Fall armyworm still a huge threat

The fall armyworm which affected about a third of the maize crop in rural areas during the last cropping season could return stronger and pose a greater food insecurity threat in the 2017-18 season, experts have warned.

This comes on the heels of the Zimbabwe Vulnerability Assessment Committee (ZimVac)’s 2017 Rural Livelihoods Assessment report which says at least 36 percent of the rural crop was affected by the invasive pest last season.

Experts are afraid the fall army- worm could return stronger this season amid reports that chemicals used last season may have killed its natural enemies and made the parasite resistant to pesticides.

The risk has been exacerbated by declining agricultural extension services, a development which has left farmers without enough information to combat the pests.

Statistics from ZimVac show that the proportion of households receiving agricultural training has remained relatively low for the past three years at 38 percent in 2015, 35 percent in 2016 and 34 percent in 2017.

Subsequently, only 36 percent of households affected by the fall armyworm last season received training on how to handle the pest.

As such, only 14 percent of households affected with fall armyworm last season used recommended control measures while 63 percent did not take any measures at all.

This, crop scientists say, has created a conducive environment for a possible outbreak.

Zimbabwe Farmers’ Union (ZFU) director Mr Paul Zakariya said the fact that the outbreak was not adequately dealt with last season means the threat is real.

“From our technical reports, the information that we are receiving is that the threat is still there and it is real,” he said.

“We have not really dealt with the problem from last season and we may find ourselves facing the same challenges again.”

Mr Zakariya said there is need to train farmers on how to deal with the pests since using wrong methods and chemicals could lead to resistance.

This was echoed by Food and Agriculture Organisation (FAO) Sub-regional Co-ordinator for Southern Africa Mr David Phiri who said the fall armyworm is “here to stay”.

“If we take, for example, in the Americas where they have taken all the effort but failed to eradicate the pest, it means even here in Africa it has come to stay,” he said.

Mr Phiri said using toxic chemicals may not be the perfect solution after evidence showed that some of the chemicals are leading to resistance.

“What has come out strongly, from all expertise including our FAO work, is that it does not make sense to use chemical pesticides because this may result in killing natural enemies of the fall army worm as has happened in Latin America, in United States and Canada.

“Fall armyworm has a lot of natural enemies and we should enhance their use to control the fall army worm.”

Research shows that in the Americas, fall armyworm is attacked by a significant number of natural enemies.

Natural predators

These natural predators including ants, earwigs, wasps and pathogens such as bacteria, virus and fungi can cause up to 50 percent natural mortality of fall army- worm in the field.

FAO argues that these natural enemies could be enhanced to totally control fall armyworm.

Fall armyworm is a dangerous trans-boundary pest with a high potential of continuing to spread due to its natural distribution capacity and trade.

The pest, an avid crop-eating caterpillar of American origin, arrived in Africa early last year, and is now present in about 22 countries in the continent.

It is not clear how it arrived in Zimbabwe but reports have emerged that it might have come as eggs with imported maize.

According to FAO, the worm has destroyed large swathes of maize in countries such as Malawi, Zambia and South Africa.

In Zimbabwe, red flags have been raised in Mashonaland Central, Matabeleland North and Midlands provinces after it emerged that they were the most affected last season.

The fact that the fall armyworm is diverse in its food choice and resistant to a number of pesticides means it is very difficult to contain.

Researchers say the pest can feed on over 80 crop plants including maize, rice, sorghum, millet, sugarcane, vegetable crops and cotton, although it prefers maize the most.

Also, while it shares almost similar appearance with common stalk borers, it is much more aggressive in its feeding and breeding, a trait that has confused farmers.

The Zimbabwean Government last year distributed chemicals, especially Carbaryl 85 wettable powder, to control the pest in affected areas.

Other chemicals such as Ampligo 150 ZC (Chlorantraniliprole), Coragen (Chlorantraniliprole), Superdash (Emamectin Benzoate) and Tide Plus 5WG (Emamectin Benzoate) have also been used to control the pest.

Government has, however, called on the nation not to panic as efforts were being taken to come up with a unified response.

Director of Crops Research in the Ministry of Agriculture, Mechanisation and Irrigation Development Mr Dumisani Kutywayo said the ministry has formed a committee with its partners to tackle the pest.

“We have realised that there is still little information on the part of the farmers, especially on how to deal with the worm,” he said.

“So the ministry has set up a committee to come up with a manual on how to respond to this issue.”

Mr Kutywayo, however, lamented that unscrupulous dealers have taken advantage of farmers by selling banned chemicals which could potentially make the situation worse.

CropLife Zimbabwe, a crop protection organisation made up of local agrochemical companies, said it will rein in on unscrupulous dealers and is ready to deal with the possible outbreak.

“We have temporary registration for chemicals that control fall armyworm and these where issued by the registrar last year when the pests where first sighted,” says CropLife chairman Mr Emmanuel Nhema.

“Agrochemical companies are in the process of procuring chemicals for the coming summer season.


“Chemical companies in conjunction with the Ministry of Agriculture will be communicating with farmers on best ways to control the pest.

“Timing and growth stage of pest is important to note when applying the chemicals, therefore regular scouting for the pest in the fields is of paramount importance.”

FAO also emphasised that the key to helping farmers manage fall armyworm is through teaching them key concepts of the pest’s biology and ecology and best practices for its management.

As such, the organisation is planning a massive rollout of a learning, training and communications programmes through village meetings, farmer field schools, plant health clinics, national extension programmes and mass communication campaigns.

While fall armyworm can be controlled, researchers say it cannot be completely eradicated.

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