Causes of slow-growing branches, pods and few stiff seedlings of rape and its prevention and treatment

Rape seedlings occur in the seedling stage, the growth is slow, after the Beginning of Spring, there are not many branches and pods, resulting in a reduction in yield. There are many reasons for the stiff seedlings of rape, and the prevention and control methods are as follows:

Rape stiff seedling

1. Infestation of insect pests: symptoms: rape leaves are wrinkled and curled down, the leaves are dark, then red or yellow, the heart leaves are not unfolded, but the roots are normal. Prevention and treatment: timely symptomatic spraying.

2. wet planting rigid seedlings: soil wet mud rotten, or transplanting in rain, soil hardening and impermeability, rape root development hindered, thin leaves red and yellow, heart leaves curled and weak. Remedial measures: immediately deep ploughing, an additional application of 750kg of soil and miscellaneous fertilizer per mu, 250kg of mixed plant ash, after mixing well, to promote rooting and rooting. After 3-5 days, 1000 kg of pig urine manure was applied as seedling fertilizer, which was effective in half a month.

3. Shoddy seedlings: the planting density is high, the seedlings are not in time, or the seedling age is too long, when transplanting, most of them become tall seedlings, bolting seedlings, less green leaves and not long after planting. Remedial measures: ploughing and cultivating soil, applying 1000 kg soil fertilizer per mu to avoid root neck exposure, while using 0.5kg urea, 150g potassium dihydrogen phosphate and 50kg water, foliar spraying to promote seedling growth.

4. Waterlogging damage stiff seedlings: low-lying, wet weight, or poor drainage, or wide and shallow ditches, the soil is moist for a long time, the soil is hardened and impervious, after the seedlings are planted, the root hairs rot, the leaves are withered and yellow, and the heart leaves are not spreading. Remedial measures: open deep ditches and narrow boxes, so that the ditches communicate with each other, and there are no dark stains in the soil. On the basis of reducing soil moisture, 200000kg plant ash per mu was used to choke or evenly remove and absorb moisture.

5. Fertilizer deficiency and stiff seedlings: (1) at the initial stage, rape leaves appeared purplish red spots, and then expanded into red leaves. In severe cases, the leaves withered and yellowed and fell off from bottom to top, lacking nitrogen. Can use 1250 kg pig urine dung, add urea 2-3 kg nest application. (2) the leaf color is dark green and dull, then it turns dark purple, and the veins and leaves are purplish red and phosphorus deficient. 20-25 kg superphosphate is applied per mu, and the nest is applied to the side of the tree, and the soil is covered after application. (3) the root system is dysplastic, the epidermis is brown, the root neck is enlarged and cracked, the leaf is small and thick, uneven and atrophic. The leaf edge curled outward, showing purplish red, and finally withered and fell off, and the heart leaves were yellowish brown and boron deficient. Can use borax (or boric acid) 150 grams per mu, 40-50 kilograms of water, evenly sprayed foliar.

6. drought stiff seedlings: the root system of this kind of rigid seedlings is normal, and the symptoms of upper branches and leaves are similar to those of waterlogging seedlings. Remedy: in the case of drought, applying dilute dung water for 3 to 4 times can restore normal growth.

7. Low-temperature rigid seedlings: most of them occur in rapeseed which are transplanted too late. Because the average daily temperature is below 10 ℃, the recovery of root system is weak, the occurrence of new root is less, and the absorption of fertilizer and water is insufficient, thus forming red or yellow leaves. Prevention and control methods: such as postponing the transplanting period, we should adhere to meticulous soil preparation, select large seedlings with soil transplanting, early topdressing, anti-freezing and heat preservation.

8. Boron deficiency rigid seedlings: rape seedling stage boron deficiency, growth stagnation, rotten root withered heart; rhizome swelling. Prevention and control method: 0.2% borax solution is evenly sprayed 6 kg per mu for 2 or 3 times in a row.