Abstract

The objective of this study was to evaluate the infestation of Vatiga illudens in cassava varieties and to correlate its infestation with the physical and morphological parameters of resistance. The experiments were conducted in the 2014/2015 and 2016/2017 seasons, out in a randomized complete block design with nine treatments and five replicates. Nymphs and adults of V. illudens were evaluated on the abaxial surface of 16 leaves of the middle third of the plant. The density of trichomes was quantified with the use of electron micrographs, and the roughness of the epicuticular wax was assigned to the leaves of the shoot and the apical third. The color components L*, a*, b*, were measured with a portable digital colorimeter. The cultivars IAC 90 and Santa Helena demonstrated the smallest infestations in the 2014/2015 season and maintained low infestation in the 2016/2017 season. The varieties Baianinha, IAC 576-70 and Catarina-Branca, maintained high infestations in the both seasons. The density of trichomes of the middle third of the plants correlated negatively to the V. illudens infestation for the two seasons. The higher density on trichomes, negatively affects the infestation of V. illudens in cassava varieties, characterizing as a specific resistance factor to this species.

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