After planting wheat into the spring, the field of diseases and insect pests gradually increased, on the one hand, due to the temperature rise, increased rainfall, to give the environment for diseases and insect pests to occur, on the other hand, the seeding agent used before sowing, the effective time and effect is getting smaller and smaller, therefore, after the year of wheat "one spray three prevention" is an indispensable management work in previous years, mentioning wheat insect pests, many farmers think of the main 3 kinds, namely aphids, red spiders and suction worms, but in the actual planting process, wheat field insect pests are more than these 3 kinds , wheat straw fly is one of them, diptera, yellow submerged fly pests, due to the appearance of similar to flies, many farmers mistakenly think that it is an ordinary fly, so relax their vigilance, to the yield and quality of wheat to bring a certain impact, based on this, this content of the small helper to wheat growers to elaborate on the relevant content of the wheat stalk fly.
1. Identification of the harm of wheat straw fly
2. Basis for the prevention and control of wheat straw fly
3. Control strategies of wheat straw fly
Adult morphology
<h1 class= "pgc-h-arrow-right" > first, the hazard identification of wheat straw fly</h1>
Wheat stalk flies are mainly in the form of larval parasitism, can burrow into the stem of wheat moth, newly hatched larvae, from the leaf sheath or stem at the internodal part of the stem into the stem, or from the heart leaf part down to eat, wheat straw fly can be harmed at different reproductive stages, the symptoms are also different.
Victims before and after the jointing period
The current time is late March, wheat in many areas is entering the jointing period, some areas have entered the jointing period, the period of wheat straw fly infestation will lead to the emergence of wheat dry heart seedlings, especially after the main stem is damaged, the stem is eaten by larvae, on the one hand, it will promote the increase of ineffective tillers, on the other hand, it is easy to cause wheat to lodging, or even directly from the stem to break, seriously affecting the normal growth of wheat, and the broken wheat plant, can not be remedied.
Larvae burrow into the stem infestation
Victimization during the gestational panicle phase
Wheat into the pregnant ear stage, is to determine the wheat panicle rate and fruiting rate of the key period, the management of this period is very important, and wheat stalk fly in the pregnant ear stage after the damage, the wheat plant itself young panicle tissue is damaged, there will also be some parasitic bacteria, on the one hand will lead to a reduction in the panicle rate, on the other hand, some wheat plants that can become ears, there will also be rotten ears, bad ears phenomenon, both of which will lead to the reduction of effective ears in the field, and then reduce yield.
Victims during the panicle phase
After the wheat enters the ear extraction period, the harm of the wheat straw fly will also exist, mainly there are 2 points of influence, one, the wheat after the ear will form a white panicle, in serious cases, it is impossible to grout and grain, second, the wheat after the ear is bad, the weight of the thousand grains is reduced, the yield will also be reduced, and under the influence of the wheat stalk fly, the quality of the wheat will also be reduced, such as small grains, more grains, etc.
Larval harm symptoms
<h1 class= "pgc-h-arrow-right" > second, the basis for the control of wheat straw flies</h1>
In the process of planting wheat, the occurrence of wheat straw flies and aphids, red spiders, pulp suckers compared, the grower's attention is not enough, whether it is distinguished, or the specific hazard symptoms are not very well understood, so the small helper in this piece mainly from the occurrence of wheat straw flies, to help growers more convenient to understand.
Basis for control in terms of varieties
Different varieties of wheat straw fly occurrence degree is different, for example, after years of observation, wheat leaf surface relatively smooth varieties compared to varieties with a lot of fur on the leaf surface, the occurrence of wheat straw fly will be relatively heavy, the reason is that there are many fur varieties on the leaf surface, not conducive to the survival of larvae, so the harm will be lighter, but there is also a premise, the external planting environment is the same, only refer to the case of varieties, because, the same varieties are planted in different areas, wheat straw flies Have the possibility of changes in weight.
