溴甲烷熏蒸对山楂叶螨和桃蛀果蛾的毒力研究

苹果是我国的重要出口水果,山楂叶螨(Tetranychus viennensis Zacher)和桃蛀果蛾(Carposinasasakii Matsumura)在苹果主产区广泛分布,严重威胁我国苹果出口。为确定溴甲烷检疫处理山楂叶螨和桃蛀果蛾的技术指标,本文系统测定了一系列温度条件下溴甲烷对山楂叶螨成螨和富士苹果中桃蛀果蛾老熟幼虫的毒力,确定在5℃、10℃、15℃、20℃和25℃下,溴甲烷熏蒸山楂叶螨死亡率达到机率值9所需浓度时间乘积(CT值)分别为126.66、84.35、59.15、45.23和40.33mg.h/L,溴甲烷熏蒸桃蛀果蛾死亡率达到机率值9所需CT值分别为128.05、81.80、52.91、41.56和36.43mg.h/L。根据上述结果,建议采用10.0～14.9℃40g/m3 2h、15.0～19.9℃32g/m3 2h、20.0～24.9℃24g/m3 2h和大于25.0℃20g/m3 2h作为出口苹果的溴甲烷熏蒸处理技术指标。     

溴甲烷对松木片中松材线虫的熏蒸作用

采用二次正交旋转组合设计,在室内条件下研究了溴甲烷剂量、熏蒸处理时间和处理温度对松木片中松材线虫熏蒸效果的影响。结果表明,溴甲烷剂量是影响熏蒸效果的最主要因子;14、18 ℃和22 ℃条件下处理24 h,松材线虫死亡率达99.9%时的溴甲烷浓度分别为17.92、16.07、14.87 g/m3; 14、18、22 ℃条件下,松材线虫死亡率达99.9%时,溴甲烷浓度和时间乘积,即CT（99.9）分别为192.52、174.705、166.229 g•h/m3。溴甲烷可用于口岸松木片中松材线虫的除害处理。     

溴甲烷对棉花枯萎病菌毒力的研究

 用溴甲烷分别对培养一周,两周、三周的棉花枯萎病菌(Fusarium oxysporum f.vasinfectum (Atk).Snyder et Hansen)熏蒸处理并且测定了它们对溴甲烷Lc₉₉的CTP值;棉花枯萎病菌在PDA培养基上培养时间越长,对溴甲烷的抗性越大。讨论了用溴甲烷处理带病土壤和种子的可行性。     

Influence of a Fungus-Feeding Nematode on Growth and Biocontrol Efficacy of Trichoderma harzianum

ABSTRACT A fungivorous nematode, Aphelenchoides sp., was isolated from field soil by baiting with mycelium of the biocontrol fungus Trichoderma harzianum ThzID1, and subsequently was maintained on agar cultures of the fungus. Interactions between the nematode and the green fluorescent protein-producing transformant, T. harzianum ThzID1-M3, were investigated in both heat-treated (80 degrees C, 30 min) and untreated field soil. ThzID1-M3 was identified in soil by epifluorescence microscopy. When ThzID1-M3 was added to soil as an alginate pellet formulation, addition of the nematode (10 per gram of soil) significantly reduced radial growth and recoverable populations of the fungus, and the effect was greater in heat-treated soil than in untreated soil. Addition of ThzID1-M3 to soil pretreated with the nematode (10 per gram of soil) stimulated nematode population growth for approximately 10 to 20 days, whereas nematode populations decreased in the absence of added Trichoderma sp. When sclerotia of Sclerotinia sclerotiorum were added to soil (10 per 200 g of soil) with ThzID1-M3 (40 pellets per 200 g of soil), addition of Aphe-lenchoides sp. (2,000 per 200 g of soil) reduced the number of sclerotia colonized by ThzID1-M3. These results suggest that fungivorous nematodes may be a significant biotic constraint on activity of biocontrol fungi in the field.     

