Fruit tree planting is an important part of forestry production, and it is also an important way for farmers to increase production and income. Pingdu City, Shandong Province, has dense vegetation, is one of the important bases for the development of forestry and fruit tree planting in China, and is rich in forest fruit products. Based on the practical experience of fruit tree planting for many years, combined with chestnut planting technology, based on forestry measures and local conditions, the authors of this paper made a brief analysis of the disease and pest control problems in the chestnut planting process for reference.
<h1 class = "pgc-h-arrow-right" >, the biological characteristics of chestnuts</h1>
1. Usage. Chestnut belongs to the shell bucket family, deciduous trees, hermaphrodites and hermaphroditic plants are pollinated, edible, medicinal value is widespread, with the advancement of the market economy, chestnuts can also be processed into leisure food and chestnut powder and other high-grade commodities, playing its commercialization potential.
2. Growth conditions. Chestnut is a light-loving plant, the number of sunshine hours should be more than 6 hours, the temperature is about 17 ° C to 25 ° C, chestnut grafting can flower and bear fruit in 3 to 4 years, 7, 8 years into the full fruit period, each year from September to October fruit ripening, because the fruit period is long, the economic benefits are considerable.
<h1 class = "pgc-h-arrow-right" > second, the cultivation and management of chestnuts</h1>
1. Soil management. Land preparation provides a more favorable basic condition for the growth of chestnut seeds, which cannot be ignored, therefore, in the selection of plots, it should ensure that the soil layer is deep (not less than 50cm), fertile and loose acidic soil, and do a good job of timely weeding and loosening the soil, so that the garden has a certain water retention capacity and air permeability, and has a good drainage function. Hilly slopes should be built into horizontal terraces, or surrounded by fish scale pits to avoid soil erosion, and a small amount of quicklime and boron fertilizer can be supplemented to reduce the phenomenon of empty buds.
2. Seed management. Strengthen seed screening, select chestnut seeds with large, plump, thin skin, bright shell, no injury, no disease and insects, take into account the dual genetic characteristics of the mother and father, and store reasonably, but in the storage process, avoid heat (temperature does not exceed 18 ° C), avoid dryness (not less than 60%), avoid wetness (humidity does not exceed 75%), avoid freezing (1-4 ° C is appropriate), generally based on sand storage.
3. Sowing. When sowing, the seeds are placed in wet soil, in order to control underground insect pests and rodents, a little sulfur or poisonous soil should be mixed to avoid seed diseases and insect infestations.
4. Colonization. Seedling colonization is best selected from 1 to 2 years old, disease-free seedlings. Before colonization, make the soil fully absorb water, keep the soil moist, and cover the soil, but in this process, it should be noted that the amount of soil cover for 1 annual chestnut seedling should be controlled below 10 cm, and the control of 2 years old should be controlled below 20 cm. The density and row spacing of chestnuts are strictly controlled, the row spacing is 3m×4m, and the number of seedlings is about 56 plants/667m2. Before colonization, keep the soil moist and cover it with a layer of soil with a thickness of less than 10 cm. If a missing plant is found, it should be replanted immediately; When the roots of the seedlings are loose, the soil of the roots is solid to ensure the stability of the seedlings. When selecting seedlings, the diameter of the main root should be greater than 0.4 cm, the main root should be more than 30 cm, and it is the best standard to have more than 5 lateral roots.
5. Fertilization management. Base fertilizer is generally based on soil miscellaneous fertilizer and organic fertilizer to improve soil water retention capacity and nutrient supply; At the flowering and fruiting stage, it should be topdressed, mainly nitrogen fertilizer, supplemented by phosphate fertilizer and potassium fertilizer, according to the growth characteristics of chestnuts with greater demand for manganese elements, with calcium, magnesium, zinc and other trace elements. From March to April, the amount of urea can be increased.
Third, the analysis of chestnut disease and pest control measures
1. Insect pests
(1) Chestnut blight. The patient is in the main branch and trunk of the chestnut, the pathogen is hidden in the skin of the disease overwintering, after the onset of the disease, the main branch, the main trunk is reddish brown, there is a bulge of the skin, the inner cortex of the skin rots, juice, every year from June to July, is the high incidence of the disease. When controlling, first of all, in the selection of seeds, varieties with strong disease resistance and certain stress resistance (such as Huaguang, Red Light and other varieties) should be selected to improve the disease resistance of chestnuts; Secondly, regular observation and monitoring, found infected branches, timely removal, centralized treatment. Or mild onset, you can scrape off the bark rot and apply 401 disease-resistant bacteria.
