What to Do About Early Senescence in Rice? Latest Cause Analysis and Control Methods

Rice can show early senescence during cultivation. So-called early senescence means growing old before its time, and it mainly occurs in the late heading stage of rice, manifesting as withering of stems and leaves, poor grain filling, an increase in empty grains, and reduced yield. Among growers it is called “standing stalk death” or “straw return.” So what causes early senescence in rice? And what should be done about it? Let us take a look together.

I. Causes of Early Senescence

1. Low-lying terrain and poor ventilation can cause excessive accumulation of harmful substances in the soil, harming root growth and development and reducing vigor. In severe cases, black roots and root rot can occur. In addition, when the soil lacks a certain element, the plant can suffer early senescence because of nutrient deficiency.

2. During planting, because the soil tends to become compacted and has poor permeability, root growth is poor, leading to weaker absorption capacity. In the later stage, the plant suffers early senescence because of fertilizer depletion.

3. During cultivation, if the planting density is too high, the rice grows thin and weak. In addition, if fertilization is skewed toward nitrogen fertilizer and too little phosphorus and potassium fertilizer is applied, the rice will grow excessively and be prone to early senescence in the later stage.

4. Long-term flooding irrigation without draining for aeration; planting in saline-alkali and infertile land where root growth is poor; withdrawing water too early before harvest, or planting late-maturing varieties too late, and other such causes can all lead to early senescence in rice.

5. During the grain-filling stage of rice, if the temperature is too low or there is insufficient light, the formation and translocation rate of assimilates will weaken. When grain filling encounters a low temperature of 5-6 degrees, varieties with lower cold tolerance will show discoloration and early senescence.

6. In addition, varieties also have a certain effect on early senescence. Experiments have shown that generally short-stalked and early-maturing varieties are prone to early senescence. This is because the ventilation of short-stalked varieties is not as good as that of tall-stalked varieties, while the leaves of early-maturing varieties are thinner and shorter-lived than those of late-maturing varieties, so they are prone to early senescence.

II. Control Methods

For low-lying or saline-alkali land, drainage works can be built before planting to strengthen infiltration. Then improve the soil by applying large amounts of farmyard manure during land preparation to improve soil structure. When planting, use rational close planting and timely intertillage to promote root growth and development. For fields highly prone to root rot, first do not apply or apply less fertilizer containing sulfate radicals. Nitrogen fertilizer should be applied in small amounts multiple times, and basal fertilizer and tillering fertilizer should not be applied too much at one time. In addition, fertilize according to the seedling stage, apply more phosphorus and potassium fertilizer to improve disease resistance, and topdress with farmyard manure high in potassium before the heading stage, which can prevent root rot.

The above are the causes and control methods of early senescence in rice. We hope this helps you. If you want to learn more related knowledge, please stay tuned to us.