| Strawberry attributes to perennial herbaceous plant of the Rosaceae family.Its fruit is bright with moderate sweetness and acidities,full fragrance and rich nutrition,which accounts for its popularity among consumers.With the characteristics of strong adaptability and precocity fruiting,it is an efficient economic crop highly favored by farmers so far and has rapidly developed into the efficient horticultural crop in Yandu district,Jiangsu province.However,due to planting in successive years,the problem of strawberry continuous cropping obstacle grows seriously,which has become the main factor of hindering the sustainable development of strawberry industry.This paper presents the status quo and causes of strawberry continuous cropping obstacle at home and abroad.The causes can be mainly concluded as strawberry autotoxic effect,nematodes,increased harm of soil borne disease,change of soil physical and chemical properties,etc.The paper also summarizes the research achievements of prevention and control of-continuous cropping obstacle of strawberry,which include a variety of soil sterilization methods,the utilization of biological controls,for instance,antagonistic bacteria,reasonable crop rotation and other agronomic measures,such as selection of disease-resistant varieties,balanced fertilization and so on.In order to ascertain the main causes of strawberry continuous cropping obstacle in Yandu district,this paper investigates the main production areas,including Panhuang,Guomeng,Qinnan and Zhangzhuang,etc,and analyzes the main soil salinity,PH value,organic matter content and main diseases' happening situation of strawberry continuous cropping greenhouses.The results show that the soil in Yandu district has acidification trend.PH value was significantly lower than CK with PH value between 5.7 to 6.1 and the strawberry production does not constitute a barrier;four places of continuous cropping strawberry soil organic matter content were significantly higher than that of control,is suitable for the planting strawberry;continuous cropping soil of strawberry main nutrients of N,P,K were significantly higher than that of control,according to the classification standard of soil nutrients,have reached a high level,especially the content of phosphorus is three to five times background field of phosphorus,soil salt content too high may be one of main factors that influence the strawberry continuous cropping obstacle;Continuous cropping strawberry main disease incidence and disease index were higher than that of rotation of strawberries,strawberry verticillium wilt,in particular,the incidence of continuous cropping strawberry reached nearly 40%,five times that of rotation of strawberry,disease index was 52.6,and more than twice rotation of strawberry.The incidence of grey mould of continuous cropping strawberry was also significantly increased,reached 30.1%,3 times that of rotation of strawberry,continuous cropping strawberry diseases increased may be the main obstacle to Yandu district strawberry crop.Taking the unprocessed soil of strawberry continuous croppingfor comparison,the paper studies the dazomet,lime nitrogen,soil disinfection and high temperature and stuffy shed influence on strawberry continuous cropping obstacle.The results show that three kinds of soil disinfection of strawberry plant height ratio control increased by 18.8%-18.8%,lime nitrogen increased 31.3%than CK,disinfection dazomet disinfection compared with 29.2%increase;Leaf area also increased significantly,compared with a 19.0%increase in the lime nitrogen disinfection,dazomet compared with 17.4%increase;Soil disinfection effect is very significant to increase production,lime nitrogen production increased by 21.0%than CK,disinfection dazomet 14.5%increase in production,high temperature and stuffy tent also a 5.3%increase in production;Soil disinfection significantly increased the content of soluble sugar,soluble solid and Vc,to improve the quality;Soil disinfection that can reduce the harm of continuous cropping strawberry diseases,especially strawberry verticillium wilt and anthrax,a significant reduction in the incidence and disease index of cotton after treatment the incidence of only 24.1%of contrast,the incidence of lime nitrogen treatment is 37.4%of the control,the incidence of high temperature and stuffy tent processing is controlled by 66.7%,but the effect of soil disinfection of strawberry powdery mildew and gray mold is not obvious.For soilless culture of strawberries comparison,this paper studied the HongXia,FengXiang,MiaoXiang 7,XiangFei,FaLaDi,five varieties of strawberry resistance to continuous cropping obstacle feature differences research.Results showed that:1)different varieties of strawberry in plant height,leaf number,number of bud,root number,total leaf number,fruit output shaft there exist differences of indicators such as growth,fruit yield per plant of plant height and the advantage of varieties is FengXiang,the number of points and the number of bud and the root advantage varieties is HongXia,suffer in leaf number advantage varieties is MiaoXiang 7.2)as you can see change range of proline strawberry resistance to continuous cropping obstacle characteristic strength in each type is aromatic,MiaoXiang 7,XiangFei,FengXiang,FaLaDi,HongXiang.3)it can be seen from the variations in chlorophyll content in strawberry resistance to each type continuous cropping obstacle feature strength is in turn:XiangFei,FengXiang,MiaoXiang 7,FaLaDi,HongXia.4)it can be seen from the change range of MAD content of strawberry resistance to continuous cropping obstacle feature strength is in turn:HongXia,XiangFei,FaLaDi,FengXiang,MiaoXiang 7.5)varieties of strawberry leaf radical scavenging enzymes SOD,POD and CAT activity compared with group controls have been falling;Differences between different varieties of patience,the extent of the changes of enzyme activity.Integrated in continuous cropping soil and soilless cultivation to take care of processing conditions,the institute of choice in the strawberry variety growth index and physiological and biochemical indexes are different,but each type continuous cropping obstacle resistance strength is not obvious. |
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