The editor said:
Some fans left a message to the editor for help, he mainly grows eggplant and peppers, but recently his family's eggplant has grown into a "flowering bun", and the leaves of the pepper have suddenly become smaller, and the growth points have shrunk together. This bothered him. After exchanges and consultations with expert teachers, it turned out that the culprit was "tea yellow mite".
The tea mite is very small, generally difficult to observe with the naked eye, although its life cycle is short, but the reproductive ability is extremely strong, can occur 25 to 30 generations a year.
In the north, protected vegetables from late June to mid-September and open-field vegetables in August are in full bloom for tea mites. Summer eggplant is most severely cracked from mid-August to early September. In the south, open-field vegetables are in full bloom from July to August.
Therefore, it is the high incidence period at present.
Tea yellow mite adult
Tea yellow mites are not only harmful to eggplant, but also to peppers, tomatoes, cucumbers, watermelons, potatoes, loofahs, bitter melons, beans, cowpeas, celery, artemisia annua, radishes, etc. In addition, its harmful symptoms are often mistaken for physiological diseases or viral diseases, resulting in "drug incorrect symptoms". Therefore, it is important to correctly identify the harmful symptoms of tea yellow mites!
<h1 class="pgc-h-arrow-right" >what are the symptoms of eggplant victimization? </h1>
Adult mites and young mites concentrate on the young parts of the plant to suck up sap. The most prominent features of tea yellow mites as harmful eggplant are:
● After the young leaves are damaged, they shrink and roll longitudinally, the leaves are green on the front, the back is shiny brown, with oily luster or oil-soaked, the leaves become stiff and brittle, brown from the leaf margin, and the leaf edge is curled downward or downward.
The back of the eggplant leaf after being damaged by the tea yellow mite
● When the young stem is damaged, the surface becomes lignified, turning yellow-brown, twisting and deforming.
● When the growth point is affected, it does not grow new leaves, shrinks, forms a "baldness", becomes yellow-brown, and the plant is short.
● Flower buds and young fruits slowly shrink after being affected, and cannot flower and bear fruit. Flowers and buds fall in severe cases. The epidermis of the stem and petiole is lignified and loses its luster.
● When the fruit is damaged, the stalk, sepals, and peel surface are woody, becoming yellow-brown, the fruit becomes smaller, stiffer, and harder, the peel has no luster, and becomes a rusty wall fruit, and in the later stage, the fruit will crack and the seed will be exposed, just like the "flowering bun".
Later fruit cracking
<h1 class="pgc-h-arrow-right" > tea yellow mite is easily confused with pepper virus disease, which can be distinguished from fruits and leaves</h1>
After peppers are infected with viral diseases, the leaves often have a gradual development process, or flower leaves, necrotic spots, or cause "three falls and one baldness", which is often said by vegetable farmers: falling buds, falling flowers, falling fruits, bald tips.
Tea yellow mites are harmful to peppers and bell peppers, and also suck the juice of young parts. Young leaves, young fruits, young stems, flower buds can not grow normally, take a magnifying glass can see the tea yellow mite on the back of the leaf. The main symptom is: the affected leaf suddenly becomes smaller, so that the growth point suddenly shrinks together or dies.
Tea yellow mites harm peppers and bell peppers, and the growth points are shrunk together
Tea yellow mites are harmful to eggplant, if it is controlled in time, generally the newly grown branches will be restored, and the surface of the re-grown stems is shiny and purple. However, the young stems of peppers are yellowish brown after being killed, twisted and deformed, and the plants are short and clumpy, dry and bald, and generally do not grow new branches until the plant dies.
So, is it pepper virus disease or tea mite? Vegetable farmer friends are mainly distinguished from leaf and fruit symptoms:
Difference in leaf symptoms: The leaves affected by pepper virus disease only thicken, while the leaves infested with tea mites not only thicken, but also are significantly stiff. The leaves infected with viral diseases fade green, appear mottled or striped, the leaves twist and narrow, in severe cases, are fern-like, linear, and the leaf margins are rolled upwards, while the leaves are green on the front and brown or gray-brown on the back, with an oily luster or oil-soaked leaf margin after being infested, and the leaf margins are rolled downwards and wrinkled.
Fruit symptoms are different: Fruits infected with viral diseases will have dark green and light green spots on them, and there will be warty protrusions. After the tea mite is harmed, the fruit will harden and no longer grow, and the skin will become yellowish brown and dull.