溴甲烷、环氧乙烷真空熏蒸杀虫灭菌技术研究

真空情况下,利用溴甲烷、环氧乙烷杀虫、灭菌是一种安全、快速、有效的技术措施。为了使此技术广泛应用到农林种子、苗木、卫生防疫以及文史资料诸方面杀虫灭菌,试制成功一台容积工立方米的PCV-1000程序控制真空熏蒸机,并进一步进行溴甲烷、环氧乙烷杀虫灭菌效果及其熏蒸后残余毒气处理方法的研究。溴甲烷75—90克/立方米处理2小时,环氧乙烷90—120克/立方米处理3小时,可杀死各种形式的包装内的谷斑皮蠹和花斑皮蠹幼虫,赤拟谷盗和锈扁谷盗成虫以及玉米象和绿豆象各虫态等害虫。环氧乙烷灭菌能力较强,对动物炭疽菌、4001芽孢杆菌500克/立方米处理5小时或300克/立方米处理12小时,灭菌效果100%。溴甲烷和环氧乙烷混合使用对棉花枯萎病菌效果良好,对棉籽发芽率影响不大。熏蒸后残余毒气处理,用5%氢氧化钠酒精液吸收溴甲烷,破坏率可达96%以上。环氧乙烷用自来水淋洗法,水合分解率可达98%以上。     

Soil solarization as a substitute for methyl bromide fumigation in greenhouse tomato production in Cyprus

Preplant soil fumigation with methyl bromide (MB) is presently standard practice in greenhouse tomato production. Since this compound is scheduled to be phased out by 2005, the possibility of using solarization as an alternative soil disinfestation method was examined in four greenhouse tomato trials. Solarization was applied for 8 weeks in July-August, using transparent polyethylene sheets for soil mulching, and compared with MB fumigation applied in September, before planting, at 80 g/m². Solarization raised the maximum soil temperature by 9°C and reduced the population density ofFusarium spp. in soil by 91–98%. Similar reductions of soil inoculum (95–99%) were obtained with MB fumigation. Both methods provided effective control of Fusarium wilt, Verticillium wilt and corky root rot on tomato plants. MB fumigation was in addition highly effective against root-knot nematodes, whereas nematode control with solarization did not exceed 50%. Both treatments resulted in similar fruit yield increases, ranging within 90–140% compared with plants grown in untreated soil. During the second cropping season following soil treatment, solarization exhibited two times higher residual effectiveness against vascular wilt diseases compared with MB fumigation. The latter treatment, however, was superior to solarization in its residual effectiveness against root-knot nematodes and to a lesser extent against corky root rot. Fruit yields from solarized and MB-fumigated soil during the second cropping season were higher than those obtained from untreated soil by approximately 35% and 60%, respectively. In Cyprus, solarization appears to be an effective alternative to MB fumigation in greenhouse tomato production, especially if integrated with other approaches enabling more effective nematode control.     

低剂量棉隆熏蒸联合生物菌肥防治黄瓜根结线虫病的应用效果

为明确土壤熏蒸联合生物菌肥对根结线虫及土壤微生态的影响,采用低剂量棉隆熏蒸处理后沟施YB-04菌肥的方法在日光大棚进行黄瓜根结线虫病的防治试验。结果显示,棉隆熏蒸联合YB-04菌肥沟施处理土壤中的根结线虫数和黄瓜植株根系的根结指数均比单独使用棉隆或YB-04菌肥的处理及对照显著降低,黄瓜移栽后90 d时线虫减退率为89.1%,根结指数为0.5,防治效果达87.8%。棉隆熏蒸联合YB-04菌肥沟施处理也具有显著的促生作用,黄瓜的产量、株高、鲜重以及有效叶数均比对照显著提高了46.4%、18.8%、63.0%和17.7%。另外,棉隆单独熏蒸处理土壤中的细菌和真菌数量、细菌/真菌比值及土壤酶活性均较对照显著降低,而棉隆熏蒸联合YB-04菌肥沟施处理土壤中的细菌数量、细菌/真菌比值及土壤酶活性均较棉隆单独熏蒸处理显著增加,其中,细菌数量及细菌/真菌比值分别达28.4×106CFU/g和201.2,蔗糖酶活性达86.0 mg·g~(-1)·24 h~(-1)。表明低剂量棉隆熏蒸联合YB-04菌肥沟施可以安全高效地防治黄瓜根结线虫病。     

Evaluating Pochonia chlamydosporia in a double-cropping system of lettuce and tomato in plastic houses infested with Meloidogyne javanica

