Pesticide Use for Aphid Control on Open-Field Peppers and Management Techniques for the Whole Growth Period and Mid-to-Late Stages

Pepper, also known as: ox horn pepper, long pepper, sweet pepper, bell pepper, green when unripe, turning red, orange or purple-red when ripe, with a spicy taste.So what should you do when there are aphids on open-field pepper plants? What pesticide should you spray? How many days is the whole growth period? What are the mid-to-late stage management techniques?

What should you do when there are aphids on open-field pepper plants? What pesticide should you spray?

1. Clean the field: clear weeds in and around the field to reduce sources of the pest.

2. Mulch cultivation: take advantage of the negative taxis of aphids toward silver-gray to achieve the purpose of repelling aphids and preventing disease.

3. Yellow trapping: take advantage of the taxis of aphids toward yellow by placing yellow sticky traps in the field to trap and kill winged aphids. The yellow board is 1×0.2 m in size, the yellow part is coated with machine oil, inserted between pepper rows, 60 cm above the plants, with 30 boards per mu.

4. Chemical control: at the initial stage of occurrence, use 10% imidacloprid wettable powder at 1000 times dilution, or 50% pirimicarb wettable powder at 1000 times dilution, or 10% duolaibao emulsion at 1000 times dilution, or 10% chlorfenapyr at 3000 times dilution, or 50.5% nongdile at 1500 times dilution, or 47% lesiben emulsion at 1000 times dilution, etc., used alternately, once every 7-10 days, for 2-3 consecutive times.

How many days is the whole growth period of open-field peppers?

The pepper growth cycle includes four stages: germination stage, seedling stage, flowering and fruit-setting stage, and fruiting stage.

1. Germination stage, from seed germination to the appearance of the first true leaf, generally about 10 days. During the germination stage, nutrients mainly come from the seed, and the absorption capacity of the young root is very weak.

2. Seedling stage, from the appearance of the first true leaf to the appearance of the first flower bud. It takes 50-60 days. The seedling stage is divided into two phases: before 2-3 true leaves is the basic vegetative growth stage; after 4 true leaves, vegetative growth and reproductive growth proceed simultaneously.

3. Flowering and fruit-setting stage, from the budding of the first flower to the fruit set of the first flower, generally 10-15 days. During this period, the contradiction between vegetative growth and reproductive growth is particularly prominent, and measures such as water and fertilizer management are mainly used to regulate the relationship between growth and development, vegetative growth and reproductive growth, and aboveground and underground growth, so as to achieve balanced growth and development.

4. Fruiting stage, from the fruit set of the first pepper to the end of harvest, this stage lasts a relatively long time, generally about 50-120 days. The fruiting stage is dominated by reproductive growth while continuing vegetative growth, and requires large amounts of water and fertilizer. During this period, water and fertilizer management should be strengthened to create good cultivation conditions, promote vigorous growth of both plants and fruits, and continuous fruit setting, so as to achieve the goal of a bumper harvest.

Appendix: Mid-to-late stage management techniques for open-field peppers

I. Skillful application of topdressing and timely watering

1. Timely topdressing

Because peppers bear many fruits and are harvested multiple times, the fertilizer requirement is relatively large in the mid-to-late stages, so topdressing is necessary. The basic principle of pepper topdressing is “control nitrogen, stabilize phosphorus, supplement potassium and match with trace elements.” For plots with good soil fertility and sufficient base fertilizer, combined with watering, apply water-soluble fertilizer (drenching fertilizer) at 4 kg per mu or urea 8 kg plus potassium sulfate 5 kg; for plots where no organic fertilizer was applied as base fertilizer, topdressing is insufficient, and there are signs of premature aging, after each harvest, combined with watering, apply water-soluble fertilizer at 6 kg per mu or urea 10 kg plus potassium sulfate 6 kg, used continuously for 2-3 times.

2. Spray foliar fertilizer. By spraying foliar fertilizer, nutrition is enhanced, plant resistance is improved, and the yield and quality of peppers are improved. When the plants bloom heavily and the number of set fruits increases, root-outside topdressing can be used, with 0.1% urea plus 0.2%-0.3% potassium dihydrogen phosphate and other trace fertilizers, which can significantly increase yield.

3. Supplement trace elements. Spray foliar zinc sulfate at 1500 times dilution, chelated high calcium, Guoguang high potassium and other trace fertilizers to improve the heat tolerance of peppers and prevent the appearance of pepper little-leaf disease.

II. Pruning

Timely remove excess vegetative branches, injured branches and diseased branches below the branching point, remove tender shoots, and promptly remove old leaves, dead leaves and diseased leaves in the lower part of the plants, to promote the concentration of nutrients in the fruits, facilitate ventilation, air permeability, light penetration and cooling, control the spread and transmission of pests and diseases, and effectively increase single fruit weight.

III. Prevent the “three drops”

The phenomenon of flower drop, fruit drop and leaf drop during the fruiting stage of peppers is called the “three drops,” and the “three drops” have a great impact on pepper yield. To prevent and control the “three drops,” the following points should mainly be achieved: cultivate strong seedlings; choose sandy loam soil with good drainage, avoid continuous cropping, and implement crop rotation; rational close planting and strengthen water and fertilizer management so that plant growth and development are moderate; according to the temperature, use different concentrations of fruit-setting hormone to spray flowers. In principle, when the temperature is high, the concentration should be lower, and when the temperature is low, the concentration should be higher. The general concentration is 30-50 mg/kg. Each flower should be sprayed only once, and repeated spraying is not suitable, and spraying should be done on cloudy and rainy days or in the evening; pay attention to the prevention and control of pests and diseases.

