大豆田化学除草技术

为提高大豆田除草效果,提出了查清豆田杂草种类,把握施药时期与条件,选用适宜的除草剂品种和助剂,选择好喷雾机械,掌握好喷雾技术和采取深翻整地农艺措施等技术,可有效防除大豆田杂草。     

湖北省油菜田灾害性杂草高效防控技术研究进展

综述了湖北省油菜田杂草及种子库种类组成和特征、油菜田主要灾害性杂草的发生危害规律以及高效化学防除和生态防除技术。探讨了建立生态调控与化学除草相结合的农田杂草可持续治理技术体系的研究前景。     

黑龙江垦区大豆田化学除草技术

文章介绍了近年黑龙江垦区大豆田杂草发生的类型、危害特点、杂草种群变化和趋势、常用的杂草防除技术措施,提出利用现有的化学除草剂,科学合理运用化学防除技术,有效降低大豆田化学除草时发生的药害问题的综合防治措施和建议。     

豆施乐防除大豆田杂草技术

应用豆施乐防除大豆田杂草试验结果表明：5．0％豆施乐用量133ml/667m^2防除豆田杂草药后15d，防效达到86．4％；5．0％豆施乐用量100ml/667m^2和5．0％普施特用量100ml/667m^2药后45d与普施特防效无明显差异。     

窄行平作密植大豆田杂草的危害特点

化学除草是窄行平作密植大豆田唯一的杂草防除方式,草害水平和除草时期将直接影响化学除草的经济效益.研究不同杂草发生密度及与大豆共生时期对窄行平作密植栽培模式下大豆产量的影响,以明确窄行平作密植大豆田杂草化学防除的适宜时期和草害水平,提高化学除草的效益.利用对角线五点取样法,调查了窄行平作密植大豆田杂草的危害特点.结果表明:野燕麦发生密度(x)与大豆收益(y)之间的曲线关系为y=2267.2Ln(x)-4934.2,野燕麦的理论密度阈限为10.75株·m-2;苍耳发生密度为6株·m-2时,与大豆全生育期共生使大豆减产61.1%.     

大豆田杂草化学防除技术试验

大豆是山东省主要油料作物,常年种植６００万亩,由于杂草为害,一般可减产１０％以上,重者达２０％,人工除草劳动强度大。近几年出现了多种防除豆田杂草的除草剂,１９９５年以来我们先后对几种新除草剂进行了试验,现将主要结果报告如下。一、材料与方法供试药剂有７...     

龙岩市新罗区水稻田杂草优势种群及防除措施

针对新罗区水稻田各阶段杂草种类与发生发展规律,综合运用防除措施,以期达到环保、经济、高效的除草效果,取得最佳经济效益。综合防除主要措施有:水旱轮作、耕作除草、晒田、放鸭和使用化学药剂除草等方式。     

20%噻磺·乙乳油防除花生田杂草药效试验报告

噻吩磺隆与乙草胺的混配药剂弥补了噻吩磺隆防除禾本科杂草及乙草胺防除阔叶杂草的不足,扩大了杀草谱,提高了单剂对杂草的防除效果。因而适用于阔叶杂草和禾本科杂草混生的花生田除草。施药方法是花生播后苗前土壤喷雾处理,使用剂量为3 000~3 750 ml/hm2。     

除草药膜防除花生田杂草及其残留的研究

１９９８～１９９９ 年，于３ 市６ 个基点对乙草胺除草药膜和乙草胺＋ 扑草净除草药膜进行防除花生田杂草试验。研究证明，两种除草药膜防除禾本科杂草的效果分别为９７７％ 和９７９％ ；防除阔叶杂草的效果分别为７２９％ 和７９９％ ；杂草鲜重较对照分别降低８７０％ 和８７３％ ，均优于地面喷乙草胺再覆普通膜（不带药）的除草效果。覆膜５０ 天，其于土壤和植株中的残留量乙草胺除草药膜比地面喷乙草胺再覆普通膜分别降低了０１８ｍ ｇ／ｋｇ 和００５６ｍ ｇ／ｋｇ。     

