Crop attacks from the destructive invasive American moth called fall army worm may have declined this year by as much as 88 percent, even though its not clear exactly how.
Latest figures from the UN’s Food and Agriculture Organisation (FAO) say the fall army worm attacked 15 000 hectares of farmland in Zimbabwe during the 2017 /18 cropping season.
Last year, when the worm was first detected across Southern Africa, more than 130 000 hectares of mostly maize were hit, the Zimbabwe Government said at the time. By end of February 2017, several Zambian farmers had been forced to replant crops after nearly 90 000ha of maize were decimated, according to FAO.
In Malawi some 17 000ha were affected by that time, while in Namibia, approximately 50 000ha of maize and millet were damaged.
The new figures from FAO read in context with those from Government show that the area of farmland attacked by the fall army worm in Zimbabwe this year could have dropped by 115 000ha. A Special Alert from the UN body on February 26 seemed to suggest that too much rain earlier on in 2018 “may have contributed to the containing of the fall army worm”.
The dry, hot weather conditions of early season would have achieved the direct opposite. At that time, when rain was scarce, FAO wasn’t at all bullish about the crop situation and the future of food security for this year.
“The impact of the invasive fall army worm, which has been detected in countries except Lesotho and Mauritius, poses a further risk to yield potential in the affected areas as dry weather conditions exacerbate the yield impact of the pest,” it said in the Special Alert.
The fall army worm was detected in Southern Africa for the first time around January of 2017. It is about this time that it may have entered Zimbabwe.
Yellow-brownish in colour, the worm is native to the Americas, but flourishes in warmer climates, like Zimbabwe’s.
It is quick on flight, not easily detectable and that makes it difficult to control.
Indeed, as a first-time attacker here, the fall army worm is a nightmare come true for both governments and farmers, who are often ill-equipped to deal with the rising incidents of crop-damaging pests fuelled by climate change.
The pest is known to destroy over 70 percent of the crop it invades, according to David Phiri of the Food and Agriculture Organisation, Harare office, eating everything in its way – from leaf to cob to stalk, and including competitors.
Climate change, and global trade, have fuelled an escalation in the spread of devastating pests such as fungi and moths, which have advanced into new territories faster than other wildlife, according to research. In the last 50 years, insects have expanded their range by dozens of kilometres a year, scientists say.
Pasipamire Wesa, a crop protection specialist with Introlab Zimbabwe, an agriculture chemical research firm, has said in a previous interview that “climate change triggers or awakens hibernating pests with potent economic damage level.”
Here, the fall army worm attack appears to support the climate change influence on pest migration. But common control measures have been ineffective. Regular contact pesticides used to deal with the more familiar African army worm or the stalk borer have failed.
So, it must be the heavy rain, as FAO said in its Special Alert, and something else that have helped to contain the spread, and limit the impact of the fall army worm in Zimbabwe and elsewhere in 2018.
Something like Zimbabwean farmers pumping washing powder down the funnel of the maize crop?
And those in Zambia’s Chongwe district putting sandy soil into the maize funnels, and others applying ash?
The sand is abrasive to the skin of the fall army worm and can kill it, says Bridget Occonnor, an organic farming expert who has worked with Fambidzanai Permaculture in Harare, but now based in Zambia.
Yet stiil, organic agriculture — fertiliser and pesticide-free farming — could be as effective. This is because the ecosystem on the organic farm is already well balanced with a lot of diversity, including flowers that attract the adults of most pest predators, say experts.
At the Food and Agriculture Organisation, the approach is more holistic and scientific.
The organisation has developed a five-year programme of action to help farmers, governments and public bodies to “quickly respond to the challenge of fall army worm infestation across Africa.”
FAO says it will support SADC countries with expertise and funding to close gaps on early warning, response, information dissemination and scientific research, which have impeded understanding of the worm and its effective control.
The UN body last year promised to spend millions of dollars acquiring specialised trap kits to control the spread of the moth.
“ . . . we are very concerned with the emergence, intensity and spread of the pest (fall army worm),” said David Phiri, FAO sub-regional coordinator for southern Africa, told a SADC emergency crop pests meeting in Harare in 2017.
Phiri showed concern that the scale of economic impact from uncontrolled pest infestations could be staggering for individual Sadc nations, as well as the region as a whole. Zambia spent at least $3 million very early on trying to control the outbreak.
Two weeks ago FAO announced a $500 000 partnership with the Japanese government to tackle the worm and a type of bird flu strain that led to the killing of two million chickens at a farm near Harare in 2017.
The intervention will help build capacity for 500 Government extension officers in integrated pest management, and is expected to equip more than 500,000 small farmers with better ways of managing pests to boost farm output.
It is difficult to point at any one specific intervention as the most effective control measure at this stage.
But the combination of efforts from FAO, Government, farmers, and other farmer interest organisations will be key to keeping agriculture as the centre that holds over 70 percent of Zimbabweans’ livelihoods.–herald.co.zw