Due to a variety of reasons such as production measures do not conform to the technical requirements, there will be some dead seedlings in rice cultivation.After a long period of a line of production, and explore the reasons of rice seedlings death and countermeasures.This article will discuss rice seedlings death for everyone to do in-depth analysis, hope to be able to meet the needs of farmers production practice.
1, rice seedling types and causes of death
1.1, fat to death
Seedling bed HanYu seedbed of fertilizer, usually water 2 ~ 3 times, in order to prevent fat, must be decomposed into fertilizers and loam uniform mixing.Reasons: (1) into the organic fertilizer rates without fully rotten, toxic substances produced during the process of rotten harm seedlings;(2) recommended uneven, not fully mixed fertilizer, soil, seedling radicle touched the fertile field burns, leading to death;(3) fertilizer to the soil before sowing nursery bed surface, which leads to the radicle charred, make seedling bud no root and gradually died;(4) good seedling emergence after one-time or uneven fertilizing, large amount of fertilizer applied and then failed to timely watering, leading to death.
1.2, dry dead seedlings
Mainly in leaf stage to 3 leaf stage, leaves from the bottom up, gradually dry up and die.The reasons are: (1) seedbed harden and magnetism shallow, can't make full use of the deep soil moisture to maintain moisture balance, combined with the seedbed moisture replenishment is not timely, under the root can't;(2) the rate is too large, miao body thin;(3) in the soil organic matter, less field harden and water supplies.
1.3 die, green seedlings
Because the seedlings a sharp drop in ambient air humidity, leaf transpiration tachycardia, root water in short supply, rapid wilting leaves, leaf color from light to dark and the phenomenon of death.Reasons: (1) from the film before too late, and miao body weak, such as abnormal weather, will happen;(2) sunny noon jie membrane after seedling drops in ambient air humidity, leaf transpiration is accelerated, dead plants;(3) the jie membrane after not timely watering;(4) rough seedbed soil preparation, arable layer soil heavy fact, not easy to cause water shortage root dry, dead plants.
1.4, high temperature burning
When the temperature is above 45 ℃ will appear in the seedbed shoot high temperature burning, burning seedlings phenomenon occurred.
1.5, pest injury seedlings
Dry rice-nursery seedbed soil loose, organic fertilizer, organic matter content high, sowing after laminating, bed high soil temperature, mole cricket, earthworms underground pests such as active, often bite, bite, and loose root, killing seedlings.
1.6, the adr damage seedlings
In order to control the underground pests to harm soil treatment and chemical weed control, because of the unequal medication, local drug concentration too high root injury or leaf water loss caused by burn, even directly caused by drug harm dead plants.
1.7, disease dead plants
Mainly include bakanae disease and rice blast, damping off type 3 kinds of diseases such as dead plants.
