0.1%果瑞特瓜实蝇诱剂对瓜类蔬菜实蝇的药效试验

应用0.1%果瑞特瓜实蝇诱剂,对瓜类蔬菜实蝇进行了药效试验示范。结果表明,0.1%果瑞特瓜实蝇诱剂对瓜类实蝇(南亚果实蝇、宽带果实蝇和瓜实蝇等)雌、雄成虫特别是对雄成虫具有较强的诱杀效果,可显著减少实蝇雌虫交配产卵为害。点喷或挂罐防治效果均显著,该诱剂适用于瓜类蔬菜无公害生产。     

斑粉脱防治白粉病效果好

白粉病是瓜类上的主要病害，分布广，为害重，其中黄瓜、西葫芦、南瓜、甜瓜最容易感病，发病后，叶片变黄、质脆，失去光合作用功能，致使作物营养不良。诺普信新开发的三唑类杀菌剂———斑粉脱（１２．５％腈菌唑EC），富含高效成膜剂，有极强的粘附性，具有强烈内吸作用，喷药后１～２h，有效成分迅速进入植株体内，阻碍子囊菌麦角甾醇的合成，抑制病菌形成孢子，阻制病斑的扩展和蔓延。经对瓜类和草莓白粉病进行大田药效试验，在发病初期用２０００倍液喷雾防治，每隔７～１０d喷１次，连续使用３～５次，对瓜类和草莓白粉病防效显著…     

重庆高山地区越冬大白菜栽培技术要点

正重庆市海拔800~1400m的高山地区,因连年种植十字花科蔬菜(甘蓝、大白菜、萝卜,俗称三白),过多施用化肥,导致土壤酸化板结,连作障碍严重,尤其是十字花科蔬菜根肿病发病普遍。经过近几年的摸索试验,高山地区4—10月份根肿病易发季节种植茄果类、瓜类或油麦菜等蔬菜,10月份至翌年4月份根肿病不易发病的季节种植一季越冬     

南方菟丝子对花卉、蔬菜的危害性试验及防治

南方菟丝子CuscutaaustralisR .Br是一种检疫性杂草。试验结果表明 :南方菟丝子可以侵染供试 1 4种花卉中的 1 2种和供试 1 8种蔬菜中的 1 5种 ,并造成严重的损失。在菟丝子长至 5～ 6cm时喷 1～ 2次 4 8%的地乐胺以及在菟丝子开花之前连同花卉、蔬菜植株一同拨除是防治南方菟丝子的最有效的方法     

喷特4%EC防除油菜田杂草试验总结

本文通过试验证明喷特4%EC在油菜田防除杂草效果良好.药后30d喷特4%EC对看麦娘株防效达83.9%～85.6%,药后45d株防效达93.6%～96.0%,鲜重防效达96.0%～98.8%,有一定的使用推广价值.     

2007年武汉市蔬菜主要虫害发生趋势预报

害虫名称发生趋势为害作物为害时期(月/旬)烟粉虱大发生所有在园蔬菜3/下~12/中蚜虫大发生瓜类、豆类、茄果类、十字花科蔬菜3/下~7/上9/中~11/下小菜蛾大发生十字花科蔬菜4/下~6/中7/上~11/上黄曲条跳甲大发生十字花科蔬菜8/上~10/中豆野螟大发生豆类蔬菜6/上~9/下蓟马中等偏重茄果类、瓜类、豆类蔬菜5/下~9/下美洲斑潜蝇中等偏重几乎所有在园蔬菜6/上~11/上瓜野螟中等偏重瓜类蔬菜6/中~8/中斜纹夜蛾中等偏重豆类、茄果科、十字花科蔬菜7/中~10/上菜青虫中等偏重十字花科蔬菜4/下~9/上红蜘蛛中等发生瓜类、豆类、茄果科4/中~9/中甜菜夜蛾中…     

