2010年湖北省下半年农作物病虫害发生趋势

湖北省植物保护总站根据16个市州及30多个区域测报站调查的病虫发生基数,结合历史资料、耕作制度、品种布局、作物长势和气象条件等因素,综合分析了下半年农作物病虫发生趋势。预计下半年湖北省农作物病虫害总体呈偏重发生趋势,其中主害代稻飞虱,二化螟,中、晚稻纹枯病大发生;稻纵卷叶螟、棉花枯黄萎病、盲蝽象等病虫害中等偏重发生,部分稻区的“两迁”害虫,局部稻区的细菌性基腐病、褐条矮缩病,部分高感品种上的稻瘟病、稻曲病有暴发风险。     

湖北省2017年下半年农作物病虫害发生趋势

2017年6月26日～28日,省植保总站在枝江市举行全省下半年农作物病虫害发生趋势会商,根据各区域测报站调查的病虫基数,结合全省历史资料、耕作制度、品种布局、作物长势和气象条件等因素,综合分析下半年农作物病虫害发生趋势.预计下半年水稻病虫害总体呈中等至偏重发生趋势,其中主害代“两迁”害虫、二化螟、纹枯病等病虫害偏重发生,局部稻区有大发生的风险,感病品种上的稻瘟病、稻曲病大流行风险较高;玉米螟、玉米纹枯病、大斑病、小斑病感病品种偏重发生;棉盲蝽、枯萎病、黄萎病、伏蚜局部偏重发生;果茶作物上,茶小绿叶蝉和柑橘红黄蜘蛛、茶尺蠖、柑橘煤烟病、柑橘炭疽病等局部偏重发生,其它病虫害中等或偏轻发生.     

湖北省2022年下半年农作物病虫害发生趋势

6月29日～7月1日,省植保总站组织17个市、州,相关县(区)植保站(局)和相关专家对下半年全省农作物病虫害发生趋势进行了会商,根据各地调查的病虫基数,结合病虫发生规律、种植结构、作物长势及气象等因素综合分析,预计下半年我省农作物主要病虫总体呈中等至偏重发生。其中,二化螟、纹枯病等常规病虫偏重发生;稻飞虱主害代偏重发生;稻纵卷叶螟偏轻至中等发生;稻瘟病在山区丘陵常发区和感病品种上、稻曲病在迟熟中稻上,局部流行几率高。草地贪夜蛾在夏玉米上中等发生,在迟播夏玉米、秋玉米上大发生。棉花、柑橘、茶树、蔬菜等作物上病虫害大部分发生平稳,与常年相当。     

2009年下半年农作物病虫害发生趋势

6月20～21日全省下半年农作物病虫害发生趋势会商会在仙桃市召开,根据各区域监测站调查的病虫发生基数,结合历史资料、耕作制度、品种布局、作物长势和气象条件等因素综合分析,预计下半年我省农作物病虫害总体呈偏重发生趋势,其中主害代稻飞虱、稻纵卷叶螟,中、晚稻纹枯病大发生;二化螟、山区常发区的稻瘟病、优质稻稻曲病、棉花枯黄萎病、盲蝽象等病虫害中等偏重发生,部分地区的稻飞虱、稻纵卷叶螟和部分优质稻上的稻瘟病、稻曲病将有暴发成灾的风险.     

湖北省2023年下半年农作物病虫害发生趋势

6月28日～29日，省植保总站组织17个市(州)、相关县(市、区)植保站(局)和相关专家对下半年全省农作物病虫害发生趋势进行了会商。根据病虫基数、发生规律、气象等因素综合研判，预计下半年我省水稻主要病虫呈偏重发生态势，局部有大发生的风险，发生程度重于近年同期。其中，主害代稻飞虱、稻纵卷叶螟、二化螟、纹枯病偏重发生，稻瘟病、稻曲病等气候性病害局部偏重发生风险高。草地贪夜蛾在夏玉米上中等发生，在迟播夏玉米、秋玉米上大发生。棉花、柑橘、茶树、蔬菜等作物病虫发生程度与常年相当。     

