MORPHO-ANATOMICAL CHANGES OF PEQUI LEAVES (Caryocar brasiliense Cambess.) EXPOSED TO SIMULATED DRIFT OF GLYPHOSATE

Lailla Queiroz Silva,Sebastião Carvalho Vasconcelos Filho,Alana Cristina Ferreira Araújo,Adriano Jakelaitis,Alan Carlos Costa

doi:10.1590/0100-67622016000400010

Lailla Queiroz Silva, Sebastião Carvalho Vasconcelos Filho + Show 3 more

Open Access

https://doi.org/10.1590/0100-67622016000400010

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Journal: Revista Árvore	Publication Date: Aug 1, 2016
Citations: 6	License type: cc-by

Affiliation: Instituto Federal Goiano

Abstract

ABSTRACT The goal of this research was to examine phytotoxicity and leaf anatomy of pequi plants (Caryocar brasiliense Cambess.) exposed to simulated drift of glyphosate. The experimental design was randomized blocks with nine replications. Each experimental unit was composed by one 18-L pot with one plant. The treatments consisted of different doses of glyphosate sprayed: 0 (control), 50, 100, 250, 500, 1000 and 1500 g ae ha-1 of glyphosate. Phytotoxicity visual ratings were carried out at 7, 14 and 21 days after spraying (DAS) by scores expressed in a percentage scale, within which zero and one hundred represent no symptom and plant death, respectively. Description of symptoms, changes in leaf anatomy and micromorphometric analysis were performed on leaves taken from plant top and middle third at 23 DAS. Poisoning symptoms were wilting, chlorosis followed by necrosis, winding of top leaves and leaf senescence, being intensified with increasing doses. Leaf anatomical changes were detected from the dose of 250 g ha-1. The observed damages consisted of plasmolized cells, epidermal disruption, distorted cells, hyperplasia, cell collapsing, necrotic tissue and accumulation of phenolic compounds.

Highlights

Pequi tree is a symbol of cerrado biome being highlighted by its economical interest, mainly because of its fruit use in regional cuisine (ALMEIDA; SILVA, 1994) and for being major source of family income for farming communities (SANTOS et al, 2013)
The key visual symptoms after herbicide phytotoxicity are plant chlorosis followed by necrosis (FRANÇA et al, 2010)
At 14 and 21 days after spraying (DAS), simple linear models were fitted to phytotoxicity, meaning the injuries increased with higher doses reaching values close to 50% for the highest dose (1500 g ha-1) compared to control in both times

Summary

Introduction

Pequi tree is a symbol of cerrado biome (savannahlike environment) being highlighted by its economical interest, mainly because of its fruit use in regional cuisine (ALMEIDA; SILVA, 1994) and for being major source of family income for farming communities (SANTOS et al, 2013). The main threat to biodiversity in this system is the growth of agriculture and animal husbandry that is strengthened by an expressive use of chemical fertilizers, intensive mechanization and high-tech pesticides, among them, the herbicides (CUNHA et al, 2008). Glyphosate is one of the nonselective herbicides most widely used worldwide in weed control due to their physicochemical and economic characteristics, besides its high agronomic efficacy, controlling a large number of weed species from mono- and eudicotyledon groups (SZEìKAìCS; DARVAS, 2012). It has caused serious environmental problems by deposition out of the target of interest, due to drifting (FRANÇA et al, 2010; PEREIRA et al, 2010). Injuring intensity and symptoms on non-target plants vary with several plant factors such as species, phenological stage and growing, besides weather conditions during application and the amount of active ingredient reaching the recipient plant (RIGOLI et al, 2008; PEREIRA et al, 2010)

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