春大棚茄瓜类蔬菜灰霉病等病害的发生与防治

自 8 0年代以来 ,伴随棚室蔬菜生产的发展 ,灰霉病等次要病害上升为主要病害 ,对茄果类、瓜类蔬菜的前期产量造成很大的损失。据在宁波蔬菜基地调查 ,仅灰霉病为害茄子 ,苗发病率平均为 1 5.4 % ,高的达71 .9% ,果发病率平均为 1 7.7% ,高的达 4 7% ;番茄、甜椒、黄瓜、瓠瓜等均有不同程度的损失 ,因病减产达2 0 %～ 50 %。几年来作者对春大棚茄、瓜类蔬菜灰霉病等病害的发生与消长、病害流行因子和关键防治技术 ,作了调查和试验研究 ,现将结果报道如下 :1　灰霉病等病害的发生与消长1 .1　田间几种病害发生情况　宁波地处浙东沿海地区 ,常…     

保护地几种蔬菜生理障碍发生原因和综合控制技术

近年来，棚室蔬菜作物生理障碍的发生日渐突出，对茄果类、瓜类蔬菜的产量及品质影响很大。据在凤台蔬菜基地调查，８０％的蔬菜田有不同程度的生理障碍发生，病株率一般达１０％～２５％，高的达５０％以上。蔬菜生理障碍的普遍发生已严重影响广大菜农的积极性。为了有效控制保护地蔬菜生理障碍的发生，笔者对此类病的主要症状、发病原因和综合控制进行了研究分析。１几种蔬菜生理障碍的主要症状１．１番茄畸形果正常果实圆形，有４～６个心室，呈规则放射状排列。而畸形果呈椭圆形，多纵沟，２～３个长在一起，横剖果实，因几个果实长在一…     

铜氨合剂对柑桔溃疡病的防治效果

从1986～1988年我们连续3年用铜氨合剂(自配),农用链霉素(750ppm),新植霉素(750ppm),1％石灰倍量式波尔多液4种药剂在柑桔苗木(椪柑苗2720株和锦橙苗1240株),成龄柑桔树(1987年,8年生雪柑成龄树36棵,1988年,4年生锦橙成龄树32棵)上进行药剂试验,试验时均设对照和重复。喷药时间和次数为:柑桔苗木在夏秋2次梢抽出时各喷3次药,每隔7～10天喷一次药;成龄树1987年于6月30日80％夏梢抽出时喷第一次药,8月11日80％秋梢抽出时喷第2次药,共喷2次;1988年于5月28日,6     

砂梨黑斑病的发生规律与无公害防治技术

经3年调查表明,在淮北地区,日韩梨品种(砂梨系统)栽培面积扩大,梨黑斑病的发生蔓延逐渐加重。叶片于4月中下旬开始发病,初侵染发生率与当年3-4月份降雨量密切相关,5-7月份为发病高峰,5-7月份高温多雨是病情严重的主要因素。生产防治应于发芽前(3月上中旬)喷布3～5波美度石硫合剂1次。在发病初期每隔7d喷10%(宝丽安(多抗霉素)WP或50%扑海因(异菌脲)WP1000～5000倍液1次,以后与进口代森锰锌、腐霉剂(速克灵)等交替使用,连续喷三四次,防效显著。     

Importance of cucurbits in the epidemiology of Papaya ringspot virus type P

Papaya ringspot virus type P (PRSV‐P) systemically infects Carica papaya and species belonging to the family Cucurbitaceae. Attempts to recover PRSV‐P from naturally infected cucurbit plants grown near or among diseased papaya trees have shown conflicting results worldwide. This study aimed to evaluate the natural infection of cucurbit species grown among and near papaya trees infected with PRSV‐P in Brazil. Natural infection of cucurbits with PRSV‐P occurred in zucchini squash but not in watermelon and cucumber. However, several attempts to recover PRSV‐P from numerous Cucurbita pepo cv. Caserta (zucchini squash) plants grown 5–80 m from diseased papaya trees in the field failed. Mechanical inoculations of Cucurbita pepo cv. Caserta, Cucurbita maxima cv. Exposição (pumpkin), Cucumis sativus cv. Primepack Plus (cucumber) and Citrullus lanatus cv. Crimson Sweet (watermelon) with five Brazilian PRSV‐P isolates showed that zucchini squash was the most susceptible species followed by watermelon and cucumber, while pumpkin was not infected. The results confirmed the variable susceptibility of cucurbit species to experimental and natural PRSV‐P infection. Given these facts, the control of the disease through roguing should focus mainly on diseased papaya plants, as has been practised successfully in Brazil for many years, and on those cucurbits particularly known to be susceptible to natural infection with PRSV‐P.     