The effect of Pochonia chlamydosporia , a facultative fungal parasite of nematode eggs, alone or in combination with oxamyl was evaluated in a double-cropping system of lettuce and tomato in unheated plastic houses infested with Meloidogyne javanica at two sites for two consecutive growing seasons. An additional treatment of methyl bromide fumigation was included to compare crop yield in nematode-free vs. nematode-infested soil. Final population densities, reproductive rate, root gall rating, and egg production were determined after each crop. Pochonia chlamydosporia was isolated from nematode eggs up to nine months after application to soil. The fungus survived in the rhizosphere for the entire growing season at one site, but only at low densities. Final population densities of M. javanica decreased after cultivation of lettuce and increased after tomato, and this pattern of population fluctuation was unaffected by treatment, experiment or site. The reproductive rate on lettuce was equal to or below 1, and it was similar among treatments in both experiments at both sites. Eggs were not found on lettuce roots. On tomato, the reproductive rate in the fungus + oxamyl treatment was significantly lower ( P  < 0·05) than other treatments in experiment 1 at both sites. Fungus + oxamyl consistently reduced root gall ratings on tomato in all cases, but numbers of eggs per g root varied depending on treatment. Methyl bromide-treated plots remained free of M. javanica at the end of the 2-year study.     

Chemical alternatives to methyl bromide for the control of root-knot nematodes in greenhouses

The complete phase-out of methyl bromide from use in developed countries by 1 January 2005 will cause many problems in agricultural industries that are now heavily reliant on its use. Three field experiments were established to compare management tactics on tomato and cucumber in commercial greenhouses naturally infested with root-knot nematodes (Meloidogyne spp). Reduction of nematode juveniles in soil and roots to nil detection levels was observed in all plots following soil fumigation with methyl bromide. A significant reduction of nematode juveniles and root-galling index was observed in plots treated with metham-sodium, dazomet and 1,3-dichloropropene compared with the control and plots treated with non-fumigant nematicides. Reduction of the nematode population led to an increase in fruit yield. However, data collected from the second cultivation season indicated that single control methods such as fumigant or contact nematicides alone cannot drastically decrease initial nematode population and those nematodes which escape control lead to population increase by the end of the cropping season.     

溴甲烷和磷化氢熏蒸杂交稻种对米象和干尖线虫的杀灭效果及对水稻发芽率的影响

在10~15 ℃、16~20 ℃、21~30 ℃3个温度范围下,不同剂量的溴甲烷、磷化氢熏蒸出口杂交稻种的试验表明：溴甲烷、磷化氢能有效地杀灭米象,但不能完全杀灭干尖线虫。熏蒸后对杂交稻种的发芽率检测表明磷化氢对杂交稻种表现安全,但16~20 ℃下,40 g/m3溴甲烷及21~30 ℃下,32 g/m3溴甲烷熏蒸处理24 h,杂交稻种子发芽率显著降低。     

棉隆与淡紫拟青霉联合防治番茄根结线虫病的效果评价

为明确土壤熏蒸与生防微生物对番茄根结线虫病的联合作用效果,采用移栽前棉隆熏蒸处理后穴施淡紫拟青霉Paecilomyces lilacinus YES-2-14生防菌剂的方法在温室大棚开展了联合防治试验。结果表明,棉隆用量为35 g/m~2时,24周拉秧时线虫数量减少90%以上,防效达到85.5%;移栽时穴施浓度10~7~10~8CFU/g的淡紫拟青霉菌剂,24周拉秧时防效为44.4%~59.6%;而当线虫初始密度达到674头/100 g土时,单一菌剂防效只有12.5%,但番茄长势和产量显著提高。棉隆熏蒸后再联合施用淡紫拟青霉菌剂,2个月和5个月时防效比单一棉隆处理分别提高14.1%和21.8%,比单一菌剂处理提高14.3倍和4.1倍,产量较对照、棉隆熏蒸和单一菌剂处理分别提高22.1%、9.5%和2.4%,且该处理地块线虫数量始终最低,与对照差异显著,而淡紫拟青霉数量则高于单一淡紫拟青霉菌剂处理。表明棉隆和淡紫拟青霉菌剂联合使用不仅能显著降低线虫数量,有效防治番茄根结线虫病,还能够促进植株生长并提高产量。     

利用ZXX-65真空循环熏蒸设备熏蒸仓储害虫的研究

用ZXX-65真空循环熏蒸设备在不同真空压力、熏蒸时间、药剂浓度条件下对选定的典型仓储实验试虫进行熏蒸，根据杀虫效果，筛选出害虫的最优熏蒸条件组合。结果表明，ZXX-65真空循环熏蒸设备可以在2h内杀死各种仓储害虫。40000Pa，60g/m^3，2h为仓储害虫的最优熏蒸条件组合。     

