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1.
A. R. Saghir 《国际虫害防治杂志》2013,59(3):282-285
Abstract Wheat and barley constitute the bulk of agricultural production in the Middle East. Unfortunately, these crops are grown on marginal soils which are infested with annual and perennial weeds. The principal weed species include Avena sterilis L., Convolvulus arvensis L., and Sinapis arvensis L. and it has been estimated that yield losses due to weeds are between 20 and 30%. Control is mostly by hand pulling, hoeing or mechanical tillage, the use of herbicides being limited to about 2–5%, of the cereal area. The chemical used is usually 2,4-D but there are a few applications of barban. With the increase in wages, and unavailability of agricultural labour it is suggested that herbicide application should be widely used in the Middle East. Mixtures with benzonitriles and dicamba should be used in addition to the economical phenoxy herbicides to widen the spectrum of control of broadleaved weeds. Glyphosate may also be used after grain harvest for the control of perennial weeds and tri-allate, chlortoluron and other chemicals for the control of wild oats and other grasses. Plant breeders should study the genetic response of newly developed varieties to the most widely used herbicides. 相似文献
2.
Abstract Basagran is the trade name of a post-emergence herbicide belonging to the thiadiazines. The active ingredient is bentazon. It was developed by BASF for the control of broadleaved weeds in soyabeans. Bentazon is a contact herbicide with low mammalian and fish toxicity. As it is absorbed by the green parts of the plants, full coverage is essential for complete success. It is selective in soyabeans at all stages of crop growth, and has a broad herbicidal spectrum. Annual weeds in soyabeans, including cocklebur. (Xanthium pensylvanicum) which is a serious problem in the soya-growing areas of the USA, are effectively controlled by 0.75–1.0 kg a.i. bentazon/ha. The most suitable time of application was found to be between the development of the first and third trifoliate leaves of the crop. 相似文献
3.
Abstract Ramie, the vegetable fibre, is obtained from the stem of Boehmeria nivea (L.) Gaud, and is used in many textile products. It is grown in tropical, sub-tropical and temperate regions and the main countries where it is grown are China, Brazil and the Philippines. However, it is only a minor crop in terms of world trade. The diseases of ramie are discussed in relation to their occurrence, symptoms and control measures. The major and most widespread diseases are white fungus caused by Rosellinia necatrix, leaf spot caused by Cercosporo spp. and Phyllosticta spp., seedling rot caused by Rhizoctonia solani, cane rot caused by Macrophomina phaseolina and eye rot caused by Myrothecium roridum. A number of diseases of minor importance are also reviewed. 相似文献
4.
P. K. JENSEN 《Weed Research》1991,31(1):1-7
In 962 field trials in different crops, the size of a number of weed species was investigated. The weeds were ranked according to their size on a single occasion. The ranks of the species were examined relative to two weed species, Viola arvensis and Matricaria inodora. The ranking was, however, independent of which of the two species were used as standard. The correlation between the rankings with Viola arvensis as standard, and the rankings with Matricaria inodora as standard were r= 0-93 for spring sown crops, and r= 0.84 for autumn sown crops. Sinapis arvensis was the largest weed species in spring sown crops, with a weight of 14.5 times that of Viola arvensis, followed by Brassica napus, Galeopsis spp., Thlaspi arvense and Amsinckia spp. Viola arvensis. Veronica spp. and Lamium spp. were the smallest weed species in spring sown crops. Galium aparine was the largest species in autumn sown crops, whereas spring germinating species such as Polygonum spp. were among the smallest. The ranks of Viola arvensis, Myosotis arvensis, Lapsana communis, Matricaria inodora and Lamium spp. were almost identical in spring sown crops and in autumn sown crops. 相似文献
5.
A weed survey methodology was used for 2 years in three provinces in Greece to determine the abundance and spatial distribution
of weeds in cotton (Gossypium hirsutum L.) fields. Based on a stratified random sampling procedure, the most frequently occurring weeds were counted in 150 cotton
fields. The field surveys were conducted late in the growing season; hence, the weed populations consisted of species that
had been present during the critical competitive period for the crop and may have contributed to yield losses.Solanum nigrum was the most abundant weed in the surveyed fields of the southern province, followed byCyperus rotundus, Convolvulus arvensis, Xanthium strumarium, Chrozophora tinctoria andCynodon dactylon, in descending order. The ranked weed flora in the fields of the northern province was differentiated, suggesting the geographical
distribution of weed species. The weedsDatura stramonium andS. nigrum were recorded in high abundance and followed byAmaranthus spp.,Abutilon theophrasti, Portulaca oleracea, Chenopodium album andXanthium spinosum, in descending order. Although the use of preplant incorporated herbicides is the dominant practice in cotton cultivation,
certain weeds continue to spread in increasing densities.
http://www.phytoparasitica.org posting July 26, 2005. 相似文献
6.