A new yellowing disease of cucurbits caused by a luteovirus, cucurbit aphid-borne yellows virus

Since 1988, a yellowing disease of melon, cucumber and zucchini squash has been frequently observed in summer and autumn crops in France. Infected plants show yellowing and thickening of the older leaves; symptom intensity differs depending upon cultivar and season, and can be easily overlooked when plants are already infected by mosaic-inducing viruses or other pathogens. The disease is associated with the presence of a virus with spherical particles c. 25 nm in diameter, which is readily transmitted in a persistent manner by the aphids Myzus persicae and Aphis gossypii , but not mechanically. Serological analysis, nucleic-acid-hybridization experiments and host-range studies indicate that the virus is distantly related to, but distinct from, beet western yellows virus (BWYV). We propose to name this virus cucurbit aphid-borne yellows virus (CABYV), and to consider it as a tentative new member of the luteovirus group. CABYV was found to reduce significantly the yields of melon and cucumber by decreasing the number of fruit per plant but not by altering the fruit shape or quality. Preliminary investigations of the epidemiology of CABYV indicate that the virus is common in weeds and in cultivated cucurbits. CABYV was frequently detected in various regions of France, suggesting that it is one of the most prevalent viruses infecting cucurbits in this country.     

The pumpkin fly Dacus frontalis (Diptera: Tephritidae): a new pest of curcubits in Tunisia

The pumpkin fly Dacus frontalis is reported in this paper for the first time in Tunisia, where it was found in several locations. It is a pest of cucurbits of economic importance and is common especially in the eastern and southern parts of Africa. D. frontalis was collected from infested cucumber fruits in the region of El‐Jebil (Kairouan) and female bait traps for the Mediterranean fruit fly Ceratitis capitata and the olive fly Bactrocera oleae. Preliminary data from Tunisia suggest that D. frontalis is already established in four regions in which cucurbits are important crops. Brief notes on the diagnostic features for the species, its ecology and geographic distribution are given. Symptoms on cucumber from Tunisia are presented.     

Resistance to benzimidazole fungicides in the gummy stem blight pathogen Didymelta bryoniae on cucurbits

Benzimidazoles were used successfully against gummy stem blight of cucurbits for only one growing season (1980). It was soon noticed in experiments in vivo that they were not effective against some isolates of the pathogen. In a survey during the 1981 crop season, 76 out of 102 isolates collected from 20 plastic greenhouses all over the main cucurbit-growing areas of Crete were resistant to benomyl. The average benomyl concentrations that reduced mycelial growth rates of seven resistant and seven sensitive isolates by 50% were 716 ± 49 and 1.2 ± 0.34μg/ml respectively. The average growth rate of resistant isolates was lower than that of sensitive isolates but there were no differences in spore production and spore germination. The pathogenicity of resistant isolates on young cucumber plants was lower than that of sensitive isolates. The application of benomyl, carbendazim, cypendazole and thiophanate methyl to young cucumber plants at the rate of 300μg a.i./ml 1 day before inoculation with 500 000 spores/ml of the resistant isolates did not affect the infection rate of the disease after 4 days. Sensitive isolates caused no onslight symptoms on similarly treated plants.     

