辽宁省玉米田农药使用现状、存在问题与建议

针对辽宁省玉米田农药使用情况进行深入调查,结果表明,当前辽宁省玉米田病虫草害防治以化学农药为主,用量最大的除草剂为莠去津,用量最大的杀虫剂是二嗪磷,用量最大的杀菌剂为福美双。在农药的使用过程中,存在农民对农药科学使用技术认知不足、用药技术落后、抗药性发展等问题。建议采取普及农药科学使用方法和安全使用准则、推广高效高质量施药机械、制定并实施合理的抗性治理对策应对玉米生产中病虫草的抗药性威胁,解决目前春玉米生产中农药不合理使用问题。     

15%磺草酮水剂防除玉米田杂草田间使用技术研究

15%磺草酮水剂于2008年进行的茎叶处理防除玉米田杂草试验表明,在800 g a.i./hm2以上剂量处理对玉米田禾本科和阔叶类杂草的综合防效分别高于80%和84%,对玉米安全.     

黑龙江省玉米除草剂施用现状

2017、2018年在黑龙江省哈尔滨市、绥化市、齐齐哈尔市、佳木斯市、鹤岗市问卷调查516户农户/合作社玉米田除草剂种类、使用方式和使用剂量等。结果表明,农户使用播后苗前土壤封闭处理除草剂种类主要包括乙草胺、莠去津、2,4-滴丁酯和噻吩磺隆;苗后茎叶处理的除草剂种类主要包括烟嘧磺隆、莠去津和硝磺草酮。采用播后苗前土壤封闭处理除草的农户分别为81.6%和52.7%,采用苗后茎叶喷雾处理除草剂的农户分别占53.1%和71.2%,两次用药的农户占34.8%和24.6%。采用播后苗前土壤封闭处理除草,超量使用除草剂的农户达82%以上,其中乙草胺和莠去津超量使用的比例在94%以上。苗后茎叶处理除草剂超量使用的农户数量达79%以上。分析讨论农户超量使用除草剂与除草剂品种选择、杂草抗性、除草方式、用药习惯、施药器械等的关系,为黑龙江省玉米田除草剂减施增效技术效途径挖掘提供科学指导。     

30%烟嘧磺隆·莠去津·硝磺草酮可分散油悬浮剂对甜玉米田杂草的防效及安全性

研究30%烟嘧磺隆·莠去津·硝磺草酮可分散油悬浮剂在甜玉米田的应用效果,在甜玉米不同叶龄期开展田间试验,评价其对杂草的防除效果及对甜玉米的安全性。结果表明,30%烟嘧磺隆·莠去津·硝磺草酮可分散油悬浮剂在甜玉米3～4叶期或6～7叶期施药,900～1 575 g a.i./hm2剂量范围内对甜玉米品种粤甜28安全,对玉米田常见杂草凹头苋、光头稗、马唐和香附子的防效及增产效果均显著高于对照药剂38%莠去津悬浮剂2 160 g a.i./hm2播后苗前处理。推荐30%烟嘧磺隆·莠去津·硝磺草酮可分散油悬浮剂在900～1 350 g a.i./hm2范围内,甜玉米3～5叶期茎叶喷雾使用。     

异噁唑草酮防除玉米田杂草及玉米安全性效果测定

采用室内生物测定和田间效果试验相结合的方法,研究异噁唑草酮在室内及田间对玉米田杂草活性及玉米安全性。室内试验结果表明,异噁唑草酮土壤处理对马唐、稗草、马齿苋和苘麻均有很好的效果且对玉米安全,其中对阔叶杂草马齿苋和苘麻的效果好于禾本科杂草马唐、稗草,对苘麻和马齿苋的GR_(90)值在2.69~6.39 ga.i./hm~2,对马唐和稗草的GR_(90)值在29.32~29.69 ga.i./hm~2。田间试验结果也表明,异噁唑草酮对玉米田杂草马唐、稗草、牛筋草、反枝苋、狗尾草均有很好的效果且对玉米安全。     