以生物测定及羧酸酯酶活性测定的方法,检测了上海地区菜缢管蚜对有机磷的抗药性。测定结果表明,金山群体对乐果、杀螟松和马拉硫磷的抗药性分别是梅陇的5.7、4.0和1.8倍。金山群体的羧酸酯酶活性高于梅陇。说明其抗性与羧酸酯酶活性增高有关。单个蚜虫的羧酸酯酶活性测定是检测抗性及抗性个体在群体内分布的一种既迅速又精确的方法。如把蚜虫的羧酸酯酶活性分成3类:低羧酸酯酶活性(OD<0.3)、中等羧酸酯酶活性(OD:0.3—0.5)和高羧酸酯酶活性(OD>0.6),则金山与梅陇种群低羧酸酯酶活性个体分别占8％、30％;中等活性个体分别占85％、68％;高活性个体分别占7％、2％。 相似文献
7.
C. T. Duval 《国际虫害防治杂志》2013,59(3):321-324
Abstract In wheat fields, irrigated with treated sewage water, the performance of six herbicides: bromoxynil/MCPA; bentazon/ dichlorprop; diclofop‐methyl; tralkoxydim; pendimethalin and bromophenoxim; and some their combinations were assessed at two different locations around the city of Riyadh. The common weeds include: Lolium spp.; Phalaris spp.; Avena spp.; Malva spp.; Chenopodium spp. and others. The best weed control treatments were: bentazon/dichlorprop followed by bromoxynil/MCPA for the broad‐leaved, and diclofop‐methyl followed by tralkoxydim for the grassy weeds. The combinations of bromoxynil/MCPA with either pendimethalin or tralkoxydim were far more effective against the broad‐leaved weeds, and significantly improved the wheat growth and yield, compared with the single treatments. However, bromoxynil/MCPA combination with diclofop‐methyl was less effective against the grassy and broad‐leaved weeds than each of them. Bromophenoxim showed an effective control of the whole weeds, with appreciable improvement in the wheat growth and yield. 相似文献
8.
Nguyen Thi Tan Nguyen Hong Son Ha Minh Trung Bruce A. Auld Shane D. Hetherington 《国际虫害防治杂志》2013,59(4):285-287
The occurrence of weeds in water rice was surveyed in the Red River Delta, Vietnam during spring and summer rice-growing seasons in 1995 and 1996. Sixty different weeds from 19 plant families were recorded. The most important plant families as weeds of rice were Poaceae and Cyperaceae. The most important weed however was Rotala indica (Willd.) Koehne (Lythraceae) followed by Echinochloa crus-galli (L.) Beauv. and Cyperus difformis L. A brief comparison of this rice weed flora and those of Australia and California was made. 相似文献
9.
Dr Soeratno Partoatmodjo 《国际虫害防治杂志》2013,59(4):430-431
Abstract Several Sporobolus species are useful range plants in the Western United States. Two of them, however, S. poiretii (Roem. and Schult.) Hitch. and S. indicus (L.) R. Br. have become important weeds in improved sub-tropical and tropical pastures, the former in the South-eastern United States, the latter in tropical America. This paper briefly reviews the distribution, plant characteristics and forage quality of these weeds. Non-chemical and chemical methods of control are also discussed. 相似文献
10.
