核桃枝枯病病原菌鉴定及其生物学特性

In May 2018,a new shoot dieback disease was found in several walnut orchards in Rizhao,Shandong Province.The fungal pathogen was obtained on PDA plate from diseased walnut shoots using a tissue isolation method.The purified fungal isolates formed white to grey colonies on PDA plate and three single spore isolates SDWa1-SDWa3 were obtained.Based on morphological characteristics and analysis of rDNA internal transcribed spacer (ITS),calmodulin (CAL),translation elongation factor 1-α (TEF1) and β-tubulin (TUB) sequences,the fungal isolates were identified as Diaporthe nobilis,a new pathogen on walnut.The test of Koch's rule confirmed that D.nobilis was the pathogen of walnut shoot dieback.To determine optimal growing conditions for the pathogen,its biological characteristics test was conducted.The results showed that the optimal growth temperature and pH value were at 25℃ and pH 5-9,respectively.The optimum carbon source was glucose,and favourable nitrogen source was peptone.     

基于生态管理的山东苹果无袋栽培“依历按需用药”病虫害综合防控方案

山东产区苹果实施无袋栽培首先要选择苹果轮纹病、苹果炭疽病、桃小食心虫、梨小食心虫等果实病虫发生基数较低的果园。实施无袋栽培前,治理果园内外环境,压低病虫基数,防止果园病虫大量繁殖蔓延。在此基础上,依据本地主要病虫害种类及其防治关键时期,设计周年监测与防治预案,即防治历:以10 d为1个周期,监测和预测病虫害的发生动态;当病虫需要用药防治时,选择相应药剂及时防治。苹果无袋栽培的病虫害防控可划分为休眠期、幼果期、雨季和果实采收前4个时期,各个时期的重点防控对象和目标各不相同。休眠期主要铲除在树体和周边环境中越冬的各种病虫,减轻生长期的防治压力;幼果期以防治苹果霉心病、苹果锈病、红蜘蛛、蚜虫、绿盲蝽等为主,兼治其他病虫;雨季以防治苹果轮纹病、苹果炭疽病、桃小食心虫、梨小食心虫为主,兼治其他病虫;采收前,病害以防止弱寄生菌在果面定殖为主,虫害主要防治各种危害果实的害虫。3年来在多个园片试验示范,绝大部分果园病虫果率控制在10%以下。     

山东产区套袋苹果病虫害综合防控“164”农药减施模式的设计与应用

针对山东产区套袋苹果的常见病虫害,设计了病虫害综合防控"164"农药减施模式,即1个重点生态防控期、6个化学防治关键期和4个病虫重点监控期。按"164"减药模式制定适用不同地区和采用不同农药公司药剂种类的具体防控方案,在栖霞、蓬莱等地的果园连续试验2年。结果表明:试验园全年用药9~14药次,与当地常规管理的对照园相比,化学农药使用量减少50%以上;试验园的病虫叶率和病虫果率都控制在5%以内,果园内无落叶现象;病虫防治效果、果实的产量和品质、优质商品果率等项指标,与当地常规管理的对照园无明显差异。     

莱阳地区梨锈病防治适期研究

在山东莱阳地区,梨锈病菌冬孢子角自梨花现蕾期开始陆续成熟,成熟的冬孢子角遇1.5 mm/d以上的降雨,萌发产生担孢子。经2～3次降雨后,冬孢全部萌发,以后不再产生担孢子。梨树初花后35 d内对锈病最敏感,即为防治期。若该期内降雨量大于1.5 mm/次、叶面结露时间长于7 h/次,担孢子即可侵染。其侵染量与梨园周围越冬菌原的数量、降雨持续时间和品种抗病性等因子有关。田间试验表明:担孢子侵染后至病斑显症前(约7 d)是内吸性杀菌剂防治的有效时期。病斑显症后只有少数杀菌剂能抑制病斑扩展,20.67%氟硅唑乳油、10%苯醚甲环唑水分散粒剂和15%三唑酮可湿性粉剂3种药剂在病原菌侵入前喷施能有效地抑制担孢子侵染,持效期约7 d;担孢子侵染后喷药能有效抑制病斑显症,因此,要特别关注梨树初花时第1次降雨后梨锈病的防治。     

苹果枝枯病病原菌鉴定及生物学特性

正苹果(Malus pumila Mill.)是世界上栽培最为广泛的水果之一,由于其生态适应性强、营养价值高、耐贮性好及供应周期长,相当多的国家都将其列为主要消费果品[1],而我国是世界上苹果种植面积最大、产量最高的国家[2]。我国苹果枝干病害以苹果轮纹病和腐烂病为主,近年来随着气候环境的改变,一些新的病害也逐渐产生。2017年7月对烟台市几个苹果果园调查时,发现一种新病害。该病害主要危害苹果枝条,产生褐色坏死病斑,严重时导致枝条枯死,发     

