Cultivation characteristics of virus-free seedlings of Strawberry

The production and application practice shows that the virus-free strawberry not only grows strongly, the plant is neat and consistent, but also the yield and quality are obviously improved. Compared with virus-infected seedlings, virus-free seedlings increased plant height by 17.7%, leaf area by 2.6%, petiole length by 14.5%, stolon number by 26.7%, harvest by 7.8%, fruit number by 8.7%, fruit weight by 0.67%, fruit weight by 0.67%, and soluble solids content by 3.8%. The growth characteristics of virus-free seedlings are different from those of ordinary seedlings, so the cultivation of virus-free seedlings should be adjusted accordingly in order to increase the yield and improve the quality of virus-free seedlings. The main results are as follows: (1) virus-free seedlings have strong vegetative growth and strong fertilizer absorption, so the topdressing before flower bud differentiation should be avoided in the stage of pseudo-planting, so as to avoid the delay of flower bud differentiation. The flower bud differentiation period can be advanced by adjusting the ratio of carbon to nitrogen by cutting roots and peeling old leaves. (2) the non-toxic seedling field is sturdy and tall, and under the condition of large amount of fertilizer application, the tolerance to strong concentration fertilizer is stronger than that of poisonous seedling. However, the production site should also avoid excessive fertilization, so as not to affect the fruit due to excessive exuberance of the plant. Compared with virus-free seedlings, virus-free seedlings should be sparsely planted. (3) the flowering period of virus-free seedlings tended to be delayed, and the initial harvest time was delayed accordingly, but the early yield and total yield were still higher than those of the control. As the number of fruits per inflorescence increased and the average yield per fruit decreased, moderate thinning of flowers and fruits should be considered to promote the increase of fruit. Botrytis cinerea and leaf blight are easy to occur when the growth is too exuberant, so we should peel off the old diseased leaves as soon as possible, control diseases and insect pests in time, and pay attention to ventilation in the greenhouse when planting in protected areas. (4) the rate of reinfection of virus-free seedlings in the process of production varies with different producing areas and cultivation and management methods. Places with small production scale and frequent control of aphids are still virus-free after two years of cultivation and are only slightly infected in the third year; reinfection often occurs in producing areas with large production scale in a short period of time. In general, it is necessary to use new virus-free mother strains to propagate the production seedlings every 2-3 years, but the original production seedlings should not be reused.