With unpredictable weather patterns, farmers are worried about preventing pests and diseases from "attacking" their summer-autumn rice crops.

(Baohatinh.vn) - Hot weather combined with low humidity has created favorable conditions for the appearance of many types of pests and diseases, causing damage to early-season summer-autumn rice crops in Ha Tinh.

The summer-autumn rice crop in these localities is currently in the tillering stage and developing well.

In Ha Tinh City, the summer-autumn rice crop in early-planted areas is entering the tillering stage and growing well. However, the small leaf-rolling caterpillar has appeared quite early, with much higher densities than in previous years and is widespread in most rice fields of many communes such as Thach Tri, Thach Van, Thach Lac, Tuong Son…

Mr. Le Van Tung (Dong Khanh village, Thach Tri commune, Ha Tinh city) said: “I cultivate 6 sao (approximately 0.6 hectares) of rice, mainly the Xuan Mai and Khang Dan varieties, and they are all currently being attacked by small leaf-rolling caterpillars. Many fields have had their leaves completely eaten by the caterpillars. From observation, this is the most severe rice pest outbreak in the past few years. Following the commune's instructions, I have proactively sprayed pesticides, but I am still very worried because the weather is sunny in the morning and stormy in the afternoon, which is favorable for the 3rd and 4th instar caterpillars to severely damage the young leaves. I may have to spray again.”

Mr. Le Van Tung (Dong Khanh village, Thach Tri commune, Ha Tinh city) sprays to control small leaf-rolling caterpillars.

According to Mr. Phan Thanh Nam, an official from the Center for Application of Science and Technology and Protection of Plants and Animals in Ha Tinh City, the first generation of rice leaf rollers in the locality are mainly in stages 3-4. Some fields have recorded high densities, from 40-50 larvae/m², and locally 70-100 larvae/m². Hot and humid weather, interspersed with showers, is an ideal condition to stimulate the hatching (emergence) of small rice leaf roller eggs, facilitating rapid development of the larvae and shortening the reproductive cycle. The relevant authorities have issued a document advising localities to inform farmers to pay attention to monitoring and promptly handling the situation to reduce pressure on the fields for the next generation of larvae.

In Lam Trung Thuy commune (Duc Tho district), the first generation of rice leaf rollers is mainly in stages 2-4, with overlapping generations between fields, making control more complicated. According to the leaders of Lam Trung Thuy commune People's Committee, the second generation of larvae will begin to hatch in large numbers from around July 5th, causing severe damage during the late tillering and panicle differentiation stages of rice. The commune authorities have issued a notice, advising farmers to proactively inspect their fields regularly to detect and treat pests at the right time.

The small leaf-rolling caterpillar "eats" the rice leaves completely.

It is known that the rice leaf roller has a long life cycle, and if not treated at the right time, it will significantly affect the growth and yield of rice later on. Areas with more severe infestations are usually concentrated in low-lying areas, early-planted fields, and fields with excess nitrogen. Accurately assessing the situation and effectively controlling the larvae from now on in each local rice crop will determine the level of damage caused by subsequent generations of the pest.

According to information from the Provincial Department of Crop Production and Livestock, the small leaf-rolling caterpillar has appeared in several localities such as Duc Tho, Cam Xuyen, Can Loc, Thach Ha districts, and Ha Tinh City... The average density is 10-15 caterpillars/ ^m² , with some areas reaching 20-30 caterpillars/ ^m² , and localized areas reaching 70-100 caterpillars/ ^m² . The main developmental stages are in the 3rd and 4th instars, with overlapping generations. The infected area covers 520 hectares, with 15 hectares severely affected.

Furthermore, monitoring has shown that the alternating sunny and rainy weather patterns are causing brown planthopper and white-backed planthopper outbreaks and damage. Currently, the average density is 300-500 individuals/ ^m² , with some areas reaching 700-1,000 individuals/ ^m² , and localized areas reaching 3,000-5,000 individuals/ ^m² . The infested area covers 15 hectares, with 3 hectares severely affected. The infestation mainly consists of adult planthoppers and those in the first and second instars, distributed in some early-planted areas in the coastal communes of Thach Ha district, Cam Xuyen coastal area, and areas outside the dike in Duc Tho, etc.