湖北省2013年下半年农作物病虫害发生趋势预报

6月18日～19日,湖北省植保总站在钟祥市召开全省下半年农作物病虫害发生趋势会商会,各市、州植保站及区域测报站参加会议.会议根据各区域监测站调查的病虫发生基数,结合历史资料、耕作制度、品种布局、作物长势和气象条件等因素,综合分析了下半年农作物病虫害发生趋势.预计下半年全省农作物主要病虫害总体呈偏重发生趋势,虫害重于病害,其中主害代稻飞虱,中、晚稻纹枯病大发生;稻纵卷叶螟、二化螟、玉米螟、盲蝽蟓等病虫害偏重发生,部分高感品种上的稻瘟病、稻曲病有暴发风险.     

四川省今年农作物病虫害预计总体偏重发生

根据农作物病虫基数、品种布局以及气侯趋势,结合病虫历年发生情况等因素综合分析,四川省植保站近期预计2012年全省农作物病虫害总体偏重发生（4级）,发生面积1．8亿亩次。其中,小麦病虫中等发生（3级）,发生面积2000万亩次;油菜病虫害偏重发生（4级）,发生面积1200万亩次;水稻病虫偏重发生（4级）,发生面积6500万亩次;玉米病虫中等发生（3级）,发生面积1900万亩次。以条锈病、赤霉病、麦蚜、油菜菌核病、稻瘟病、稻曲病、水稻螟虫、稻飞虱、玉米螟和西藏飞蝗等为主。     

2008年湖北省下半年农作物病虫害发生趋势预报

6月17~18日,湖北省植保总站组织16个市、州及区域监测站就下半年全省农作物病虫发生趋势进行了会商,根据当前病虫发生基数,结合历史资料、耕作制度、品种布局、作物长势和气象条件等因素综合分析,预计下半年我省农作物病虫害总体呈偏重发生趋势,其中主害代稻飞虱、稻纵卷叶螟、     

广西2015年农作物主要病虫害发生概况

2015年,广西主要农作物病虫草鼠害总体发生程度为中等偏重,发生程度与上年基本持平,其中水稻病虫害略轻,果树病虫害偏重,其他基本持平.稻飞虱、稻纵卷叶螟、稻纹枯病、稻瘟病、柑橘红蜘蛛等主要病虫仍是监测防控的主要对象.     

2005年下半年湖北省农作物病虫害发生趋势

根据6月29日～30日在石首市召开的全省农作物病虫发生趋势会商会结果,结合当前病虫基数、历史资料、耕作制度、品种布局、作物长势和气象条件等因素综合分析,预计下半年湖北省农作物病虫害总体呈偏重发生趋势,其中主害代稻飞虱、稻纵卷叶螟、第2代二化螟、中稻纹枯病、第4代棉铃虫、棉花红蜘蛛、斜纹夜蛾、棉花枯黄萎病等病虫害将呈中等偏重以上程度发生（4～5级）,局部地区的稻飞虱、稻纵卷叶螟和部分优质稻上的穗期综合症将有可能暴发成灾。     

Viruses of pepper in plastic houses in Crete

During a survey of virus diseases affecting pepper grown in plastic houses in Crete, during 1984–1986, tomato mosaic virus (ToMV) and tobacco mosaic virus (TMV) were detected. The most common virus was TMV, being present in samples of alle pepper cultivars carrying the L₁ resistance gene, while ToMV was isolated only from susceptible pepper cultivars. According to responses ofCapsicum spp. the isolates from 640 samples checked were classified into three pathotypes: P₀, P_1.2 and P_1.2.3. Results of this study show that P_1.2 represents at present the major threat to the Cretan pepper industry.Samenvatting Bij een in de jaren 1984–1986 gehouden inventarisatie van virusziekten in paprika in plastic-foliekassen op Kreta werd zowel het tabaksmozaïekvirus (TMV) als het tomatemozaïekvirus (ToMV) aangetoond. TMV kwam zeer algemeen voor: het werd aangetroffen in alle monsters van de paprikarassen met het resistentiegen L₁. ToMV werd alleen geïsoleerd uit planten van vatbare paprikarassen. Volgens de waargenomen symptomen die de isolaten van 640 monsters opCapsicum spp. vertoonden, konden de isolaten in drie pathotypen, nl. P₁, P_1,2 en P_1,2,3, worden geklassificeerd. Uit het onderzoek is gebleken dat P_1,2 de belangrijkste bedreiging vormt voor de teelt van paprika op Kreta.     

