Yield, fiber quality and distribution of cotton production as a function of shading and mepiquat chloride

• Grant number: 20/14494-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2020
• End date: November 30, 2021
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Fábio Rafael Echer
• Grantee: Ana Flávia de Souza Rorato
• Host Institution: Faculdade de Ciências Agrárias. Universidade do Oeste Paulista (UNOESTE). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

The development of the reproductive structure of the cotton is directly associated with the intensity of the light received, which can vary due to the shading propagation by the cloudiness or high leaf area index and this can be modulated with the use of mepiquat chloride. The objective of the study will be to evaluate yield, fiber quality and mapping cotton production according to the shading of plants and application of mepiquat chloride. The experiment will be conducted at the UNOESTE experimental farm, in Presidente Bernardes - SP, on a sandy textured soil. The experimental design will be in random blocks, with five repetitions. The treatmentswill be: 1) shaded without a regulator; 2) with shade and regulator at -4, 0, 4 and 8 days after the beginning of flowering; 3) with shade and regulator 0 and 8 days after flowering; 4) with shade and regulator 8 days after flowering; 5) without shaded and without regulator and 6) without shaded and with regulator in normal rates for height control. Artificial shade (50% reduction in luminosity) will be installed in the F1 phase of the cotton, remaining for 8 days. The mepiquat chloride will be used as a growth regulator. The leaf area index (LAI) will be measured before, end and 10 days after the end of the shade.After removing the shading, fruits and leaves will be collected from the lower, middle and upper third of the plant to assess the carbohydrate content. During the harvest, the plant will be mapped, number of bolls, average boll weight, fiber yield and quality, as well as the harvest index. The data will be included in the analysis of variation and as means compared by the Tukey test at a minimum level of 5% probability (p<0.05).