Ministry must take lead in combating lethal maize pest

The maize lethal necrosis disease has become a thorn in the flesh of many farmers. It is also a serious threat to food production.

The disease causes between 30 to 100 per cent crop losses.

It was first reported in Peru in 1973 but was first detected in Kenya in September 2011 in Longisa, Bomet County where it struck 200 hectares of the second maize season.

It later spread to Sotik, Chepalungu, Narok South and North and in Naivasha. This season, lethal necrosis has punished farmers in Nakuru and Elgeyo Marakwet counties, attacking the late planted crop.

It is important to first understand the disease before recommending what should be done by policy makers.

The disease arises from two viruses — maize chlorotic mottle virus and any of several potyviruses that include sugar cane mosaic virus, wheat streak mosaic virus and maize dwarf mosaic virus.

THREAT TO SEED QUALITY

Although lethal necrosis is spread by insect vectors, it has the ability to attack maize irrespective of the growth stage. The severity of the disease depends on the stage the crop is.

Plants show symptoms on tassels, leaves, stems and cobs. It starts as early as two weeks after germination up to the cob formation stage and even during storage.

The symptoms include leaves turning bright yellow, starting with the upper parts, then dwarfing and premature ageing of the plant, cob husks appear mature and later turn brown while the grains inside are still milky and the rest of plant is green, partial grain or no grain filling on the cob while the grains formed become mouldy with brown discoloration.

The impact of the disease on maize in Kenya cannot be gainsaid. Maize is the major staple and any drop in production means food scarcity.

Lethal necrosis is also a threat to quality seed production for growers and companies. One of the main reasons most farmers plant maize is the availability of certified seed.

The seed industry in the country is maize dominated by up to 90 per cent. Other staple crops like potatoes which would offer an alternative to maize face serious challenges in certified seed availability.

PLANTING SEASON
A drop in maize yields due to disease further means a decline in incomes.

The largest share of income for farmers is from maize production.

Other losers are transporters and middlemen. With reduced volume of business and insufficient maize harvest, silos and other grain stores will be useless. 

The government should thus move with speed to tackle this deadly disease.

It should design and enforce maize closed season in all regions. The reason why lethal necrosis has become persistent is that some farmers do not adhere strictly to the planting season.

This year, for instance, maize that was planted late has been attacked by the disease, which means the vector will certainly spread when farmers plant next season.

This could have been avoided if all farmers had planted at the same time.

The government’s field officers should also monitor maize movement from affected areas and enforce the removal of infected crop from the farm. Some farmers do not destroy the crop.

CROP ROTATION
The government should also design and implement crop rotation schedules for all regions to ensure the vector does not survive.

It has been four years since the disease emerged and we are far from eliminating it. The Agriculture Ministry, must take the lead.

Farmers are losing hope as they see their crops being decimated by a disease that the government promised to deal with in a few months when it emerged.

However, farmers should not sit back and wait for the government. They should do their part by seeking advice on the altitude, rainfall, temperature and soil type of their regions before selecting the maize variety for planting.

They should also adopt best agronomic practices during land preparation, use the right and correct quantity of fertiliser, control pests and realise that early planting is mandatory, not an option.