Ecological studies on Echinochloa crus-galli and the implications for weed management in direct-seeded rice
Ecological studies on Echinochloa crus-galli and the implications for weed management in direct-seeded rice
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DOI：
10.1016/j.cropro.2011.07.013
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发表时间：
2011-11-01
期刊：
影响因子：
2.8
通讯作者：
Johnson, D. E.
中科院分区：
文献类型：
--
作者：
Chauhan, B. S.;Johnson, D. E.
棘球藻，一种C(4)草，是世界上最严重的杂草之一。该物种的杂草管理决策可以从其种子生物学知识中得出。研究确定了光对发芽的影响；种子埋深和水稻残茬对出苗和生长的影响以及淹水时间和深度对该物种的萌发、生存和生长的影响。光刺激种子萌发，但不是萌发的绝对条件。土壤表层种子萌发率最高（92%），萌发率随埋深的增加而下降；8厘米深处未出苗。埋深仅为0.4 cm，出苗率降低50%。高水平（6吨/公顷）水稻残茬可降低苗木出苗率和幼苗生物量。早期和深度淹水显著抑制了十字花菜幼苗的生长。在淹水条件下，随着水深的增加，杂草以牺牲根为代价，将更多的生物量分配给芽。从本研究中获得的信息有助于改进杂草控制方法。通过耕作将杂草种子埋在其最大出芽深度以下的土壤翻转，使用作物秸秆作为覆盖物和作物早期淹水可以作为管理十字花菜和其他具有类似发芽要求的杂草物种的重要工具。但是，这些管理办法必须与其他作物管理要求相协调。(C) 2011 Elsevier Ltd.版权所有。
Echinochloa crus-galli, a C(4) grass, is one of the world's most serious weeds. Weed management decisions for this species can be derived from knowledge of its seed biology. Studies were conducted to determine the effects of light on germination; seed burial depth and rice residue on emergence and growth; and flooding time and depth on emergence, survival and growth of this species. Light stimulated seed germination but it was not an absolute requirement for germination. The proportion of seeds germinating was greatest for seeds placed on the soil surface (92%), and emergence declined with increasing burial depth in soil; no seedlings emerged from the depth of 8 cm. A burial depth of only 0.4 cm reduced seedling emergence by 50%. Seedling emergence and seedling biomass were reduced by the addition of high level (6 ton ha(-1)) of rice residue to the soil surface. Early and deep flooding significantly suppressed growth of E. crus-galli seedlings. In flooded conditions, with increased water depth the weed allocated more biomass to shoots at the expense of roots. The information gained from this study could contribute to improve weed control approaches. Soil inversion by tillage to bury weed seeds below their maximum depth of emergence, use of crop residue as mulch and early flooding of the crop could serve as important tools for managing E. crus-galli and other weed species with similar germination requirements. These management options, however, would need to be compatible with other crop management requirements. (C) 2011 Elsevier Ltd. All rights reserved.