Effectiveness of native parasitoids of Myzus persicae in greenhouse environments in India

Myzus persicae (Sulzer) is an economically important agricultural pest with over 500 known host plants in the world. The present study recorded the major parasitoids found parasitizing M. persicae on sweet pepper (Capsicum annuum [L.]) crops in greenhouses in Himachal Pradesh, India. Three species of hymenopteran parasitoids were reared from M. persicae from this source: Aphelinus asychis Walker (Aphelinidae), Aphidius matricariae Haliday (Braconidae), and Aphidius ervi (Haliday) (Braconidae), with parasitism rates per sample date ranging from 2.3–38.6%, 4.8–58.2%, and 2.9–28.4%, respectively, during 2011–2012. This is the first report of parasitoids associated with M. persicae in greenhouse environments in India. The present findings suggest that the management of M. persicae could be possible with the addition of augmentative releases of these parasitoids, which should help reduce pesticide use in Indian vegetable production greenhouses.     

Frequency of Avirulence Alleles in Field Populations of Leptosphaeria maculans in Europe

This paper describes the first large-scale Europe-wide survey of avirulence alleles and races of Leptosphaeria maculans. Isolates were collected from the spring rape cultivar Drakkar, with no known genes for resistance against L. maculans, at six experimental sites across the main oilseed rape growing regions of Europe, including the UK, Germany, Sweden and Poland. Additionally in Poland isolates were collected from cv. Darmor, which has resistance gene, Rlm9. In total, 603 isolates were collected during autumn in 2002 (287 isolates from Germany and the UK) and 2003 (316 isolates from Poland and Sweden). The identity of alleles at eight avirulence loci was determined for these isolates. No isolates had the virulence allele avrLm6 and three virulence alleles (avrLm2, avrLm3 and avrLm9) were present in all isolates. The isolates were polymorphic for AvrLm1, AvrLm4, AvrLm5 and AvrLm7 alleles, with virulence alleles at AvrLm1 and AvrLm4 loci and avirulence alleles at AvrLm7 and AvrLm5 loci predominant in populations. Virulent avrLm7 isolates were found at only one site in Sweden. Approximately 90% of all isolates belonged to one of two races (combinations of avirulence alleles), Av5-6-7 (77% of isolates) or Av6-7 (12%). Eight races were identified, with four races at frequencies less than 1%. The study suggested that Rlm6 and Rlm7 are still effective sources of resistance against L. maculans in oilseed rape in Europe. The results are comparable to those of a similar survey done in France in autumn 2000 and 2001.     

Effects of temperature onPhytophthora porri in vitro,in planta,and in soil

Cardinal temperatures for mycelial growth ofPhytophthora porri on corn-meal agar were <5 (minimum), 15–20 (optimum) and just above 25 °C (maximum). The number of infections after zoospore inoculation of young leaf plants was relatively low at supra-optimal temperatures, but was not affected by sub-optimal temperatures. Even at 0 °C plants were infected. The incubation periods needed for symptom formation were 36–57 d at 0 °C, 13–18 d at 5 °C, and 4–11 d at > 11 °C, and were fitted to temperature between 0 and 24 °C with a hyperbolical model (1/p=0.00812^*T+0.0243). Oospore germination, reported for the first time forP. porri, was strongly reduced after 5 h at 45 °C, and totally absent after 5 h at 55 °C. Soil solarization for six weeks during an exceptionally warm period in May–June 1992 in The Netherlands raised the soil temperature at 5 cm depth for 17 h above 45 °C, but did not reduce the initial level of disease in August significantly.     