Resistance to acylalanines in Pseudoperonospora cubensis1

Resistance to acylalanine fungicides in Pseudoperonospora cubensis, the downy mildew of cucurbits, is reviewed. Insensitive strains of the fungus predominated during the second year of metalaxyl application in cucumber glasshouses in Greece and Israel. Resistance was detected either on detached cucumber leaves floated on metalaxyl solutions or on potted plants treated (sprayed or drenched) with this fungicide. Metalaxyl-resistant strains of P. cubensis showed good pathogenicity and fitness, and competed favorably with the sensitive strains in the absence of the fungicide. A synergism between these two biotypes resulted in an increased virulence of the resistant forms on metalaxyl-treated plants. Metalaxyl-resistant strains of the pathogen exhibited cross resistance to other acylalanine fungicides. Strains resistant to acylalanines and to the chemically unrelated oomycete-fungicides fosetyl-Al and propamocarb were isolated in Israel, as well. In Greece, however, protective sprays with fosetyl-Al, cymoxanil and mancozeb gave good control of cucumber downy mildew when the pathogen was resistant to metalaxyl. P. cubensis is the first case of fungus which developed resistance to acylalanines in the field.     

生物诱抗剂草酸对黄瓜叶片中过氧化物酶的系统诱导作用

 本文进一步证明草酸是一种有效的非生物诱抗剂,它能显著提高黄瓜对炭疽病的系统抗性,进而研究了草酸对黄瓜叶片中与抗病有关的过氧化物酶(POD)的系统诱导作用及其内在机理。结果表明:40mmol/L草酸诱导可溶态POD活性效果最佳;在测定时间范围内,草酸诱导的可溶态POD活性在第7d后逐渐下降,而细胞壁离子键结合态POD活性被诱导后保持稳定;草酸在快带区诱导出一种新的POD同功酶,其Rf值为0.63;自由基清除剂甘露醇和抗坏血酸可明显抑制草酸对可溶态POD活性的诱导作用;草酸诱导可溶态POD的作用信号可在5h左右从被处理的第1片真叶传导至未处理的第2片真叶,被处理叶的保留时间越长,其诱导效果越好。     

THE USE OF THREE SIMPLE,RAPID BIOASSAYS ON FORTY-TWO HERBICIDES*

Three rapid bioassays were tested on forty-two herbicides having several different modes of action. A 50% or greater inhibition of growth was found at 1 ppm with thirty-one herbicides in one or more of the bioassays. Of the remaining eleven herbicides, seven were detected at 10 ppm, two at 20 ppm and two at 30 ppm. The techniques used were a Chlorella bioassay, a root bioassay with sorghum, oat and cucumber and a shoot bioassay with sorghum and oat. The duration of the bioassays was 1, 2 and 4 days respectively. As a general rule, the Chlorella bioassay was especially sensitive to photosynthetic and respiratory inhibitors but not sensitive to herbicides with other modes of action, whereas the root and/or shoot bioassays were sensitive to most of the herbicides except the photosynthetic inhibitors. The use of the three bioassays simultaneously is suggested as a possible method for primary screening of herbicides.     

Genetic diversity and pathogenicity of cucurbit-associated <Emphasis Type="Italic">Acidovorax</Emphasis>

Bacterial fruit blotch of cucurbits is a destructive disease caused by Acidovorax avenae subsp. citrulli, which is a typical seedborne pathogen. In seed health testing for this disease, we have detected many strains of Acidovorax with some differences from A. avenae subsp. citrulli. Their 16S rRNA sequences were divided into six types. The most common sequence was completely consistent with that of A. avenae subsp. avenae originally isolated from rice. The other sequences were over 99% similar but not identical to those of A. avenae subsp. avenae and A. avenae subsp. citrulli. Some commercialized antibodies against A. avenae subsp. citrulli reacted with several of these strains. Some of these strains incited yellow spots or brownish water-soaked lesions mainly on young true leaves of cucumber and squash after spray inoculation. Histological observations showed that these strains entered the leaf tissues of cucurbit plants through stomata and multiplied in the intercellular spaces of parenchymatous tissues as well as in the vascular tissues. The amount of bacterial multiplication and spread in the tissues differed among the strains, presumably reflecting their ability to induce symptoms. These isolated strains are therefore different from A. avenae subsp. citrulli, and their potential threat to the cultivation of cucurbits is lower than that of A. avenae subsp. citrulli.     

