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1.
2002年6月,湖北省长阳县火烧坪高山反季节蔬菜基地大面积萝卜田突发黑斑病。病情发展迅速,为害损失严重。6月份发生面积达1万亩以上。其中毁茬超过80亩,产量损失达50%以上的面积约2000亩,损失20%～50%的约3000亩。8～9月该病又流行,发病面积成倍增加。春、夏两季发病面积4万亩以上,萝卜产量损失超过3万t,直接经济损失2000万元以上。针对蔬菜生产中出现的这一新问题,笔者请有关专家进行了病原鉴定,并对发生情况进行了初步的调查和观察。1症状初步观察该病发生在萝卜叶片上。病斑初起于叶片背面,为水渍状绿色斑块,一般不突破叶脉表现为角斑。… 相似文献
2.
1990年我县马铃薯晚疫病大流行,发生面积14.5万亩,其中发病程度达四级的8.1万亩,占总发生面积的55.9%,发病程度2～3级的6.4万亩,占总发生面积的44.1%,总平均减产损失15%,总计损失马铃薯3.3万吨(烂薯),折经济损失456.8万元。其大流行的原因:一、气象条件适宜,有利发病1990年6月下旬至7月底40天总降雨量289.8毫米,比近20年(1970～1989年)平均值多140.6毫米;雨日24天,比20年平均多4.5天;空气相对湿度76.2%,偏高平均值 相似文献
3.
稻曲病(Ustilaginoidea virens.)是近年来上升的一种重要病害,过去仅在山区一季中、晚稻上偶有零星发生。近年来,特别是桂朝二号等感病品种的引进和扩大种植,发病面积不断扩大,为害程度逐年加重。1981年赣南全区据18个县(市)统计,二季晚稻发病面积达94万多亩,1982年仅16个县(市)发病面积扩展到126万多亩,占二季晚面积的45.7%。病穗率一般4—5%,高的达15%,严重田块达78%。每个病穗有病粒3—4粒,多的达48粒,严重影响水稻的产量与品质。 相似文献
4.
稀点雪灯蛾在保定地区暴发 总被引：2，自引：0，他引：2
稀点雪灯蛾[Spilosoma urticaeEsper)]自1980年以来在保定地区年年都有发生,一般未造成大的危害。但1989年5月底至6月上旬,全区270万亩麦套玉米普遍受到灯蛾危害,发生面积大、来势猛、密度高、损失重。据统计全区严重受害的面积达120万亩,一般虫口密度3—5头/m~2,严重的10头/m~2以上。涞水县13万亩麦套玉米有10万亩被吃光,全区毁种面积达40多万亩。 相似文献
5.
近年来,葡萄白腐病在我市发生普遍,危害重,且有逐年加重的趋势。1988、1989两年累计发病面积6700亩,占栽培面积的80％,一般地块减产20—30％,严重者达60％以上,个别地块几乎绝产,经济损失高达187万元。1990年8月上旬普查全市发病面积已达4000亩,占栽培面积的96％,估计减产30％左右。 相似文献
6.
水稻瘤矮病的发病规律及防治研究 总被引：2，自引：0，他引：2
水稻瘤矮病主要为害晚季稻,尤以杂优稻受害特重,这与杂优稻秧苗田播种量和大田插植苗数较少有关。目前病区未有免疫或高抗品种。早季稻一般受害较轻,仅零星发病,但成为晚季稻的主要侵染源。晚季稻播种后从秧针期开始(播后4-5天)即受侵染。特别是在7月中旬早季稻收割时介体叶蝉被迫大量迁移,秧田的虫数激增,秧苗感染率也激增。愈靠近早稻病田的秧苗感染率愈高。早播早植比迟播迟植发病重。秧苗在6叶龄前最易感染发病,苗龄愈小受害愈重,9叶龄后感染的不发病,所以大田的发病率基本上就是秧苗期的感染率。
防治本病主要抓晚稻秧田下述两项措施:(1)播植期适当推迟7-10天,即在7月中旬播种,8月上旬移植;(2)秧苗田从秧针期开始每4-5天喷药1次,共4-5次,如结合迟播则只需喷药2-3次。1983年的2,670亩防治试验和1984年病区全面推广防治结果,防效极为显著。1984年发病面积仅3.36万亩,为1982年发病面积50万亩的6.7%;发病率在0.5%以下,(1982年一般发病率为20-30%,严重的达98%)基本不造成为害,保产约2,500万公斤。 相似文献
防治本病主要抓晚稻秧田下述两项措施:(1)播植期适当推迟7-10天,即在7月中旬播种,8月上旬移植;(2)秧苗田从秧针期开始每4-5天喷药1次,共4-5次,如结合迟播则只需喷药2-3次。1983年的2,670亩防治试验和1984年病区全面推广防治结果,防效极为显著。1984年发病面积仅3.36万亩,为1982年发病面积50万亩的6.7%;发病率在0.5%以下,(1982年一般发病率为20-30%,严重的达98%)基本不造成为害,保产约2,500万公斤。 相似文献
7.
