Foliar characterization and influence of pH on Sulfentrazone and Saflufenacil herbicides to control species Merremia aegyptia, Mucuna aterrima and Luffa aegyptiaca

• Grant number: 12/02300-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: June 01, 2012
• End date: May 31, 2013
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Patrícia Andrea Monquero
• Grantee: Raysa Maduro Alves
• Host Institution: Centro de Ciências Agrárias (CCA). Universidade Federal de São Carlos (UFSCAR). Araras , SP, Brazil

Abstract

The knowledge of leaf surface characteristics is important to understand some aspects of absorption of herbicides and plant behavior in the environment, as well as determine the influence of pH on the efficacy of herbicides. The objective of this work will be to assess the foliar surface of Merremia aegyptia, Luffa aegyptiaca, and Mucuna aterrima using a scanning electron microscope and evaluate the effectiveness and the pH of Saflufenacil and Sulfentrazone solutions applied in post-emergency. In the first part of the experiment, the foliage through scanning electron microscopy will be carried out in two phases: before applying herbicides and five days after the implementation. To analyze the foliar surface, there will be removed two segments of approximately 50 mm² median regions of the young leaves Merremia aegyptia, Luffa aegyptiaca, and Mucuna aterrima, but fully expanded, to the analysis of the adaxial and abaxial surfaces. The samples shall be fixed, dehydrated, mounted on stubs, and taken to the metallizer, where they will be coated with a thin layer of gold with a thickness of 0.05 ¼m. After this process the stomata and trichomes will be analyzed and classified, observing the differences among the species of plants and the initial effect of herbicide on the leaf surface by scanning electron microscope, being photographed with the best images. In the second experiment, conducted at greenhouse, the herbicide Saflufenacil and Sulfentrazone will be applied in recommended dosages in post-emergency of Merremia aegyptia, Luffa aegyptiaca e Mucuna aterrima. Apply grout herbicides with different pHs (2.0; 4.0; 5.5; 8.0 and 10,0), in addition to witness without herbicide. Analysis of visual control to 7, 14, 21, and 28 days after application and dry biomass will be determined.(AU)