PREVENTION OF WHITEFLY ON GUAVA TREES

In recent years, the area planted to guava trees has increased considerably in the Mekong River Delta. Guava is a easily-grown fruit tree, quick bearingfruit, often chosen to be intercropped with other plants in the garden or grown in a specialized form. Many delicious varieties of guava such as Queen guava, purple guava, seedless guava, Taiwanese guava, etc. Due to high economic efficiency, the guava growing area is increasingly expanding.

Guava trees are often attacked by many pests, in which whitefly is a fairly common pest in the Mekong River Delta region, causing quite heavy damage on guava trees, significantly affecting yield and quality. ty of fruit, reducing costs, and reducing farmers income.

Whitefly has the scientific name Aleurodicus dispersus, belongs to the family Aleyrodidae.

- Adults are small, about 1.5-2mm long, have two pairs of white wings, short antennae.

- Young planthoppers have white tentacles covering the body.

- Powdery mildew lays eggs on the underside of leaves, scattered in spiral circles and covered with fine white waxy hairs, each spiral has about 15 to 25 eggs. Eggs are about 0.5 mm long. About a week after laying, the eggs hatch into young planthoppers.

- The young planthopper stage consists of 4 years old and lasts about 1 month. Young planthoppers secrete white waxy fibers all around the body, these waxy tendrils have created a white powdery cotton layer on the underside of leaves.

- Both adult and young planthoppers are concentrated on the underside of leaves sucking sap. They cling to young buds, young leaves, on fruits (especially young ones) causing young buds, young leaves to be curled, young fruits may fall. If it is heavy, it will affect the yield and quality of guava. In addition, the waste of powdery mildew contains bile, which is a favorable environment for soot fungi to grow, reducing the photosynthetic area of ​​leaves, thereby affecting the growth and development of plants.

- Whitefly has many natural enemies such as parasitic wasps, carnivorous flies, nettle beetles, white ladybugs, parasitic fungi, etc.

Hình ảnh: Vòng đời của rầy phấn trắng Aleurodicus dispersus

Image: The life cycle of the white planthopper Aleurodicus dispersus

To prevent powdery mildew, some measures should be applied:

- Do not plant too thick guava, regularly prune and remove diseased branches, branches hidden in the foliage, old branches that cannot bear fruit so that the garden is always open.

- Regularly clean up the grass, trash, and rotten leaves around the base to break the habit of foul ants living in symbiosis with whitefly.

- Using a water pump with high pressure to spray water strongly on the places where there are many hoppers clinging will have the effect of washing away the hoppers.

- Regularly visit the garden to detect and spray insecticides to kill leafhoppers in a timely manner, especially in the period when the tree is having young buds, young leaves, flowers and fruits. Spray a combination of Osago 80 WG (Pymetrozine 60% + Nitenpyram 20% w/w) and SK Enspray 99 EC mineral oil with the recommended dose:

Mix a pack of Osago 80WG/15gr + 40ml SK EnSpray mineral oil for a 25 liter water bottle

+ Osago 80WG (Pymetrozine 60% + Nitenpyram 20% w/w) is a mixture of drugs to prevent groups of sucking insects such as aphids, aphids, thrips, etc. Because both active ingredients directly affect the system. When the insect  nerve is hit by the drug, the planthopper immediately stops stinging and stops transmitting viral diseases. Osago 80WG has drainage, deep penetration, contact and toxic taste, is quickly absorbed by the plant, is less washed away, takes a long time to decompose, has a long-lasting effect, so it is highly effective to prevent hoppers and is less expensive because it has to be sprayed. again.

+ SK EnSpray 99 EC mineral oil is a high quality mineral oil extracted from crude oil distillation technology to prevent pests on many crops, effective on stinging insects such as spiders, thrips, mealybugs , hoppers, worms draw charms, ...

Note:

Guava is a fruit that is eaten fresh and has many stages of large, small or flowering fruit on the tree, so when mixing the mixture before spraying, pay attention to the following:

Put ½ of water in the bottle, then mix the insecticide first, stir gently to dissolve.

SK EnSpray mineral oil mix 40ml separately with the remaining amount of water, then pour it into a bottle to gently stir the mixture, spray it in the early morning or late afternoon.

Avoid spraying SK EnSpray mineral oil higher than the recommended dose, it will affect plants especially when young buds, young fruits and when flowering.