Rational application of nitrogen fertilizer to control plant diseases and insect pests

Nitrogen fertilizer is a commonly used fertilizer, in fact, it can be proved in a lot of research and practice that reasonable fertilization can control crop diseases and insect pests. In the process of fertilization, it can not only fertilize, but also not pollute the environment, which can be said to kill many birds with one stone. So how to use nitrogen fertilizer to control plant diseases and insect pests?

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The main results are as follows: 1. Ammonium nitrogen fertilizers such as ammonium bicarbonate and ammonia have strong volatility and have certain stimulation, corrosion and fumigation to pests, especially for small and weak endurance pests such as red spiders, aphids and thrips. Application method: use 1% ammonium bicarbonate or 0. 5% ammonia solution is sprayed evenly, once every 5 mi 7 days, 2 Mel 3 times in a row.

2. Urea has the function of destroying insect chitin. "urine washing mixture", which is mixed with urea, washing powder and water according to the ratio of 4 to 1, 400, has a good control effect on aphids, cabbage insects, red spider beads and other pests that harm cotton, vegetables and flowers.

3. When wheat rust occurs sporadically, spray with 50% fresh urine or 3% ammonium sulfate aqueous solution has a good effect.

Control of plant diseases and insect pests in winter-in winter, most of the pests overwinter in eggs, larvae, cocoons and adults (shell insects) in soil, litter, weeds, bark, cracks, bud axils, branches and so on. Bacteria are mostly overwintered by mycelium and spores in the disease residue and soil. For example, the leafhopper overwinters the eggs on the branches of sweet-scented osmanthus, yinxiang and camphor (there is a white substance on the spawning place), and the branches above wither and die; the leafy banyan planthopper overwinters with nymphs and eggs in the axils of the leaves. It is necessary to remove these overwintering diseases and insects and clean the overwintering places in time.

Withered branches, fallen leaves and weeds should be removed; diseases and insect pests and overlapping branches should be cut off, which can directly eliminate a large number of overwintering pests and pathogens, improve plant ventilation and light transmission conditions, and enhance tree potential in the coming year; artificial removal of cocoons, egg blocks, buds, scraping of overwintering scale insects; ploughing soil sun resistance to reduce overwintering diseases and pests; at the same time, pay close attention to the control of trunk borer pests.

The trunk should be whitened after falling leaves to before the soil is frozen, which can not only kill the diseases and insects overwintering on the trunk, but also effectively reduce the freezing injury. The whitening materials are raw lime, sulfur (or stone-sulfur mixture), water and salt, and the whitening height is 1.1 meters.

We should also pay attention to anti-freezing in winter. The freezing injury is caused by the cell death caused by the non-lipid gap with high permeability on the plant protoplasmic membrane and the leakage of intracellular substances caused by the sudden drop of air temperature. The twigs can be cut off in early winter to promote the Lignification and nutrition accumulation of the branches, improve the cold resistance, stop applying nitrogen fertilizer to the trees, and properly apply some phosphorus and potassium fertilizer; spray antifreeze to enhance the frost resistance of plants and reduce the mechanical damage to the membrane system caused by the formation of frozen crystals in the protoplast at low temperature; root neck soil cultivation can prevent frostbite of root neck and tree roots, and reduce soil moisture evaporation at the same time. For valuable tree species that are not cold-resistant, wind barriers can also be erected in the upwind direction of the trees. Prevention and control of diseases and insect pests of palms

Most palms are native to tropical and subtropical regions with high temperature and humidity, and the climate in this area is very suitable for the breeding and reproduction of diseases and insect pests. With the continuous expansion of plant production and introduction area, the types and harm degree and scope of diseases and insect pests have gradually increased, and the prevention and control has become more and more complex, which has become a major problem that can not be ignored in palm cultivation and management. On the basis of previous research results, this paper makes a superficial discussion on the common and relatively serious diseases and insect pests and control methods of palm plants in the Pearl River Delta region of Guangdong Province.

1. Major diseases:

1. Heart rot: harms many kinds of palm plants, mainly harms triangle coconut, wine bottle coconut, red palm, loose tail sunflower, fish tail sunflower, coconut, fox tail Bangzi and so on.