Mr. Nguyen Van Hinh (Trung Dong village, Cam Duong commune, Cam Xuyen district) shared: “I cultivate more than 5 sao (approximately 0.5 hectares) of rice, so I planted early, resulting in a high density of rice planthoppers. The rice is in the stage of strong leaf and stem development, but these insects attack, suck sap, cause yellowing of leaves, and reduce tillering. I have to regularly inspect the fields to monitor the density and spray pesticides promptly. This time, the weather often has sudden thunderstorms, which significantly reduces the effectiveness of the pesticides.”

Agricultural experts, in coordination with local authorities, are inspecting the situation regarding pests and diseases affecting the summer-autumn rice crop.

Golden apple snails have also appeared in large numbers, devouring young rice plants and causing headaches for many farmers. According to reports, the number of golden apple snails is much higher than in previous years, especially in low-lying fields and newly planted rice paddies. The snails eat up the young seedlings, forcing farmers to replant multiple times, costing them extra effort and money. Ms. Tran Thi Phuong (Van Cu village, Xuan Loc commune, Can Loc district) shared: “We had to replant 4 sao (approximately 0.4 hectares) due to heavy rains from June 12-13. The rice seedlings were severely damaged by golden apple snails. Although we regularly check the fields manually, after a thunderstorm in the late afternoon, the snails crawl out in large numbers overnight.”

According to the Ha Tinh Meteorological and Hydrological Station's forecast, the weather from now until the end of June will continue to be hot and sunny with intermittent showers, with an average temperature of 28-35°C. This creates favorable conditions for the emergence and severe damage caused by rice leaf rollers, brown planthoppers, white-backed planthoppers, and golden apple snails. It is expected that the second generation of rice leaf rollers will hatch in large numbers from around July 5th onwards; brown planthoppers and white-backed planthoppers will continue to accumulate and multiply, causing significant damage during the rice heading and flowering stages; and golden apple snails are likely to continue to emerge.

Farmers need to focus on thinning and replanting to ensure proper density, which helps rice plants grow well.

To proactively prevent and minimize damage caused by pests and diseases, the Department of Agriculture and Environment of Ha Tinh province requests the People's Committees of districts, cities, and towns to coordinate with irrigation companies in the area to regulate water regimes appropriately, ensuring sufficient water supply for rice growth and development, and closely monitor the situation to apply fertilizer during the tillering stage.

At the same time, the specialized departments, centers for the application of science and technology and the protection of crops and livestock, and the People's Committees of communes, wards, and towns are directed to assign staff to focus on monitoring fields and effectively carrying out investigation and detection work. Based on the specific conditions of each locality, determine the area requiring pest control; inform farming households to enhance their proactive approach in monitoring and treating pests and diseases in their fields.

For rice leaf rollers: Regularly inspect and monitor the fields, conduct thorough investigations and detection, and based on the specific conditions of each locality, accurately determine the time when the second generation of larvae hatches in large numbers, the density of the pest causing damage, in order to decide when and where to focus treatment, using one of the following pesticides containing active ingredients: Indoxacarb, Emamectin benzoate, Chlorantraniliprole… Common commercial pesticides include Clever 150SC, Obaone 95WG,…

For brown planthoppers and white-backed planthoppers : initially, focus on treating areas where planthoppers have already appeared to limit their spread in the fields; regularly monitor fields, conduct thorough investigations and detection, paying attention to low-lying areas and areas where planthoppers frequently cause damage annually. Proactively warn and guide localities and farmers to promptly spray when planthoppers are in their first or second instar using one of the following chemical insecticides containing active ingredients: Pymetrozine, Imidacloprid, Clothianidin, Acetamiprid… Common commercial insecticides include ChessÒ 50WG, Sutin 50SC, Dantotsu 50WG,…

For golden apple snails: collect and remove egg clusters, using bait such as sweet potato vines and papaya leaves, combined with drainage ditches to attract snails, and then collect and destroy them. For high-density fields, treat with chemical pesticides containing the following active ingredients: Metaldehyde, Niclosamide, etc. Some common commercial products include StarPumper 800WP, Anhead 12GR, Boxer 15GR, etc.

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