Influence of fungicidal control of cucumber and tomato grey mould (Botrytis cinerea) on fruit yield

The fungicides tebuconazole, tebuconazole + dichlofluanid, fenethanil, diethofencarb + carbendazim, and vinclozolin combined with chlorothalonil were tested for their ability to control grey mould (Botrytis cinerea Pers. ex Fr.) of cucumber and tomato grey mould in greenhouses under commercial conditions. In winter 1987/88 the number of diseased female fruits of cucumber (Cucumis sativus L.) was reduced by diethofencarb + carbendazim (2·5 mg dm^?3 each) by 93% and by tebuconazole (2·5 mg dm^?3)(phytotoxic when alone) or tebuconazole (1 mg dm^?3) + dichlofluanid (4 mg dm^?3) by 54–57%. Vinclozolin (5 mg dm^?3) + chlorothalonil (25 mg dm^?3) significantly reduced disease incidence on fruits by 40%. Infection foci on cucumber stems were significantly decreased by vinclozolin + chlorothalonil. A more pronounced decrease was obtained with diethofencarb + carbendazim, tebuconazole, or tebuconazole + dichlofluanid. During the season of winter 1988/89, tebuconazole + dichlofluanid (1·5 + 6 and 3 + 12 mg dm^?3) and RH7592 (1 mg dm^?3) significantly reduced diseased fruits by 30–71%. Grey mould of tomato (Lycopersicon esculentum Mill.) leaves was reduced by more than 90% and on fruits by 78–87% when tebuconazole + dichlofluanid (1·5 + 6 and 3 + 12 mg dm^?3) or diethofencarb + carbendazim (2·5 mg dm^?3 each) were applied. Yields of cucumber fruits of the common parthenocarpic cv. Kasem 292 were weighed. There was no correlation between disease level and yield in any experiment, plot or date except for two measurements. Compesation in fruit production by the plant may be regarded as the reason for no positive yield response to efficient control. The possibility of reducing fungicide application is discussed. Control of grey mould on tomato resulted in yield increase.     

Mating type and sexual reproduction of <Emphasis Type="Italic">Pseudoperonospora cubensis</Emphasis>, the downy mildew agent of cucurbits

The oomycete Pseudoperonospora cubensis is a leaf pathogen causing severe damage to members of the Cucurbitaceae, especially cucumber and melon. It propagates clonally by sporangia. Oospores of P. cubensis were previously observed in nature but their formation in the laboratory was never reported nor their germination or infection. Here we report on the sexual reproduction of P. cubensis under controlled conditions in the laboratory. When field isolates were inoculated singly onto detached leaves of cucurbits in growth chambers no oospores were produced. However, when pairs of selected isolates were mixed and inoculated onto detached leaves, oospores were formed in the mesophyll within 6–11 days, suggesting that P. cubensis is heterothallic, having two opposite mating types, A1 and A2. Isolates belonging to pathotype 3 were all A1 whereas isolates belonging to the new pathotype 6 were either A1 or A2. Oospores were spherical, ~40 μm in diameter, hyaline to red-brown in color. Oospores were produced regularly, in large numbers, in Cucumis sativum and Cucumis melo, very seldom and in very small numbers in Cucurbita pepo, Cucurbita maxima and Citrullus lanatus, and not in Cucurbita moschata. Oospores were formed at 12.5–21°C but not at 25°C. Under moisture-saturated atmosphere oospores were also produced in leaves of intact plants. Oospores inoculated onto detached leaves in growth chambers produced F1 downy mildew lesions at 6–21 days after inoculation, many in Cucumis sativum, Cucumis melo and Cucurbita moschata, very few in Cucurbita pepo or Citrullus lanatus, and none in Cucurbita maxima. This report shows that P. cubensis is heterothallic, having A1 and A2 mating types which can cross and enable sexual reproduction in cucurbits. A preliminary report on part of the results has been published earlier.