Spatial distribution of nematode population densities and nematode damage in roots of three banana cultivars in Uganda

The spatial distribution of nematode populations and damage in roots of Nab usa (Musa AAA-group 'Matooke'), Pisang Awak (Musa ABB) and Sukali Ndizi (Mu sa AB) three banana cultivars widely grown in Uganda, was investigated at t hree locations, each with a distinctive nematode population and composition . At Namulonge, central Uganda, where Radopholus similis was the dominant n ematode species, and at Ntungamo, southwestern Uganda, where Pratylenchus g oodeyi was the dominant species, suckers were removed from established mats and assessed for nematode reproduction and damage. At Namulonge, Ntungamo, and Mbarara, southwestern Uganda, where R. similis and P. goodeyi coexist, suckers removed three months after planting were assessed for nematode rep roduction and damage. Nematode population density distribution along the pr imary roots was observed to be random for both plant types of the three cul tivars at all locations. An exception was recorded for three-month-old suck er-derived plants of all three cultivars at Mbarara, where higher P. goodey i densities were recorded closer to the corm. Nematode densities in primary roots, secondary roots, and root tips were generally not significantly dif ferent for both plant types of a single cultivar except for three month old sucker-derived Pisang Awak plants at Ntungamo where higher Meloidogyne spp . densities were observed in the root tips. Consistently, nematode damage ( root necrosis) was higher (P < 0.05) close to the corm than further along t he primary roots, regardless of cultivar and location.