What causes white heads in wheat? Detailed explanation of causes and control methods
When wheat is nearing maturity, large numbers of white heads often appear, causing a serious drop in yield, and many farmers do not know what causes this. What causes white heads in wheat? They can be caused by diseases as well as by environmental and human factors. Let us take a look at the detailed introduction to wheat.
1. Diseases
There are many disease-related causes of white heads in wheat, generally caused by wheat take-all, wheat root rot, wheat sheath blight, and wheat sheath blight. When take-all occurs, the wheat is short and stunted with many yellow leaves, and the roots turn black; if infected during the grain-filling stage, the root crown gradually turns black, and eventually the whole plant dies, resulting in white heads. When root rot occurs, dark brown spindle-shaped spots or streaks appear on the leaves and the base of the stem, and eventually the root system rots and the plant dies, producing white heads. The symptoms of sheath blight are similar to those of root rot; when it occurs, brown lesions appear, and as the lesions gradually expand and cover the entire stem, in severe cases the stem base rots, causing the plant to die and producing white heads. Fusarium head blight mainly occurs during the flowering and grain-filling stages, and is more severe in rainy weather.
2. Low-temperature freeze injury
Today wheat plants are generally spring wheat and winter wheat, and both experience cold seasons during cultivation. If the temperature is too low, the plants will suffer from freeze injury, and the tillers and growing points of non-cold-tolerant varieties will freeze to death, causing incomplete development of the spikelets and grains, so that grains cannot form, resulting in empty heads, and finally causing large areas of white heads at maturity.
3. Insect pests
Like diseases, insect pests are also one of the causes of white heads in wheat at the later stage. As productivity increases, former cultivation practices are gradually replaced by mechanization, and unscientific pest and disease control measures cause insect damage to worsen year by year. After being damaged by insect pests, wheat often shows dead seedlings and stunted seedlings at the seedling stage, and combined with relatively large climate changes, this often leads to dead seedlings in the early stage and dead heads in the later stage.
4. Human or mechanical damage
Mechanized cultivation patterns are gradually replacing traditional planting patterns. During planting, the wheat stems may be damaged for some human and mechanical reasons, so that they cannot normally absorb and transport nutrients during growth, and the plants are also prone to water loss, causing white heads.
5. Control measures
Attach great importance to the prevention and control of pests and diseases. During planting, carry out reasonable crop rotation to reduce sources of pathogens and insects and make the plants grow vigorously. In addition, strengthen fertilizer and water management during planting, apply more organic fertilizer and increase the application of phosphorus and potassium fertilizer to improve the disease resistance of the plants, and deal with pest and disease damage promptly when found. Choose relatively cold-tolerant varieties to resist losses caused by low temperatures.
The above are the causes of white heads in wheat and the control methods. We hope this helps you. To learn more about wheat cultivation knowledge, please follow us.