保护地秋冬茬西芹栽培中常见的几个问题及解决对策

保护地秋冬茬西芹栽培中常见的几个问题及解决对策 Several common problems in Protected Cultivation in winter and autumn celery and Countermeasures 2009-10-29 18:45, about the breeding time and cold stratification Big shed, Greenhouse Celery from early December to late January should be listed, in mid June on seedling age of 75 ~ 80 days after. Early sowing to seedling planting. After the seedlings are cool, it will be beneficial to give full play to the potential of individual production in autumn. Late sowing has short growth time, small tree and low yield. Celery likes cold and cool, and if the temperature is higher than 25 degrees centigrade, the seeds are difficult to germinate, suitable for germination temperature of 18-22 degrees. In summer, it is necessary to create low temperature conditions and to create low temperature conditions in 2 ways: (1) seeds in 30 minutes 48 to 55 DEG C and soaked in warm water, after soaking, hanging in the wells, or in the shade of 60 cm dug pit, sprouting in the pit, the upper cover insulation material. (2) low temperature heat release dormancy, germination temperature. The seeds were soaked in warm water for 30 minutes at 48~55 degrees Celsius. After soaking seeds, they were placed under the temperature of l0 for 8 days, and then the germination rate was above 60% at room temperature (30-32 DEG C). Two, a sunshade rainproof seedling and Seedling Celery seeds are small, thin soil, seedling emergence growth if, summer heat, light, rain on the seedling so unfavorable, using sunshade, rainproof, seedling pest control measures. The seedbed should be protected from flooding, and the awning should be around 1 meters high for ventilation. Don't pay attention to a net cover in the end, cloudy, morning and evening, under the weak light to uncover. Celery planting soil is shallow, high temperature, long hypocotyls after seedling emergence, seedling emergence should be carried out after a soil cover, 2 leaves, 3 leaves of each show usually thinning time, seedling distance of 3-4 cm square is appropriate, every time after thinning watering. Seedling seedbed humidity, should have cataplexy, after sowing, seedbed spraying EM bacteria is a kind of effective method. Three, suitable for planting depth and density Celery after 60 ~ 80 days were long, with 10cm, with 5-6 leaves, the base stem diameter of 0.6 cm or more, as planting requirements, general colonization in late August -9 month. When planting, it is necessary to take a few points: (1) planting depth, should be in the depth of the seedbed is appropriate, in order to prevent silt heart, it is best to pre planting water, and then planting. Pouring water planting; (2) before planting beds don't irrigate flood, prevent seedling root tangles, after lifting to classification of colonization, and to do with the lifter, with planting with water; (3) planting density, seedling spacing of 30 x 20 cm, medium seedling of 25 * 20cm, 20 * 20cm. Only sparse planting can grow trees, in order to achieve high quality and efficient purposes. Four, after planting and fertilizer dunmiao Qi The first row of 1 weeks after planting, second weeks for third times to promote the cultivation, root; from mid September to late October, about 50 days, is the first growth peak, topdressing irrigation of celery, once every 10 days after urea l0kg / 667m2, every 5 ~ 7 days of irrigation water. L 0 the end of the month the temperature is getting cold, especially at night low temperature growth in negative celery, then you should protect the film, the daytime temperature should not exceed 20 degrees, the night off the air, extending the temperature time in protected conditions, and second growth peak of nearly 40 days. Five, about celery "heartburn" Celery "heartburn" is divided into two stages, one is the early growth stage, one is the adult stage, the onset of symptoms: at the beginning of browning of leaf interveinal leaf margin, after the cells die, dark brown, near the point of growth of new leaf necrosis. The cause of the disease is mainly caused by calcium deficiency. After a large amount of chemical fertilizer is used, soil acidification and calcium deficiency are easy to be done, and excessive fertilization, especially nitrogen and potassium fertilizer, will affect the normal absorption of calcium by roots. In addition, low temperature, high temperature, drought and other adverse environmental conditions will reduce root activity, weaken the absorption capacity of root system to calcium, and increase calcium deficiency. Six, about celery hollow" Celery is a kind of phenomenon of hollow tissue aging, starting from petioles