What are the causes of stiff seedlings in rapeseed and the control methods?

Rapeseed is a common vegetable. It can not only be pressed for oil, but is also a delicious vegetable with high economic value, and it is planted all over the country. During cultivation, stiff seedlings occasionally occur. When stiff seedlings occur, rapeseed stops growing, and in severe cases the stems wither and the roots rot, reducing yield. So why do stiff seedlings occur? Below, the editor brings you the control methods for stiff seedlings.

1. Drought and waterlogging damage

Drought in the climate and soil not only causes the plants to lack water and wilt, but also affects the roots' absorption of nutrients, causing nutrient deficiency symptoms, triggering purple and red leaves, and causing stiff seedlings. After transplanting, if the soil drains well but there is long-term rainy weather, the soil accumulates too much water, causing waterlogging damage, making the roots breathe with difficulty, causing oxygen deficiency, and triggering stiff seedlings.

Control methods: For stiff seedlings caused by drought, the problem can be solved by furrow irrigation or watering. For furrow irrigation, dig a furrow between the rows and fill it to two-thirds with water; watering allows better control of moisture, and frequent watering to keep the soil moist is enough. For stiff seedlings caused by waterlogging damage, drain water and prevent flooding in time, especially in rainy weather, and combine this with intertillage and loosening the soil to maintain soil permeability so that the roots can breathe normally.

2. Fertilizer deficiency

When plants lack fertility during growth, they cannot grow normally, causing stiff seedlings. Generally, stiff seedlings caused by fertilizer deficiency are very easy to identify. First, the plants are shorter than normal plants, and the leaf color fades and turns yellow. In severe cases, the leaves at the base of the stem turn red and purple, and the leaves wither, yellow and fall off; this indicates the plants lack nitrogen. If the upper half of the leaves is dark green and lusterless while the lower half is purple-red, then it is phosphorus deficiency. There are many other nutrient deficiency symptoms that will not be introduced one by one.

Control methods: For fertilizer deficiency, fertilize to supplement nutrients. Apply sufficient base fertilizer before transplanting. For the base fertilizer, fully decomposed organic fertilizer can be used together with nitrogen, phosphorus and potassium fertilizers. Organic fertilizer contains extremely comprehensive elements, and applying enough organic fertilizer generally prevents nutrient deficiency symptoms. When stiff seedlings caused by fertilizer deficiency appear, topdress in time and combine with foliar spraying; the effect is excellent and can restore the plants to normal growth and development as quickly as possible.

3. Pests and diseases

The common pest that causes stiff seedlings is aphids. The nymphs gather on the leaves of the seedlings and suck the leaf sap, causing the leaves to wilt and curl, and finally the plants shrink, the leaf color turns yellow, and the heart leaves do not unfold, but root growth is affected; the leaves' photosynthesis is extremely poor, nutrient synthesis is slow, and this can also trigger virus disease damage, making stiff seedlings very likely to form.

Control methods: Do a good job in preventing and controlling aphids. When aphid damage is found, spray with 3000-fold dilution of Yashijing for control. If virus disease symptoms appear, spray with 300-fold dilution of 5% Junduqing, once a week for 2-3 consecutive times.

4. Inferior seedlings

During sowing and seedling raising, because the sowing density is relatively high, thinning is not carried out in time after emergence, or the seedling age is too old at transplanting, tall-foot seedlings will form after transplanting, and the seedlings have fewer leaves during growth and stop growing.

Control methods: Pay attention to density when sowing. After emergence, thin and fill in seedlings reasonably according to density. Choose a suitable age in days when transplanting, and remove diseased and weak seedlings. If the tall-foot seedling phenomenon still appears after transplanting, strengthen intertillage and weeding, and combine with fertilization to promote its growth.

The above are the causes of stiff seedlings in rapeseed and the control methods. I hope it can help you. To learn more about rapeseed cultivation knowledge, please follow us.