Inheritance of virulence in Fusarium circinatum,the cause of pitch canker in pines

Wildtype strains of Fusarium circinatum, the causal agent of pitch canker, were crossed to obtain an F₁ generation. Progeny of this cross were tested for virulence by inoculating Pinus radiata seedlings, and were found to induce a wide range of lesion lengths. Two strains from the F₁ generation that induced long lesions (= high virulence) were used as parents to produce an F₂ generation, followed by a second round of selection for high virulence to obtain an F₃ generation. Mean lesion lengths were not significantly different between the three generations (P ≥ 0.196). A parallel set of crosses was performed to select for low virulence by using progeny in the F₁ and F₂ generations that induced short lesions as parents for F₂ and F₃ generations, respectively. In this case, both rounds of selection resulted in a significant reduction in mean lesion length, from 33.8 ± 0.8 mm in the F₁ generation, to 19.7 ± 0.7 and 12.9 ± 0.7 mm in the F₂ and F₃ generations, respectively. Thus it is apparent that F. circinatum retains the genetic capacity for avirulence to pines, which could reflect a lack of strong selection for virulence in nature. Progeny of a cross between high and low virulence parents manifested nearly continuous variation in lesion lengths, consistent with virulence being a quantitatively inherited trait. Based on this cross, broad‐sense heritability (H²) was determined to be 0.74, which suggests that virulence is under strong genetic control.     

Overproduction of reactive oxygen species involved in the pathogenicity of Fusarium in potato tubers

Differences in virulence between Fusarium sulphureum and Fusarium sambucinum were compared. Changes in reactive oxygen species production and metabolism in inoculated slices of potato tubers were also compared. The result showed that Fusarium infection induced significant production of ROS, lipid peroxidation and loss of cell membrane integrity, but low activity of superoxide dismutase (SOD) and ascorbate peroxidase (APX). Compared to F. sambucinum, F. sulphureum led larger lesion diameters on potato tubers and slices. It resulted in more superoxide anion ($O_2^{-}$) and earlier peak of hydrogen peroxide (H₂O₂), but lower activity of catalase (CAT) and APX, and accompanied with higher malondialdehyde (MDA) content and lower cell membrane integrity. These findings suggested that overproduction of ROS involved in the pathogenicity of Fusarium in potato tubers.     

Mechanism of hydantoin ring opening in iprodione in aqueous media

The hydrolysis kinetics of iprodione in alkaline solutions of pH 8.3 to 12 at 25°C have been determined by ultraviolet spectrophotometry. Under these conditions, iprodione leads quantitatively and irreversibly to N-(3,5-dichloroanilinocarbonyl)-N-(isopropylaminocarbonyl)glycine. The reaction is not subject to a general basic catalysis and the rate law takes the form K_obs = K_OH- [OH^?1]. The activation entropy of -77 J mol^?1deg^?1, the value of the kinetic solvent isotope effect k_OH?/k_OD? of 0.79 and the value of 0.60 for the Hammett parameter σ, obtained for the hydrolysis of a series of 3-aryl-N-isopropyl-2,4-dioxoimidazolidine-1-carboxamides are all in agreement with the rate-determining attack by the hydroxyl ion on the carbonyl in the 4-position of the hydantoin ring of the fungicide.     

