无人机播前喷施除草剂防除棉田杂草效果评价

【目的】 分析不同喷药处理喷施33%二甲戊灵乳油对棉田杂草防效及棉花生长发育的影响,为棉田无人机播前喷施除草剂提供理论依据。【方法】 在新疆机采棉种植模式下,选择土壤封闭剂二甲戊灵为供试除草剂,设计播前无人机3个不同浓度喷药,车载喷药机喷药和不喷药5个处理,分析不同处理对棉田杂草防效及棉花生长发育的影响。【结果】 无人机喷施二甲戊灵进行棉田播前土壤处理,处理2(3 450 mL/hm²时)控草效果与车载喷药机处理相当,防治效果均达到94.00%,且显著好于不施药效果,出苗率均达59.71%,与不施药处理差异不显著。增加药剂浓度1 200 mL/hm²对棉花出苗有影响,出苗率降低7.54%,但差异不显著。无人机喷药处理株高、叶龄、地上部干物质重、叶面积指数与车载喷药机喷药处理间差异不显著,显著高于不喷药处理。【结论】 无人机喷施播前二甲戊灵浓度3 450 mL/hm²时与车载喷药机喷施浓度3 450 mL/hm²防草效果和棉花生长发育相当,可在大田推广使用。     

21%氟磺·烯草酮油悬浮剂对绿豆田一年生杂草防效研究

为寻找绿豆田适宜除草剂,于绿豆1~2片复叶期,一年生禾本科杂草3~5叶期进行21%氟磺·烯草酮油悬浮剂药效评价试验。结果表明:21%氟磺·烯草酮油悬浮剂对绿豆田稗草、狗尾草、藜和反枝苋等一年生杂草具有较高防除效果,对绿豆生长安全。在生产中推荐应用剂量为1 800g·hm-2,喷药量为450L·hm-2。     

Effects of mechanical and chemical methods on weed control,weed seed rain and crop yield in maize,sunflower and soyabean

Eight field experiments with maize (Zea mays L.), sunflower (Helianthus annuus L.) and soyabean (Glycine max (L.) Merr.) were carried out in central Italy in order to evaluate the effects of mechanical and chemical methods (spring-tine harrowing, hoeing, hoeing-ridging, split-hoeing, finger-weeding, herbicides in the row + inter-row hoeing, herbicides broadcast) on weed control, weed seed rain and crop yield. The choice of chemical and mechanical treatments in maize and soyabean compared to sunflower, required to be managed more carefully in order to maximize the weed control reducing yield losses. A global rating of weed control methods, based on their weed control efficacy, was obtained as useful means to assist farmers and technicians to choose the more appropriate weed control method. The combination of herbicides intra-row and hoeing inter-row gave best efficacy (on average 99% of weed control), with a 50% reduction in the chemical load in the environment. Hoeing-ridging gave good results, both inter- and intra-row (on average 93% of weed control); this method was also effective in reducing competitive ability and seed production of uncontrolled weeds. Split-hoeing or finger-weeding showed some limitations giving satisfactory results only when combined. Harrowing gave lowest weed control, although when combined to other mechanical methods, can help achieve a better efficacy.     

控草和施肥对桉树生长影响的试验研究

为探索永安地区桉树速生丰产的营林抚育技术,通过采用随机组合,对2010年造林的巨桉桉树林设计了控草和施肥量不同的抚育组合：试验结果表明,对桉树林实行控草和施放肥料有利于促进林木生长,提高林分生物量和生产力;同时通过经济效益分析表明,在永安地区桉树林的最佳施肥量为底肥施放0.5kg桉树专用肥＋0.5kg钙镁磷（永安地区土壤缺磷元素）,当年追施一次0.25kg桉树专用肥,次年追施一次0.25kg桉树专用肥;控草方式以人工控草为主,有条件的林地实行化学除草,特别是五节芒等恶性杂草较多的山场优先考虑进行化学除草。     

威尔伯在幼林抚育中的应用研究

以红松、红皮云杉、长白落叶松造林地为对象,利用化学制剂威尔伯进行幼林抚育试验,结果表明:450 ml·hm-2剂量除草效果最差,仅有12%,在生产上无应用价值;450 ml·hm-2剂量有一定的除草效果,但不明显,持效期也短;1 125 ml·hm-2剂量无论除草效果还是除草速率都优于450 ml·hm-2和750 ml·hm-2。长白落叶松对威尔伯敏感,不能应用。化学除草抚育较人工抚育更能促进幼树生长,而且费用较低。     

