What three things should be noted in spring management of dryland rapeseed?
Sclerotinia rot of rapeseed is a major disease harming rapeseed, and its control must be taken seriously to reduce the damage and minimize losses. Symptoms: when the disease occurs, the lesions on rapeseed leaves are round or irregular, grayish brown or yellow-brown in the center, dark bluish in the middle, with a yellow halo on the outer edge. When dry, the lesions rupture and perforate; under humid conditions...
From last winter to this spring, overwintering rapeseed in most parts of our country suffered severe and sustained drought, which brought very adverse effects on the normal growth and development of rapeseed. After the Spring Festival, rapeseed gradually enters the vigorous growth stage of bolting to early flowering, and the drought in various regions has still not been completely relieved. In view of the growth characteristics of rapeseed, the following three points should be noted in spring management:1. When supplementing fertilizer, do not neglect boron supplementation. Because sustained drought greatly reduces the availability of "boron" in the soil, crop roots cannot absorb it, which in turn leads to boron deficiency in rapeseed plants, flowers without seed set, and severe yield reduction. Therefore, for drought-affected rapeseed, while doing a good job in drought resistance and topdressing, special attention should also be paid to supplementing boron fertilizer. Even in rapeseed fields where boron fertilizer was already applied as a base fertilizer at sowing or transplanting, foliar boron spraying is still needed at the flowering stage. At the same time, Zhuangjingling should also be sprayed to improve and enhance the plant's absorption function for various urgently needed elements and strengthen the nutritional growth function of the plant.
2. When temperatures rise, do not forget cold protection. As spring returns to the earth and temperatures rise, rapeseed fields are about to turn green and resume growth. But the climate is very unstable, and once cold air strikes suddenly, freezing damage will occur. Therefore, an 800-fold dilution of Xingaozhimo should be sprayed all over the field. While preserving soil moisture, retaining fertilizer, and preventing pathogen invasion, the key is to protect against cold and preserve warmth so as to avoid disaster.
3. Timely suppress excessive main shoot growth to promote flowering and fruiting. At the beginning of green turning and stem elongation, Chuhuawang No. 3 should be sprayed in time, which can promote the transformation from vegetative growth to reproductive growth function, promote flower bud differentiation, and suppress excessive shoot growth. At the early flower bud stage, young pod stage, and full seed stage, Caiguo Zhuangdiling should be sprayed, which can enhance the quality of pollen fertilization, strengthen the cyclic fruit-setting rate, promote fruit development, and result in no malformed fruit, no empty shells, and no shriveled grains, effectively increasing the yield increase rate.