 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Growth, Yield Attributes, Yields, and Weed Characteristics as Influenced by Integrated Nitrogen Fertilization and Weed-Control Measures of Maize (Zea mays L.) in Central Rif ผู้เขียน: Girma WOLDETSADIK,  ดร.สมบัติ ชิณะวงศ์, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractAn experiment was conducted during the rainy season of 2003 at Dera and Melkassa, to study the influence of nitrogen fertilizer levels and weed control measures on growth, yield attributes, yields, and weed characteristics of maize (Zea mays L.) under rainfed condition. The experimental treatments were split plot design, comprising four nitrogen fertilizer levels [N0, control, N1, 10, N2, 20, and N3, 30 kg N/ ha in main plots and four weed control measures [W0, weedy check, W1, atrazine/s-metolachlor at 3.0 kg/ ha (pre-emergence); W2, atrazine/s-metolachlor at 3.0 kg/ha + 2, 4-D at 1.0 kg/ha (pre + post-emergence); and W3, 2, 4-D at 1.0 kg/ha (post-emergence)] in sub–plots and were replicated thrice. Total biomass, straw yield, harvest index, plant height and lodging percentage were increased with an increase in N levels at both sites. Application of 30 kg N/ha was found helpful in reducing the dry matter accumulation by weeds probably because nitrogen requirement of weeds and crop was met at this level and crop could compete better with weeds due to increased growth. Leaf area increased with an increase in nitrogen, being maximum at 30 kg N and minimum in the control at Dera and Melkassa, respectively. Weed control measures not only increased the leaf area, yield attributes and the grain yield of maize but also decreased the weed population and dry matter of weeds. Suppression of weeds by weed-control measures resulted in better growth and development of maize. Weed population and dry matter production of weeds were effectively suppressed with pre and post-emergence application of atrazine/smetolachlor at 3.0 kg/ha + 2, 4- D at 1.0 kg/ ha increased the grain yield of maize by 13.4 % over control non-weeded. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Nitrogen Fertilization and Moisture Conservation Practices on Maize (Zea mays L.) Grown Under Dryland Conditions of Ethiopia) ผู้เขียน:Girma WOLDETSADIK, ดร.สมบัติ ชิณะวงศ์, รองศาสตราจารย์, รังสิต สุวรรณเขตนิคม, นางสุนันทา จันทกูล, ผู้ช่วยศาสตราจารย์ , ดร.อภิพรรณ พุกภักดี, ศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractA Field experiment was conducted during the rainy season of 2003 to study the effect of nitrogen levels and moisture conservation practices on soil, water, yield and yield components of maize (Zea mays L.) in the rift valley of central Ethiopia. Grain yield was influenced by nitrogen fertilizer levels but 1000 grains weight, total biomass, straw yield, soil temperature, soil moisture content, and infiltration rate were not affected by nitrogen levels. Signifcant effects of harvest index and water use efficiency by nitrogen levels were observed only at Dera and Melkassa respectively. Moisture conservation practices gave more improvement in grain and straw yields, harvest index, and total biomass over flat bed due to availability of moisture than separate application. Bulk density, infiltration rate, water use efficiency, and soil moisture content were also affected by moisture conservation practices. The effect of mulch to reduce the soil temperature was observed prior to maize maturity. |
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หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Weed Control Measures and Moisture Conservation Practices Effects on Seedbank Composition and Vertical Distribution in the Soil) ผู้เขียน:Girma WOLDETSADIK, ดร.สมบัติ ชิณะวงศ์, รองศาสตราจารย์, รังสิต สุวรรณเขตนิคม, นางสุนันทา จันทกูล, ผู้ช่วยศาสตราจารย์, นายวิสุทธิ์ วีรสาร, ผู้ช่วยศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractChange in the weed seedbank due to crop production practices is an important determination of subsequent weed problems. Research was conducted to compare weed seed bank composition and vertical distribution of weed seed in the soil among four weed control measures and four moisture conservation practices at Dera Sub-Center and Melkassa Agricultural Research Center. Seed numbers at 45 cm depth were lower in pre-emergence of primagram at the rate of 3 L/ha treatment (137 seeds/m-2) and pre- and post-emergence of primagram at the rate of 3 L/ha plus 2, 4-D at the rate of 1 L/ha (105 seeds/m-2) at Dera and Melkassa, respectively. More than 60% of the weed seed bank was concentrated in the upper 15 cm of soil layer in post-emergence treatment at Dera and pre plus post-emergence at Melkassa site. The seed bank of the moisture conservation treatments was more uniformly distributed over depth and greater than the other systems. Chenopodium fasciulosum, Cyprus rotundus, Eragrostis aspera, and Sorghum arundenanceum were the most commonly found in the seed bank. |