苏州地区机插水稻病虫草害发生特点、原因与对策研究

通过定点系统调查与大面积普查相结合的方式,查明了苏州地区机插水稻田主要病虫草害的发生为害规律,分析了该地区机插稻田病虫草害发生规律变化的主要原因,并据此提出了相应的综合控制策略和措施。     

Herbicide options for weed control in papaya

This paper reviews the literature on weeds and weed control in papaya. There is limited research on this topic, and nearly all of the research focuses on herbicides. Effective use of paraquat and glyphosate in papaya is dependent on avoidance of spray contact to green bark and foliage. Pre-emergence herbicide tolerance is dependent on papaya age, size and maturity, and soil type. Only one herbicide, oryzalin is shown to be tolerated by papaya immediately after transplanting. Herbicides such as diuron and oxyfluorfen with a broader spectrum of weed control generally injure young papaya, however they can be effectively used if the initial application of these herbicides is delayed until papaya attains certain size or maturity indices. There is a need for further research on weeds and weed control to improve the efficiency of papaya production     

3种除草剂对水稻旱直播阔叶杂草防效及安全性研究

为明确不同除草剂茎叶处理对旱直播水稻田旱生阔叶杂草防除及安全性的影响,采用随机区组试验设计,选用30% 2,4-滴丁酸钠盐AS、84%氯酯磺草胺WG、480 g/L灭草松AS 3种除草剂在水稻4叶期、5叶期施用,施药后每间隔7 d测定杂草株防效、鲜重防效和水稻目测药害,同步测定水稻生长指标和抗逆酶活性。结果表明:30% 2,4-滴丁酸钠盐AS 900.0 g/hm2在水稻4叶期的杂草防效最佳,第28天杂草株防效及鲜重防效仍可达93.55%和96.42%,且对大龄鸭跖草防效显著,施药后水稻生长与人工除草相比无显著差异。叶片SOD、POD活性和MDA含量均先升后降,至施药后28 d恢复正常。30% 2,4-滴丁酸钠盐AS 900.0 g/hm2可高效防除阔叶杂草,该药剂在水稻4叶期和5叶期施用对旱直播水稻安全。     

浙沪小麦田杂草调查及优势杂草化学防除技术研究

为了明确浙沪小麦田杂草发生情况及优势杂草控制技术,采用唐氏五级目测法和随机取样计数法相结合的方法,对上海和浙江的116块冬小麦田杂草进行了抽样调查,同时采用盆栽试验和田间小区试验测定了7种除草剂对主要危害杂草的防效。结果表明,浙沪冬小麦田共调查到杂草43种,隶属于14科,其中菊科杂草种类最多,有10种,其次是禾本科杂草9种,再次是石竹科杂草5种。杂草群落组成以禾本科杂草为主,优势杂草为日本看麦娘Alopecurus japonicus Steud.、菵草Beckmannia syzigachne(Steud.) Fern.、棒头草Polypogon fugax Nees ex Steud.、硬草Sclerochloa dura(L.) Beauv.、早熟禾Poa annua L.、鹅肠菜Myosoton aquaticum(L.) Moench、救荒野豌豆Vicia sativa L.、猪殃殃Galium spurium L.和小藜Chenopodium ficifolium Smith。室内除草活性及田间药效试验结果表明,日本看麦娘可用15%炔草酯WP、5%唑啉草酯EC、30 g/L...     

Suppressing Weeds in Direct-seeded Lowland Rice: Effects of Methods and Rates of Seeding

High weed infestation is a major constraint to widespread adoption of direct seeding of rice (Oryza sativa L.) The experiments were conducted in 1998 wet and 1999 dry seasons in the Philippines to examine the effects of seeding methods and rates on suppressing weeds in direct-seeded lowland rice. Treatments consisted of four seeding methods: conventional and modified broadcast seeding, drill seeding with east–west and north–south row orientations; three seeding rates: 40, 80 and 160 kg seed ha⁻¹ as well as two weed control levels: weed control with herbicide and no weed control. Among the seeding methods drill seeding with east–west row orientation had the lowest rice grain yield loss caused by weeds (38 % in the wet and 20 % in the dry season), whereas the highest losses because of weeds were observed with conventional broadcast seeding (59 % in the wet and 27 % in the dry season). Seeding rate was inversely correlated to weed interference. Severe rice yield reduction (71 %) caused by weeds was found at a seeding rate of 40 kg seed ha⁻¹ in the wet season. Using seeding rates of 80 and 160 kg seed ha⁻¹, respectively, lowered yield loss to 47 and 26 % in the wet season, 32 and 18 % in the dry season. Therefore suitable method and/or rate of seeding can significantly suppress weeds in direct-seeded lowland rice.