Effective weed management in maize-wheat (M-W) cropping systems are accountable for higher yield and plant biomass. The objective of this study was to evaluate the effectiveness of manual weeding and chemicals (pre- and post-emergence herbicide) for actual weed control to enhance maize yield and M?W system productivity. Herbicides were treated as pre-emergence (sole), post-emergence (sole) and its combined application (pre- and post-emergence) for weed eradication and suppression. Sole pre-emergence herbicide (acetyclour?+?atrazine) and sole post-emergence herbicides (nicosulfuron), and its mixed application were used in the experiments. The experiment was comprised on 6 treatments with one weedy check or control plot: W1?=?weedy check, W2?=?acetyclour?+?atrazine, W3?=?atrazine, W4?=?nicosulfuron, W5?=?nicosulfuron?+?atrazine, W6?=?acetyclour?+?atrazine?+?nicosulfuron and W7?=?manual weeding. Main weeds were Cyperus rotundus, Tribulus terrestris, Dactyloctenium aegyptium and Cynodon dactylon. Experiential findings revealed that manual weeding was found most effective in terms of controlling weed and suppression. Among the herbicides application, promising results in terms of weed destruction and suppression were shown by combined application of acetyclour?+?atrazine?+?nicosulfuron which effectively controlled weeds as compared to other treatments. It was concluded that manual weeding drastically reduced weeds frequency and biomass while among the herbicides application acetyclour?+?atrazine and nicosulfuron could be promising for weeds suppression and clamp downing as compared to all other treatments under M?W cropping system.
相似文献11.
A.A.S. IBRAHIM 《Weed Research》1984,24(4):227-231
Losses of about 40% in cane yields due to natural stands of weeds were found in experiments conducted in sugarcane var. Co 527 in the year of planting at Guneid Sugarcane Research Station, Sudan. Weed competition lowered millable stalks per metre row by 32%, stalk height by 24%, stalk thickness by 15% and number of nodes per stalk by 14%. Tillering was the growth phase most affected by weed competition. Cane yields were increased as number of hand weedings increased, but four weedings were not markedly better than three. The average yield (67·04 t ha?1) obtained from four weedings was not significantly (P= 0·05) better than that of three weedings carried out at 3, 6 and 9 weeks after cane planting. Juice analysis components were also affected by weeds and a 15% reduction in sucrose recovery was recorded. Reductions in the other components were only 4–7%. Atrazine and diuron (3·3 kg ha?1), metribuzin (2·4 kg ha?1) and metribuzin (1·3 kg ha?1) in tank mixture with diuron (1·5 kg ha?1) gave excellent residual weed control of the dominant weed species, Ipomoea cordofana Choisy., Brachiaria eruciformis (Sm.) Griseb., Corchorus fascicularis Lam., Ocimum basilicum L. and Dinebra retroflexa (Vahl) Panz., for most of the first growing season. Excellent control of weeds achieved by the herbicide treatments resulted in comparable yields to frequently-weeded cane. These herbicides were not phytotoxic to sugarcane var. Co 527. 相似文献
12.
Abstract A field experiment was conducted in 1973 and 1974 at Udaipur, India to evaluate the selective weed control efficacy of stale seed-bed prepared with paraquat (1 kg/ha) or by cultivation, pre-planting incorporation of EPTC (1.5 kg/ha), and post-emergent application of MCPB (0.5 kg/ha). Two crop protectants, NA and activated carbon, were also field tested as seed treatments against injury by EPTC. It was found that stale seed-bed prepared by desiccation of weed seedlings with paraquat a day before planting berseem (Trifolium alexandrinum L.) and pre-planting incorporation of EPTC were both effective in significantly reducing weed growth and boosting yields of berseem. Berseem seeds coated with activated carbon before planting provided appreciable protection to the crop against EPTC, but NA stunted berseem growth. A combination of stale seed-bed and EPTC caused maximum reduction in weed growth. Post-emergent MCPB, though efficient in controlling weeds, was highly phytotoxic to the crop. Chenopodium spp. and Phalaris minor were lower in net energy content than berseem. 相似文献
13.
独脚金属（Striga spp.）及列当属（Orobanche spp.和Phelipanchce spp.）杂草是世界范围内对农业生产危害严重的根寄生杂草,主要依靠寄生茄科、豆科、谷类等作物获得水分和营养。根寄生杂草种子只有在合适的萌发诱导物（如独脚金内酯）刺激下才能萌发。文章从根寄生杂草的分类、分布及危害,种子萌发剂类型及适用范围,种子萌发剂独脚金内酯的生物合成及分离鉴定,根寄生杂草种子萌发诱导剂的作用机制以及种子萌发过程中激素间协同调控作用等方面进行了综述,并展望了种子萌发剂设计筛选及其在根寄生杂草化学防控中的潜在应用前景。 相似文献
14.
