Occurrence and comprehensive control of gum disease of Lycium barbarum

Brown disease spot and gray-white mold layer appeared on the branches after 15 days, and no disease was found in other inoculated bacteria. This result is consistent with the research results of Ningxia Academy of Agricultural Sciences. According to the characteristics of field symptoms and the results of isolation, it is considered that Cladosporium is the pathogen of rheumatosis, and Streptomyces and Fusarium are saprophytic bacteria of secondary infection.

3The regularity of disease.

3 1 pathogen overwintering and its transmission route

In November, the structural phase branches with disease spots were placed in the surface and underground 20m-30Cm soil of the field, respectively, and were collected and isolated in April of the following year. The results showed that Xanthomonas aeruginosa could survive the winter in 20-3OCm soil with a survival rate of 20%-30%, indicating that the bacteria could survive the winter not only on diseased plants in the field, but also in soil with residues of diseased plants, becoming the main source of primary infection.

32 the relationship between soil and disease

Generally, the incidence of planting in sandy loam is lower than that in saline-alkali soil. According to the survey, the incidence rate of planting in sandy loam is only 32%, and the incidence is 37.5% in saline-alkali soil, especially in newly reclaimed saline-alkali land, the incidence rate can be as high as 73.8%.

3. The relationship between climatic conditions and morbidity.

In general, the disease is more serious in spring and autumn, which is related to the climatic conditions in Northwest China. The temperature in spring is between 15-25C, which is not conducive to the growth of bacteria and the incidence is low. In the mature period of fruit in autumn, the temperature is 22-25C, the rainfall is more than that in spring and summer, and the incidence is higher. Therefore, rainy and suitable temperature are the main factors affecting the disease.

3 4 the relationship between other diseases and insect pests and disease

According to the investigation, the trees with higher population density of thin pupae, aphids and shell insects have weaker tree potential, more tree wounds, serious gum disease and mixed with other diseases. At the same time, stick trees with serious sarcophagus powdery mildew and anthracnose were found in the field, and gum disease occurred seriously in the middle and later stages of growth. Therefore, the occurrence of other diseases and insect pests leads to the weakening of tree potential and the decrease of disease resistance, which is also the main inducement of gum disease.

4 integrated prevention and control technology

4 1 choose a suitable garden site

Jibai is resistant to salt and alkali, but it is too saline-alkali, or the soil is sticky, the drainage is poor, the groundwater level is high, and the incidence is high, so this kind of soil is not suitable for planting. Generally, it is better to choose sandy soil with salt content less than 0.33%.

4 2 cultivate strong seedlings and enhance the tree potential

421 rational fertilization is sensitive to water and fertilizer. in order to make the fertilizer mature fully in the soil and give full play to its effect, all kinds of mature farm manure are generally applied from late October to November. That is, at a distance of about 0.3-0.5 m on one side of the tree, half of the circular ditches are dug to cover the soil with human fertilizer and irrigated. In the second year, the other side of the tree was ditched and fertilized. From May to June, it is necessary to apply nitrogen fertilizer 2-3 times, about 150-1OOg per plant.

422 reasonable ploughing in the garden in order to prevent the consolidation of the garden soil, turning the garden and drying the soil twice a year to increase the ability of soil ventilation and soil moisture conservation and promote the development of the root system. The first time after the land was thawed in early spring, 12-15cm was dug shallowly, and the second time before winter irrigation or August, the depth was 21-25Cm. During the growing period, attention should be paid to weeding in the middle tillage, and the depth of the middle tillage is about 6-10cm.

423 reasonable pruning to enhance tree potential is the key measure of disease resistance. Generally, after the plant sprouts in April, the new shoots are pruned in spring, mainly by pruning dead branches, and in summer from May to August, mainly by pruning overgrown branches, intermediate branches and dense branches, and properly cutting off the first and second fruiting branches to facilitate the cultivation of new fruiting branches and a bumper harvest in autumn. Autumn pruning was carried out from October to November, cutting off withered branches, disease and insect branches and only growing branches.

4 3 scrape the bark

When the gum spot was developed to the ulcer stage, scrape off the bark and apply 10% Shuangxiaoling solution or 12.5% solution of 90O@L Ye Kuning, the therapeutic effect reached 75.3% and 70.8%.

4 4 chemical spray control

In the early stage of the disease, 64% disinfectant alum 10O@t solution, 50% carbendazim wettable powder solution 10% solution. 50% carbendazim 2%-10% solution was smeared on the disease spot, and then combined with 64% disinfectant alum 0.125% solution, 50% kuntui special wettable powder solution 0.1% solution, 50% carbendazim 0.125% solution leaf surface, branch spray, the control effect can reach more than 85%. At the same time, after sprouting in spring, 40% dimethoate 0.1% lSo@1 solution or 50% malathion 0.1%-0.05% solution was sprayed to control thin pupae and aphids in order to improve tree potential and enhance disease resistance.