After the jujube tree was healed in July and August, fruit drop phenomenon occurred one after another. The jujube of jujube was particularly serious. Through investigation, we found the cause of fruit drop and adopted appropriate prevention and control measures, and achieved good results.
First, the physiological reasons Since June of this year, rain, humidity in the field, suitable for jujube fruit set, a date hanging ten dates, or even more. However, due to the large amount of jujube fruit, the nutrient consumption of the tree body, combined with the rain, the transpiration of the tree body caused a serious lack of tree nutrients. The onset date of jujube fruit is mostly descended from the base of jujube hanging. The diseased part starts from the top of the jujube (handle), and the entire jujube gradually shrinks and withers, forming a gourd shape, and finally falling off. In particular, jujube jujube is still the peak of fruit drop after mid-July and the fruit drop lasts for a long time. Under normal circumstances, jujube trees begin to drop fruit in the young fruit period, but the severity of fruit drop is inextricably linked with climate, management, fertilization, watering, nourishing, soil and other factors. The trees in the jujube garden that do not open, snafu, grow long, and are not airy and light are heavier; fruit content is too single, or there is too much of one element, resulting in malnutrition, leaf hypertrophy, and jujube hanging. Severely, sand lands with poor performance in conservation and jujube gardens with woody jujube hanging results in serious fruit drop due to loss of water and insufficient supply of nutrients.
Second, the disease 1. Ring barrage disease, also known as jujube berry disease, the main endangered jujube fruit, often leading to early fall off of jujube fruit, reduced quality, and even can not eat. The disease mainly occurs in the crisp ripening period of jujube fruit, that is, the color conversion period begins to occur. After the damage of jujube fruit, water-stained light-brown small lesions appeared centered on the lenticels, and the lesions rapidly expanded to reddish-brown, round-shaped spots. There were dark and light color bands on the lesions. The victim's light flesh becomes brown and soft, with sour odor but no bitterness, and can not be eaten; the heavy whole fruit pulp is damaged, resulting in a large number of fruit drop. 2. The onset time of fruit shrinking is usually from the middle sentence of July to the coloring period of jujube fruit. The disease is mainly caused by the infection of bacteria after the sucking mouthpart pests. Jujube fruit suffered from irregular yellow spots on the victim's damaged parts. In severe cases, the flesh became yellow-brown and taste was inedible. The lesions of the jujube fruit that were infested after the enlargement were not obvious, the peel began to turn red in advance, and the meat was soft and rot. It fell off before ripening. 3. Sunburn The high-temperature weather from the end of June to July is prone to onset. Most diseased jujube fruit on the results of many branches on the lignification of jujube hanging, due to the results of more leaves less fruit exposed to strong sunlight, easy to cause sunburn disease. The site of the disease is usually in the middle of the jujube fruit. The damaged fruit surface is yellow, the vertical lines are deep, and the transverse lines are shallow. Most of the victim's jujube fruit fell off in succession, and some of them were kept in a concave shape on the tree to continue growing.
Third, control methods 1. Top dressing. Each strain of the tree was applied with 1.5-2 kg of "three elements" compound fertilizer and 0.5-1 kg of trace elements in "Waufengyuan" with 4-8 points. 2. Leaf spray fertilizer. Spray 0.3% potassium dihydrogen phosphate solution or 0.3% urea solution, once every 7-10 days, spray 2-3 times. It can enhance blade function, increase single fruit weight, improve quality and reduce fruit drop. 3. Naphthalene acetic acid. From the middle of July, the canopy was sprayed with 15-20 ppm of naphthylacetate at intervals of 15-20 days for a total of two times. 4. Prevention and treatment of date rust, rust, fruit shrinkage, ring disease, etc., can choose to use M-45, or thiophanate-methyl, triazole copper 800 times for prevention and treatment. It is also possible to use 25% triadimefon or a multiform Bordeaux mixture (1:2:200) for control. After every 7-10 days, the fungicide should be sprayed again according to the precipitation. Bordeaux mixture and other fungicides alternately work better.
Lactobacillus Acidophilus,Lactobacillus Acidophilus Powder,Lactobacillus Acidophilus Probiotic,Lactobacillus Acidophilus Supplements
Jiangsu Biodep Biotechnology Co. ,Ltd. , https://www.mbioda.com