COMMON NAMESPearl millet smut (English); onhimbe (Oshikwanyama);PEST STATUSSmut is a common fungal disease on pearl millet heads (Pennisetum glaucum). It is considered to be widespread in north central Namibia, but there are no records of actual distribution or importance.DESCRIPTIONSpores from broken sori or from the seed coat germinate and can under favourable weather conditions send out thousands of spores (sporidia) into the air. These spores land on flowers of pearl millet and infest the florets. Smut sori can be noticed after 2 weeks and they are mature after another 2 weeks. A secondary infestation may take place some years, but this will not be so important as the primary infection.The development of smut is favoured by high humidity at flowering time, and a susceptible variety of pearl millet. SYMPTOMSThe infested pearl millet ear contains a number of abnormal flowers or seeds. Infested flowers develop into large green smut spore sacs (sori) that are easily noticed on the head. During seed setting, the smut sori turn dark brown or black, while normal seed are pale yellow or grey.CONTROLPearl millet smut is seed-borne, either as sori mixed with the seed or as tiny spores sticking to the surface of seeds.It is important to use clean seed of high quality. Sori are larger and darker than seed and can easily be seen if a seed sample is infested. The sori are also lighter than pearl millet seed and they will float if they are submerged in water. There is a difference in infestation among pearl millet varieties. Where farmers notice that their local variety is more infested by pearl millet smut, they may try another variety for comparison. It is possible to control smut in pearl millet by using chemicals, but chemical control is not recommended for farmers. The chemicals are seldom available, and it is most unlikely that chemical control is economical. Farmers should instead rely on good seed hygiene and selection of good varieties.
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