Efeitos da calda bordalesa na fotossíntese e do ambiente no desenvolvimento de mudas de figueira

Abstract

The fig tree (Ficus Carica L) is a plant of historical and cultural importance for humanity, being one of the first species domesticated by man, and one of the first crops to be introduced in Brazil by colonizers. Due to its easy adaptation to different edaphoclimatic conditions, the fig tree found in Brazil excellent conditions for its development, which made the country the 9th largest producer of the fruit in the world. However, national production is concentrated in a few states in the south and southeast regions, which makes the expansion and commercial adhesion of the culture difficult, requiring studies for its implementation in the new agricultural scenarios that arise in the country. The present dissertation was carried out through two scientific experiments, on the performance of the culture in the middle north of the state of Mato Grosso. The first experiment was related to the application of Bordalesa mixture to control rust, the main disease of the crop in Brazil, where we sought to evaluate whether the film formed by the Bordalesa mixture solution alters the characteristics of the photochemical step of photosynthesis, as well as the fluorescence of chlorophyll A, when applied to combat rust. Being carried out in plants previously installed with 7 months of age, and administered on the leaves of 8 plants sectioned in three parts of the branch: apical with an average of 59 leaves, segments: median and basal with (65 and 60 leaves) respectively, along of the experiment, totaling an average of 180 leaves per evaluation. Resulting in the non-interference of the film formed by Bordalesa mixture in the photochemical step of photosynthesis and in the fluorescence of chlorophyll A. The second experiment was related to the propagation by cuttings of fig tree seedlings under increasing levels of shading, where segments of the branch (apical, median and basal) were placed to root and sprout in different levels of luminosity throughout the development of the cuttings in the dry period. from the northern region of the State of Mato Grosso, an experiment carried out between May and August 2020, where the seedlings were distributed in suspended nurseries, one treatment was exposed to the sun and the others were covered with black polyephine screens with commercial indications of 35; 50; 65 and 80% global radiation attenuation. The results indicate that 'Roxo de Valinhos' fig seedlings from herbaceous cuttings conducted in full sun have high mortality rates. Shadings of 50, 65 and 80% for the middle and basal branches of the fig tree provide tolerance to stress by solar radiation during bud sprouting, shoot development and rooting of cuttings.