Organic fertilization affecting pests and production of Lippia sidoides Cham. (Verbenacea)

The objective of this paper was to study the effect of four levels of organic fertilization (0, 3, 6 and 9 kg m-2) to produce the essential oil of Lippia sidoides Cham. (Verbenacea) and its pests. A higher number of red mite Tetranychus sp. (Acari: Tetranychiidae) was observed on the abaxial face of the median and basal leaves of L. sidoides plants with eight weeks of age cultivated with 6 kg m-2 of organic fertilization. On the other hand, the smallest number of this mite was noted in control (0 kg m-2). L. sidoides cultivated with 6 kg m-2 of organic fertilization produced a greater quantity of essential oil. The highest number of mealy bug Phenacoccus sp. (Hemiptera: Pseudococcidae) was observed on the apical leaves (both leaf surfaces) of L. sidoides plants with nine and ten weeks of age cultivated with 3 kg m-2 of organic fertilization. No significant effect of the organic fertilization on Aphis gossypii Glover (Hemiptera: Aphididae) was detected. However, a greater number of this aphid and of its predator Scymnus sp. (Coleoptera: Coccinelidae) was observed on the abaxial face of the bottom leaves of L. sidoides plants with eight weeks of age. The dose of organic fertilization recommended for the production of essential oil of L. Sidoides is 6 kg m-2, however, one must pay attention to the fact this dosage favors the attack by Tetranychus sp.. And, when needed, pulverization must always be directed to the lower surface of the leaf.