土壤处理与茎叶处理防除马铃薯田杂草的比较试验

化学除草省工省时,操作简单,劳动效率高,对于规模化生产意义重大。应用金银尔和施田补作为土壤处理剂,应用2甲4氯钠盐与收乐通混施作为茎叶处理剂,以探讨不同处理对防除马铃薯田杂草的最佳防效。结果表明,2甲4氯钠盐与收乐通混施作为茎叶处理剂防除马铃薯田杂草,株防效与鲜重防效较对照相比达95.64%和97.38%;较土壤处理提高了7.62%,是理想的马铃薯田除草混施组合。     

苏北垦区大豆田中国菟丝子生物学特性及防除

苏北垦区大豆田中国菟丝子幼苗出土分散，苗期生命力脆弱，发生蔓延与温度、雨水、杂草及耕作、轮作制度等关系密切，且具有“转株寄生”，“自寄生”和“断肢再生”等习性，是大豆毁灭性的寄生杂草。以合理轮作、耕作、播前种子处理和消灭杂草等农业措施为基础，以化学防除为主要手段的综合防除技术可以达到控制其为害的目的。     

苏北垦区豆田杂草生长为害习性

苏北垦区豆田杂草分属15科,36属,41种,恶性杂草有稗,苍耳等9种。在大豆整个生育期间通常出现1～2个萌发高峰,主要集中在6月中旬～7月下旬。杂草种子于8～10月成熟。种子在土壤中的埋深及出苗期,直接影响杂草的出苗和繁殖。杂草与大豆的相互竞争,以在大豆播种一个月后最为剧烈。0～2cm和6～25cm耕层中贮葳的杂草种子最多。     

沿江地区直播稻生产现状及发展对策

介绍了沿江地区直播稻应用面积逐年扩大、主体品种较为明确、产量及效益较为显著的应用现状,并对直播稻不推自广成因进行了阐述;同时指出直播稻生产中存在的播后多种因素影响出苗、除草技术要求高、防倒措施不可忽视、"杂草稻"清除比较难等问题;提出精整抢播、科学用药、合理肥水运筹、采取综合措施防治"杂草稻"等对策。     

66%乙·嗪·滴丁酯微乳剂防除春大豆田杂草安全性及药效试验

66%乙·嗪·滴丁酯微乳剂是三元复配混剂,在春大豆田播后苗前进行土壤均匀喷雾,对大豆出苗及生长安全,药后40d对一年生禾本科及阔叶杂草的株防效均大于90%,鲜重防效均大于95%,并且持效期长达45d以上。     

Weed competition in muskmelon and its effects on yield and fruit quality

Field studies were conducted at Newe Ya'ar (northern Israel) during 1986 and 1988 to examine the critical period of weed competition in muskmelon (Cucumis melo L. cv. Galia). The yield of the control (weed free throughout the season) in 1988 was 45% higher than in 1986. In 1988, weed control was required within 6 weeks after seedling emergence in order to maintain fruit quality. Total yield was reduced significantly only if weeding started 7 weeks after emergence or later. Muskmelon remained competitive and maintained optimal yield potential if kept weed free during the first month of crop growth. The critical period for weed control in muskmelon was at the initiation of the rapid fresh-weight accumulation of the weeds and the pistillate flowering peak of the crop. Under Newe Ya'ar conditions this occurred 4–6 weeks after emergence of the crop.     

A model to simulate yield losses in winter wheat caused by weeds,for use in a weed management decision support system

The ‘within-season’ module of the Weed Manager decision support system (DSS) predicts the effect of twelve UK arable weeds on winter wheat yields and profitability. The model and decision algorithm that underpin the DSS are described and their performance discussed. The model comprises: (i) seedling germination and emergence, (ii) early growth, (iii) phenological development, (iv) herbicide and cultivation effects and (v) crop yield loss. Crop and weed emergence are predicted from the timing and method of cultivation, species biology, and the weather. Wheat and weeds compete for resources, and yield losses are predicted from their relative leaf area at canopy closure. Herbicides and cultural control methods reduce weed green area index, improving crop yield. A decision algorithm identifies economically successful weed management strategies based on model output. The output of the Weed Manager model and decision algorithm was extensively validated by experts, who confirmed the predicted responses to herbicide application were sufficiently accurate for practical use. Limited independent data were also used in the validation. The development of the module required integrating novel and existing approaches for simulating weed seedling establishment, plant development and decision algorithm design. Combining these within Weed Manager created a framework suitable for commercial use.     

