The infected area is many times larger than last winter-spring crop.
In the 2023-2024 Winter-Spring crop, the province will plant over 39,000 hectares of rice. Currently, the early spring rice crop is in the flowering - green firming stage; the late spring rice crop is in the panicle differentiation - panicle embracing stage. In general, across the province, rice is growing and developing well. However, through the results of the survey of the pest situation in the fields, it is shown that some objects are emerging and have the potential to cause widespread damage to rice fields. The scale and level of damage are higher than in the 2022-2023 Winter-Spring crop.
Specifically: The total area infected with pests as of April 16 is over 6,700 hectares (nearly 7 times higher than the 2022-2023 Winter-Spring crop). Of which, the heavily infected area is 664.5 hectares (many times higher than the 2022-2023 Winter-Spring crop), the area that has been controlled is 3,800.5 hectares. The main pests are: small leaf rollers, planthoppers, rats, and rice blast disease.
Engineer Nguyen Thi Nhung, Head of Technical Department, Department of Crop Production and Plant Protection of the province, added: In the winter-spring crop this year, the density of leaf rollers in the fields increased dramatically, in some places in Kim Son, Yen Mo, Yen Khanh, the density reached hundreds of worms/m2. Up to now, the total area infected with leaf rollers in the whole province is over 6 thousand hectares, the area heavily infected is 650 hectares (while in the same period in 2023, there was no infected area). Although many localities have sprayed pesticides in the past, through field surveys, the area infected with leaf rollers is still increasing.
"In the coming time, the second generation of small leaf rollers will appear, causing widespread damage to late spring rice fields at the stage of panicle differentiation to panicle embracing in Kim Son, Yen Mo, Yen Khanh, Hoa Lu districts and Tam Diep city. The common density of worms is from 50-70 individuals/m2; in high places, 100-150 individuals/m2; in some cases, over 300 individuals/m2. If not detected and sprayed promptly, some severely damaged areas will cause the panicle leaves to turn white, greatly affecting rice yield" - Engineer Nguyen Thi Nhung warned.
According to the investigation of the professional sector, along with the small leaf roller, in the coming time, the second generation of rice planthoppers will also bloom, causing widespread damage to rice fields, especially the late spring rice fields in the stage of panicle differentiation - panicle embracing. The common density is 400-500 individuals/m2; in high places 1,000-2,000 individuals/m2; nests over 3,000 individuals/m2 (Kim Son, Yen Mo, Yen Khanh, Hoa Lu districts...). The scale and level of damage are higher than the same crop of the 2022-2023 winter-spring crop. If not detected and sprayed in time, it will turn the rice fields red in the late spring fields, causing nests to burn in the early spring rice fields in the stage of green filling to ripening. In addition, planthoppers also carry viruses that are vectors of black-striped dwarf disease in the fields.
In addition, leaf blast disease is appearing sporadically and causing local damage on green rice areas with excess nitrogen fertilizer, susceptible varieties such as: TBR 225, BC 15, Nep, LT2, Bac Thom No. 7, Dai Thom 8... Neck blast disease is causing local damage on early Spring tea in the milky to green stage, the disease rate is high at 20-30% of the flowers, mainly in Nho Quan district. The infected area of brown spot disease is also 1.7 times higher than the same period in 2023. Some areas are also affected by two-spotted stem borer, silver leaf, bacterial stripe spot, weedy rice, black smut disease, and spider mites.
Focus on peak spraying for prevention during the holiday season of April 30 - May 1
We were present at Nam Yen Cooperative, Yen Lam Commune, Yen Mo District in late April. Faced with the complicated situation of rice pests and diseases, members of the Cooperative's Service Team and officers of the provincial Department of Crop Production and Plant Protection are focusing on checking the fields, clearly classifying rice fields, assessing density, determining the age of pests to come up with timely and appropriate control measures when the threshold is reached.
Mr. Vu Van Hanh, Director of Nam Yen Cooperative, said: In early April, when the first generation of leaf rollers appeared, the Cooperative directed a round of spraying. However, up to now, through field investigations, the second generation of leaf rollers continues to appear at a fairly high density. In addition, some fields also have rice blast and planthoppers. It is expected that the second generation of leaf rollers and larvae will bloom from April 28 to May 2 - this is the most effective time for spraying. Therefore, we are increasing announcements on the commune loudspeaker system so that all farmers know and proactively spray effectively. The Cooperative has also prepared a sufficient quantity of plant protection chemicals to supply and provide services to the people.
