1. When the nitrogen deficiency of nitrogen-deficient rapeseed is short of nitrogen, the new leaf grows slowly, leaves are few, the leaf is light, gradually chlorosis is purple, the ratio of stem to leaf is redden, the shape of the stem is pale, and pale red veins appear; the plant growth is thin and thin, the main stem Dwarf, slender, loose plant type, few pods, early flowering and short flowering time, early flowering earlier. Control methods: Nitrogen-deficient land can be composted with fermented bacteria or fully decomposed organic fertilizers. Application of coated urea, long-term ammonium bicarbonate, controlled release fertilizers, etc. In emergency, every 667m2 can be topped with 7-8kg of urea or 15-20kg of ammonium bicarbonate. After topdressing, it is necessary to water after top dressing to prevent burning of seedlings. In addition, foliar fertilizers may also be applied, and foliar may be sprayed with 1%-2% urea aqueous solution 40-50 kg. 2. Phosphorus deficiency Phosphorus leaves dark blue-green to lavender, small leaves, thick leaves, no petioles, purplish red spots or plaques at the edges of veins, small number of leaves, yellow leaves on lower leaves, easy to fall off, severe leaf margins Necrosis, the old leaves withered in advance, the leaves became narrow, the plants were short, the stems became thin, the branches were few, the plant shape was thin and upright, the roots were small, the development was poor, the lateral roots were few, and the rapeseed maturity was delayed 1-2 days. Control methods: P-deficient plots are mainly applied to calcium magnesium phosphate fertilizer or 667m2 calcium superphosphate 20-30kg, timely irrigation after application, if necessary, foliar spray Fengbao liquid fertilizer No. 1 400-500 times liquid or foliar spray Potassium dihydrogen phosphate per 667m2200-250g to 50kg water, dubbed 0.4% -0.5% of the aqueous solution, spray a total of 2-3 times. 3. Potassium-deficient seedlings are sickle-shaped, dark green leaves, small leaves, scalded leaves like boiling water, leaves rolled down, leaf surface uneven, crunchy, easy to break. Leaf rims or chlorosis between veins, initially showing small spots, followed by plaque necrosis. All severe potassium deficiency leaves withered, but did not fall off. The lack of potassium is first manifested in the vigorous metabolism of the leaves, not easy to see on the old leaves. The potassium-deficient main stem grows slowly and is small and easily broken off. The pods are short and the keratin is brown. Control methods: Potassium deficiency plots can be applied with silicate bacterial biopotassium fertilizer or 667m2 topdressing potassium sulfate or potassium chloride 5-10kg or plant ash 100kg. Can also be sprayed on the foliar potassium dihydrogen phosphate 200-250g water 50kg, dubbed a 0.4% -0.5% aqueous solution. 4. Magnesium deficiency often leaves the leaves with a lack of green, but the veins are still green, and the old leaves of their bases are yellow; flowering is often inhibited, the petals are pale, and the size of the plants does not change significantly. Control methods: When the magnesium is lacking, spray 0.1%-0.2% magnesium sulfate solution to 250kg per 667m, and continue 2-3 times. 5. The new leaves of calcium deficiency are withered and the old leaves are withered; the leaf margins and veins are white, the leaf margins are rolled down, and the apical bud bases are bent or died. Control methods: The calcium-deficient block is first sprayed with 2% of superphosphate calcium leachate and 667m2 of 50-75kg pounds, and 25-30kg of superphosphate is applied every 667m2. 6, sulfur deficiency symptoms and nitrogen deficiency symptoms are basically similar, seedlings narrow yellow, veins lacking green, later gradually throughout the whole leaf and bolting and flowering stems and inflorescences; pale yellow flowers often become white, flowering continued In addition to mature and immature pods on mature plants, there are flowers and buds. The tip of the pods dry up and about half of the seeds are stunted. The plants are short and the stems are easy to lignify or break. Control methods: When sulfur deficiency is used in formula fertilization or severe sulfur deficiency, topdressing potassium sulfate 10-20kg per 667m2. 7. Boron-deficient rapeseed lacks boron at the seedling stage, the roots turn brown, new roots are few, the roots and necks are swollen, and individual roots have small nodules; stems do not have long stories that turn white and withered; leaves are dark green, shrinking, and appear mauve Plaque or all the leaves are purple, causing dead seedlings when severe. The buds are lack of Boron, the buds are withered, the buds are brown, the moss is thin and short, the top buds are chlorosis and withering, the flowers are dark, the petals are shrinking and dry, they are not normally flowering and fruiting, and the flowers are not real, and they are not conducive to the formation of normal pods and young fruits. A large number of shedding, individual malformed development of pods of less pods, different sizes of mature. Control methods: When boron deficiency is applied to apply boron directly, apply 21% high-efficiency instant boron fertilizer 100g or 667kg borax 0.5-1kg per 667m2, and re-apply to areas with severe boron deficiency, generally mixed with nitrogen, phosphorus and potassium, or 667m2 Need to spray 100-200g of borax 50-60kg of water, continuous 2-3 times. 8. In the absence of zinc in zinc-deficient rapeseed, the chlorosis between leaves and veins is slightly thicker and the severe leaves are all white. Plants generally grow short Control methods: Zinc-deficient blocks can be topdressed with zinc sulfate, sprayed with 0.3%-0.4% zinc sulfate solution per 667m23-4kg or foliar 50kg. Tuna Loin,Frozen Tuna Loin,Fresh Tuna Loin,Yellowfin Tuna Loin ZHEJIANG RETRONX FOODSTUFF INDUSTRY CO.,LTD , https://www.retronxfoods.com