Watermelon cracking causes
Watermelon crack tendril is caused by the temperature or dramatic change and water physiological diseases, is relatively rare in the production of tendril longitudinal crack, channel cause tissue damage, cause he grew slowly, body size, quality, production decline, serious when he stopped growing, plant diseases and insect pests occur in great quantities, fruit wilting, whole plant water and crop.
1, the variety is not appropriate
Crack in the production of some varieties had more easily, such as zheng miscellaneous, continuous cropping black overlord, some varieties have crack tendril mild or no crack, such as double happiness, Jin Zhongguan dragon, etc.Qianyang county in shaanxi province in 2012 Laurence family inn, grass green village, such as planting zheng miscellaneous, continuous cropping black overlord varieties occur crack, crack rate of tendril by an average of 5.3%, production rate of 2.6%, to the farmers' cause bigger loss, and the distinction, thousand tableland village grow Red Cross rate is only 0.1%, basic no crack tendril.
2, climate impact
Mainly is the rapid changes in temperature or greatly influenced by rainfall.Crack tendril often occurs in early summer, when temperature stability is poor, especially in the morning and evening temperature difference is bigger, easy cause crack tendril.Summer high temperature after the sudden rainfall most easy to cause crack, serious when crack tendril rate can reach more than 80%, and often accompany dehiscent fruit.2010 summer qianyang county sustained high temperature encountered some 4 ~ 5 days after 1 month continuous rain, causing a lot of watermelon crack, crack tendril rate was 23%, and the production rate of 10% above, losses.
3, cultivation management is not reasonable
In low-lying, heavy clay soil, barren land planting watermelon is prone to crack tendril.Imbalance of the management on water supply, irrigation, lack of high temperature water and fertilizer, partial nitrogen, etc all can cause watermelon crack tendril.
Watermelon stem blight prevention and control
1, choose suitable varieties
Production should observe more, can't consider variety production, to analyze factors, try to choose not to split tendril or split tendril fewer varieties, such as performance good fortune in recent years, high yield, excellent quality, strong disease resistance, less crack tendril, is worth promoting.
2, strengthen the management of cultivation
(1) a reasonable choice to choose the higher ground, drainage good fertile sandy loam.
(2) to improve the way of cultivation Mulch, instead of the traditional open for double film covering cultivation and greenhouse cultivation, which can effectively reduce or even eliminate the occurrence of crack tendril, significantly improve the quality of watermelon and production, increase efficiency.Thousand tableland, DaZhai Village adopts the model of greenhouse watermelon and greenhouse vegetables rotation, effectively prevent the crack tendril, production of village red brand watermelon with light, though full color bright red flesh, sweet and refreshing crisp, high sugar content, juice, fleshy, famous fragrance is pure and surrounding areas.
(3) strengthen the water management Water management to keep the equilibrium of supply for the principle, and proper control, strictly grasp the irrigation water, to keep it is advisable to see dry wet soil, irrigation manner appropriate USES num furrow irrigation, drip irrigation, (poa pratensis), membrane under dark, beware of flood irrigation;Appropriate irrigation, in the evening or night at high noon water, avoid by all means in a timely manner after the rain drains., fertilization with organic fertilizer is given priority to, appropriate control nitrogen phosphorus, potassium, NPK ratio is 1:1.5:1.5, general 667 m2 soil manure 5, 000 kg, 80 kg of 50 kg ammonium bicarbonate, calcium superphosphate, potassium sulfate, 90 kg, he kept strong and stocky, enhance the crack resistance.Organic fertilizer can be used in the production of oil residue, human excrement, pedosphere of livestock and poultry dung, marsh fertilizer, etc., in which performance is better marsh fertilizer, not only can reduce the crack, and can improve the watermelon and yield, sugar content can effectively prevent all kinds of plant diseases and insect pests, should be vigorously promoted.
3, timely repair calcium
Stretch tendril growth is accelerated, the issue of watermelon leaf internode elongation, leaf area gradually expanded, and pregnant bud flowering, this phase is the key to calcium supplements to prevent crack tendril period, this period 2 ~ 3 times 0.3% calcium nitrate liquid spraying, can increase the cell wall thickness, prompting mechanical hardness and strength increase, improve the anti-cracking ability of he.
4, to protect
Has occurred for crack tendril of chemicals should take timely protection, available 43% granules 3 g e listed 5 kg of water, daub cracking with the writing brush, or with 5% fungus poisonous clear water 50 mL of water 1 kg daub crack tendril wound.Do not daub should timely spraying broad-spectrum fungicide for protection, protective agent can choose 80% mancozeb wettable powder 600 ~ 800 times liquid ketone or 68.75% bacteria manganese zinc 1 200 times liquid or 10% water dispersible granule (doxycycline wettable powder 1 000 ~ 1 500 times liquid, etc.Crack tendril wound bacterial infection occurs after spraying 80% mancozeb wettable powder 600 ~ 800 times liquid or 77% cupric hydroxide wettable powder 500 times liquid, and 7 ~ 10 days 1 times, 2 ~ 3 times.