香蕉花叶心腐病是香蕉的重要病害,危害严重,广东省列为检疫对象。 据报道,本病30年代以前在菲律宾、澳大利亚、巴布亚新几内亚、北婆罗洲及南美洲等地有发生。我国最早于1974年前后在广州市郊、东莞和顺德等地发现,以后不断扩散蔓延,到1987年全省约有10多个市、地,30多个县的蕉园发生,估计发病面积近1万亩,局部地方造成严重为害。梅县地区1987年全区普查,发病面积1338亩,其中发病株率在60—92.5％的有30亩,发病株率50％以下的有1305亩。肇庆地区发病面积660多亩,发病严重的病株率达70％ 相似文献
8.
9.
于2018—2019年以44份不同抗倒性的白菜型冬油品系(种)为试材,依据改良倒伏系数(ILC)法对其抗倒伏性进行聚类分析和评价,探讨白菜型冬油菜株型、茎秆力学特性、干物质积累量等对其倒伏性的影响。结果表明:依据ILC可将白菜型冬油菜参试材料聚为3类:Ⅰ类为强抗倒性材料,包含2个品系(种);Ⅱ类为中等抗倒性材料,包含15个品系(种);Ⅲ类材料抗倒性最弱,包含27个品系(种)。聚类结果与田间倒伏分级结果基本吻合,两者呈极显著正相关(r=0.452~(**)),表明利用ILC评价白菜型冬油菜的抗倒伏性具有可靠性。与Ⅱ类、Ⅲ类材料相比,抗倒性强的Ⅰ类材料株高显著变矮,重心高度显著降低,其平均株高和重心高度比倒伏Ⅲ类材料分别降低19.8 cm和17.8 cm。白菜型冬油菜茎秆抗折力在三类材料间均存在显著差异,抗倒伏Ⅰ类参试材料平均茎秆抗折力是Ⅲ类材料的2.59倍。白菜型冬油菜倒伏系数与株高(r=0.346~*)、地上部鲜质量(r=0.344~*)、重心高度(r=0.579~*)呈显著正相关,与茎秆抗折力(r=-0.518~*)呈显著负相关。与Ⅱ类、Ⅲ类材料相比,Ⅰ类参试材料根长增长38%～41%,根鲜质量增大71%～102%,分枝部位降低32%～44%,一次分枝数增加10%左右、单株角果数增加30%～38%、角果长度增长1%左右、每角粒数增加11%～14%,千粒重增加21%～23%。白菜型冬油菜参试材料抗倒伏性存在显著差异,植株高度、重心高度、地上部鲜质量、茎秆抗折力等是影响其抗倒伏性的关键因素,株高较小、重心高度较低、茎秆抗折力大的白菜型冬油菜品种更高产抗倒伏。 相似文献
10.