Basis for control in terms of sowing time
China is mainly winter wheat," sowing time is basically around the beginning and middle of October, about planting wheat, farmers have such a proverb "early autumn equinox, late frost, cold dew planting wheat is just in time", this proverb is not suitable for all planting areas, but most areas can learn from, for example, if the sowing time is earlier than the autumn equinox of wheat fields, the occurrence of wheat stalk flies in the second year is relatively serious, one of the reasons for sowing wheat prematurely, due to higher temperatures, is prone to flourish, and the resistance of long wheat itself is relatively weak. The harm of insect pests will be aggravated. If sowing is later than the cold dew season, wheat has relatively few effective tillers in the past few years, plant growth is relatively weak, and it is also vulnerable to wheat straw flies.
Basis for the prevention and control of pre-sown seed mixing
Wheat sowing before seeding is an effective measure to prevent underground pests, some aboveground pests and some diseases, in recent years, pre-sowing seeding has been popularized, but there are still a small number of farmers who do not mix seeds before sowing, and through observation, the wheat after sowing before sowing is greatly reduced than in the wheat fields that are not mixed, for example, the use of 600g/L of imidacloprid for seed mixing before sowing, the occurrence of wheat straw flies and the infestation are greatly reduced.
Basis for water and fertilizer control
Soil fertility, sufficient water and fertilizer, water retention and fertilizer retention ability of wheat fields, the occurrence of wheat stalk flies compared to poor soil, poor water retention and fertilizer retention ability of wheat fields, as a whole, much smaller, because the former is mainly a type of wheat field, the latter two or three types of wheat fields are more, growing in the former wheat field, its own resistance is better than the wheat in the latter wheat field, such as wheat in drought for a long time, the plant growth is short, wheat appears yellow, its own resistance is weak, the occurrence of wheat stalk flies and the degree of harm increased.
<h1 class="pgc-h-arrow-right" > third, the control strategy of wheat straw fly</h1>
Wheat stalk flies can occur 2 generations a year, with larval hosts overwintering in gaps that add weeds, disease residues and soil, and by around March of the following year, as the temperature rises, the larvae begin to pupate and then feather into adults, so farmers can effectively reduce the occurrence of wheat stalk flies by doing a good job of initial prevention.
Select varieties with strong insect resistance and pre-sow seed mixing
Purchase suitable for local planting of insect resistant varieties, in addition to pay attention to the narrow leaf base, fur relatively long varieties, wheat stalk fly occurrence is relatively weak, can rely on the characteristics of the variety to reduce the harm, after the purchase of seeds, before sowing to carry out seed treatment, commonly used seed mixing agents are 70% imidacloprid (357-500 grams of mixed seeds 100 kg of seeds) and 30% of thiothiazine (450-600 ml of seed mixing 100 kg of seeds) and so on.
Emphasis is placed on field management
Through normal field management to reduce the harm of wheat stalk flies, according to local conditions to ensure the safe and normal growth of wheat, increase their own resistance, create conditions that are not conducive to the occurrence of wheat stalk flies, such as its sowing time should be timely, early to mid-October; the second sowing density should not be too dense, the sowing amount per mu can be 25-30 catties; the third should be deep ploughing of the land, especially the land that has been rotated for many years, deep ploughing of about 10cm; its four water and fertilizer management should be appropriate, especially the plot with relatively poor water retention and fertilizer retention ability. The amount of bottom fertilizer used under normal circumstances is about 100-120 kg, which can be appropriately increased to 150 kg, and the urea can also be increased to 20-25 kg per mu when topdressing, for the demand for water, overwintering period, rejuvenation period, jointing period, pregnant ear stage, etc., if there is drought in the field, irrigation and watering should be carried out in time.
Appropriate spraying of chemicals for control
Because the wheat stalk fly is a larval way to parasitize in the stem as a pest, so to the control work brings a certain degree of difficulty, because the larvae are difficult to directly contact the liquid medicine, farmers on the one hand to pay attention to the control period, can be in the early stage of adult bloom control, the period has not yet spawned or spawned very little, is the best period for control, on the other hand, pay attention to the choice of the right agent, commonly used 10% imidacloprid wettable powder 2500 times liquid or 50% octylthion emulsion 2000 times liquid spray and so on.
Summary: Wheat straw fly harm is relatively large, to attract the attention of growers, at present is the early stage of wheat stalk fly, I hope that this content can bring help to everyone, timely prevention and control measures, to ensure the final high yield of wheat.