Laikipia west farmers worried by new Maize diseases

By Samuel Nzioka

Farmers within Laikipia west sub-county are worried of new maize disease that is destroying their crop. Maize Lethal Necrosis disease has affected maize crop in many farms leaving farmers panicking for their produce.  The disease has been declared as ‘New threat to Maize production’. Being a new disease in Laikipia County, farmers lack information on how to tackle its spread.

The disease

According to Ministry of Agriculture, Livestock and Fisheries State department of Agriculture, Maize Lethal Necrosis Disease (MLND) results from co-infection of two viruses; Maize chlorotic Mottle Virus and Sugarcane mosaic Virus. The disease is reported to be spread by insect vectors such as Maize thrips, Maize leaf hoppers, leaf beetles and aphids. In Kenya, the disease was first reported in Bomet County in September 2011.

Commonly grown maize varieties are susceptible to the disease. Losses associate with the disease ranges from 30 to 100% depending on crop growth stage when the disease attacks.

Symptoms and effects of MLND

• Bright yellowing starting with the upper young leaves
• Stunted growth with shortened internodes
• Death of inner parts of the plant leading to premature plant death

Infected crop in Matwiku, Laikipia west sub-county

• Poor pollen production and sterility of plants
• Comb husks appear mature (brown color) while the grains inside are still milky and the rest of the plant is green
• Partial grain or no filling capacity, the formed grains also become moldy with brown discoloration
• At late stages of plant growth, there is a lot of fugal growth on stems and combs
• Death of entire crop gives a blighted appearance to the maize field. The disease can be seen from as early as two weeks after emergence on wards

What to do about it

a)      When planting maize;

·         Use certified seeds approved by relevant authority (KEPHIS)

·         Use manure and include basal and topdressing fertilizers

·         Plant at onset of rains, undertake timely weeding and field sanitation

·         Planting tolerant or resistant maize varieties would be the longterm and sustainable solution

b)      Do not grow maize in consecutive seasons

c)       Practice crop rotation and diversify crop choices with alternatives like irish potato, sweet potato, beans and vegetables

d)      Practice regular scouting for insect vectors and early appearance of MLND

e)      At early stages of disease onset, rogue out infected plants. This material can be used to feed livestock

f)       Grains and cobs that are rotten are not supposed to be fed to humans or animals but rather be destroyed by burning

g)      Do not move green maize materials from infected regions to disease free areas within and outside the country to minimize spread of MLN disease.

There is a need to have farmers trained on intervention measures so as to have them prepared to tackle the disease whenever it strikes and to avert crop losses cause by the disease.