Eficiência do uso fungicidas biológicos e quimicos na cana-de-açucar

Abstract

Among the managementpractices of the sugarcane crop, observing the control issuesrelated to pests and diseases is essential for a controlled result in the production of theplant. The use of biological and chemical fungicides is increasingly demonstrating its importance in order to improve the quality of planting. Thus, the present experiment aimed to analyze the effectiveness of chemical and biological fungicides on the vegetative growth of sugarcane cultivated in Brejo Paraibano. In order to achieve this objective, an experimental research was carried out considering variables such as, stem diameter, number of plants and number of internodes. A posteriori, the collecteddata were submitted to tests of normality of residues (Shapiro-Wilk) and homogeneityof variance (Bartlett). Non-parametric data were analyzed using the Friedman test at a5% probability level. In the graphs generated, eight genera of fungi were incident, with Nigrospora sp. and Leptosphaeria sp. the most significant.From these two consciples, more in-depth data were generated, detailing treatments and incidence. Thus, treatment 6, AZOXYSTROBIN 120 g/L and TEBUCONAZOL 200 g/L in the 1st and 2nd application at a dose of 0.5 L ha-1, proved to be the most efficient in controlling the incidence and severity of illnesses. However, the other treatments had average performance in certain analyses, also highlighting the importance of using biological agents.For the variable Height ofplants T2 and T5 died being the most responsive, this may be associated with the development phase of each sugarcane clump; The stem diameter T4 was the most responsive when applied both chemical and biological fungicide doses. Such an answer to this can be connected to greater efficiency using both products; T5 stood out more than the others in Tiller Numbers, this may be associated with the morphological characteristics that present a good tillering. For thevariable Number ofinternodes, the climatic conditions were more comfortable for T2, T3, T4, T5 and T6, being propitious for the development of the culms, promoting a greater increase in diameter. For the parameter Tons of Sugarcane per Hectare (TCH),the treatments that stood out in terms of productivity were T5 and T6. In view of this, agood responseis observed under the applications of the fungicide in ratoon cane cultivated in rainfedconditions in the Brejo Paraibano.