黄土高原南部覆膜玉米农药使用现状

对位于黄土高原南部覆膜玉米产区的长武、旬邑、彬州、淳化和永寿5个县15个农药经销商和100个农户2017～2019年的农药使用现状进行调查分析。结果表明,2019年杀虫剂、杀菌剂和除草剂的销售量分别占农药销售总量的35.8%、26.1%和38.2%。杀虫剂主要种类有13种,杀菌剂主要种类有10多种,除草剂主要种类有11种。2017～2019年,农户玉米田的农药使用次数以杀虫剂最多,平均为1.6次,平均每次用药量为591 mL/hm2;除草剂均使用1次,使用量2 257 mL/hm2;杀菌剂使用最少,仅为0.3次,用药量每次为909 mL/hm2。     

东北玉米田除草剂减施增效技术途径探讨

以东北春玉米种植区为基地,分析杂草种群结构、发生规律和对玉米的产量损失。在此基础上,论述东北玉米田除草剂减施途径,包括高风险除草剂替代技术、除草剂高效使用技术和多策略除草剂减施技术,提出采用替代长残留除草剂莠去津和易漂移的除草剂2,4-滴,实施精准选药、适时用药、对靶喷药的3S施药技术,结合农作措施、生态措施、除草决策支持系统及加快耐除草剂玉米推广的多策略除草剂减施技术,实现除草剂减量,为东北玉米田除草剂减量增效实施提供技术指导。     

5%丁硫克百威在花生植株及土壤中消解动态及最终残留研究

采用气相色谱—氮磷检测器(GC-FTD),对5%丁硫克百威颗粒剂在花生植株及土壤样品中的消解动态和最终残留进行了研究。两年三地试验结果表明,丁硫克百威在花生植株及土壤中的残留消解动态符合一级动力学反应模式,在植株和土壤中的消解半衰期分别为9.5~12.1d和9.8~13.3d。5%丁硫克百威颗粒剂按照推荐使用上限量3750g a.i./hm~2和推荐上限量的1.5倍5625g a.i./hm~2,于花生播种时一次性使用,收获时在花生植株、果壳、籽仁以及0~15cm耕层中的最终残留量0.01mg/kg,低于国标0.2mg/kg的限量。表明,当花生播种时一次性使用剂量为3750~5625g a.i./hm~2的5%丁硫克百威颗粒剂,收获时产品是安全的,也不会造成土壤污染。     

2016年我国农药应用呈现九大特点

2016年我国农药应用的九大特点,包括杀虫剂投入最大,玉米除草剂用量下降,农药总用药成本高于上年、用药量低于上年,水稻用药成本投入占全国总用药成本的近1/4,12种主要作物中苹果亩用药商品量最高,大棚蔬菜用药次数最多,四大主粮除草剂用量最多,杀菌剂用药量最少,农药零增长促进非化学防治方式快速增长等特点.     

大豆苗后除草剂灭草松与精喹禾灵联合防除马唐、反枝苋的研究

在温室内采用单轴等效线法测定大豆苗后除草剂灭草松与精喹禾灵联合作用的结果表明 ,灭草松与精喹禾灵混用对马唐有增效作用 ,随着灭草松的剂量从 0增加到 60 0 ga .i./hm2 ,精喹禾灵抑制马唐 90 %的有效剂量 (ED90 )随之从 14.88ga .i./hm2 下降到 4 .89ga .i./hm2 。当灭草松与精喹禾灵以低剂量混用时 ,对反枝苋表现为拮抗作用 ,而两者以高剂量混用时 ,表现为增效作用     

Weed control with pre-emergence herbicides in vegetable soybean (Glycine max L. Merrill)