IV. Intertillage and weeding

In the mid-to-late stages of pepper growth, due to watering, fertilization, rainfall and other farming operations, soil compaction and damage to soil moisture are likely to occur. Before the canopy closes, the film should be broken in time for intertillage, so as to promote deep root growth and prevent premature aging; the depth and range of intertillage should be based on not damaging the root system; generally, after intertillage and hilling, timely watering is beneficial to pepper growth; removing weeds is beneficial to the vegetative growth and reproductive growth of peppers; if the field management work throughout the whole growth period of peppers is done well, the plants grow robustly, stress resistance is relatively enhanced, pest and disease damage is lighter, the number of pesticide applications can be reduced, production costs are lowered, yield increases, and the income from peppers can also be increased.

V. Disease control

The main diseases in the mid-to-late stages of peppers include viral disease, phytophthora blight, anthracnose, bacterial wilt and sunscald, and the insect pests include fruit borers, red spider mites, aphids, etc.

(I) Control of pepper diseases

1. Viral disease: aphid control should be done well to reduce virus transmission. After peppers are infected, they suffer flower drop, fruit drop and leaf drop. Generally, yield is reduced by 20%-30%, and in severe cases by 60%-70%. When aphids are found in the field, spray immediately for control, using 20% acetamiprid 8-12 g or 70% imidacloprid 6-8 g, mixed with 60 kg of water, and sprayed evenly to control aphids. At the early stage of disease occurrence, use 30% dufulin at 60 g per mu mixed with 60 kg of water to spray for control of viral disease, once every 5-7 days, for 2-3 consecutive times, which can achieve good results. If the disease is severe, with leaf shrinkage and shortened internodes, add 98% sodium fusidate or brassinolide 4 g to the above agents to promote faster cell division and reduce damage.

2. Anthracnose: insufficient fertilization or excessive nitrogen fertilizer, poor field drainage, and sunscald on fruits all easily induce anthracnose. High temperature and rainy weather are conducive to the occurrence and epidemic of anthracnose. Control methods: apply more phosphorus and potassium fertilizers to improve the disease resistance of plants; plant reasonably densely to reduce the occurrence of sunscald; at the early stage of disease occurrence, spray: 65% zineb at 500 times dilution; 70% thiophanate-methyl at 1000 times dilution. Once every 7-10 days, for a total of 2-3 sprays.

3. Phytophthora blight: control methods: chemical control should be carried out at the early stage of disease occurrence. Choose 72.2% propamocarb aqueous solution at 600-800 times dilution for root drenching. Or use 52.5% cymoxanil and famoxadone 25 g per mu mixed with 60 kg of water for even spraying.

(II) Control of pepper insect pests

1. Fruit borer: the key is to seize the period from the peak hatching stage to the peak second-instar stage, when the larvae have not yet bored into the fruit, to apply the pesticide. You can use 200sc chlorantraniliprole (Kangkuan) 20 mL per mu mixed with 60 kg of water for spray control, with very good control effect.

2. Red spider mite: the key to chemical control is to promptly spray for control when curled leaves are found on central plants in the field. The focus of spraying is the young tender parts of the upper part of the plants, especially the backs of the top few tender leaves. You can spray with 1.8% abamectin at 1500-2000 times dilution. After the first spraying, a second spraying must be done within 3-5 days for the best effect, and then spray again after 7 days, for 3 consecutive times. Conventional spraying should be carried out after 5 p.m.

3. Aphids: mainly damage plant leaves and cause leaf deformity. In production, prevention should be carried out in advance, using 20% acetamiprid 8-12 g or 70% imidacloprid 6-8 g, mixed with 60 kg of water, and sprayed evenly for control. If the weather is dry and the number of aphids is large, continuous spraying for control is necessary.

VI. Prevent premature aging of peppers in the late stage

Peppers often suffer premature aging of the plants due to lack of water and fertilizer in the late stage. At this time, attention should be paid to taking measures to keep the plants robust, prevent plant decline, promote fruit ripening, and ensure yield. Do a good job in the “three preventions”: prevent excessive vegetative growth, prevent shading and closure between rows, and prevent delayed fruit picking. Maintain soil moisture, with the principle of seeing dry and wet on the surface. Pay attention to supplementary fertilization in the late stage. Although the late growth stage of peppers has passed the peak period of fertilizer demand, sufficient fertilization is still required. Pay attention to the principle of more frequent fertilization with smaller amounts each time.

VII. Timely harvesting

1. Green peppers: most peppers are eaten as green tender fruits, so as long as they grow to a certain size they can be picked; but green peppers are most suitable for picking when the fruit skin is dark green, relatively firm and glossy; early fruits should be picked appropriately earlier so as not to affect plant growth, and they can also fetch a good price; mid- and late-stage fruits should be picked after reaching a certain degree of maturity to improve quality and yield; because green peppers are marketed earlier and sell at a relatively high price, picking green peppers for market can obtain relatively high economic value. Green peppers can be picked and marketed 15-20 days after the flowers fade. The same plot is generally picked once every 2-3 days.

2. Red peppers: for harvesting red peppers, they can generally be picked about 50 days after the flowers fade. Harvesting should be timely, and they should be picked as they turn red. Otherwise, it will affect plant growth and fruiting.

While picking peppers, take diseased fruits, insect-damaged fruits, dead branches and rotten leaves out of the pepper soil and destroy them centrally to reduce damage.