Seeds and winter-spring rice crop

STARRING:

* TS. Pham Van Du - Deputy Director of Mekong Delta Rice Institute.
* KS. Nguyen Thuan Khiet - Deputy Director of Seed Production and Research Center, An Giang Plant Protection Joint Stock Company.
* MSc. Nguyen Van Minh - Syngenta Vietnam Company.
* KS. Tieu Minh Tam - Head of Technical Transfer Department, An Giang Plant Protection Joint Stock Company - Representative for the coordinating unit to implement the program.

Question: What is the current risk and the mechanism of spreading yellow dwarf and twisted leaves diseases from one rice crop to another?

* Response (Dr. Pham Van Du): According to the recommendations of scientists, farmers should not go down to the third rice variety. But nowadays, this tea is still in the field and has about 60,000 hectares of rice. infected with yellow dwarf diseases and very severe twisted leaves. This is a very clear risk of brown plant hopper which will suck these rice plants into disease of winter-spring rice.

According to the Southern Plant Protection Department's forecast, by the end of October, there will be a northeast monsoon wind blowing and the brown planthopper will follow the wind moving from the eastern provinces to the western provinces in mid-November. far from 300-500km, there is nowhere in the Mekong Delta that can avoid pests spreading germs. Therefore, people need to be very careful, trying to thoroughly destroy the rice tea that is suffering from diseases, especially the rice blight and the rice fields cannot be harvested. With the movement of brown backed rice plant hoppers, close monitoring is required by arranging light traps. The safest time for sowing is to avoid the migratory brown backed rice plant hopper, sow it early so that when it comes to rice field which has been from 30 days onwards, the probability of damage will be low, or it may be sown later. the brown hopper moves.

Stunted and twisted leaves are not stored in the soil, so when sowing rice seedlings is not affected, we only need to pay attention to brown plant hoppers.

Question: Could you introduce suitable rice varieties that are resistant to pests in winter-spring season?

* Answer (Nguyen Thuan Khiet Engineer): Currently there is no rice variety that is strong against psyllids, but only medium-resistant varieties or those with less pests. For example, if a normal breed of aphids 15, then the seed is less susceptible to pests, only 3-5 children;

(Photo: tropicalisland)

or in the case of high psyllid population, it is normal to have a density of 30-50 heads, while the low-density plant has a density of about 10-15 individuals and in case of high BPH pressure, attention should be paid to the control of varieties. less infected. However, if using less susceptible varieties, it will be easier to control brown planthoppers, less chance of paddy rice infection and less damage than those of normal rice varieties. The varieties that are less susceptible to pests today include: OM 4088, OM 4498, OM 2395, but the number of these varieties in the Mekong Delta is very small, so in this winter-spring crop, farmers can choose the varieties grown in previous crops. infected with little dwarf gold, such as: OM 576, IR 50404, VND 95-20, IR 64.

Question: Rice fields are about 80% dwarfed by yellow rice, plowed and discarded, then lime is applied, 2 months later, the rice is sown again, please ask if there is dwarf gold or not?

* A (Mr. Nguyen Van Minh): The plowing of rice fields with severe yellow dwarf disease to thoroughly eliminate pathogens is a good job. Stunted, twisted leaf dwarf disease does not spread through water, soil, and corpses of plowed plants, but it cannot be confirmed that the next rice crop will not suffer from dwarfism. According to some scientists, about two-thirds of the hoppers to the field carry pathogens, so in the next season, if there are migratory pests, the possibility of aphids will be high. After seeding, farmers need to closely monitor the migration of hoppers in the field to take timely measures. When you see the hoppers migrating to the field, farmers should consult with local technicians to choose the time of spraying. Besides, liming as the way in the question is a good measure, also need to consider the problem of organic poisoning. Because in about 2 months of incubating sick rice and soaking in water, the rice stem can be itemized but the amount of organic matter is still quite large in the ground, can supply the amount of phosphorus from the beginning or add lime to help the decomposition process Organic happens faster. In the process of cultivation, it is necessary to have time to withdraw the water alternately in the field so that the toxins in the soil can evaporate, reduce the damage to the rice roots. In fact, in some localities, in the past time, if rice fields with organic poisoning combined with dwarfism, the damage will be higher.

Question: In the field there are short wing hoppers, spraying the day before the next day saw a long wing hopper flying to the field with a lot of density. Please ask if you need to spray again right away, if you should spray Actara or Bassan?

* A (MSc. Nguyen Van Minh): In the past when there was no yellow dwarf and twisted leaves dwarf disease, when the remote hoppers migrated far, it did not significantly affect the growth of rice. But with the current situation we know that two-thirds of the aphids that fly to the field carry yellow dwarf disease and twisted leaves dwarfs if high density we need to treat the drug. Both Actara and Bassan are very suitable for treating BPH. Actara is a drug that has good flowability and long-lasting effect but slow death, but for Bassan it dies quickly and effectively. Can be divided into two stages for people to choose to handle.

+ If rice is small for about 1 month, migrating psyllids can be used, more suitable Actara medicine can be used, because it is safe for natural enemies. In addition to the drug that will lead to the inside of the plant when the psyllid sucked it will be poisoned and die, the drug also has contact characteristics, that is, when the rice field is sparse, spraying down to the root of rice the psyllid comes into contact with the medicine. skin and died. Actara aphids will immediately stop smoking, so the ability to spread healthy rice plants will be limited.

+ If the hoppers migrate to rice fields over 40 days old and the density is high, people should use immediately effective drugs like Bassan.

Besides choosing the right Actara, Bassan, using the right amount of water and spraying it to the root helps the medicine to be effective. People should adhere to the principle of 4 right, because this is a condition to help the medicine to promote, the ability to manage pests in the field reaches the optimal level.