Prevention and treatment: eradicating diseased plants and burning them or burying them deeply is one of the most effective control methods. After eradicating the diseased plant, 1% Bordeaux solution should be sprayed to the surrounding environment (including plants) to protect it. The harm of the disease is so great that if it is negligent, it will lead to varying degrees of loss. The disease focuses on "prevention". 65% zinc and 300 times ammonium are sprayed once a week from March to June every year, and fertilizer and water management are strengthened, moisture control is not biased, and nitrogen fertilizer is not applied to prevent the harm of shell insects.

two。 Dry cracking disease: mainly harms single-dried plants, such as coconut, horseradish and other common palm plants.

Prevention and treatment methods: we should prevent the mechanical damage to the tree trunk, strengthen the fertilizer and water management of the diseased tree, apply less chemical fertilizer and more organic fertilizer to prevent drought and waterlogging, carry out surgical treatment on the tree trunk, scrape off the diseased tissue with a knife, apply 1%HgCI or potassium permanganate disinfection on the incision, and then apply Ruisse or Bordeaux slurry to treat the wound for three or five times, then seal the wound with glass glue or cement paste.

3. Root rot: mainly harms triangle coconut, Washington coconut, etc., causing root tip blackening and rot, leading to plant death.

Prevention and control methods: in prevention and control, we should mainly pay attention to "prevention". In cultivation, we should ensure that the soil is well drained, do not accumulate water, and reduce the groundwater level as much as possible. Chemical control includes 500-700 times carbendazim or regulating soil acidity and alkalinity and so on.

4. Leaf spot disease: mainly harms king coconut, short-spiked fish tail, false betel nut, loose-tailed sunflower, betel nut, sea jujube, golden horseradish, triangular coconut and so on.

Prevention and control methods: first cut off the diseased leaves, appropriately increase the application of phosphorus and potassium fertilizer, foliar spraying 1% Bordeaux solution, Dyson zinc 500ml 700 times, crown fungus copper 800ml 1000 times or 50% gram carbendan 300ml 500 times, once a week for several weeks. & bsp

5. Anthrax: mainly harms false betel nut, king coconut, golden horseradish, fish tail anemone, sea jujube, triangular coconut and so on.

Control methods: first of all, to strengthen fertilizer and water management, enhance plant disease resistance, the initial stage of the disease can spray good life 500 times, 50% carbendazim 800 times, 75% chlorothalonil 500 times, crown fungus copper 600-800 times Dysen zinc, Fumei 800 times, and so on, several times in a row.

2. Major insect pests:

1. Red striped beetle: mainly harms the genus Jujube. Both larvae and adults caused harm, and the dense drilling of larvae was the most serious, and the larvae bored from the inside of the leaf sheath until the tree trunk caused plant death.

Control method: this insect should be discovered early, the adult can be caught when the adult is Eclosion, or 80% dichlorvos 600 times, spray the adult worm, for the larvae can be 90% trichlorfon, 80% dichlorvos 200-300 times plus potassium amidophos 500 times spray tree body and cotton dipped in high concentration dichlorvos faecal hole and sealed fumigation for a week, which can be effectively controlled several times in a row. It is worth noting that the insect has spread throughout most parts of the province (especially in Zhanjiang area, causing damage to the king coconut), and even professional breeders have supplied the restaurant with edible larvae.

two。 Scale insects: damage the leaves of sunflower, balsam nut, brown bamboo, false betel nut and so on.

Control methods: after first cutting off the leaves of diseases and insect pests, spraying pine mixture 16-20 times, 40% omethoate 800times, 44% dimethoate 1000 times, 25% imidophos 1000 times and adding 1000 times mechanical oil or quick culling 1000 times, once a month, the control effect can be achieved by spraying 3 times.

3. Moth butterfly larva: mainly harms the leaves of loose-tailed sunflower, false betel nut, beautiful needle sunflower, triangular coconut and so on.

Control methods: after cutting off the leaves of diseases and insect pests, spray methamidophos 500times, dichlorvos 900times, deltamethrin 4000 times, several times in succession.

4. Beetle larvae, mole cricket and other underground pests: harm a variety of plant roots, especially triangular coconut, Hawaiian coconut, three medicine betel nut and so on.

Control method: soil mixed with trichlorfon powder, after the plant is planted, it can be drenched 500-800 times methyl isophos near the root, 5% Wangdan 500 times, or furoshudan, Suhua 203 and so on.

In addition, damage to coconut, sunflower, king coconut, king coconut, Washington coconut and other undeveloped heart leaves, prevention and control can strengthen quarantine, comprehensive spraying of new seedlings, regular spraying of dichlorvos 600 times, enemy killing 800 times, and so on.