What reason is chilling injury of rice
(1) climate change.Climate change is bigger, in the past two years the spring or autumn often appear cold wet weather for a long time, or the lack of rain in summer, causing the accumulation of the accumulated temperature for rice growth was prolonged, the plant growth is slow, the growth period delay.Most farmers friend didn't prepared, as a result, the late rice suffered from delayed chilling injury.As our county in 2010 rice in low temperature and rainy time is long, accumulated temperature, growth period, suffer chilling injury of late rice planting delay impact as a result, to relax to prevent pit field delayed chilling injury, such as lake city township of most farmers caused great losses.
(2) mountain microclimate condition.Cold rice field in mountainous area, especially the cold soak field, paddy field, etc., its slow field to heat up in the morning, high temperature short time at noon, afternoon cooling fast, always less active accumulated temperature, the chilling damages occur frequently, low temperature during whole growth period and make rice breeding is slow, often delayed chilling injury.As filter in 2010 and 658 in our county township LuGang hybrid late rice varieties (mountain) in more than 700 mu less earing or no earing phenomenon is such reason.
(3) varieties accumulated temperature characteristics.Cultivated varieties required to accumulated temperature more than local fertility accumulated temperature.Farmers have no choose ripe period according to local conditions of accumulated temperature suitable varieties, blind pursuit of high yield and mature varieties planted, blind introduction varieties and so on, the more area mature rice are not security.Huang Huazhan conventional rice varieties, high quality and high yield as the whole growth period is 135 days, the rice planting in our county for both high yield and safety, but for late rice planting often suffer from delayed chilling injury, cause serious production.Introduced without mastering this feature, many farmers are so often suffer.
(4) improper cultivation management.Such as early sowing early, cause a lot of weak seedlings in low temperature, bad management and or late sowing waste accumulated temperature, will lead to growth period delay, so as to delay late rice transplanting and mature;Improper fertilizer application, such as excessive nitrogen fertilizer, fertilizer period too late, cause moderate growth, growth period delay rice plants;By disease and insect harm is serious, water too long, or suffer from flooding in rice and its growth period will be delayed.Cause by above knowable, improper cultivation management of rice the most easily affected by delayed chilling injury.
How to control rice chilling injury
1) choose suitable varieties.According to local conditions to choose good accumulation period, strong resistance of rice varieties, centered on safe heading stage, period, to classify fertility cultivation planning program, make full use of the resources of field, ensure security mature, not blindly pursue high yielding variety and planting varieties.Choice of varieties of accumulated temperature should be less than the local annual accumulated temperature of 100 ~ 150 ℃, in order to avoid the occurrence of delayed chilling injury.Paying special attention to this point in a new varieties introduced.
(2) cultivating strong seedling.Early rice should do well in seed treatment, select the mulch seedlings, and early nanny seed dressing the seed (agent and the proportion of the seed is 1:5 ~ 6), improve the disease resistance, drought resistance and cold resistance ability, cultivating strong seedling, achieve the purpose of defense seedling chilling damages.
(3) timely sowing and transplanting.According to the variety characteristics and local temperature conditions to determine the suitable seeding time, arrange stubbles, achieve timely sowing and in suitable transplanting, ensuring the safety of late rice in full panicle stage before full panicle.My county early rice generally choose stability in more than 12 ℃, the average daily temperature is about 20 March rob fine planting, yields transplanting is about 25 days;Late rice, on June 15 ~ 20 yields after 35 days prior to the plant, to ensure safe heading grouting and avoid delayed chilling injury.
(4) scientific reasonable fertilization and irrigation.According to the soil fertility characteristics and to determine the fertilizer rate, nitrogen, phosphorus and potassium, best every other year full of rotten farmyard manure applied per acre 10000 ~ 15000 kilograms, the conditional area can also make straw returned and planting clover, enriching the soil fertility.Fertilizer rate because of soil fertility, soil quality, planting varieties and plan production factors determine, a precise quantitative or soil testing and fertilizer general nitrogen, phosphorus and potassium ratio of 1:0.45:0.45.
(5) take effective emergency measures.In rice meiosis stage and heading stage, the key period, if encounter the same day average temperature below 20 ℃, or daily lowest temperature is lower than the 17 ℃, should be ready to prevent delayed chilling injury.More than 5 cm deep water, can improve the temperature of 1 ~ 2 ℃;Spraying on the leaf potassium dihydrogen phosphate solution 100 ~ 150 g/mu, or foliar fertilizer containing SOD enzymes, enhance the ability of plant resistance to chilling injury;Take 1 g per acre start heading gibberellin, 45 kg with alcohol dissolves in water spraying on the leaf, ears can accelerate progress, full panicle stage 3 days ahead of time.