生物熏蒸用于治理蔬菜根结线虫病的研究

将甘蓝(Brassica oleracea)、芥菜(B.juncea)和雪里蕻(B.junceavar.multiceps)的叶及芥菜疙瘩(B.napifor-mis)的块根组织以3.5 kg/m²的量分别施入密封于棉纱缸中的严重感染根结线虫(Meloidogyne incognita)的土壤中,在25℃和32℃下熏蒸6 d后对活体线虫的测定结果表明,在25℃下用上述4种材料熏蒸后活体线虫数量分别比对照减少80%、85%、87%和91%。32℃下的熏蒸效果明显优于25℃下的熏蒸效果,各处理土壤中均未发现活体线虫,而无处理对照土壤中的活体线虫数量为1 540条/kg土壤。对各类添加物增效作用的调查结果表明,添加麦麸的增效作用最明显。田间试验结果表明,植物材料单独或与添加物混合使用对根结线虫病的防效均显著高于太阳能和土壤还原消毒法的防效。其中芥菜添加麦麸在开花期和盛果期的防效分别为65.2%和66.0%,与对照药剂98%棉隆可湿性粉剂的防效无显著差异;各植物材料熏蒸效果大小依次为芥菜>雪里蕻>芥菜疙瘩>甘蓝。     

小杆线虫Oscheius tipulae JL1的鉴定及生物学特性

利用大蜡螟Galleria mellonella L.诱集法,从采自吉林省的土样中分离到小杆类昆虫病原线虫1种。经形态学、ITS及28S rDNA序列分析鉴定,明确了该线虫为Oscheius tipulae JL1。室内生物测定结果表明:24 h时,线虫JL1浓度为120 IJs/larva及以上时,大蜡螟的死亡率达90%以上;48 h时,浓度40 IJs/larva时,大蜡螟死亡率达93%以上;60 h时,浓度高于20 IJs/larva时,大蜡螟死亡率100%。耐热性方面,在38℃下处理8 h,线虫死亡率快速增加,35℃处理16 h,线虫死亡率开始快速增加。线虫JL1在35和38℃条件下,分别至少可耐16和8h的高温,死亡率分别在3.2%和15.3%以下。结果表明该线虫具有较好的耐热力、侵染力和致死力,未来有望用于害虫防治。     

我国土壤熏蒸消毒60年回顾

熏蒸剂棉隆和氯化苦于20世纪60年代在我国曾用于棉花黄萎病的防治,由于缺乏施药机械、相关施药标准和方法,加之与国外交流甚少,虽然发现熏蒸剂对土传病害有一定的效果,但一直未形成规模化应用。我国大量使用熏蒸剂进行土壤消毒处理始于20世纪90年代,随着溴甲烷的引进与广泛应用,溴甲烷的替代技术及产品研发,开启了我国土壤熏蒸消毒的新纪元。伴随着土壤消毒技术与理论的不断丰富,新型配套机械装备的成功研发,社会化服务模式的广泛运用,土壤熏蒸消毒在我国进入快速发展时期,大批专业化服务组织应运而生,为我国农作物病虫害的绿色防控、实施乡村振兴战略提供了强有力的技术支撑。该文从土壤熏蒸剂的种类、发展历史、基础理论的建立与阐明3方面综述了我国土壤熏蒸发展情况,并对我国土壤熏蒸消毒未来发展方向提出了展望。     

Effect of soil physical factors on methyl iodide and methyl bromide

Production and importation of methyl bromide is scheduled to be banned by 2001. Methyl iodide was evaluated as a possible replacement soil fumigant. The effects of soil moisture, temperature, soil texture and fumigation time on the efficacy of methyl iodide for the control of two common weeds, Abutilon theophrasti and Lolium multiflorum, were characterized and compared with those of methyl bromide. The optimal soil moisture for methyl iodide to kill both weed species in sandy soils was 14% water content (w/w). Greater efficacy was obtained when the temperature during fumigation was above 20°C. Compared to methyl bromide, the efficacy of methyl iodide was more consistent in different soils. Time to 100% mortality of weeds was 24 h for methyl iodide fumigation and 36 h for methyl bromide when 200 μM of fumigant was used. On a molar basis methyl iodide was consistently more effective than methyl bromide across the range of environmental factors tested. In terms of application technology and spectrum of activity, methyl bromide can be directly replaced by methyl iodide. © 1998 SCI     

Investigation of alternatives to methyl bromide for management of Meloidogyne javanica on greenhouse grown tomato

