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71.
棉田种植诱集作物对天敌的保护及增殖作用   总被引:10,自引:1,他引:10  
1987—1988年在河北省邯郸地区的试验结果表明,在棉田种植油菜及高粱诱集带,棉花主要害虫发生期内捕食性天敌数量比对照田增加25—51%;当棉田施用化学农药时,诱集带对保护天敌、促使捕食性天敌数量回升的效果明显。两种诱集作物综合种植的相互衔接,对保护、增殖天敌和控制害虫作用明显优于单一种植高粱诱集带。  相似文献   
72.
Damage caused by nematodes is one of the limiting factors in crop production. Traditional nematode management is based on the use of crop rotations, resistant cultivars, nematicides, or combinations of these methods. For a crop like peanut (Arachis hypogaea), cultivars resistant to root-knot nematodes are not available. There are soybean (Glycine max) cultivars resistant to some of the species of root-knot nematodes (Meloidogyne spp.); however, most fields have nematode infestations composed of mixtures of species. Research at Auburn has shown that tropical crops can be used effectively in rotation to manage nematode problems. Rotations with American jointvetch (Aeschynomene americana), castor (Ricinus communis), hairy indigo (Indigofera hirsuta), partridge pea (Cassia fasciculata), sesame (Sesamum indicum), and velvetbean (Mucuna deeringiana) have resulted in good nematode control and increased yields of peanut and soybean. Some crops (castor, sesame) are considered ‘active’ in that they produce compounds that are nematicidal, whereas others (e.g. corn, sorghum) are simply non-host, that is, ‘passive’.  相似文献   
73.
The pea leafminer,Liriomyza huidobrensis (Blanchard), recently introduced into Israel, has proven to be extremely proliferous and difficult to control. It is a much more serious pest of vegetable and flower crops than the previously introducedLiriomyza trifolii (Burgess). Photosynthesis is reduced and cosmetic damage is incurred when adult flies stipple plant leaves with feeding punctures and larvae mine the leaves. This paper will review briefly the history, biology and potential control measures of the pea leafminer.  相似文献   
74.
几种饲料作物在内蒙古呼和浩特地区的生产性能评价   总被引:4,自引:2,他引:2  
李青丰  徐军  李治国 《草业科学》2003,20(12):22-25
在内蒙古呼和浩特地区,种植并评价了6种(品种)饲用高粱和高丹草类植物的生产性能及作为饲用植物的价值。结果表明,此类植物具有高产、饲用价值高、利用方便等特点,应用前景广阔,可以考虑作为饲用玉米和苏丹草类植物的换代产品。从植物产量、叶量和分蘖特性等方面综合考虑,饲用高粱大力士和高丹草健宝明显优于其他品种,可以作为该地区的首选推广品种。  相似文献   
75.
Vegetables attract high applications of pesticides, and farmers in developing countries use many acutely toxic insecticides to control pests on these crops. With the liberalisation of agricultural markets in developing countries, the number of small-scale farmers growing vegetables for both domestic and export markets is increasing. Demand for supplies of year-round and exotic fruit and vegetables has grown in industrialised countries, but with rising quality standards and traceability requirements it is difficult for small-scale farmers to benefit from this lucrative non-traditional agricultural export trade. The demand is high for vegetables in the expanding cities in developing countries, and farmers in peri-urban areas, or rural areas with good access to the cities, are in a position to find a growing market for their produce. Poor storage facilities will often mean that farmers are forced to sell at peak times when prices are low. Farmers rarely have access to training in pesticide use, and have only limited or no access to advice on the complicated management of pesticides. The Food and Agriculture Organisation of the UN is concerned about high levels of poor quality and adulterated pesticides on sale in developing countries. Surveys repeatedly show that without training, farmers are unable to make good crop decisions: recognition of pests and their predators is generally low, leading to decisions to spray to kill any insect; knowledge of product selection, application rates and timing is poor; different products are often combined in the belief that the effect will be greater; re-entry periods after spraying and essential harvest intervals are not known; and without knowledge of alternatives, farmers will often assume that the only solution to pest problems is to spray more frequently. From a consumer's point of view, few developing countries are able to monitor pesticide residues, particularly for produce grown for home consumption: most countries do not have laboratories for even simple residue testing. Changes in European Maximum Residue Limits means that export crops will be rejected if they contain residues at the Limit of Detection of pesticides not registered in Europe. Season-long field level training in Integrated Pest Management can help farmers to become better decision-makers, and to greatly reduce pesticide use while reducing risks to their own health and environment, producing safer products for consumers, maintaining yields, and increasing incomes.  相似文献   
76.
