DENSIDAD DE POBLACIÓN DE TRIPS EN UNICULTIVO DEL GLADIOLO (Gladiolus grandiflorus Andrews.) Y ASOCIADO CON GIRASOL (Helianthus annuus L.).

Abstract

Gladiolus (Gladiolus grandifloras Andrews) is one of the main ornamental crops worldwide; it is in third in terms of global production, surpassed only by roses and chrysanthemums. In Mexico, Mexico state accounts for 31.48% of the nationally cultivated area, and the state of Puebla has the highest production. Gladiolus production suffers from serious phytosanitary problems, including wilt (caused by Fusarium oxysporum fs. Gladioli) and thrips (Thrips simplex Morison and F. occidentalis). Thrips are small insects, measuring between 0.8 and 3 mm, which over the last few decades have become a major worldwide pest of vegetables, agricultural crops, and ornamentals. They have a widely flexible diet but which feed on pollen to complete their life cycle and ensure their fertility. The genus Frankliniella is the largest within the family Thripidae. One of the main causes of increasing pest impact is the expansion of monocultures. One of the measures of pest control in agroecological crop management is the strategy of host diversification, including the use of polycultures. This practice is rarely used in ornamentals, especially those grown outdoors. In order to evaluate the effect of sunflower (Helianthus annus) as an attractant or trap crop for thrips and white fly in association with gladiolus, a trial was carried out during the 2018 spring-summer growing cycle to quantify the density of thrips and white fly in gladiolus and sunflower grown together compared to gladiolus and sunflower monocultures, as well as determining the population progress curve over time. The treatments were distributed in random blocks with 5 replicates. Monochromatic (yellow) traps were used to capture the insects to be analyzed in the program SAS. The results showed that there was a preference among thrips for the two ornamental species when grown in monoculture. It was also evident that there was a non-preference, distractor, or undesired host effect when the two plants are cultivated together, making this practice an alternative for ecological and/or cultural management of thrips in gladiolus. It was found that the gladiolus-sunflower association reduced the incidence of both insects by 50% in the different sampling dates compared to the population captured in monoculture, which was a statistically significant difference among treatments. There was a similar effect on the population progress curve over time, which was greater in monoculture than in the population captured in the associated crops. The quality of the gladiolus flower spikes was statistically similar in the monoculture and sunflower-associated crops.