| Summary: | The population dynamics of Mononychellus tanajoa as influenced by varietal resistance of cassava was determined over two cassava planting seasons (dry and wet season), using biweekly samples from 11 cassava genotypes in Ibadan, Nigeria. The population size of M. tanajoa and the damage scores were higher during dry than wet season. In 1993, there was a higher mite population and damage peak in January than in March, while in 1994, the peak occurred only in April. Mite population and damage generally varied significantly among genotypes and sampling dates, and decreased as the plant aged. High relative humidity rainfall, and low temperature inhibited the mite population growth. During dry season, the rate of mite increase was higher on the susceptible cassava genotype than on the resistant genotypes while situation was reverse in wet season. The study showed that varietal resistance of cassava had a significant effect on the population growth rates of M. tanajoa. January was the favourable period for screening cassava genotypes for resistance to M. tanajoa in Ibadan, Nigeria regions.
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