and gradually to the development of hollow, hollow parts appear white floc suberification organization. Reason: (1) water control in late growth stage, If the soil water supply is not uniform, the physiological water celery growth process, will inhibit the root absorption of the various elements of the delivery, not only affects the growth of buds, petioles close to the pith parenchyma, the first rupture shrinking, the formation of the hollow rod. (2) improper management of fertilizer during celery growth. During the whole growth period, nitrogen fertilizer always occupied the main position. At the beginning of growth stage, the deficiency of phosphate fertilizer was disadvantageous to the differentiation and elongation of leaves, and the seedlings were thin and weak. Therefore, the initial application of phosphate fertilizer was very important. In the middle and late stage, potassium fertilizer played a big role in nutrient transportation, and the petiole was strong, full and shiny. At the growth stage the growth of celery if not fertility or water, it inhibited the growth of hollow petiole. If the soil is dry or too much nitrogen will hinder the plants to trace boron and calcium absorption, such as celery on boron sensitive plants when boron deficiency initially leaves brown petiole will crack, crack, calcium easy to induce heart rot. (3) late harvest, celery and other factors, will lead to decreased celery root absorption ability of the water, do not have enough nutrition, physiological function of leaves decreased, making nutrients deficiency, leading to tissue loose, aging and hollow petiole. Seven. Basal petiole cracking and rotting The outer leaf petiole and basal stem split, and then brown and rot. Causes: one is caused by boron deficiency; two is in low temperature and drought conditions, the growth caused by water shortage; in addition, early or late, sudden high temperature, humidity, plants absorb too much, resulting in rapid water filling, also cause cracking. Eight, Celery Soft Rot The disease often occurred in the early stage of celery transplanting, delayed seedling stage or delayed seedling stage. Usually begins at the base of the tender and succulent petiole. At the onset of the lesion, pale brown, hygrophanous, fusiform or irregular in shape, slightly sunken, the rapid expansion of internal organization after dark brown rot, smelly, finally only residual skin. One reason is that the two field is planted too deep; the three is the continuous cropping Nine, autumn celery seedling death, root rot There are many reasons for the root rot of celery: First: planting depth, watering large, but also prone to root rot seedlings. Second: the reasons for the land. If in a large number of long-term use of organic fertilizer, the use of a large number of non decomposed organic fertilizer; it would be easy to rot. The principle is also related to water, and the solution is to reduce the proportion of organic matter in the soil. Third: the soil fertilizer imbalance, especially boron deficiency, the symptoms will be finally dead seedling root rot. Solution to the amount of boron supplementation, attention must be appropriate, because boron needs little, it is easy to fill the boron excess surface, causing fertilizer. Do soil sterilization before planting, before planting with borax 2~3 kg per mu can be used as base fertilizer, after the onset of 50% DT or kocide 72% streptomycin and 2~3 time later. Can be used metalaxyl +DT and the prevention of evil spirit ling. Nine, strengthen the late management, to prevent celery cold Temperature management: the suitable temperature for celery seedling is 18~22, and the optimum temperature for growing period is 12~18. In the late growth stage, keep the temperature above 5. Celery Hardy is frozen, when -3 low temperature will appear in the cold. In late November, when the external minimum temperature dropped to -5 degrees, the single shed will be reduced to -3 DEG C, attention to anti freezing. Ten, strengthen disease prevention and pest control The Septoria previcur-n and DuPont curzate, chlorothalonil, DT fungicide quantian uniform spray, do not leak Tian Tian households do not leak, no leakage of leaf strain, strain. In rainy weather, use every frost, smoke, and smoke to light the smoking shed. Conditional greenhouse can use oxygen machine to produce ozone sterilization of shed. At the same time, the diseased leaves should be removed in time before sealing the ridges, so that they can be taken out of the shed to be burned so as not to form a new source of infection. Insect pests include aphids, Bai Feishi, and root knot nematodes