Field and laboratory experiments were conducted in the early and late rainy seasons in Thailand to evaluate the effect of pre-emergence application of herbicides and determine the herbicide residues on vegetable soybean (Glycine max L. Merrill cv. No. 75) production. No visible crop injury was observed after application of alachlor 469 g a.i./ha, clomazone 1080 g a.i./ha, metribuzin 525 g a.i./ha, pendimethalin 1031.25 g a.i./ha, tank-mixed clomazone 960 g a.i./ha + pendimethalin 928 g a.i./ha, or tank-mixed metribuzin 350 g a.i./ha + pendimethalin 928 g a.i./ha. However, acetochlor 1875 g a.i./ha, isoxaflutole 75 g a.i./ha, and oxadiazon 1000 g a.i./ha caused visible crop injury. Plant bioassay of herbicide residues in the soil after harvest showed no phytotoxic effect on baby corn (Zea mays Linn. cv. Suwan 3), cucumber (Cucumis sativus L. cv. Pijit 1), pak choi (Brassica chinensis Jusl. cv. Chinensis), and soybean (G. max L. Merrill cv. CM 60). Gas Chromatography-Mass Spectrometry (GC–MS) analysis showed no significant herbicide residues on crop yield (or MRLs < 0.01 ppm) for all herbicides used in this study. The application of metribuzin at 525 g a.i./ha was sufficient to provide satisfactory full-season control of several weed species and gave the highest crop yield. In addition, pendimethalin at 1031.25 g a.i./ha, and tank-mixed metribuzin at 350 g a.i./ha + pendimethalin at 928 g a.i./ha can provide a similar level of weed control as an alternative to reduce herbicide dosage thereby increasing food and environmental safety in vegetable soybean production.     

Response of weeds and soil microorganisms to imazaquin and pendimethalin in cowpea and soybean

Herbicides applied to combat weeds and increase crop yields may also have undesired effects on beneficial soil microorganisms. Field studies were conducted in 2005 and 2006 in Zaria, Nigeria, to evaluate the response of weeds and soil microorganisms to imazaquin applied at 0.05, 0.10, 0.20 and 0.40 kg a.i./ha and pendimethalin applied at 1.0, 2.0, 4.0, and 8.0 kg a.i./ha in cowpea and soybean. Hoe-weeded and unweeded (no herbicide) plots were controls. Both herbicides significantly reduced weed biomass in both crops, when compared to the unweeded control, which had the highest weed biomass at all sampling dates. Treatments with 0.40 kg a.i./ha of imazaquin, 2.0 and 4.0 kg a.i./ha of pendimethalin, and the hoe-weeded control, had the highest cowpea grain yield. The unweeded control had the lowest grain yield which was comparable to that in all other herbicide treatments. All treatments except 4.0 and 8.0 kg a.i./ha of pendimethalin had higher soybean grain yield than the unweeded control. Soybean yield was lowest in the unweeded control, and treatments that received 4.0 and 8.0 kg a.i./ha of pendimethalin. All rates of imazaquin gave similar soybean grain yields that were 29–41% higher than that from pendimethalin. The hoe-weeded control had the highest yield, which was 79% more than that in the unweeded control. Higher rates of imazaquin and pendimethalin reduced nodulation, nitrogen fixation, and vesicular arbuscular mycorrhizal (VAM) fungi colonisation in both crops. VAM fungi species diversity and species richness in cowpea rhizosphere soil and species diversity in soybean rhizosphere soil were reduced relative to the controls due to application of both herbicides with the rates of 0.10, 0.20, and 0.40 kg a.i./ha of imazaquin and 8.0 kg a.i./ha of pendimethalin being significantly effective.     

新疆玉米有害生物发生、施药现状及减药对策分析

通过问卷调查、走访种植大户及田间实地调查等方式,对新疆玉米主产区玉米有害生物发生与用药情况进行系统调查,明确新疆玉米有害生物发生种类、农药使用水平,分析存在问题并提出相应减药对策,从而为新疆玉米有害生物的科学防控及化学农药增效提供指导。结果表明,新疆玉米主要病害6种、害虫36种、杂草38种,主要以"6虫6草"为主。玉米有害生物防治常用农药共26类,其中杀虫剂14类,主要为拟除虫菊酯类、新烟碱类及生物源类;除草剂12类,主要为三氮苯类、磺酰脲类及酰胺。农药使用频次为2～6次/年,制剂施用量为1.938～6.193 kg/hm~2,其中,昌吉州农药使用频次和制剂施用量最高,分别为5～6次/年、4.033～6.193 kg/hm~2;喀什地区农药使用频次和制剂施用量最低,分别为2～3次/年、1.938～3.356 kg/hm~2。     