Ms. Nguyen Thi Nhung, Head of Technical Department, Department of Crop Production and Plant Protection of the province emphasized: In the reproductive stage of rice, standing and forming panicles as at present, farmers absolutely must not be subjective or negligent. Unlike the tillering stage, the density of pests can be 10-30 insects but the rice still has the ability to compensate, but when entering the panicle formation stage, the rice plant no longer has this ability. Farmers need to remember that the panicle leaf set plays an important role in grain yield because about 60% of the products stored in the grain are direct photosynthetic products of the rice leaves after flowering. Therefore, it is necessary to manage and protect the panicle leaf set very well.
Regarding the time of spraying, the Department of Crop Production and Plant Protection informed: It is expected that the larvae of the small leaf roller will bloom from April 28 to May 11. Therefore, the optimal prevention time will coincide with the holidays of April 30 and May 1. The professional sector also noted that farmers need to clearly distinguish the rice fields, closely monitor the weather and pest developments for timely prevention, and not spray pesticides indiscriminately to protect natural enemies and protect the environment. In addition, to save costs and spraying labor, it is possible to combine spraying for small leaf rollers, rice blast, and planthoppers at the same time. However, it is important to choose the right type of pesticide and mix it at the right concentration according to the instructions. Fields with a high density of over 200 insects/m2 must be sprayed twice, the second time 5-7 days after the first.
Instructions for pest control on winter-spring rice of the Provincial Department of Crop Production and Plant Protection * For small leaf rollers: Spray on fields with a worm density of 20 worms/m2 or more when the 2nd instar larvae hatch. Spraying time is from May 1 to May 12 with one of the following specific pesticides: Clever 150SC, 300WG; Incipio® 200 SC; Director 70EC; Virtako 40WG; Voliam Targo 063SC; Silsau super 3.5 EC; Dylan 10WG... Fields with a high worm density of 200 worms/m2 or more must be sprayed twice, the second time 5-7 days after the first. * For brown planthoppers and white-backed planthoppers: spraying time is from April 27 to May 8. Specifically: - At the stage of panicle differentiation - panicle embrace: spray on fields with a density of ≥ 2,000 individuals/m2 when the 2nd instar hoppers are in high numbers, with one of the systemic insecticides such as: Penalty 40WP, Chess 50WG, Titan 600WG, Applaud-Bas 27 WP, Palano 600WP, Sutin 5 EC; 50WP... - At the green-red tail stage: spray on fields with a density of ≥ 1,000 insects/m2 when the 2nd instar hoppers are in full bloom, using one of the contact pesticides such as: Nibas 50EC, Bassa 50EC, Vibasa 50EC... Note that when using contact pesticides, it is necessary to separate rows so that the sprayed pesticide comes into direct contact with the hoppers and it is necessary to choose pesticides that ensure a quarantine period before harvest. * For neck blast disease: spray according to the rice flowering rate in fields that have been infected with leaf blast disease, in green fields, near the source of the disease, and in susceptible varieties. The prevention time is when the rice is 3-5% early flowering with one of the following specific drugs: Kasoto 200SC, Bump 650WP, Katana 20SC, Kabim 30WP, Filia® 525SE, Beam® 75WP, Bamy 75WP,... * For 2-spot rice stem borer: spray on fields with egg density of 0.3 nests/m2 or more, spraying time after May 15 for Nho Quan and Gia Vien districts, after May 25 for Yen Mo, Yen Khanh, Kim Son, Hoa Lu districts, Tam Diep city, Ninh Binh city, with one of the following specific pesticides: Prevathon® 5SC, Virtako® 40WG; Voliam Targo® 063SC,... * For harmful rats: continue to kill rats by measures, focusing on manual measures such as: digging, catching, smoking, setting traps, these are highly effective measures to limit the damage caused by rats in the fields. In addition, combine spraying to prevent brown spot and grain rot; treat weedy rice by uprooting. (Note: Depending on the specific situation, localities need to determine which pests are the main ones to have timely and effective control measures; it is possible to combine spraying to prevent the above pests but must ensure sufficient dosage, the amount of mixed medicine water from: 25-30 liters/sao). |
Article and photos: Nguyen Luu
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