通过采取一年三熟间套作三年定位培肥的方法,设三季栏肥还地、三季秸秆 冬绿肥还地、三季秸秆还地、冬绿肥还地及主施化肥(对照)等5个处理,进行不同培肥方法对一年三熟间套作物增产效果和土质改良效果的研究。试验结果表明:栏肥还地对各熟作物增产效果显著,并有效改善了土壤肥力,其次为三季秸秆 冬绿肥>三季秸秆>冬绿肥>对照。  相似文献   
77.
黄土丘陵区垄沟改良措施对玉米水分利用效率的影响   总被引:2,自引:1,他引:2  
选择延安地区作为黄土丘陵区的代表,在延安地区应用地膜、液态地膜、保水剂、PAM(土壤改良剂)和间作套种措施优化大垄沟种植方式种植玉米,分析了不同优化措施种植玉米的水分利用效率。结果表明,地膜、保水剂、PAM和间作方式有利于大垄沟较好地保持土壤水分,其保水能力分别比平种高出17.4%、8.5%、11.6%、5.3%;液态地膜、地膜、间作和PAM表现出很好的增产效果,其产量分别比平种高出77.7%、72.0%、64.1%、30.8%。  相似文献   
78.
The recent upsurgence ofBemisia tabaci (Genn.) as an important insect pest and vector ofTomato yellow leaf curl virus (TYLCV) is directly linked to serious damage to tomato crops grown throughout Japan. The molecular genetic identification and phylogenetic relationships of 12B. tabaci populations collected from representative locations in Japan were determined based on the mitochondrial cytochrome oxidase I (mtCOI) sequence. Phylogenetic analysis of the whitefly mtCOI sequence indicated that both the invasive B and Q biotypes now occur in Japan. The Q biotype was found at four locations: Mihara in Hiroshima, Nishigoshi in Kumamoto, Miyanojo and Okuchi in Kagoshima prefectures; the remaining eight collections were identified as the B biotype. This is the first report of the introduction of Q biotype in Japan. http://www.phytoparasitica.org posting July 21, 2006.  相似文献   
79.
Two experiments were undertaken in southern Greece during 2000–2002 in which turnip-rooted parsley was tested for its suitability for cultivation in comparison with locally grown curly-leafed and plain-leafed forms. Plants were harvested when the foliage was acceptable for marketing, rather than on completion of the vegetative cycle, hence root size was relatively small. In year 1, the foliage development of plain-leafed parsley was significantly higher than that of the other two forms, irrespective of sowing date. In year 2, both plain-leafed and curly-leafed parsley produced more foliage than turnip-rooted parsley in the early sowing (November), but not in subsequent sowings (December and February). During both years, root development was higher in turnip-rooted parsley than in curly-leafed parsley, although in the November and February sowings of year 1 the root weight of both plain-leafed and turnip-rooted forms were similar. In all three types of parsley, foliage yield fell off significantly in the spring sowing (February), and in year 1 there was a considerable decrease in root production as well. In most cultivars, foliage weight was higher when plants were grown from transplanted seedlings rather than by direct sowing, whereas the effect of sowing method on root weight was sowing date dependent. Cultivar differences in the foliage weight of direct sown and transplanted plants were reflected by differences in plant height and, in some cases, by leaf number. It is concluded that although overall turnip-rooted parsley produced rather less foliage than that plain-leafed parsley, this was compensated for by the satisfactory production of roots and therefore turnip-rooted cultivars may constitute a suitable crop for introduction to the Mediterranean region.  相似文献   
80.
比哈小爪螨在3种南方果树上的发育与繁殖   总被引:4,自引:1,他引:4  
为了探明比哈小爪螨在龙眼、荔枝、杧果上的种群增长情况,采用以上3种果树叶片为寄主材料进行饲养,以观察其发育、存活及繁殖。结果表明,比哈小爪螨取食龙眼世代发育历期最短为14.57d,取食杧果最长为20.71d;世代存活率龙眼最高为93.8%,荔枝最低为83.8%;产卵量以龙眼最高为46.63粒,杧果最低7.32粒;内禀增长率以龙眼最大为0.1328,杧果最小为0.0467;种群趋势指数的顺序为:龙眼>荔枝>果。  相似文献   
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