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冷季型草坪杂草综合防治技术与策略 总被引:6,自引:1,他引:5
冷季型草坪发展速度很快 ,但养护管理技术滞后 ,杂草危害严重。在调查掌握杂草的种类、数量及发生规律的情况下 ,应采取以下防治策略 :(1)严格杂草检疫制度 ,清洁播种材料 ;(2 )合理耕作 ,深埋杂草种子或幼苗 ,清洁坪床 ;(3)科学栽培管理 ,诱杀或抑制杂草 ,具体技术包括草种选择、播期、播量、施肥、浇水、修剪等 :(4)化学防除 ,具体包括播前诱杀除草 ,播后苗前和播后苗期除草 相似文献
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The genetics of resistance of common vetch (Vicia sativa L.) to broomrape (Orobanche crenata Forsk.) was studied for two years by using the P1, P2, F1, BC1, BC2, F2 F3, and F4 generations obtained from crosses between resistant and susceptible lines. Resistant lines were selected by screening a world collection m a naturally infested plot. Resistance was tested both under field and greenhouse conditions. The best index to measure resistance was the number of emerged broomrapes per host plant. The results fit the additive-dominance model. The main component of the variation was additivity; dominance and interaction effects seemed to depend on the environment. When dominance is expressed, a low number is dominant over a high number of broomrapes per host plant. 相似文献
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Biological control is proposed as an ecological strategy to manage the threat of invasive plants, especially in natural areas. To pursue this strategy, we need to know that the host specificity criteria used to evaluate ecological risk with deliberate introduction of an exotic insect for biocontrol are sufficient to predict potential impact on native species. Host specificity is defined by adult feeding and oviposition preferences and larval development. One way to evaluate the criteria is to re-examine case histories where ecological effects are recorded, such as that of Rhinocyllus conicus Frölich. This flower head weevil, released in North America in 1968 to control exotic thistles like Musk thistle (Carduus nutans L), is now reducing seed production by multiple native North American thistle species (Cirsium spp.), and local population density of Platte thistle (Cirsium canescens Nutt.). We hypothesized that host specificity of R. conicus has changed since pre-release testing, providing an explanation for the unexpected magnitude of the documented ecological effects. Instead, when we re-tested host specificity of weevils naturalized over 28 generations, we found that host specificity has not changed. Naturalized adults of R. conicus showed strong feeding and oviposition preference for Musk thistle over Platte thistle. In addition, larval development by these weevils was faster and more successful (to larger size) on Musk thistle than on Platte thistle. Thus, our results indicate that a change in host specificity cannot explain the unexpectedly large build-up of R. conicus and significant ecological effect on Platte thistle. We conclude that accurate prediction of the potential level of impact on native host plants in the field requires further ecological information in addition to host specificity. 相似文献
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T. N. Ul'janova 《Genetic Resources and Crop Evolution》1997,44(1):5-8
The paper presents a survey of the situation existing now in nature with wild relatives of crop species from the group of segetal and ruderal plants, found within the territories of Russia and of other CIS countries. The majority of non-specialized annual and perennial weeds have been shown still to occur in the territory of the former USSR. For the past 50 years they have not seriously vanished from agriculture. Some of them even have a tendency to expand their areas and to become more abundant. Hence they need not be conserved in gene banks. It is only for a relatively small group of species of specialized contaminants that care should be taken to preserve them and to store their seeds in gene banks. 相似文献
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Exotic plant invasions threaten ecological communities world-wide. Some species are limited by a lack of suitable pollinators, but the introduction of exotic pollinators can facilitate rapid spread. In Tasmania, where many non-native plants are naturalised, exotic honeybees (Apis mellifera) and bumblebees (Bombus terrestris) have become established. We determined how these species affect the pollination of Lupinus arboreus, an invasive, nitrogen-fixing shrub, which is rarely visited by native pollinators. The proportion of flowers setting seed and the number of ovules fertilised per flower were positively related to the visitation rates of both exotic bee species. There was no effect of bee visitation rates on the proportion of seeds aborted prior to maturity, possibly due to post-fertilisation environmental constraints. We conclude that the spread of B. terrestris may not alter the fecundity of L. arboreus because of the pollination service provided by A. mellifera, and discuss potential interactions between these two bee species. 相似文献
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北方地区的旱直播稻田杂草群落属于水旱共生型复合群落,具有2个杂草发生高峰期,第1次高峰期为旱生型杂草,第2次高峰期以水生及湿生型杂草为主导群落.用百草枯除苗前大草,秧苗3叶期用“快杀稗+苯达松”茎叶处理,杂草综合防效可达95%以上. 相似文献
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采用农民乐防除休闲地杂草,结果表明,74.7%农民乐对苣荬菜的防除适宜剂量为1 500g.hm-2;对野胡萝卜为750—1 050g.hm-2;赖草、硬枝早熟禾为2 250g.hm-2;对西伯利亚蓼、三脉紫菀、茵陈蒿为3 000g.hm-2。 相似文献