Influence of canopy height and fertilization levels on the resistance of Lycopersicon hirsutum to Aculops lycopersici (Acari : Eriophyidae)

The objective of this work was to study the effect of NK fertilization leve ls and canopy height on the resistance of Lycopersicon hirsutum and Lycoper sicon esculentum to Aculops lycopersici (Acari: Eriophydae). The effects of NK fertilization levels and canopy height in the leaf size and density of trichomes and their effects on tridecan-2-one (2-TD) and undecan-2-one (2-U D) limiting the attack of A. lycopersici on tomato plants were assessed. Di fferent NK fertilization levels had no effect on the resistance of L. hirsu tum to A. lycopersici. No significant differences were found in attack rate s of this mite on leaves of the top and median parts of L. hirsutum canopy. The type and density of trichomes were the main determining factor of A. l ycopersici attack on tomato plants. High trichome densities and type VI gla ndular trichomes which produce tridecan-2-one are important resistance fact ors on tomato plants. L. hirsutum showed a high resistance level to A. lyco persici due to high densities of type VI glandular trichomes and consequent ly higher levels of tridecan-2-one in its leaves.