(2) Powdery mildew. The onset site of powdery mildew is in the leaves, shoots, young shoots, etc., through the ascomycete spores infestation, after infection, the infected leaf spots appear irregular halo, and gradually make the entire leaf covered by white powder mold. When preventing and treating, 400 times the liquid M-45 should be sprayed, or the prevention and control should be carried out with the M-45800 times of the large biological M-45800 times, and the effect is remarkable.
2. Insect pests
(1) Heart-eating worms. Heart-eating insects belong to the family Lepidoptera borer moths. The old mature larvae are about 35 cm long, and the 3rd to 4th generations are the most harmful to chestnuts, generally overwintering in the skin, cracks and fallen fruit, and feather in May of the following year. When this insect infestation occurs, it can cause chestnuts to fall fruit or be eaten in large quantities after harvesting. When controlling, the overwintering pests should first be removed, the management of autumn and winter orchards should be strengthened, and the cleaning, picking, shaping and pruning of chestnut orchards should be carried out regularly, and the fruits of the falling insects should be collected and buried or burned in a concentrated manner; Secondly, after harvesting, the accumulation is about 5 days, when most of the chestnut buds are cracked, they are threshed in time, at this time the larvae have not yet been mothed into the chestnut fruit, or the can be used to add 500 times the water to the 45% of the enemy insect crystals, sprayed evenly on the chestnut buds, and can also avoid heart-eating insects mothting chestnut fruits during the accumulation of chestnut buds. Or use pest phototropism to trap insects by luring and killing insects through black light. Or smoke with a piggyback smoke machine (diesel and permethrin pesticide mixture) to kill adult insects, or spray 25% borer pine 500 times liquid 1 to 2 times during the larval incubation period. In addition, according to the biological characteristics of the heartworm parasitic natural enemy as the yellow orbital alien wasp, the natural enemy should be introduced, and biological control should be carried out through artificial evacuation or reproduction to improve the quality of chestnut fruit and increase economic benefits.
(2) Chestnut weevil. Adult chestnut weevils are smaller and generally emerge in July, lay eggs, and begin to hatch in September. Mainly harmful to chestnut fruit. When controlling, it should be harvested in time, threshed in time, and reduce the number of larvae defruiting into the soil base. Completely remove the source of diseases and insects such as diseases and insect branches, dead branches, fallen leaves, fallen buds and weeds in the chestnut garden, prohibit long-term accumulation, eliminate the wintering places of diseases and insects, and reduce the harm. Or through biological control, to protect birds and beneficial insects, spray once with a stone sulfur compound of 3 to 5 degrees in Boumé, and spray 0.5 degrees of stone sulfur compound after leaf spreading. or spray the canopy with 40% oxidized 500 times liquid during the adult period of activity; or spray octylthion 1500 times liquid, or fumigate with bromomethane for 36 hours under closed conditions; Or through physical means, soak in warm and hot water for 1.5 hours to soak the larvae, and the effect is remarkable.
(3) Chestnut aphid. Chestnut aphid eggs are generally distributed on the branches of chestnut trees for wintering, and in late April of the following year they hatch into wingless females. When controlling, through physical methods, scrape off the cracked old bark, artificially remove eggs, detachment disease and insect spots, eliminate moth-dried pests, burn the scraped bark in time, and use white after scraping. Clearing weeds and garbage around fruit trees, pruning diseased branches, diseased fruits, dead branches, burning or deep burial treatment; During the incubation period of the eggs of the giant aphid, the natural enemies of the insect pest should be introduced, and the natural enemies should be released and introduced through artificial evacuation or reproduction for biological control. For chemical control, a higher concentration of bio-stone sulfur compound can be sprayed, or 40% Lego emulsion 1500 times liquid can be sprayed.
3. Precautions
(1) Eliminate the arbitrariness of drug administration, under the premise of reasonable proportion and appropriate medicine, achieve the continuity and consistency of drug administration, ensure the prevention and control effect of diseases and insect pests, and avoid repeated increases in costs of diseases and insect pests.
(2) In order to ensure the yield and quality of fruit, pollution-free and safe, chemical control should be used in high-efficiency, non-toxic, pollution-free chemical agents, reasonable dispensing, increase the utilization rate of pesticides, reduce the number of insect mouths and environmental pollution.
(3) In the 14 days before chestnut harvesting, the use of chemical pesticides is prohibited.