The root galling index and the densities of eggs in roots and juveniles in soil of the root-knot nematode Meloidogyne javanica (Treub) Chitwood on tomato, and the effect of these on crop yield were assessed in greenhouse experiments applying various treatments at two different sites in Crete, Greece. Tomato crops were grown for four cycles by rotating nematode-resistant (first and third spring crops) with susceptible (second and fourth autumn crops) cultivars and receiving the following treatments: (a) untreated control; (b) methyl bromide application before the first and third crops; (c) application of the fungus Pochonia chlamydosporia (Goddard) Zare, Gams & Evans before planting the first, third and fourth crops with a supplementary application three weeks after the beginning of the fourth crop; (d) application of oxamyl in both sites and fenamiphos in site 1 only at the second and fourth crops; (e) combination of treatments (c) and (d). The fungus density in soil was monitored three weeks after application and at the end of each crop, when roots were lifted. Pochonia chlamydosporia had a variable establishment and did not control the nematode. Its pathogenicity on eggs was not demonstrated, as in all cases galls were big, with all egg masses inside and protected from infection. The methyl bromide treatment significantly reduced root galling and egg production compared to other treatments in all crop cycles and the yield of the fourth crop was significantly greater. Nematicides reduced nematode densities compared with untreated controls and the fungus treatment, but they were less effective than methyl bromide and resulted in increased yield in one site only.     

拟粗壮螺旋线虫对棉花的致病力及其与棉枯萎病的复合症

 温室测定结果:拟粗壮螺旋线虫(Helicotylenchus pseudorobusius)接种量在每100cm³土壤100~1000条的条件下,接种30天后棉苗生长量比无线虫对照苗显著降低(P<0.05)。抗枯萎品种86-1在单接枯萎菌无线虫处理中不发生枯萎病,在枯萎菌(Fusarium oxysporum f. sp. vasinfectum)接种量为每克土7.5×10⁵孢子和线虫(每100cm³±500~1000条)组合处理中发病,棉苗枯萎病情指数与线虫接种量之间呈正相关(γ=0.97)。田间试验结果表明:防治线虫和枯萎病复合症用薰蒸剂棉隆每m²8~14g处理土壤比用非薰蒸性杀线虫剂克百威(呋哺丹),丙线磷(益收宝)和克线磷的效果更好。     

Dose response of weeds to methyl iodide and methyl bromide

Labonuory bioassay and field experiments were conducted to characterize the dose response of weeds to methyl iodide and methyl bromide as soil fumigants. The patterns in potency of both fumigants and in sensitivity of diffcretit weed species to the fumigants were distinguished with the use of logistic dose-response models. Similar to its response to methyl hromide fumigation. Amaranthus retrofleus L. was the most sensitive to methyl iodide fumigation. Cyperus rotundtis L. was the least sensitive to methyl iodide fumigation, whereas Portuloca oleracea L. was the least sensitive to methyl hromide. Lolium multiflorum Lam. Abutilon theophrasti Medik. Chenopodium album L. P. ateracea . Brassica kaber (D.C.) L.C. Wheeler and Cyperus escuden-tus L. were similar in sensitivity to methyl iodide. Methyl iodide was as potent as methyl bromide for A. retroflexus but more potent than methyl bromide for L. multiflorum , A. theophrasti. C. album. P. oleracea. B. kaber, C. esculentus and C. rotundus. The dose response for weeds in the field was similar to that obtained in laboratory bioassays. Under fieid conditions. 280 kg ha^-1 methyl iodide killed all species tested except Solanum nigrum L Methyl iodide appears to be a suitable replacement for meihyl bromide because it can be used in situations simitar to methyl bromide fumigation, has superior efficacy against a broad spectrum of pests and has a low potential for degrading the earth's ozone lavers.     

Evaluation of methyl iodide as a soil fumigant in container and small field plot studies

Methyl iodide was evaluated as a soil fumigant as a potential replacement for the widely used soil fumigant methyl bromide. In container trials, methyl iodide was significantly more effective than methyl bromide against the plant parasitic nematodes Meloidogyne incognita, Heterodera schachtii and Tylenchulus semipenetrans and the plant pathogenic fungus Rhizoctonia solani. In small field plots, soil populations of root-knot nematodes were no longer detected after methyl iodide fumigation at an application rate of 112 kg ha^-1. However, after growing a susceptible lima bean host for two months, substantial root-knot galling occurred, while Rhizobium nodulation was absent. At 168 kg ha^-1 of methyl iodide, root-knot galling was reduced to less than 1%, and no Pythium propagules were recovered on selective detection media. These efficacy data support the conclusion that methyl iodide is a likely candidate for replacing methyl bromide as a soil fumigant. © 1998 SCI.