After the tea yellow mite harms the bell pepper fruit, the surface of the fruit forms a large wooden plug
<h1 class="pgc-h-arrow-right" > tea yellow mites are also very harmful to cucumbers and watermelons</h1>
The damage of cucumbers to cucumbers is somewhat similar to that of peppers, and the leaves will suddenly become smaller, the plant will become shorter, and sometimes the heart leaves will die. The damaged melon strips have wood-bolted plaques, but generally do not crack.
Cucumber leaves suddenly become smaller
The upper heart leaves of the cucumber die
Cucumber strips appear wood-embolized plaques, but do not crack
When the tea mite is harmful to the watermelon, in addition to the smaller leaves, the young melon will also crack.
After the watermelon stem is infested by the tea yellow mite, the leaves become smaller
It is harmed by tea yellow mites, and the watermelon young melon cracks
<h1 class="pgc-h-arrow-right" > How to control tea yellow mites? </h1>
1, first of all, clean the countryside
In August, there is a lot of rainfall, and in the warm and high humidity environment, the occurrence of tea mites is large, so it is necessary to remove the weeds in the field, ditch, shed and around the shed in time.
At present, at the peak of the colonization of autumn stubble vegetables, vegetable farmers should pay more attention to cleaning the shed to eliminate the source of insects. It can be fumigated with sulfur powder before seedlings and colonization, and each 1000 square meters greenhouse is mixed with 10 kg of sulfur powder with 5 kg of dry sawdust, and in the evening when there is no wind, it is divided into 2 to 3 piles to ignite, and then open the air the next morning, and wait for 5 to 7 days to breed or colonize.
2. Pay attention to the prevention and control of seedlings
The seedlings of pepper and eggplant are relatively old, and in the process of seedling breeding, if the prevention and control of the nursery shed is not in place, the risk of the seedlings being harmed by tea yellow mites is greater. If tea mites occur at the seedling stage, it is necessary to apply the drug to control it twice before transplanting.
3. Tea yellow mites are afraid of high temperature and can be prevented and treated with large temperature differences
The most suitable temperature for the growth and reproduction of tea yellow mites is 22 ~ 28 ° C, and the relative humidity is 80% to 90%. However, tea mites are afraid of high temperatures, when the temperature reaches 34 ~ 35 ° C, lasting 2 to 3 hours, if the mite mortality rate can reach 80%, adult mite mortality rate of up to 60%. So using this, we can combine field management with large temperature difference prevention. During the day, the shed temperature is raised to 34 ~ 35 ° C, controlled for 2 to 3 hours, and the night temperature is reduced to 11 ~ 12 ° C, strengthening ventilation and reducing the humidity in the shed.
4. Medication prevention and treatment
In terms of pharmaceuticals, first of all, biological and mineral source pesticides are selected, such as 1.8% avermectin emulsion 3000 times liquid, 2.5% amniotic alkaloid water agent 500 times liquid, 45% sulfur gum suspension 300 times liquid, 99% motor oil (mineral oil) emulsion 200 to 300 times liquid. Then choose a highly efficient and low-toxic chemical pesticide, please refer to the table below.
Tea mites are mainly active on the back of fresh leaves, and prefer to feed in the creases of the leaves before they are unfolded. Therefore, focus on spraying young leaves, especially the back of the top few leaves. Generally, every 7 to 10 days spray once a drug, spray 2 to 3 times, the agent should be rotated.
There are also vegetable farmers who use pesticides to "shabu-shabu", that is, in the evening, the growth point of the tea yellow mite plant is dipped in the medicinal solution. Some vegetable farmers also release natural enemies to prey on tea yellow mites, such as Chilean small plants, cucumber new small mites, pasteurized new small mites, Si's blunt mites, Largo blunt mites, Yiyi mites, small flower bugs and so on.
5. Pay attention to crop rotation
It should be noted that the same vegetable cannot be planted for many years, otherwise it will increase the number of insect mouths of tea yellow mites. To rotate crops frequently, peppers and eggplants can be rotated with cruciferous vegetables, green onions, etc., cutting off the food chain of tea yellow mites.
At present, when the tea yellow mite is the most harmful, the vegetable farmer friends must pay attention to observation, increase vigilance, and find that the tea yellow mite is prevented and controlled in time to avoid yield losses.