向日葵菌核病的防治现状及前景

文章主要论述了向日葵菌核病在我区的发生、分布、危害、及防治的现状和发展前景。

Reasearch on Occurrence Rules of Asian Corn Borer Ostrinia furnacalis in the Field of Waxy Corn

[Objective] This program aimed at providing basis for timely and effective control of Asian corn borer Ostrinia furnacalis in waxy corn fields through investigations and researching on occurrence and damage characteristics of Ostrinia furnacalis in the main producing area of waxy corn of Shanxi Province.[Method] Attraction and collection of the adults,fixed-points and random investigations on eggs and larvae were the main methods in this research.[Result] Ostrinia furnacalis appeared in two generations per year in the field of waxy corns,the generations were basically nonoverlapping with significant interval.The peak period of the overwintering generation adults in the field of waxy corn was early to middle of June,peak period of the first generation adults was from early August to late August;peak period of the first generation eggs was from the end of early June to the binning of late June,the peak period of the second generation eggs was from the middle of early August to late August.Egg-laying performances of Ostrinia furnacalis on waxy corns in different growth period suggested that the temptation of waxy corns to egg-laying of Ostrinia furnacalis had gradually increased with the continuation of growth stages before the heading of waxy corns;while after the heading of waxy corns,the temptation of waxy corns to egg-laying of Ostrinia furnacalis had gradually reduced with the continuation of growth stages.The amount of eggs on waxy corns was more than eggs on normal corns with the same growth period and growth conditions.The first generation of Ostrinia furnacalis caused more serious damages than the second generation.The first generation larvae caused more serious damages on waxy corns with early sowing period than with middle sowing period,while the late sowing fields basically uninjured.The early sowing and middle sowing corns were damaged but lightly,due to the slight occurrence of the first generation larvae.The second generation larvae caused more serious damages in late sowing waxy corn field than in middle sowing waxy corn field.As the early sowing waxy corns were harvested before the beginning of damage peak period of the second generation larvae,they were basically uninjured or slightly damaged by the second generation larvae in general years.Because the second generation larvae were in large-scale occurrence,they had caused serious damages to late and later middle sowing waxy corns.Incidence of ear rot disease on the female ears of waxy corns was closely related to the damages of Ostrinia furnacalis on ears,which was higher on the ears infested by Ostrinia furnacalis.[Conclusion] Comprehensive control on the second generation of Ostrinia furnacalis in the mid and late sowing field of waxy corn should be strengthened.

Advance in Rice Bacterial Leaf Streak Researches

Rice bacterial leaf streak,caused by Xanthomonas oryzae pv.oryzicola,is an important bacterial disease in rice-planting areas in South China and Southeast Asian countries.It occurs every year in local areas.This paper reviews the research advance in the occurrence and harms of rice bacterial leaf streak in China,classification of Xanthomonas oryzae and infection characteristics,pathogenic factors and pathogenicity of rice bacterial leaf streak and breeding of bacterial leaf streakresistance rice cultivars.Some issues involved in occurrence and control of rice bacterial leaf streak were presented,and the areas on which the future studies might be focused were discussed.

Risk Assessment of Secondary Geological Disasters Induced by the Yushu Earthquake

The Yushu Ms 7.1 earthquake occurred on April 14,2010 in Qinghai Province,China.It induced a mass of secondary geological disasters,such as collapses,landslides,and debris flows.Risk assessment maps are important for geological disaster prevention and mitigation,and also can serve as a guide for post-earthquake reconstruction.Firstly,a hazard assessment index system of secondary geological disasters in the earthquake region was built in this paper,which was based on detailed analysis of environmental and triggering factors closely related to geological disasters in the study area.GIS technology was utilized to extract and analyze the assessment index.Hazard assessment maps of secondary geological disasters were obtained by spatial modeling and overlaying analysis.Secondly,an analysis of the vulnerability of hazard bearing bodies in the area was conducted,important information,such as, population density,percentage of arable land, industrial and agricultural outputs per unit area were regarded as assessment indices to evaluate socioeconomic vulnerability.Thirdly,the risk level of secondary geological disasters of the area was obtained by the formula:Risk=Hazard×Vulnerability. Risk assessment maps were categorized into four levels,including"low","moderate","high"and"very high".These results show that some urban areas are at very high risk,including Jiegu,Chengwen,Xiaxiula and Sahuteng towns.This research can provide some references and suggestions to improve decisionmaking support for emergency relief and post- earthquake reconstruction in the study area.

Effects of Droughts and Floods on Crops and Preventions in Puyang City

The research analyzed characters of rice/wheat growth and yield structure in Puyang and explored the effects of droughts and floods on the crops. The re-sults showed that droughts and floods had significant effects on crop growth and yield. In Puyang, the relieving and prevention technology of the disasters is con-cluded. Specifical y, it is recommended to make ful use of agricultural climate re-sources in a rational way and select suitable crop varieties according to climate and disaster characters, fol owed by timely sowing and scientific crop arrangement. What＇s more, ploughing should proceed in deeper soil layers and management measures should be optimized to reduce the effects of disasters on crops. In addi-tion to that, disaster index system should be reinforced in terms of establishment, monitoring, warning and prevention to lay scientific foundations and provide refer-ences for safe crop production and preventing and reducing disasters.