湿润直播稻田杂草出苗动态与发生规律

 1996～1997年在浙江嘉兴调查了湿润直播稻田杂草出苗动态和发生规律,并比较了直播与移栽,早稻、单季晚稻与连作晚稻直播,翻耕与免耕直播间杂草发生差异。湿润直播稻田杂草以稗草、千金子、异型莎草、节节菜、陌上菜为主,其次有通泉草、丁香蓼、水芹。禾本科、莎草科和阔叶杂草种类数分别占25.0%、18.8%和56.2%,出苗数量分别占11.2%、11.6%和77.2%。单季晚稻直播田稗草、千金子发生重于其他直播田,直播田稗草和千金子数量明显高于移栽田。直播田杂草于播种后3～4 d陆续出苗,1～3周达到高峰。连作晚稻直播田播后6～8周出现明显的第二个出苗高峰。以阔叶杂草为绝对优势的翻耕直播田杂草发生重于免耕田。直播田杂草数量自然消长呈现与出苗动态相同的趋势。直播田杂草发生以稗草、千金子、丁香蓼较早,节节菜、陌上菜、通泉草次之,异型莎草和水芹较迟。稗草、千金子及其他几种主要杂草出苗高峰均呈单峰状态,而节节菜、陌上菜在连作晚稻直播田的出苗则为双峰。     

水稻新基质无土旱育苗技术研究

通过对水稻新基质育苗与常规育苗的对比试验研究,结果表明:新基质育苗秧苗出苗比对照晚2 d,出苗率和成苗率低于对照,地上部长势不如对照,地下部长势强于对照,产量低于对照15.6 kg/667 m2;新基质可替代常规土育苗,解决了育苗取土难的问题。     

Ecological studies on Echinochloa crus-galli and the implications for weed management in direct-seeded rice

Echinochloa crus-galli, a C₄ 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.     

Weed emergence as affected by maize (Zea mays L.)-cover crop rotations in contrasting arable soils of Zimbabwe under conservation agriculture

Weed control in smallholder farming systems of sub-Saharan Africa is labour intensive or costly. Many researchers have therefore advocated for the use of cover crops in weed management as an affordable alternative for smallholders. Cover crops may be grown in rotations to suppress weeds and reduce the reliance on herbicides. The use of cover crops creates microenvironments that are either conducive or inhibitive to the emergence of certain weed species. A study, initiated in 2008 in contrasting soils at four different locations of Zimbabwe, investigated the effect of maize (Zea mays L.)-cover crop rotations on the emergence of weeds that showed dominance in those soils. Weed assessments were however, carried out from 2011 to 2014. The weed species Galinsoga parviflora Cav., Commelina benghalensis L., and Richardia scabra L. showed dominance in all four locations with weed densities as high as 500 plants m⁻² being recorded for R. scabra L. in a sandy soil. Maize-cover crop rotations resulted in higher densities of Bidens pilosa compared with maize monocropping (control treatment) due to its high nitrogen (N) requirement to produce more seeds. On the other hand, the integration of cover crops such as pigeon pea [Cajanus cajan (L.) Millsp.] that had poor shading qualities, due to large gaps or spaces and slower initial growth, had limited effects on competitive weeds such as Cyperus esculentus L. which tend to dominate exhausted soils. The density of C. esculentus was 38% greater in maize–pigeon pea rotations compared with the control treatment. Variability between seasons and sites affected emergence of all weeds in the present study, which masked long-term trends. The results suggest that there is need to identify the germination and emergence requirements of specific weeds and select cover crops best suitable for their control. The study provides useful information for farmers and advisors on the best cover crops for control of certain problematic weeds in different soil types of Zimbabwe.