宿州市地处皖北 ,下辖 4县 1区 ,西瓜种植历史悠久。 2 0 0 0年全市西瓜种植面积近 5万ｈｍ2 ,达历史最高年份。 2 0 0 0年因多种原因 ,造成西瓜病毒病暴发流行 ,经济损失严重。据市及各县 (区 )植保站 6月上、中旬普查 ,全市西瓜病毒病发生面积达 3 .85万ｈｍ2 ,占种植面积的 82 .4 %,发病株率 90 %以上 ,严重度 3级 (按5级划分 )。 6月 1 0、1 8日市植保站会同植保专家、教授先后调查 桥区 1 2个乡镇西瓜连片种植区 ,病毒病病田率 1 0 0 %,一般田块发病株率 3 2 .4 %～ 97.2 %,平均 91 .3 %,重病田块 85%以上植株难以坐瓜 ,或瓜呈畸形 ,… 相似文献
11.
姜瘟病病原细菌的鉴定 总被引：8，自引：0，他引：8
我国栽培的姜上发现有几种细菌为害,分别引起叶枯、软腐和蔫萎等症状,而一般所谓"姜瘟"是指为害最严重的萎蔫型细菌病害。根据江苏和山东两地姜瘟病细菌的形态、染色反应、生长适温、培养性状、生理生化反应、血清反应和致病性等性状的测定,并与番茄的青枯病细菌进行比较,证明引起姜瘟的细菌是青枯病假单胞杆菌(Pseudomonas soIanacearum(Smith) Smith)。初步交互接种试验证明,姜瘟菌株与番茄青枯菌株的致病性有一定的差异,姜瘟菌株对番茄的致病性很弱;而番茄青枯菌株则不能为害姜。 相似文献
12.
四季豆枯萎病病原鉴定及防治 总被引：2，自引：0，他引：2
从南宁市郊11个病区采集的四季豆枯萎病株标样,经分离培养鉴定和致病性测定,证明其病原菌为尖孢镰刀菌菜豆专化型(Fusarium oxysporum f. sp. phaseoli Kend & Syd)。此病在南宁于4月上中旬四季豆初花期开始发生,5月中下旬盛花至结荚期为发病高峰期。用滤纸碟法进行药效试验的结果,40%灭病威300-500倍液的抑菌圈最大,田间灌根防治也有一定效果。可用种子重量的0.5%多菌灵可湿性粉拌种。品种间抗病性有显著差异,秋抗19号和秋抗6号较抗病。 相似文献
13.
南通棉花枯萎病菌对22个棉花品种致病性的田間和盆栽試驗说明:中棉品种如辽阳一号、鶯湖棉、长丰黑籽、常紫一号、南通白花鸡脚桠鈴果、云南布沼土棉等抗病性比較強,以中棉为母本的中印杂交棉的抗病性也較強;陆地棉和海島棉一般感病程度都較高,但四川选育的陆地棉品种52—128則具有一定的抗病性。将枯萎病菌接种到甘藷等27种作物上,均未感病。五个地区的棉花枯萎病菌致病性的盆栽試驗说明:四川、陝西、辽宁的病原菌致病力較強,江苏的其次,安徽的最弱。以葡萄糖、果糖、半乳糖、甘露糖、乳糖、蔗糖、菊糖、溶解淀粉、阿拉伯糖醇等九种糖和糖醇为碳素营养料时,除四川的病原菌在以半乳糖为碳素营养料时生长中等外,其他都生长旺盛。不同地区病原菌的色素形成、小型孢子、大型孢子和厚膜孢子的产生,随碳素营养料的不同而有所差異。 相似文献
14.
