Oviposition and larval performance of Monochamus alternatus (Coleoptera: Cerambycidae) on the Japanese cedar Cryptomeria japonica

To determine whether Monochamus alternatus can use the Japanese cedar (Cryptomeria japonica) as a host tree, experiments were conducted in a laboratory using three insect populations of different localities. Adult females chose Pinus densiflora bolts as oviposition substrate when supplied with cedar and pine bolts simultaneously, whereas some females from one locality oviposited on cedar bolts when supplied with them exclusively. Seventy-three percent of 40 eggs hatched in cedar bolts. When the first instar larvae were inoculated on cedar bolts, the development was stunted greatly and all died during the larval stage. Two of 20 larvae that were inoculated on cedar bolts at the third instar entered the diapause and one larva developed into an adult female, which produced viable eggs but was much smaller than those obtained from pine bolts. The results did not exclude the possibility that M. alternatus can use recently killed C. japonica trees as a host.     

10个红掌品种在生产上的表现

叙述了在云南西双版纳网棚基质栽培条件下,10个红掌品种的生长和产花表现,讨论了商业品种选择和抗病品种选育对云南热区发展红掌商业种植的重要性。     

杉木种子园球果病虫害监测研究

经调查统计,杉木种子园健康果、发育不良果、病害果、虫害果、病虫兼有果比例分别为55.1%、3.4%、8.4%、9.0%、24.1%,各无性系之间球果产量、不健康果比例,百果重、千粒重、出粒率、发芽率都达到极显著差异水平。球果病虫危害率与球果产量、球果出籽率、种子发芽率之间存在极显著负相关,病虫危害是种子园种子产量下降的主要原因之一。用1%波尔多液或500倍敌克松溶液喷洒种子园接株,效果十分理想,病虫危害可以控制在10.0%以内。     

Seedborne Fusarium on Douglas-fir: Pathogenicity and seed stratification method to decrease Fusarium contamination

Twelve Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlots from coastal British Columbia were assayed for seedborne Fusarium. All of the seedlots were contaminated with Fusarium. Percent of nonstratified seeds from individual seedlots harboring Fusarium ranged from 0.3% to 95.4%. Sixty-seven percent of the seedlots had Fusarium on less than 2% of the seeds. Post-stratification seedborne Fusarium levels were significantly less for running water imbibition compared to standing water imbibition. However, seedling growth at a container nursery was not consistently different for stratified seed imbibed initially in standing or running water. Fusarium disease symptoms were not observed in the nursery environment. The species of Fusarium isolated from seed were F. acuminatum, F. avenaceum, F. lateritium, F. moniliforme, F. oxysporum, F. poae and F. sambucinum. Twelve Fusarium isolates, comprising six species, were assessed for pathogenicity. Disease symptoms were observed after four weeks incubation and Fusarium isolates ranged in virulence from low to high. Fusarium oxysporum isolates were the most pathogenic.     

冬枣黑斑病发生规律的研究

报道了山东省近年来发生的一种新病害-冬枣黑斑病。该病在山东境内冬枣栽培区均有分布,主要危害叶片和果实,一般病果率在30％左右,感病重的枣园达80％以上;病原茵以茵丝在枣树牙鳞和皮痕内越冬,可通过伤口和自然孔口侵入,25℃下潜育期7天左右;7月下旬、8月上旬为发病盛期;病害的发生与气候、树龄、枣园种植结构、昆虫危害等因子密切相关。     

药剂防治橡胶树外褐型死皮病试验

三种药物防治橡胶树割线外褐型死皮病3年的试验结果:B药物防效最好,防效为69.5%和70.4%,干胶净增产率5.2%;其次为“保-01”,防效为49.9%和43.8%,干胶净增产率9.1%;最差为A药物,防效为3.5%和26.8%,干胶净增产率0.1%,     

山区杨树人工林树干病害综合防治的研究

杨树干部病害是杨树人工林的主要病害之一。侵染性病原有污黑腐皮壳菌(Valsa sordida)和小穴壳菌(Dothiorella g(?)egaria)。本文指出了7个诱病因子,提出化学药物和营林技术防治这种病害的具体措施。     

百合真菌性病害化学防治方法的研究

从百合种球消毒、圃地消毒、药剂防治方面开展百合真菌性病害化学防治试验。结果表明,联合运用圃地消毒和种球消毒,可以有效地预防百合真菌性病害初次侵染发生,采用25%的蓝点可湿性粉剂1 200倍液、1 500倍液,80%的云生可湿性粉剂600倍液,10%世高水分散粒剂1 000倍液防治百合真菌性病害能取得较好的防治效果。     

石榴溃疡病害病原学研究

对石榴溃疡病害3菌株所引起的病害症状、病原菌的形态学特征、培养学特性、生理学特性及分子遗传多样性等方面进行比较研究.结果表明:石榴疮痂病与石榴果实上增生型症状的病原菌具有更近的亲缘关系,应为同一病原菌引起,推测该病原菌首先侵染石榴侵染枝干,然后侵染石榴的花萼和果实;而石榴干腐病病原菌主要侵染枝干,是否侵染果实及引起症状特征需要继续进行研究和鉴定.