Aetiology of Rhizoctonia in sheath blight of maize in Sichuan

Rhizoctonia isolates obtained from maize grown in commercial fields in 33 representative counties (or cities) in Sichuan province in China were characterized according to colony morphology, hyphal anastomosis and pathogenicity. Of 141 isolates, 116 were identified as R. solani , 23 as R. zeae and two as binucleate Rhizoctonia . The isolates of R. solani were assigned to four anastomosis groups (AG): AG-1-IA (101 isolates, accounting for 71.6% of the total), AG-1-IB (2, 1.4%), AG-4 (9, 6.4%) and AG-5 (4, 2.8%). The two isolates of binucleate Rhizoctonia belonged to AG-K. On maize, isolates of AG-1-IA caused typical sheath blight symptoms. Lesions produced by isolates of AG-4, AG-5, AG-1-IB and AG-K were darker than those of AG-1-IA. Rhizoctonia zeae usually caused discontinuous lesions with a dark brown margin and a brown centre on the leaf sheaths, as well as ear rot. Isolates of AG-1-IA were the most virulent to maize, with an average lesion length of approximately 15 cm. Isolates of R. zeae produced lesions approximately 12 cm long, while those of AG-4, AG-5, AG-1-IB and AG-K were progressively shorter. On potato dextrose agar (PDA; pH 6.4), the minimum temperature for mycelial growth of R. zeae isolates was 14–18°C, the maximum 38–40°C and optimum 30°C. Isolates of R. zeae did not grow on PDA (28°C) at pH 2.0, the optimum for growth being pH 6.4.     

Viruses of tomato in plastic houses in Crete

Tomatoes grown in plastic houses in Crete have been inspected since 1980 for virus diseases. Plants with virus-like symptoms were checked by sap inoculation to test plants and the isolated viruses were identified by host reaction and serology. The most common viruses were, in order of frequency, tomato mosaic virus (ToMV), potato virus X, tomato bushy stunt virus (TBSV), potato virus Y and cucumber mosaic virus. The large use of ToMV-resistant cultivars reduces gradually the importance of ToMV while TBSV tends to become a serious problem of tomato in Crete.Samenvatting Van 1980–1984 werden op Kreta de in plasticfolie-kassen geteelde tomaten geïnventariseerd op de aanwezigheid van virussen. Verdachte plante werden door sapinoculatie op toetsplanten onderzocht. De daarbij geïsoleerde virussen werden daarna via de symptomen op de waardplanten en serologisch geïdentificeerd. In volgorde van belangrijkheid werden de volgende virussen het meest aangetroffen: tomatemozaïekvirus, aardappelvirus X, tomatedwerggroeivirus, aardappel Y virus en komkommermozaïekvirus, De laatste jaren is door de toenemende teelt van tomaterassen met resistentie tegen tomatemozaïekvirus het belang van dit virus sterk verminderd, terwijl het tomatedwerggroeivirus een steeds ernstiger probleem lijkt te worden.     

Invasiveness of agronomic weed species in wheat in Western Australia

Weed seeds are introduced to agronomic systems naturally or through human-mediated seed dispersal, and introduced seeds have a high chance of being resistant to selective, in-crop herbicides. However, colonisation (invasion) rates for a weed species are usually much lower than rates of seed dispersal. The current research investigated colonisation of a winter annual wheat cropping system in Western Australia by a range of winter or summer annual weed species. The weed seeds were sown (at 100 seeds/m²) directly before seeding the crop in 2016 and allowed to grow in the following 3 years of wheat. Selective herbicides were not applied, to simulate growth of weed populations if the initial seed had been resistant to herbicide. Bromus diandrus, Hordeum leporinum, Rumex hypogaeus, Sonchus oleraceus, Polygonum aviculare, Lolium rigidum, Citrullus amarus and Tribulus terrestris colonised the crop, while Dactyloctenium radulans, Chloris truncata and Salsola australis failed to establish over 3 years. The most successful weed was B. diandrus, with a plant density of 1,170/m² by the third year and seed production of 67,740/m². The high density of B. diandrus reduced wheat density by 76% in the third year and reduced average yield by 36%. Lolium rigidum reduced average yield by 11%, and the other weed species did not affect crop yield. Further research is required on the invasiveness of these species in other regions, but it is clear that the spread of B. diandrus to new areas or the introduction of resistant B. diandrus seeds via contaminated grain should be avoided.