First, the symptoms of pepper fertilizer deficiency
1, nitrogen deficiency
At this time, the growth of pepper plants is poor, the plants are thinner, and old leaves are easy to appear. The color of leaves will change from dark green to light green and then to yellow, becoming smaller and thinner. Yellowing will spread from vein to the whole leaf, and then slowly spread from the lower leaf to the upper leaf. In the later stage, leaves will fall off, petiole and leaf base will turn red, which will lead to the increase of flowering node of pepper and the phenomenon of near-top flowering. In more serious cases, flowers and fruits will fall off. If nitrogen is lacking in the early growth stage, the plant growth will basically stop at this time.
Preventive measures: topdressing ammonium nitrate on the roots of pepper plants with water, and spraying 300 ~ 500 times urea and 100 times sweet and sour on the leaves.
2. Phosphorus deficiency
Similar to nitrogen deficiency, this plant is stunted, short and prone to old leaves. The leaves are dark green, the lower veins are reddish purple, and the top leaves are dark green with uneven surface. The top of pepper plants turns black or dies, and the growth will stagnate. The veins of the lower leaves are red and begin to descend from the bottom to the top. At this time, it is easy to form a short style, resulting in late fruit, small fruit, late maturity or no fruit at all.
Purple patches with irregular shapes and different sizes sometimes appear on the green fruits of pepper, ranging from 1 to several. What's more, half the fruits are covered with purple patches.
Preventive measures: topdressing the roots of plants with available phosphate fertilizer, or spraying 500 times of potassium dihydrogen phosphate and 200 times of calcium superphosphate extract on the leaves.
3. Potassium deficiency
Symptoms mainly appear at flowering stage, and begin to appear on mature leaves when the fruit expands. The tip and edge of the lower leaf began to turn yellow, and then yellow spots were formed between veins along the veins. In contrast, the leaf margin will gradually dry up, in sharp contrast to the dark green part near the vein, and then spread from the inside out to the whole leaf, showing burning or necrosis. In severe cases, the leaves will turn yellow and die, and a large number of leaves will fall from the lower part, from the old leaves to the heart leaves, and from the tip to the petiole. There will be stripes between the leaf margin and veins, and the leaves will shrink.
Pepper plants are easy to lose water and cause wilting. If the flowering period is short of potassium, the plant will grow slowly, the leaf edge will turn yellow, and the leaves will fall off easily, which will lead to fruit deformity and hinder the expansion period, and then the fruit will be small and easy to fall off.
Preventive measures: Foliar spraying 500 times of potassium dihydrogen phosphate or 1% plant ash extract to supplement potassium fertilizer.
4. Calcium deficiency
If there is calcium deficiency at flowering stage, the plant will be dwarfed, the top leaf tip and leaf edge will turn yellow, and the lower leaves will remain green, but the leaf edge near the growing point will turn brown or stop dying. In the later stage, these leaves also dry inward from the edges. There are also some leaves whose middle ribs will protrude, causing the top of the fruit to brown and rot. In the late stage of calcium deficiency, yellow-white circular spots will appear on the leaves, and the edges will turn brown, and the leaves will slide from top to bottom. Finally, the whole plant is polished, and the pepper fruit is small and yellow, or produces navel rot or stiff fruit.
Precautionary measures: For the soil lacking calcium and vegetables such as peppers that need more calcium, more calcium fertilizer should be applied appropriately. It is suggested that 50 ~ 75 kg of calcium nitrate should be added per mu, and appropriate amount of biological fertilizer and organic fertilizer should be applied to create a good soil environment for the absorption of calcium fertilizer. At the beginning of flowering, calcium fertilizer can be sprayed on new leaves and newly grown inflorescences.
5. Lack of trace elements such as sulfur, boron, molybdenum, iron, manganese and zinc will do harm to the growth of pepper. Preventive measures can be supplemented by spraying on leaves.
Second, the correct fertilization method of pepper
1, seedling fertilizer
In order to ensure the normal growth and development of pepper seedlings, it is necessary to prepare fertile seedbed soil. The general formula of pepper seedbed soil is: 6 parts of field soil, 3 parts of decomposed horse manure or peat, fine furnace ash 1 part, and 2 ~ 3 kilograms of chicken manure per square meter.
In order to cultivate strong seedlings, prevent the slow growth of seedlings and improve the survival rate after planting, nutrition pots are mostly used to raise seedlings at present.
2. Base fertilizer
When preparing soil and applying base fertilizer before planting pepper seedlings, we should insist on? High quality farmyard manure with chemical fertilizer? The principle of. It is suggested to apply about 8000 kg of high-quality farm manure (soil miscellaneous fertilizer and chicken manure) and about 50 kg of ternary compound fertilizer per mu.
3. Surface treatment
The main function of fertilization is to promote the growth and health of pepper plants from slow planting to flowering, and lay a good foundation for flowering and fruiting. Generally speaking, 7 ~ 10 days after pepper planting, the seedlings will gradually resume growth. It is suggested to topdressing 8 ~ 10 kg of high nitrogen liquid fertilizer with low concentration. The bud stage should not only meet the nutritional needs of pepper plants for germination, branching and budding, but also prevent excessive growth. Therefore, it is necessary to apply nitrogen and phosphorus fertilizer together, and it is suggested to topdressing urea 5 ~ 7.5 kg and calcium superphosphate 7.5 kg per mu.
In most pepper plants? Four fights? After the pepper bears fruit, it needs more nutrients because of the expansion of the pepper fruit and the continuous branching of the plants, so this period is the period when the demand for fertilizer is the greatest in the whole growth period. It is suggested to apply 25 ~ 30 kg high potassium compound fertilizer per mu. After each fruit harvest, topdressing should be done. Pay attention to the coordination of water and fertilizer to preserve soil moisture. Because the concentration of fertilizer is relatively high, furrow application or strip application should be carried out at a distance of 6 ~ 10 cm from the plant. Water in time after each topdressing to improve fertilizer efficiency and prevent fertilizer damage.
After summer, the temperature will gradually decrease. Beginning of autumn? And then what? Summer? Once before and after fertilization, it is suggested that biogas slurry 1000 kg+ NPK compound fertilizer 20 kg should be applied topdressing per mu. This method can promote the germination of new branches of pepper and increase the number of flowering and fruit setting of pepper.
Pepper can be sprayed with 0.5% urea and 0. % ~ 0.3% potassium dihydrogen phosphate promoted fruit setting and fruit expansion at flowering stage. In addition, trace element boron will have a great influence on the yield and quality of pepper. Spraying 0.2% borax or 0. 1% boric acid aqueous solution on leaves during flowering and fruit setting for 2 ~ 3 times continuously.
Pepper topdressing should avoid excessive fertilization, uncoordinated nutrients and inappropriate application methods and time.