Latest: Causes and Solutions for Weak, Stunted Rapeseed Seedlings

Spring plowing is about to begin, and rapeseed has successively entered the bolting and flowering stage. At this time, the main task is to prevent low-temperature cold damage, but some farmers have found that their rapeseed shows signs of poor nutrition and stunted growth. What causes this? How should it be solved? Let's take a look together.

1. Waterlogging in the field

If rapeseed is not growing tall, the first thing to suspect is waterlogging in the field. It causes poor root growth and development in rapeseed, leading to insufficient nutrient absorption, so the seedlings appear poorer and do not grow as tall as normally growing rapeseed. This situation is especially prone to occur in rapeseed fields following a previous crop, mainly because drainage ditches were not properly opened, and drainage was not carried out in time after the Beginning of Spring. When there is waterlogging in the field, low temperatures can also easily cause freezing damage, so special attention should be paid.

Solution: For waterlogging in the field, the first thing to do is to clear the ditches and drain water in time to reduce the harm caused by waterlogging. Then, spray the rapeseed field with foliar fertilizer such as potassium dihydrogen phosphate, multi-element micro-fertilizer and brassinolide to speed up rapeseed growth. After that, appropriately apply green-up and bolting fertilizer to promote normal rapeseed growth.

2. Fertilizer deficiency

If waterlogging in the field is ruled out, then it is very likely caused by fertilizer deficiency. Rapeseed is a crop with a relatively high fertilizer requirement. When nitrogen is deficient, it causes short plants, narrow leaves and yellow-green leaf color; in severe cases, the leaves at the base of the stem also turn red. When phosphorus is deficient, the lower leaves turn purple and growth is slow. When boron is deficient, not only does the phenomenon of flowering without setting seed occur during the flowering stage, but boron deficiency at the seedling stage also causes poor root development, swollen and cracked root stems, leaf margins curling outward and turning purplish-red, and yellow-brown heart leaves.

Solution: According to the colors appearing on rapeseed leaves, supplement the corresponding nutrient elements. When fertilizing, pay attention to balancing nitrogen, phosphorus and potassium fertilizers, and fertilize reasonably according to the growth of rapeseed. For those with poor growth before overwintering, apply winter fertilizer in time; for those with good growth, it may not be necessary. Boron fertilizer can be applied as a base fertilizer. If it was not applied as a base fertilizer, boron fertilizer can be sprayed at the seedling stage, bolting stage and early flowering stage.

3. Rapeseed clubroot

If the previous two causes are ruled out, then it is the harm of rapeseed clubroot. In recent years, the occurrence of rapeseed clubroot in the Yangtze River Basin has increased year by year, mostly occurring from autumn to the beginning of spring. This is a disease that has been overlooked, especially because farmers do not know much about it. In the early stage of the disease, the symptoms on the upper part of the plant are not obvious. Some rapeseed plants show yellowing leaves and slowed growth. When the rapeseed plant is pulled up, spindle-shaped tumors can be seen on the roots. If rapeseed in the field grows slowly and the leaves turn yellow, pull up a few plants and take a look, and it can be diagnosed whether it is clubroot.

Solution: When diseased plants are found, pull them out in time, and treat the diseased holes with quicklime. When the condition is more severe, spray rooting agent diethyl aminoethyl hexanoate or 22.5% picoxystrobin 35-45 milliliters per mu, with an interval of 7 days, for 2-3 consecutive applications to control the disease.

The above is an introduction to the causes and solutions for weak, stunted rapeseed seedlings. We hope it can help you. If you want to learn more related knowledge, please stay tuned to us.