Question: If high quality rice is easily susceptible to yellow dwarf disease and twisted leaves dwarf disease, I want to use IR50404 resistant seed for winter-spring crop, for advice? Between selecting IR50404 and Jasmine 85 good quality rice, which one to choose, what should you choose if you choose Jasmine varieties to limit yellow stunt and twisted leaves? Are resistant psyllid resistant to yellow dwarf and twisted leaves dwarf diseases?

* Answer (Nguyen Thuan Khiet, KS): For many years, varieties like IR 50404 and Jasmine have relatively similar gold, so both of them can be grown in the winter-spring season. However, to produce safe winter-spring crops, farmers need to use synthetic methods. The first is the time of sowing, if the adjacent areas are harvested, the hoppers will fly to their fields and the risk of transmitting yellow dwarf diseases and twisted leaves dwarfs is very fast. Second, treat seeds with Actara medicine or Cruiser to help make rice more healthy and prevent early compensations, brown plant hopper at first. One of the results we recently tested showed that, if in the case of seed treatment with Cruiser, 5 days after handling the seed with a hopper migrating to the field, the rate of hoppers died to 90-100 %, if 15 days after treatment, the psyllid to the field will reduce the rate of death but still at 70-90%, which means that the Cruiser does not completely prevent brown backed rice plant hopper in the first stage but it contribute to preventing brown planthopper. Therefore, when sowing in the first stage, it is necessary to regularly visit the field, in case it is necessary to immediately destroy the pests that carry the disease to the field, the spread for the rice crop will be less. When using the drug during this period, people have to pay attention to choose drugs capable of eradicating psyllids, but at the same time have the ability to protect the natural enemies in their fields. Actara is a medicine that works well in this condition.

The psyllid resistant varieties are not sure to be resistant to yellow dwarf and twisted leaves dwarf diseases. Currently, there is no strict pest resistance, but only a little infected with aphids. This means that the hoppers are able to go to their fields, if they carry the disease, it can still transmit the disease, so using aphids resistant to hoppers is less likely to be infected with gold.

Q: How many brown plant hoppers will occur in this winter-spring crop and at what time?

* A (MSc. Nguyen Van Minh): The condition of the Mekong Delta in the middle of the winter-spring, summer-autumn and winter-autumn seasons is not significantly different, so the development of brown plant hoppers is almost similar. The average lifespan of BPH is about 25-30 days. Therefore, the winter-spring crop growth period of rice is mostly 90-95 days, it is likely that there will be 3 litters appear. If it is possible to avoid the migratory psyllid at the small rice stage, it will reduce 1 batch of hoppers and be able to suffer from remaining 2 batches of hoppers. In the coming winter-spring crop, if the middle of November has a migratory psyllid, then in mid-December, there will also be some adult psyllids appearing in the field. An experience can predict brown plant hoppers by monitoring the brown plant hopper in the light: when the hoppers fly into the high lights, about 1 week later in the field, there will be a group of bran pests.

Q: What varieties of sticky rice are resistant to brown plant hoppers? As recommended, it is recommended to seed in a uniform manner to divide the hoppers. Please ask when taking the Cruiser medicine until you see the hoppers use Actara and Bassan to manage the BPH in the first stage, how to use such medicine to prevent yellow dwarf and twisted leaves dwarf disease?

* Answer (Engineer Nguyen Thuan Khiet): Sticky rice is also very infected with brown planthopper, so it is necessary to monitor the field regularly and prevent brown backed rice plant hoppers from the beginning.

If the relatives simultaneously seeded one turn, when the brown backed rice plant hopper came to the area, it was divided into a few people, so the management was also easier, the damage caused by the dwarf gold was few. In fact, in the same field, the fields that were sown early in the field were more susceptible to brown backed rice plant hoppers and yellow dwarf disease. If you handle the Cruiser, the rice will be much stronger, the stem is heavier, the height is 1-2 centimeters taller, the roots are longer and whiter.

Keep track of the field regularly, because at present, the psyllid has more than 70% of the pathogens and the chances of transmission are high, so when the psyllid comes to the field, it is necessary to use medicine to prevent it. The drug used at this time must be a medicine that can kill psyllids, migratory hoppers but can protect the natural enemy system in the field.

In short : The disease of yellow dwarf and twisted leaves in this winter-spring crop is inevitable, only with a heavy or light degree. Currently we are starting a rice crop in which there are about 60 thousand hectares of rice in the field, the ability to transmit this disease to the winter-spring crop is very large, so the most positive measure is to bury all the fields. Rice is sick, especially rice to cut . Should be sown in a large scale to cut the bridge can be from one field to another. Brown plant hoppers carry the virus that spreads disease and spreads according to the wind. People need to pay much attention to the direction of provincial and district plant protection departments; especially tracking light trap system. The light trap shows that on the first day of brown rice hoppers, during the time of rice sowing, about 10-15 days, the damage will be very serious. Therefore, people should be very careful about the time of sowing, how can it be coincided with the time of brown planthopper migration or then a couple of days.

Cultivating under the program 3 decreases 3, especially nitrogen fertilizer if excess fertilizer is applied, the rice plant will be a good place for brown planthopper which can absorb protein in plants and will reproduce a lot.

Spraying with BPH must follow 4 correct steps. When people see brown backed rice plant hoppers in the field starting on the first day, they should not spray. Because the brown backed rice plant hopper moves in the evening, it will land in the field in about 8-9 pm, the virus has already passed the virus, then it also spawns the first egg, if it is sprayed with the aphids, the eggs are dead will continue to expand, so wait for the first batch of rice bran after 10-12 days of spraying once, so the ability to destroy it will be reduced.

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