​To deal with this problem, the Chairman of the provincial People’s Committee has issued a document to direct the provincial Department of Agriculture and Rural Development to take responsibility for hosting and coordinating with concerned departments and localities to monitor the production of corn and manioc to give directions on varieties, seasons, and methods of treating mosaic disease on leaves, autumn armyworms, and so on; strengthen investigation for the early detection of the areas infected with mosaic disease and autumn armyworms; offer measures to prevent and fight against diseases according to the technical process of prevention and control of mosaic disease on cassava leaves and autumn armyworms of the Department of Protection Plants; direct the agricultural promotion system to focus on propaganda activities and give training to farming households to bring them preventive measures; conduct rapid investigation to find out varieties of cassava varieties with great resistance to mosaic disease on leaves and varieties of corn with high resistance to autumn armyworms and then show farmers how to replace severely-infected varieties; and continue to implement the production models of disease-free cassava varieties to ensure that disease-free varieties will be put into production.

Also, the Chairman of the provincial People’s Committee instructed the People’s Committees of districts and cities to strengthen its activities to disseminate propaganda and technical information on how to prevent mosaic disease on cassava plants and autumn armyworms from the Plant Protection Department; recommended that farmers do not use the cassava-root cuttings that originate in Tay Ninh, in the localities where the disease has been announced, and in the places where the epidemic has occurred and that farmers do not grow cassava varieties severely infected with HL-S11 and KM 419 but use disease-free and less-susceptible varieties of KM 94; and prevented mosaic disease from spreading by using leaf sticky traps hanging in the field to kill spiraling whiteflies. The areas at risk of outbreaks need to be sprayed to kill spiraling whiteflies by using plant protection products or Dinotefuran or Pymetrozine.

For the cassava-growing areas that have been severely infected with mosaic disease, farmers are recommend to rotate other crops but not to plant tobacco, tomatoes, gourd, squash, chili, and so on. Also, it is urgent to mobilize farmers to destroy the stalks of cassava leaves and post-harvest plant residues in infected areas; strengthen the inspection and strictly control the transport of sick cassava leaves from the infected area to the uninfected area and prohibit the trading of infected cassava varieties; and so on. At the same time, the investigation is need to early detect the cassava growing area infected with mosaic disease on cassava leaves and armyworms on corn plants and then instruct farmers how to strictly take preventive measures.

According to Dong Nai Department of Cultivation and Plant Protection, in order to timely detect and prevent autumn armyworms from spreading widely, localities are supposed to implement some of the following measures:

For the areas that have been damaged by autumn armyworms and the other areas that are being harvested, after the harvest it is completed, collection for destruction of all the corn residues is carried out; all the weeds around the corn-planting areas, it is necessary to pull up all the weeds around the corn-growing places; and till and dry soil carefully for all the larva and pupa in the soil to die or easily be destroyed by natural enemies.

For the areas in which corn has not been harvested, it is necessary to regularly investigate worms’ harmful development. If autumn armyworms are found, it is necessary to focus on the implementation of killing measures; break eggs to destroy them; use yellow sticky traps with sex pheromones, and sweet and sour baits or light traps to kill grown-up worms. In addition, the places with a low-density of pests kitchen ash can be used or diluted soapy water can be poured into corn kernels to kill larvae and it is necessary to use green fungus products, white fungus, Bt bacteria, and NPV virus like Ometar, Biovip, Vi-BT 32000WP, 16000WP, BT Xentary 35WDG, Firibiotox P in powder form, Firibiotox C, Vis, ViHa, and so to spray as worms are still at their small age; use such active chemicals Bacillus Thuringiensis, Spinetoram, Indoxacarb, Lufenuron like Bitadin WP, Map - Biti WP 50000 IU/mg, Akido 20WP, Radiant 60SC, Spinet 60SC, Map wing 45WP, Amater 150SC, Clever 150SC , Indocar 150SC, Indosuper 150SC, Lufenron 050EC, Match 050 EC, Caranygold 120EC, and to spray insecticides in the areas with a high density as worms are mostly 1-2 years of age, and spraying must be conducted in the early mornings or late afternoons.

For the areas that are ready for new planting preparation, implementing and controlling the prevention of autumn armyworms by using integrated pest management measures according to the technical process to prevent autumn armyworms.

Duy Minh (T. Lien)