Yonglin He Yuanyuan Chen Yaowen Zhang Xiaofang Qin Xiaolan Wei Dehong Zheng Wei Lin Qiqin Li Gaoqing Yuan 《Plant pathology》2021,70(6):1445-1454
Bacterial wilt, caused by the Ralstonia solanacearum species complex (RSSC), is a destructive plant disease in Guangxi, China. However, the diversity of RSSC populations in the area is unknown. To this end, we performed an extensive bacterial wilt survey from 2015 to 2018. Using phylotype-specific multiplex PCR (Pmx-PCR) and an egl-based tree, 189 strains collected from 20 plant species were identified as R. pseudosolanacearum phylotype I, which included 14 sequevars (12, 13, 14, 15, 16, 17, 18, 30, 34, 44, 48, 54, 70, and 71); two strains isolated from potato plants belonged to R. solanacearum phylotype II, sequevar 1. Sequevars 13, 17, and 44 were prevalent in Guangxi, and sequevar 13 dominated the RSSC sequevars of four Cucurbitaceae plants. The susceptibility of different Cucurbitaceae species to bacterial wilt and the host range of 16 representative strains were further tested. Members of the Cucurbita, Momordica, and Luffa genera were susceptible to bacterial wilt, with wilt incidence ranging from 73% to 100%. Most strains were pathogenic to solanaceous plants, mulberry, and ginger plants but not to melon crops; however, the strains from kidney bean, pepper, and Cucurbitaceae plants were highly virulent to melon crops. This is the first comprehensive report on the genetic and host range diversity of the RSSC in Guangxi and the susceptibility of different Cucurbitaceae species to bacterial wilt, which can provide valuable information for the development of bacterial wilt control strategies. 相似文献
15.
Natural recovery from wilt disease symptoms was evaluated in young olive trees root dip inoculated with Verticillium dahliae in a growth chamber over a 12 week period and, later on, when the trees were transplanted in a V. dahliae-free soil in a lathhouse during a period of 127 weeks. Recovery in an individual tree was considered when a plant showed
symptom remission after having reached a maximum value of symptom severity. Recovery accounted for 53% of 464 trees that showed
wilt symptoms during observations in the two environments. The remaining trees died. Recurrent wilt symptoms were not observed
in recovered trees, and recovery was usually accompanied by the production of new green tissues. Recovery was clearly higher
in trees inoculated with a non-defoliating (ND) isolate (86.4%) of the pathogen than in those inoculated with a defoliating
(D) isolate (23.9%). The percentage of recovery and the level of resistance were significantly correlated. Recovery accounted
for 92.1% of the cases in resistant and moderately susceptible cultivars, reaching 100% in plants inoculated with the ND isolate
(Table 2); meanwhile it was three times lower (30.1% of the plants) in susceptible and extremely susceptible diseased trees.
In the lathhouse, periodical tissue isolations for monitoring the progress of infections over a period of 127 weeks in recovered
trees, showed that the pathogen could only be isolated from trees 19 weeks after inoculation. Pathogen isolation was significantly
higher from susceptible and extremely susceptible cultivars (84.6%) than from resistant and moderately susceptible ones (33.3%).
Results showed that if a tree overcomes infection by pathogen from a single inoculation, and it is able to begin a recovery
process, it will not express wilt symptoms again in a pathogen-free environment. The pathogen remained inactive or dead over
time in recovered trees. Thus, new infections from rootlets would be necessary for new symptom expression. Recovery from Verticillium wilt is an important natural mechanism that occurs in a high percentage of infected olive trees, and can complement the resistance
of the cultivar, particularly in conditions of low inoculum densities of low virulence isolates of the pathogen in the soil. 相似文献
16.
提前接种非致病尖孢镰刀菌防治西瓜枯萎病试验 总被引：3，自引：0，他引：3
将尖孢镰刀菌203株菌系接种在西瓜苗上,从中选出非致病尖孢镶刀菌系109个,分3个类群。用有促生作用,能在西瓜导管定殖的10个代表菌系提前接种,经温室和田间试验,结果表明316和317菌系的防病效果最好。在土壤含枯萎菌量2％条件下,推迟发病7～10天。在土壤含病菌量0.01％条件下,接种后25天,交叉保护防效分别为34.6％和68.2％。防病效果随枯萎菌量的下降而提高。 相似文献
17.