The dynamics of weed populations were ana lysed in intensified cereal-based cropping sys tems of the northern Guinea savanna in Nigeria, A total of four common weed associations were identified through cluster analysis. Five factors describing soil fertility conditions and field his tory best differentiated the weed communities according to a discriminant model. The analysis shows that maize-based cropping systems with a high frequency of cereal cropping and a low fre quency of noncereal cropping tended to be domi nated by weeds such as Commelina spp. and Kyllinga squamulata. As soil fertility declined, Vernonia spp. and Eclipta prostrata became more important. Increased frequency of noncereal crops in mixed cropping with cereals was associ ated with reduced incidence of weeds such as Leucas martinicensis, Oldenlandia corymbosa, Spermacoce verticillata, Litdwigia hyssopifolia, Celosia laxa, and,Ipomoea spp. Further diversifi cation of cereal-based systems to obtain a re duced frequency of cereals is likely to increase the incidence of Dactvloctenium aegyptium in crop fields. The information provides guidance for technology development and transfer on weed control for intensifying systems in the northern Guinea savanna of Africa. 相似文献
15.
Abstract A field experiment was conducted for two years during 1977–78 and 1978–79 to evaluate the efficiency of methabenzthiazuron, terbutryn and metoxuron in controlling weeds in peas (Pisum sativum) at the Punjab Agricultural University, Ludhiana, India. Pre-emergence application of methabenzthiazuron at 1.05 and 1.40 kg a.i./ha gave efficient weed control and gave comparable yields to two hand hoeings. Post-emergence application of methabenzthiazuron proved inferior. Terbutryn pre-emergence showed promise but as a post-emergence application it was ineffective. Metoxuron both pre- and post-emergence showed phytotoxic effects on the crop. 相似文献
16.
17.
S. J. Eden-Green 《国际虫害防治杂志》2013,59(1):99-104
Abstract The white powdery scale Cribrolecanium andersoni (Newstead), which occurs on citrus in South Africa and Swaziland, is of economic importance. The scale secretes honeydew on which sooty mould develops. Parasitoid sampling entailed the collection of C. andersoni‐infested leaves at seven different localities. Female and male Euxanthellus philippiae Silvestri (Aphelinidae), the female Coccophagus pulvinariae Compere (Aphelinidae), Metaphycus spp. (Encyrtidae), an unidentified encyrtid (probably a new genus), Tetrastichus sp. (Eulophidae) and a male Coccophagus sp. were found to be parasitoids of C. andersoni. E. philippiae and the unidentified encyrtid appeared to be the most common parasitoids of C. andersoni. No parasitoids were collected from first‐instar C. andersoni. The number of parasitized C. andersoni was the lowest during October to December. 相似文献
18.
Abstract Research into weed control in Iraq is largely the responsibility of the Ministry of Agriculture. The recommendations which the Department of Weed Control have made on the basis of this research are presented. The principal weed species of Iraq are listed with some indication of their occurrence and importance. Both research and control of weeds in Iraq are limited at present. 相似文献
19.
Abstract In Nigeria only six pathogens were recorded on sweet potato in 1966. Between 1973 and 1977 about twenty were documented. These cause various foliage, stem, root and tuber diseases. They include diseases caused by Albugo ipomocac, Phaeoisariopsis bataticola, Pseudocercospora timorensis, Phyllosticta batatas, Septoria bataticola, Corticium sp., Elsinoe batatas, Mcliola clavulata, Coleosporium ipomoeae, Puccinia spp., Uromyces sp., Fusarium oxysporum, Plenodomus destruens, Sclerotium rolfsii, Rhizopus stolonifera, Monilochaetes infuscans, mosaic virus and internal cork virus. Detailed studies on the nature of the diseases incited under Nigerian conditions have not been carried out on most of the pathogens. However, there are indications that although the foliar diseases may not be of serious economic importance, the stem, root and tuber diseases may be major contributors to post-harvest loss, a common problem in root and tuber production in Nigeria. 相似文献
20.
M. Ibrahim Ali 《国际虫害防治杂志》2013,59(3):328-333
Abstract In an insect pests survey of soybean during 1977–1980, in the rabi and kharif seasons, 14 species were more, and 33 species less abundant, representing 19 families under seven orders. The occurrence of Aphis spp., Atractomorpha spp., Spilosoma obliqua W., Monolepta signata Olv., Nezara viridula L., Myllocerus spp., Riptortus spp., and Jassids were most notable. 相似文献