Suppression of junglerice [Echinochloa colona (L) Link] by irrigated rice cultivars in Latin America
Suppression of junglerice [Echinochloa colona (L) Link] by irrigated rice cultivars in Latin America
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DOI：
10.2134/agronj1997.00021962008900030023x
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发表时间：
1997-05-01
期刊：
影响因子：
2.1
通讯作者：
Lozano, J
中科院分区：
文献类型：
--
作者：
Fischer, A;Ramirez, HV;Lozano, J
连续稻（Oryza sativa L.）在拉丁美洲和加勒比地区，除草剂的种植导致了严重的杂草问题和除草剂的过度使用。有竞争力的水稻品种有助于减少对除草剂的依赖。1994年和1995年在哥伦比亚的帕尔米拉进行了一项研究，目的是（一）评估适应拉丁美洲和加勒比直播系统的半矮秆灌溉水稻作物类型的竞争力，（二）查明造成这种竞争力的植物性状，（三）查明竞争力对水稻产量潜力的不利影响。1994年和1995年，分别用10个和14个半矮秆水稻品种的早胚种子播种在排水积水土上。栽培品种无杂草或有杂草[Echinochloa colona（L.）Link]（40粒活种子m（-2），播种水稻后立即播种），并间歇灌溉以保持土壤接近饱和。在出苗后20、40、60、90和120天（DAL）记录水稻和Junglerice生物量、叶面积指数、分蘖数和高度。水稻品种对水稻的竞争力不同。在高达5.9毫克干物质公顷（-1）的饱和丛林虫害下，平均产量损失范围为27%至62%。叶面积指数、分蘖数和冠层光截获量在竞争中与水稻竞争力呈显著正相关，但在40 DAE之前变化不大。竞争力的半矮秆品种可以大大减少除草剂的应用系统中，次优的水控制不允许杂草抑制洪水的数量。育种，以提高水稻的竞争力似乎是一个有效的目标，因为竞争力和高产品种在这项研究中确定。
Continuous rice (Oryza sativa L.) cropping in Latin America and the Caribbean has resulted in serious weed problems and herbicide overuse. Competitive rice cultivars could help reduce herbicide dependence. A study was conducted during 1994 and 1995 at Palmira, Colombia, to (i) assess the competitiveness of semidwarf irrigated rice plant types adapted to Latin America and the Caribbean's direct-seeding systems, (ii) identify plant traits responsible for such competitiveness, and (iii) detect adverse effects of competitiveness on rice yield potential. Pregerminated seed of 10 and 14 semidwarf rice cultivars was sown on drained puddled soil in 1994 and 1995, respectively. Cultivars were grown weed-free or with junglerice [Echinochloa colona (L.) Link] (40 viable seeds m(-2), broadcast immediately after seeding rice), and were intermittently irrigated to keep the soil near saturation. Rice and junglerice biomass, leaf area index, tiller number, and height were recorded at 20, 40, 60, 90, and 120 days after emergence (DAL). Rice cultivars differed in their competitiveness against junglerice. Average yield losses ranged from 27 to 62% under saturating junglerice infestations of up to 5.9 Mg DM ha(-1). Leaf area index, tiller number, and canopy light interception recorded in competition, and not much before 40 DAE, correlated positively with rice competitiveness. Competitive semidwarf cultivars can substantially reduce the number of herbicide applications in systems where suboptimal water control does not allow weed suppression by flooding. Breeding to enhance rice competitiveness appears as a valid objective, since competitive and also highly productive cultivars were identified in this study.