How to identify nutrient deficiency symptoms in rapeseed cultivation?
Rapeseed is one of the important oilseed crops in China, and both the tender rapeseed greens and the unopened rapeseed flowers can be eaten as vegetables. Rapeseed has strong resistance and is grown all over China, but mainly in Anhui, Henan and other places. However, when we grow rapeseed, there are inevitably some shortcomings in our fertilization techniques. So today, the editor will tell you about the symptoms rapeseed shows when it lacks nutrients, and how we should remedy the situation after nutrient deficiency.
I. Symptoms of nutrient deficiency
The symptoms of nutrient deficiency in rapeseed are mainly divided into four types. When different fertilizer types are lacking, the symptoms shown are also different, and naturally the remedial measures will also differ. The four types of nutrient deficiency symptoms in rapeseed are: nitrogen deficiency, phosphorus deficiency, potassium deficiency, and boron deficiency. Let's take a look below.
1. Nitrogen deficiency
Nitrogen fertilizer is mainly used to promote the growth of rapeseed plants, and its critical fertilization point is from bolting to early flowering. If rapeseed lacks nitrogen fertilizer, the plants grow slowly, are short and small, and have few branches, and the weight and number of seeds per pod and rapeseed seeds will also decrease. Secondly, the leaves of rapeseed are thin and small, and the leaf color is pale, sometimes even appearing red.
2. Phosphorus deficiency
If rapeseed lacks phosphorus fertilizer, the root system of the rapeseed plant is underdeveloped and the roots are relatively small. Secondly, the leaves of rapeseed will not be very large either; the leaves are relatively thick, and the leaf color is relatively dark, usually appearing dark green or even dark gray. When phosphorus fertilizer is severely lacking, the leaves are very likely to turn dark purple and show symptoms of withering. Finally, another symptom is that the flower bud differentiation rate of rapeseed is relatively slow, seriously affecting the optimal fruiting period of rapeseed.
3. Potassium deficiency
When potassium fertilizer is lacking in the rapeseed field at the early stage, the leaves at the bottom of the rapeseed plant will gradually turn yellow. Of course, special cases cannot be ruled out; sometimes the bottom leaves will curl, wither, and the stems will show obvious signs of breaking due to stem wilt disease. Secondly, the flowering of rapeseed buds becomes abnormal, and the growth and development period is prolonged, which will cause rapeseed to miss the best time for yield and quality.
4. Boron deficiency
Rapeseed is very sensitive to boron fertilizer, so once boron fertilizer deficiency occurs, symptoms can be found in the rapeseed plants. Especially during the late flowering and fruiting stages, the symptoms of boron deficiency are most obvious. If boron fertilizer is lacking during the flowering and fruiting period, the phenomenon of flowering without fruiting will occur, which will seriously affect the yield of rapeseed.
II. Fertilization techniques and remedial measures
In order to avoid nutrient deficiency in rapeseed, we first need to apply a heavy base fertilizer, and then scientifically carry out fertilizer topdressing. For example, apply seedling fertilizer early and in increased amounts, apply bolting fertilizer steadily, apply flower fertilizer skillfully, and supplement with grain fertilizer, etc. Then, after rapeseed shows nutrient deficiency, we need to take remedial measures in time. If nitrogen fertilizer is lacking, then an appropriate amount of 5—10 jin of urea should be topdressed per mu. If phosphorus fertilizer is lacking, then 8—10 jin of calcium phosphate should be topdressed per mu. If potassium fertilizer is lacking, then 10—15 jin of potassium sulfate and about 400 jin of plant ash should be topdressed per mu. If boron fertilizer is lacking, then about 200 grams of borax should be topdressed, mixed with water and sprayed on the leaves.
The above is what the editor wants to share with you today: the analysis of rapeseed nutrient deficiency symptoms, its correct fertilization methods, and remedial measures after nutrient deficiency. I hope it can help everyone. If you want to learn more about rapeseed cultivation, remember to follow us.