Pre-transplant herbicides for weed control in irrigated onion (Allium cepa L.) in northern Nigeria

Field trials were conducted at Samaru in the northern Guinea and at Bakuta and Kadawa in the Sudan Savanna ecological zones of Nigeria to identify suitable herbicides for weed control in irrigated onion. The herbicides tested were chlorthal-dimethyl, fluorodifen and oxadiazon. In the trials each herbicide treatment was compared with an identical treatment which received supplementary hand-weeding. The results of these experiments show that oxadiazon at 1·0–2·0 kg a.i./ha, with or without supplementary hoe-weeding at 6 weeks after transplanting, combined effective weed control with high bulb yields in irrigated dry season onions. While fluorodifen at 1·5 kg a.i./ha followed by supplementary hoe-weeding may be effective at sites with low weed infestation, a higher rate (3·0 kg/ha) may be desirable at sites with a higher broad-leaved weed infestation. Chlorthaldimethyl at 10·0 kg a.i./ha effectively controlled weeds at all the sites and gave high onion yields at sites with 6–12% clay; the selectivity was, however, lower at Bakura with very light soil. Uncontrolled weed growth caused 49–86% reduction in the bulb yields compared with the best herbicide treatments.     

Effect of trifluralin,pronamide, haloxyfop-p methyl,propaquizafop, and isoxaben on weed control and oilseed rape yield in Iran

In order to investigate the effect of trifluralin, pronamide, haloxyfop-p methyl, propaquizafop and isoxaben on weed control and oilseed rape yield, a two year field experiment was conducted at Darab, Iran, during 2004–2005 and 2005–2006 growing seasons. Herbicides reduced weed biomass compared with the weedy check. In 2004–2005, at 16 WAP (weeks after planting), application of trifluralin plus propaquizafop plus isoxaben at 1200 + 200 + 250 g a.i./ha and trifluralin plus haloxyfop-p methyl plus isoxaben at 1200 + 100 + 500 g a.i./ha provided best control (80%) of wild mustard (Sinapis arvensis L.), compared to other treatments. At 8 and 16 WAP, wild mustard control decreased to 47 and 42%, respectively, when trifluralin was applied alone at 1400 g a.i./ha. In 2005–2006 at 16 WAP, maximum reduction in wild mustard biomass (82%) was achieved with trifluralin plus propaquizafop plus isoxaben at 1200 + 200 + 250 g a.i./ha. In both years, all herbicide treatments controlled fumitory (Fumaria officinalis L.) 64–96%. In 2004–2005, at 16 WAP, wild oat (Avena fatua L.) biomass reduction by trifluralin plus propaquizafop plus isoxaben at 1200 + 200 + 250 g a.i./ha was 95%. In 2005–2006, at 8 and 16 WAP, minimum biomass reduction of wild oat (37–53%) was observed with trifluralin at 1200 and 1400 g a.i./ha. In both years, at 8 and 16 WAP, the most effective herbicide treatments were trifluralin plus propaquizafop plus isoxaben and trifluralin plus haloxyfop-p methyl plus isoxaben regardless of the dose applied and provided maximum reduction in total weed biomass (77–89%) compared to other treatments. Results of both years showed that all herbicide treatments increased oilseed rape grain yield as compared with the weedy check but percentage of oil was not affected by various herbicide treatments. Maximum grain yield was obtained with trifluralin plus haloxyfop-p methyl plus isoxaben at 1200 + 100 + 500 g a.i./ha.     