梨黑星病流行时间动态分析

用不同的流行学模型拟合2002年和2003年莱阳地区梨黑星病（Venturia nashicola）的系统监测数据，结果表明：Logistic模型能较好地描述梨黑星病病叶率随时间的变化动态；Gompertz模型能较好地描述平均病斑数随时间的变化动态。根据Logistic模型。梨黑星病的最佳防治时期是在梨树初花期后的60d内。     

福星和尿素对梨黑星病病菌假囊壳形成的影响

梨黑星病是我国梨树的主要病害,分布广泛且危害严重。梨黑星病病菌能以不同的形式越冬,病芽梢一直被认为是主要初侵染来源[1-3],但最近的研究结果表明,梨黑星病病菌有性生殖不需要特殊的条件,假囊壳和子囊孢子在我国北方地区梨园内的越冬病叶上都能形成,子囊孢子是梨黑星病的另一重要初侵染来源,对于某些梨园来说是主要的,甚至是唯一的初侵染菌源[4]。因此,有效控制子囊孢子形成,降低初侵染菌源量,对于控制梨黑星病的发生与流行有重要作用。福星是目前防治梨黑星病的有效药剂,尿素能有效地抑制苹果黑星病菌(Venturia inae-qualis)和柑桔球…     

苹果枝枯病病原菌鉴定及生物学特性

In July 2017, a new shoot dieback disease, caused brown necrotic spots with black granules on the shoots in the late stage, was found in several apple orchards in Yantai, Shandong Province. The fungal pathogen was isolated on PDA plate from the infected shoots using the tissue isolation, which formed white to grey colonies bearing abundant fruiting bodies on Czapek solid media with lactose as carbon source. The purified fungal isolates La1-La3 were obtained from single spore isolation after spore tendrils exuding from pycnidia generated on the plates. This study was to identify and characterize the causal agent . Based on morphological characteristics and analysis of rDNA internal transcribed spacer (ITS), β-tubulin (TUB) and translation elongation factor 1-α (TEF1) nucleotide sequences, the fungal isolates were identified as Lasiodiplodia pseudotheobromae, a new pathogen on apple tree. The test of Koch's rule confirmed that L. pseudotheobromae was the pathogen of this disease. Effects of different temperature, pH value, carbon and nitrogen sources were tested against the growth of isolated fungus in vitro. The results showed that the optimal growth temperature and pH value were at 30℃ and pH 6-9, respectively, while the optimum carbon source was sucrose, and favourable nitrogen sources were sodium nitrate, ammonium nitrate and peptone.     

套袋苹果黑点病的发病诱因、机制与条件

 “套袋苹果斑点病”是套袋果实的重要病害,每年导致3%~10%损失,而“套袋苹果黑点病”是套袋苹果斑点病的一种类型。本研究采用病原菌分离、接种、诱导发病等方法,揭示了黑点病发病的诱因、机制与条件,可为病害的防治提供科学依据。结果表明,诱发套袋苹果黑点病的病原菌是粉红单端孢(Trichothecium roseum);苹果谢花30 d后,幼果上就潜带有大量病原菌;自未喷施过杀菌剂的果园内摘取苹果幼果,在20℃~30℃、100%的相对湿度条件下保湿培养3 d可以诱发黑点病斑;在2周时间内,保湿培养的时间越长,诱发的黑点病斑数量越多;黑点病菌侵入果肉组织后能诱发寄主细胞木栓化,木栓化细胞进一步阻止了病菌的生长与扩展;5月下旬(谢花后30 d)采摘的幼果可诱发产生黑点病斑,但病斑较小;7月上旬(谢花后60 d)苹果果实对黑点病菌最敏感,保湿后诱发的病斑数量最多,形成的病斑大;进入8月份,果实的抗病性明显增强;所测试的9种杀菌剂都能有效抑制黑点病斑的形成,降低果实发病率,但不能完全阻止黑点病斑的形成。苹果果实套袋前,喷施杀菌剂降低果实的带菌量是防治黑点病的重要技术措施。     

蝽类害虫在苹果果实上的危害状及其防控

正茶翅蝽、黄斑蝽、梨蝽等椿象是苹果生长中后期果实上的重要害虫,其危害主要是叮吸果实,吸取果汁,导致果实畸形,成为残次果,失去商品价值。山区果园和周边有山岚林地的果园受害严重,虫果率可高达60%,损失惨重。近成熟期的果实被椿象叮食后,常形成近圆形、先为白色、后变黄色或红色、略凹陷、质地松软的叮吸斑,直径0.5～1.0厘米(图1、图2)。受害严重的叮吸斑表皮组织坏死,叮吸斑上有不规则形状的枯死