Root-knot nematode [RKN] (Meloidogyne incognita) can increase the severity of Verticillium (V. dahliae) and Fusarium (F. oxysporum f.sp.vasinfectum) wilt diseases in cotton (Gossypium hirsutum). This study was conducted to determine some of the physiological responses caused by nematode invasion that might decrease
resistance to vascular wilt diseases. The effect of RKN was investigated on spore germination and protein, carbohydrate and
peroxidase content in the xylem fluids extracted from nematode-infected plants. Two cotton cultivars were used with different
levels of resistance to both of the wilt pathogens. Spore germination was greater in the xylem fluids from nematode-infected
plants than from nematode-free plants. The effect on spore germination was greater in theFusarium-resistant cultivar (51%). Analysis of these fluids showed a decrease in total protein and carbohydrate levels for both wilt-resistant
cultivars, and an increase in peroxidase concentration. Fluids from nematode-free plants of theVerticillium-resistant cultivar contained 46% more peroxidase than theFusarium-resistant cultivar. The results provide further evidence that the effect of RKN on vascular wilt resistance is systemic and
not only local. Changes in metabolites in the xylem pass from the root to the stem, accelerating disease development. 相似文献
18.
Taro Mori Katsumi Ozaki Hiromi Matsusaki Naotaka Matsuzoe 《Journal of General Plant Pathology》2007,73(2):142-146
To study the behavior and mutation of Ralstonia solanacearum in Solanum toxicarium, which is resistant to bacterial wilt, S. toxicarium was grown in aseptic culture and inoculated with R. solanacearum. Although 60%–80% of the inoculated plants were wilting after 2 to 3 days, most wilted plants had recovered by 20 days after
inoculation. The pathogen was reisolated from over 98% of inoculated plant stems, but the percentage of recovery decreased
the closer the isolation sites were toward the upper stem sections. Three colony types, characterized as fluidal white, nonfluidal
red, and a mixture of fluidal white and nonfluidal red, were reisolated from the stems. Nonfluidal red colonies were less
virulent on tomato plants than fluidal white colonies. 相似文献
19.
Jan-Kees C. Goud Aad J. Termorshuizen Ariena H. C. van Bruggen 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(3):451-465
Verticillium wilt can cause high losses in tree nurseries. To be able to predict disease and unravel disease dynamics over
time and space, the relationship between verticillium wilt and soil inoculum densities of Verticillium dahliae and the nematode Pratylenchus fallax was studied in two 4-year field experiments with Acer platanoides and Catalpa bignonioides in the Netherlands. Best-fit regression equations showed that pre-planting inoculum densities of V. dahliae can be used to predict verticillium wilt over a period of at least 4 years. Pratylenchus fallax contributed significantly to disease severity in A. platanoides in some years. Disease can already occur at the detection limit of the pathogens. The 5% infection thresholds for V. dahliae were at 1 (A. platanoides) vs. 3 (C. bignonioides) colony-forming units (CFU) g−1 soil. Analysis of spatial relationships indicated that diseased plants had a higher influence on neighbouring plants at low
V. dahliae inoculum densities (<5 CFU g−1 soil) than at high densities (≥5 CFU g−1 soil). Seventy-four percent of the diseased plants recovered during the following year. After that year, recovered plants
had a significantly higher probability of becoming diseased again than plants that were healthy during the two previous years,
at high inoculum densities of V. dahliae, indicating that inoculum density in the soil, rather than incomplete recovery, was the most important factor for disease
development. 相似文献
20.
Fusarium oxysporum is a soil borne hyphomycete that causes vascular wilts in several crop plants. A variety of remedial measures such as the use of fungicides, soil amendments and biological antagonists have proved insufficient in controlling F. oxysporum. Ever since it was first reported in banana crop, the only effective control strategy known is planting of resistant cultivars. However, presumably due to the high mutation rates and rapid co-evolution with its host, Fusarium wilt has surmounted host defense barriers and has already begun infecting even the resistant Cavendish varieties that dominate export markets worldwide. Transgenic banana plants showing enhanced resistance to Fusarium wilt have been developed in recent past, but they remain largely confined to the laboratory. The importance of banana as source of food and income in developing countries world over and the need to develop Fusarium wilt tolerant cultivars by novel biotechnological approaches is detailed herein. In this communication, we review the biology and management of Fusarium wilt in banana with the aim of providing the baseline of information to encourage much needed research on integrated management of this destructive banana crop disease problem. 相似文献