Source: Fall armyworm: Nightmare for farmers | The Herald February 2, 2017
Elita Chikwati Senior Agriculture Reporter —
The fall armyworm, a foreign pest, has wrecked havoc in farming areas, attacking the maize crop at different stages of growth countrywide. The pest has become a nightmare for most farmers as they do not have adequate knowledge of it.
Incidences of fall armyworm have been reported in all eight provinces including peri-urban areas of the country.
Government has distributed chemicals especially Carbaryl 85 wettable powder to control the pest in affected areas.
The department of PPRI is also carrying out research to determine the origins of the pest and the stage at which it came in.
PPRI chief entomologist, Dr Godfrey Chikwenhere said fall armyworm samples were being cultured under laboratory conditions at Mazowe Plant Quarantine and Harare Plant Protection laboratories.
“Imported maize grain was collected from Grain Marketing Board depots in Matabeleland North Province and Concession depot and the samples are being cultured at Plant Quarantine laboratories in Mazowe.
“We want to know if the pest came as eggs or pupae. This will take two weeks. This will help us control the pest,” he said.
According to the Plant Protection and Research Institute, in Masvingo Province, the fall armyworm has affected Masvingo, Chiredzi, Bikita and Zaka districts.
In Mashonaland Central, Bindura, Mazowe, Guruve, Muzarabani, Rushinga and Shamva districts have been affected while in Manicaland the pest has affected Chimanimani and Nyanga.
Goromonzi, Marondera, Hwedza, Murehwa, Uzumba Maramba Pfungwe in Mashonaland East and all seven districts in Matabeleland North have been affected by the fall armyworm.
In Matabeleland South districts such as Gwanda, Umzingwane, Insiza, Bulilima and Mangwe, Ingwizi (Agricultural Rural Development Association) have also been affected while in Mashonaland West affected districts are mainly Makonde, Zvimba, Kadoma, Chegutu, Sanyati, Ngezi, Hurungwe and Kariba.
The fall armyworm has also hit Zvishavane, Shurugwi, Gokwe South, Gweru, Kwekwe districts of Midlands.
The fall armyworms have spread and now have infested all the provinces including peri-urban areas.
The pest’s damage varies widely on maize crop depending on stages, areas and rainfall received during the last week.
At the moment, more countrywide pest damage assessments are in progress.
In Bubi and Tsholotsho districts of Matabeleland North, irrigated maize crop damage is low ranging from one to five percent with the crop having recovered in most cases.
The pest is now observed attacking cobs from milk stage to maturity.
Chemicals used for the control of the fall armyworm pest are: Ampligo 150 ZC (Chlorantraniliprole), Coragen (Chlorantraniliprole), Superdash (Emamectin Benzoate) and Tide Plus 5WG (Emamectin Benzoate). The pest is fairly under control.
Superdash stock is currently not available in the country but an order (TSA) of 2000 litres is expected in a fortnight.
In Bubi fall armyworm has been reported on pasture grasses near maize fields.
When carefully observed, overlapping generations of up to four cycles were seen at Mary Ellen Farms and other areas in Umguza and Tsholotsho irrigated maize crops.
The use of registered Carbaryl 85 percent WP was effective in Masvingo and Lupane achieving up to 100 percent control of fall armyworms but in other parts of the country, Carbaryl 85 percent WP failed to effectively control fall armyworms.
In Raffingora, fall armyworm is widespread on irrigated and rain-fed maize crop at different development stages.
The pest has been persistent mostly on irrigated maize crop which was towards tasselling stage.
The maize crop looks generally good as most plants have recovered due to chemical control strategies used.
The effective chemicals used in Raffingora were Lampda, Carbaryl 85 WP and Fernkill in mixtures or as sole applications.
Farmers have also come up with own methods of dealing with the pest.
The recent is Boom washing powder which farmers claim destroys the pest in few minutes. The headache is that the farmers do not know the side effects and the exact amount required per hectare. The cost of the washing powder is also another cause of concern as it may not be viable.
According to the PPRI, farmers should use approved chemicals from registered dealers.
The department discouraged farmers from using unregistered chemicals as these could harm the crop, environment and the farmer.
The good rains being received generally in the region coupled with early planted (irrigated crops) are factors blamed for the sudden increase of fall army worm on maize crop as it was the only available green vegetation to attract the pest.
Crop damage has been widespread with the affected areas varying from 1 to 10 percent.
The crop in most areas has since recovered. Carbaryl 85 percent WP has been successful on early vegetative crop. Variable results have been experienced by some farmers on maize from tasselling to maturity.
Zimbabwe is battling both African armyworm and the fall armyworm using mostly chemical control and because of current good rains, some farmers are still planting maize especially in agro-ecological regions III, IV and V where the rains started slightly late this season.
Dr Chikwenhere said management of fall armyworms required control in the early stages of both the caterpillars and the crops to reduce the recurrence of the pests and achieving high levels of control and rate of recurrence.
He said quick control was largely by use of pesticides but when the crop become bigger the chemical do not get to the targeted caterpillars because of their effective hiding inside the maize plant growing parts.
The outbreak of fall armyworms — an invasive Latin American species which is harder to detect and eradicate than African armyworm — has erupted in Zambia, Malawi, Botswana, Zimbabwe and most recently Namibia and follows an El Nino triggered drought which affected much of the region last year and followed by La Nina triggered wet season.
However, fall armyworm detection and subsequent reports in the SADC region is not known or not properly documented. The pest is likely to have been in the region for some five or more years back but due to drought and other factors, was not known to be present.