season of 2010 and 2011 at Regional Agriculture Research Station (RARS), Parwanipur, Bara to develop appropriate weed management practices for dry direct- seeded rice. The trial was laid-out in randomized complete block design (RCBD) and replicated thrice. Observations were taken on weed, plant growth and yield attributing, yield, and socio-economic parameters. The weed density, dry weed weight and weed control efficiency resulted significantly different as influenced by integrated weed management practices. Low weed population density, low weed index and highest weed control efficiency resulted by pendimethalin followed by 2, 4- D followed by one hand weeding were at par with weed free check. Highest yield resulted from weed free plot followed by pendimethalin followed by two hand weeding and pendimethalin followed by 2, 4- D followed by one hand weeding. However, the net return per unit investment resulted highest in pendimethalin followed by 2, 4- D followed by one hand weeding. This proved that amid increasing wage rate and labour scarcity integrated weed management through pendimethalin 30 EC (Stomp) @1 kg a. i. /ha as pre- emergence herbicide application followed by 2, 4- D sodium salt 80 WP @ 0.5 kg a. i. /ha followed by one hand weeding or stale seed bed followed by pendimethalin 30 EC (Stomp) @1 kg a. i. /ha followed by bispyribac (Nominee gold) @25 g a. i. /ha 10% @200 ml/ha at 20 days of seeding resulted best alternative for manual hand weeding practices giving higher net return per unit investment. DOI: http://dx.doi.org/10.3126/njst.v14i2.10413 ? Nepal Journal of Science and Technology Vol. 14, No. 2 (2013) 33-42
The effects of different autumn-seeded cover crops on subsequent irrigated corn response to nitrogen fertilizer  [PDF]
Gholam Reza Mohammadi, Mohammad Eghbal Ghobadi
Agricultural Sciences (AS) , 2010, DOI: 10.4236/as.2010.13018
Abstract: A common crop rotation in the west Iran is wheat-fallow-corn. The fallow period after wheat harvest (during fall and winter) can lead to soil erosion, nutrient losses (e.g. nitrate leaching) and offsite movement of pesticides. This period is an ideal time to establish a cover crop. In order to investigate the effects of different autumn-seeded cover crops on subsequent irrigated corn response to nitrogen fertilizer, field studies were carried out during the 2007-2008 growing season at the Agricultural Research Farm, Razi University, Kermanshah, Iran. The experiment was conducted in a split plot arrangement based on a randomized complete block design with three replications. The main plots consisted of four cover crops including alfalfa (Medicago sativa L.), berseem clover (Trifolium alexandrinum L.), common vetch (Vicia sativa L.) and winter rye (Secale cereale L.) and a control (no cover crop). The sub plots consisted of two fertilizer N rates (0 and 250 kg ha-1). Cover crops were grown for nearly 5 months and then were incorporated into the soil as green manures. The results indicated that corn plant traits including seed yield, the number of seeds per ear and leaf chlorophyll content were significantly influenced by cover crops. Whereas, the cover crops had no signif-icant effects on the number of ears per plant, 100-seed weight and harvest index of corn. Among the cover crop species, common vetch produced higher dry weight and showed the highest positive effects on the corn plant traits. Dry weight produced by this cover crop was 56.41, 120.16 and 124.19% higher than those of winter rye, berseem clover and alfalfa, respectively. Common vetch enhanced seed yield, the number of seeds per ear and leaf chlorophyll content of corn by 46.30, 21.95 and 8.52%, respectively, compared to control. All of the corn traits under study, except the number of ears per plant and harvest index were significantly improved by nitrogen fertilizer. In general, this study revealed that the autumn-seeded cover crops, especially common vetch can be used to improve corn yield. However, the cover crops should be supplemented with nitrogen fertilizer to obtain optimal results.
Weed Infestation in Direct Seeded and Transplanted Aus Rice as Affected by Method of Planting and Weeding Regime  [PDF]
M.Y. Sarker,M. Mosaddeque Hossain,M.K. Hasan,M.A.H. Khan
Journal of Biological Sciences , 2002,
Abstract: The experiment was conducted to determine the weed vegetation due to the effect of planting methods and weeding regime. Two factors included in the experiment were: methods of planting and weeding regime. The results revealed that weed vegetation in the two methods of planting varied remarkable. Fifty-five weed species belonging to 17 families infested the crop. Among the weed species, Fimbristylis miliacea (L.) Vahl was the principal weed in direct seeded aus rice and Panicum repens L. in the transplanted aus rice. Twenty-four weed species were found to grow only in the direct seeded crop and only eight in the transplanted crop. Weed density and weed dry weight was significantly affected by the method of planting and weeding regime. Weed density and dry weight was significantly higher in direct seeded than in transplanted crop.
Bio-Economic and Qualitative Impact of Reduced Herbicide use in Direct Seeded Fine Rice Through Multipurpose Tree Water Extracts Impacto Bioeconómico y Cualitativo del uso Reducido de Herbicidas en Arroz de Siembra Directa a través de Extractos Acuosos de árboles Multipropósito  [cached]
Abdul Khaliq,Amar Matloob,Yasir Riaz
Chilean Journal of Agricultural Research , 2012,
Abstract: Weed control program should be environmentally benign and cost-effective so that reduced herbicide use can help meet these goals. Field trials were conducted to assess the bio-economic and qualitative impact of reduced doses (25 and 50% of label dose) of a postemergence pyrimidinyloxybenzoic acid herbicide (bispyribac-sodium) applied alone or in combination with multipurpose tree (eucalyptus Eucalyptus camaldulensis Dehnh., mango Mangifera indica L., and mulberry Morus alba L.) water extracts in direct seeded rice (Oryza sativa L.) fields. The label dose of bispyribac-sodium and penoxsulam along with weed control were included for comparison. Tank mixing of multipurpose tree water extracts with reduced herbicide doses accounted for > 55% suppression in weed density and > 75% in dry weight; they were quite higher than those recorded for the same herbicide doses used alone. A combination of these extracts with 50% reduced dose of bispyribac-sodium improved rice yield and quality attributes similar to the label dose of this herbicide. Despite the higher net benefits associated with label herbicide dose, the maximum marginal rate of return was achieved with a tank mix of 25% label herbicide dose with multipurpose tree water extracts. Los programas de control de malezas deben ser respetuosos del medio ambiente y rentables, y la reducción del uso de herbicidas puede ayudar a cumplir estas metas. Los ensayos de campo se llevaron a cabo para evaluar el impacto bioeconómico y cualitativo de dosis reducidas (25 y 50% de la dosis etiqueta) de un herbicida de post-emergencia pirimidiniloxi benzoico (bispiribac-sodio) aplicado solo o en combinación con extractos acuosos de árboles multipropósito eucalipto (Eucalyptus camaldulensis Dehnh.), mango (Mangifera indica L.), morera (Morus alba L.) en campos de arroz (Oryza sativa L.) de siembra directa. Se incluyó dosis recomendada en la etiqueta de bispiribac-sodio y penoxsulam y un control de malezas para comparación. Mezcla de estanque de los extractos acuosos de árboles multipropósito con dosis de herbicida reducida causó supresión de > 55% en densidad de malezas y > 75% en peso seco, lo que fue superior cuando estas dosis de herbicida se utilizaron solas. La combinación de estos extractos con un 50% de reducción de la dosis de bispiribac-sodio registró granos por panícula, peso 1000 granos y rendimiento de grano similar a la dosis de etiqueta del herbicida superiores a la aplicación de dosis reducida de este herbicida. Este tratamiento también mejoró los atributos de calidad del grano sobre el control similar a la dos
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.