Chemical control of weeds in wheat (Triticum aestivum L.) in Iran

Experiments were conducted in 2006–2007 at six research stations of the Iranian Plant Protection Research Institute to study the efficacy of different herbicides to control weeds in wheat. Treatments included mesosulfuron-methyl plus iodosulfuron-methyl-sodium plus mefenpyr-diethyl (WG) at 45 + 45 + 135 g a.i./ha, respectively, sulfosulfuron at 21, 31.5, 42 and 51 g a.i./ha, chlorsulfuron at 15 g a.i./ha, bromoxynil plus MCPA at 600 g a.i./ha with clodinafop propargyl at 64 g a.i./ha, sulfosulfuron plus metsulfuron-methyl at 36 g a.i./ha, mesosulfuron-methyl plus iodosulfuron-methyl-sodium plus mefenpyr-diethyl (OD) at 15 + 3 + 45 g a.i./ha, respectively, and a full season weed-free control. Herbicides were applied at wheat tillering. Results showed that sulfosulfuron plus metsulfuron-methyl, and bromoxynil plus MCPA with clodinafop propargyl resulted in satisfactory weed control and wheat grain yield at most locations. Weed control efficacy of both formulations of mesosulfuron-methyl plus iodosulfuron-methyl-sodium was variable across locations. Efficacy of the OD formulation appears to depend upon location, so that application of this herbicide at Shiraz and Gorgan resulted in better weed control compared to use of the WG. Satisfactory performance of the OD formulation at Gorgan and Shiraz could be attributed in part to the even pattern of rainfall distribution during the growing season and wheat cultivar used, respectively. With respect to grain yield, however, the OD formulation was better than WG formulation at most of the locations.     

The response of onion couch (Arrhenatherum elatius ssp. bulbosum (Willd.) Schub. & Mart.) to glyphosate and other foliage-applied herbicides

Two experiments were conducted in which foliage-acting herbicides were applied to onion couch (Arrhenatherum elatius ssp. bulbosum). The first experiment used an artificially established population and investigated the effects of straw burning on the performance of autumn-applied treatments of glyphosate, aminotriazole and dalapon. Spring barley was sown without cultivation. The second experiment, conducted on a naturally occurring infestation, compared the performance of glyphosate applied at alternative autumn timings and a single application of flamprop-methyl made in the following spring, in the presence of a winter wheat crop. In the first experiment, assessments made after 15 months suggested that straw burning resulted in increased growth. In addition, herbicide performance appeared less effective after burning. In neither case were these differences significant. Glyphosate at 1·0 and 1·5 kg a.e./ha gave the highest levels of control of both shoots and bulbs, whereas control from aminotriazole at all doses (1·5, 3·0 and 4·5 kg a.i./ha) was poor. Dalapon (6·0, 12·0 and 18·0 kg a.i./ha) was intermediate in its effectiveness. In the second experiment, applications of glyphosate at 1·0 and 1·5 kg a.e./ha resulted in high levels of control of both shoots and bulbs with no significant difference between application dates. Flamprop-methyl at 0·52 kg a.i./ha reduced the number of shoots and bulbs by 55% and 58% respectively. All treatments significantly reduced the number of inflorescences present in July.     

砜吡草唑对玉米田杂草的除草活性及其安全性评价

采用生物测定方法研究新型除草剂砜吡草唑对玉米田主要禾本科杂草马唐、牛筋草、稗草、狗尾草的除草活性,通过安全性测定评价砜吡草唑对玉米等作物的安全性。结果表明,砜吡草唑土壤封闭处理对马唐、稗草、牛筋草、狗尾草均具有良好的生物活性。砜吡草唑处理剂量(有效成分)为120 g/hm~2时,对马唐、稗草、牛筋草、狗尾草的鲜重抑制率分别为98.76%、97.77%、100%、100%,对四种杂草的鲜重GR90(有效成分)分别为120、73.30、13.88、20.72 g/hm~2。砜吡草唑对玉米的安全性最高,对高粱和谷子的安全性较差,对玉米的鲜重GR10(有效成分)为602.01 g/hm~2。砜吡草唑在玉米和四种杂草间的鲜重选择性指数不小于8.21。砜吡草唑可作为玉米田理想的土壤封闭处理剂。