What are the common diseases and insect pests in maize seedling stage? How to prevent and cure scientifically?

The period from jointing to seedling emergence of maize is called the seedling stage, and it is also the stage with the most species, the most concentrated occurrence and the most serious harm of pests in the whole life of corn. So, what are the common diseases and insect pests in maize seedling stage? How to prevent and cure scientifically?

First, what are the common diseases and insect pests in maize seedling stage?

The main diseases in maize seedling stage are maize root rot, seedling blight and so on, and the main insect pests are grub, thrips and so on.

Second, how to scientifically control common diseases and insect pests in maize seedling stage?

1. Root rot

Symptoms: corn root rot is caused by rot mold, which is mainly characterized by the gradual browning, softening and decay of mesocotyl and the whole root system, serious hindrance of root growth, short plants, yellowing leaves and seedling death.

Control methods: in areas where root rot disease is serious, seed coating agents containing fungicides should be used to coat corn seeds, or seeds should be mixed with fungicides before sowing. For root rot caused by Fusarium and Rhizoctonia, 75% chlorothalonil wettable powder, 50% carbendazim wettable powder and 80% mancozeb wettable powder can be used to mix seeds with 0.4% of seed weight, or Weifu seed dressing agent can be used to mix seeds directly. For Rhizopus root rot, ovicidal agents such as 58% metalaxyl manganese zinc wettable powder, 64% alum wettable powder and Luheng No. 1 seed dressing agent should be used to mix seeds with 0.4% of the seed weight.

2. Seedling blight

Symptoms: generally show symptoms from emergence to the three-leaf stage, first causing maize seedlings base 1-2 leaves yellowing, leaf tip and leaf (margin) drying up, from the basal leaves gradually to the upper, and then cause heart leaf curl, serious plant peripheral leaves dry, heart leaves withered and wilted, plant death.

Prevention and control methods: timely use of drugs in the early stage of seedling blight. You can use 70% thiophanate 800 times, or 20% triadimefon 1000 times, or triadimefon 3000 times. Spraying twice (each time is about 7 days) can be sprayed at the same time as spraying Nongxizhi, blue Jingdian, Zhuang Han, Liugao dihydrogen potassium efficient nutrition regulator to promote early seedling development, to enhance plant stress resistance, disease resistance, can effectively prevent and control seedling blight.

3. Grub

The insect likes to eat newly sown seeds, roots, tubers and seedlings. It is a worldwide underground pest with great harm.

Prevention and control methods:

(1) weeding

Ploughing, drying and weeds on the edge of the field should be carried out as soon as possible. To reduce the number of larvae and pupae in the soil.

(2) catching larvae

Every morning, before watering and replenishing seedlings, pay attention to poking away the topsoil around the killed plants to hunt for larvae.

(3) Prevention and control of toxic soil

Phoxim granule 800g / mu mixed with dry fine soil 125-175kg was applied along the ridge in the evening to form a protective zone around the seedlings.

(4) Prevention and control of poison bait

Spray 50kg crushed cottonseed cake, bean cake or rapeseed cake with 90% trichlorfon crystal 0.5kg and 2.5-5kg. Spread poison bait around the rhizosphere of the seedlings.

(5) Pesticide control

Spray on the ground with 800 times of 90% trichlorfon solution, 75-100 kg per mu, or irrigate seedlings, 250-300 ml per plant.

4. Thrips

The main damage is that the back of the leaf shows intermittent silver-white stripes on the back, accompanied by small stains, and the opposite part of the leaf front shows yellow stripes. The seriously injured leaf back, such as coated with silver powder, the end half of the yellow and withered, or even destroy the seed.

Prevention and control methods:

The main results are as follows: (1) the corn fields adjacent to wheat fields should strengthen the management of water and fertilizer, and it is found that timely watering and fertilization can reduce the damage.

(2) 20% carbosulfan EC or 10% imidacloprid wettable powder, 1% imidacloprid EC, 2000 times EC, 1500 times omethoate EC and 15002000 times Huifeng Kuaike EC were sprayed in time on the plots with high population density or high probability of occurrence.

The management of maize seedling stage directly determines the production of corn in the later stage, which has a vital impact on the quality and yield. Therefore, growers must do a good job in the prevention and control of diseases and insect pests at seedling stage.