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 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Growth and Physiological Responses to Supra-Optimal Nitrogen and Pre-Anthesis Drought Stress in Maize) ผู้เขียน: Md. Samim Hossain Molla,  ดร.สุตเขตต์ นาคะเสถียร, รองศาสตราจารย์ , ดร.เอ็จ สโรบล, ศาสตราจารย์ , ดร.วิจารณ์ วิชชุกิจ, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractWater and nitrogen (N) are major limiting factors in the production of maize (Zea mays L.) in the tropics and subtropics. A field experiment was conducted during the dry season in 2010–11 at the National Corn and Sorghum Research Center, Thailand to determine the sole and interactive effects of N, water and variety on the growth, physiology and grain yield of maize. Two water regimes (wellwatered and water-stressed) formed the main plots and two hybrids (Pioneer 30B80 and Suwan 4452) and three N levels (0 kg.ha-1, 160 kg.ha-1 (optimal) and 320 kg.ha-1 (supra-optimal) were subplots with three replications using a split plot design and a factorial randomized complete block arrangement. Zero and supra-optimal N, and water-stress significantly reduced the green leaf area (37.86, 6.76 and 17.64%, respectively, at silking), root dry matter (RDM) (62.48, 15.66 and 48.83%, respectively), grain number (20.43, 11.96 and 16.76%, respectively) and grain yield (GY) (31.64, 14.07 and 19.20%, respectively) but not leaf rolling when compared to the control. The leaf relative water content (RWC) decreased (12.87%) significantly only with water-stress. The two hybrids responded differently to N with regard to leaf area—Suwan 4452 was more sensitive to zero N and Pioneer 30B80 was more sensitive to supraoptimal N. Suwan 4452 was lower in RDM (53.92%), grain number (12.90%), and GY (9.66%) than Pioneer 30B80, with the latter performing better under single or combined stress. Higher RDM levels in the surface soil during vegetative growth, the amount of kept green leaves and more grain and a higher RWC were exhibited as drought and N stress tolerance indicators. |
หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Anthesis and Silking Dynamics of Maize under Contrasting Nitrogen and Water Levels) ผู้เขียน:Md. Samim Hossain Molla, ดร.สุตเขตต์ นาคะเสถียร, รองศาสตราจารย์, ดร.เอ็จ สโรบล, ศาสตราจารย์, ดร.วิจารณ์ วิชชุกิจ, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractAnthesis-silking and kernel setting may vary with the plant growth rate and environment. Two field experiments were conducted in December 2010 and January 2012 focusing on the short pre-anthesis and the prolonged bracketing-flowering stage drought (PBD), respectively, at the National Corn and Sorghum Research Center, Thailand. A split plot design with factorial randomized complete blocks was established with three replications, where two water regimes (well-watered and water-stressed) formed the main plots and two maize hybrids (Pioneer 30B80 and Suwan 4452) and three nitrogen levels (0, 160 (optimal) and 320 (supra-optimal) kg.ha-1 of N) collectively formed subplots. Under all conditions, relatively more biomass partitioning to the roots during the early vegetative stage might have lowered aerial growth and subsequently caused a slight delay in anthesis and silking in Pioneer 30B80. Albeit the plant and silk growth rates during the bracketing-flowering stage were higher in Pioneer 30B80 (even under combined stresses, which shortened the anthesis-silking period and interval (ASI) that caused more kernel setting than Suwan 4452), Pioneer 30B80 failed to complete 100% silking under PBD. Silking was more affected than anthesis by both stresses especially under PBD. Across the varieties, optimal nitrogen and water accelerated plant and silk growth, which also subsequently influenced timely flowering and shortened the ASI followed by more kernel setting. |
Researcherดร. วิจารณ์ วิชชุกิจ, รองศาสตราจารย์ที่ทำงาน:ภาควิชาพืชไร่นา คณะเกษตร สาขาที่สนใจ:การผลิตพืช และสรีรวิทยาการผลิตพืชไร่, การผลิตและการปรับปรุงพันธุ์มันสําปะหลัง การบริหารและการจัดการ, การจัดการดูแลสนามกอล์ฟ Resume |
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