Abstract : According to practical experience, the defense methods of delayed chilling injury, cold chilling injury and mixed chilling injury are summarized for your reference. The low-temperature chilling injury of rice can be divided into three types: delayed chilling injury, barrier chilling injury and mixed chilling injury. The main defense measures are as follows. I. Delayed chilling defense measures 1. Select the appropriate variety According to the local accumulated temperature conditions, select the appropriate maturity period, focus on the safe heading period, determine the fertility limit period, implement the planned cultivation, make full use of local light and heat resources, ensure the safety of maturity, not blindly pursue high yield and planting For late-maturing varieties, the accumulated temperature of the selected varieties should be 100-150°C lower than the local accumulated temperature. 2, large and medium shed nursery large and medium shed with warming, insulation performance, so you can raise early seedlings, nursery seedlings, make full use of greenhouse temperature, to achieve the purpose of defense against seedling cold damage. 3, do a good seed treatment 15 days before sowing Sun type 2 to 4 days, can increase seed coat permeability, increase germination rate, germination potential. Soaking: 11 ~ 15 °C water temperature soaking species for 7 days, water up to 25% of its own, when the accumulated temperature reached 80 ~ 100 °C for dipping good species. Germination: 30 °C high-temperature rupture of the chest, 25 °C germination, 20 °C dry buds, to bud Qi, full, strong, lay the foundation for timely sowing. 4, timely sowing, timely transplanting according to the characteristics of the species and the local temperature conditions to determine the appropriate sowing date, so that timely planting appropriate transplanting, to ensure that the panicle before the safe heading period. 5, scientific fertilization, reasonable irrigation According to the soil fertility and species characteristics to determine the amount of fertilizer, nitrogen, phosphorus, potassium, the full maturity of the farmhouse fertilizer applied every year 30 to 45 tons per hectare, the conditions of the area can engage in straw return. Fertilizers for the whole growth period are determined by factors such as soil fertility, variety, and planned yield. The general nitrogen, phosphorus, and potassium ratios are 2:1:1. Second, barrier-type cold damage defense measures 1, deep water tire protection, shallow water grouting rice meiosis period (about July 10 ~ 25) is the most sensitive period of rice in the life of low temperature, in order to prevent cold damage, when the forecast is below 17 °C low temperature, irrigation 15 ~ 20cm deep water layer, tire protection. 2. Because of the differences in morphology, physiology, and other characteristics of selected varieties, the seed setting rate and the ability to resist low temperatures are also different. Therefore, varieties with strong resistance and high seed setting rate should be selected. 3, appropriate sowing, timely transplanting 4, scientific fertilization, reasonable irrigation water and fertilizer management will affect the soil temperature, root activity, N, P, K with the use of (using the same method) and reasonable irrigation, to ensure the healthy growth of rice seedlings and panicle nutrient production, Transshipment and accumulation. Third, the combination of low-temperature chilling defense measures Delayed chilling injury and obstacle cold injury occur at the same time as mixed chilling injury. Refer to the above method for defense. In short, the prevention of low-temperature chilling injury should be centered on cultivating strong fish and shallow water irrigation. The key period is to protect the seedlings with water, increase the water temperature and the ground temperature of the field, promote the warming and promote the early-maturing cultivation techniques, and insist on promoting early ripening all year round. Ensure that rice grows, develops, and maturates within a suitable range of normal accumulated temperature. Poly-Lok Ligating Clips,Weck Hemoclip Applier,Ligating Clips Use,Polymer Ligation Clips Qingdao DMD Medical Technology Co., LTD , https://www.conston-tech.com