Chemical change during storage of crambe cultivated with application of plant growth regulators / Alterações químicas durante o armazenamento de crambe cultivado com aplicação de reguladores vegetais

This study aimed to characterize the chemical composition of crambe grains produced with plant growth regulators in the 2014 and 2015 harvests and stored for 180 days. During crambe cultivation, two foliar sprayings were carried out with the following treatments: 1) control treatment with distilled water; 2) indole-3-acetic acid 100 mg L-1 (IAA); 3) 3-gibberellic acid P.A. 100 mg L-1 (GA3); 4) Stimulate®. After harvesting, the grains were analyzed initially and after 180 days of uncontrolled storage. We checked water content, lipids in hot extraction (HE), lipids in cold extraction (CE), proteins, acidity and antioxidant activity. The Tukey test was used to compare the averages (p<0.05) and the parameters were grouped using a multivariate clustering technique presented in dendogram. The CE and HE lipid contents were reduced after storage, whereas the protein content and antioxidant activity of the grains were not altered by storage. However, the grains that received IAA application showed an increase in the CE lipid content and their preservation after storage. GA3 application, on the other hand, reduced the protein content. Lipid contents remained constant at the end of storage, and the acidity was reduced due to the application of GA3 and Stimulate® plant growth regulators. The 180-day storage changed crambe quality and regulators can assist in preserving grain quality during storage. The CE and HE lipid content and the grain acidity were good indicators for evaluating effects.

O objetivo do presente trabalho foi caracterizar a composição química dos grãos de crambe produzidos com reguladores vegetais nas safras de 2014 e 2015 e armazenados por 180 dias. Durante o cultivo do crambe, realizaram-se duas pulverizações foliares seguindo os tratamentos: 1) tratamento controle com água destilada; 2) ácido indol-3-acético 100 mg L-1 (AIA); 3) ácido 3-giberélico P.A. 100 mg L-1 (GA3); 4) Stimulate®. Após colhidos, os grãos foram analisados inicialmente e após 180 dias de armazenamento não controlado. Aferiu-se o teor de água, lipídeos em extração a quente (EQ), lipídeos em extração a frio (EF), proteínas, acidez e atividade antioxidante. As médias foram comparadas pelo teste Tukey (p<0,05) e os parâmetros agrupados pela técnica multivariada de agrupamento apresentado em dendograma. Os teores de lipídeos EF e EQ reduziram com o armazenamento enquanto que o teor de proteína e a atividade antioxidante dos grãos não foram alterados por esse fator. A aplicação de IAA destacou-se pelo aumento no teor de lipídeos EF e conservação desse após o armazenamento. A aplicação de GA3 reduziu o teor de proteínas. Os teores de lipídeos se mantiveram constante no final do armazenamento e houve redução no teor de acidez em decorrência da aplicação dos reguladores vegetais GA3 e Stimulate®. O armazenamento de 180 dias altera a qualidade de crambe e os reguladores podem auxiliar na preservação da qualidade dos grãos durante o armazenamento. O teor de lipídeos EF, EQ e a acidez dos grãos mostraram-se bons indicadores para avaliação dos efeitos.

Foliar application of plant growth regulators changes the physiological quality of crambe seeds

The application of plant growth regulators can manipulate the development of cultivated plants, and their physiological effects may be reflected in the physiological quality of the seeds. This study evaluated the effects of plant growth regulators (PGR) on the physiological quality of crambe seeds produced in the 2014 and 2015 harvests. During crop development, we applied two foliar sprayings of the following treatments: 1) control treatment with distilled water; 2) indole-3-acetic acid 100 mg L-1 (IAA); 3) 3-gibberellic acid P.A. 100 mg L-1 (GA3); 4) commercial PGR Stimulate® 6 mL L-1. The seeds were harvested and evaluated for water content, germination percentage and germination speed index (GSI), electrical conductivity and concentrations of leached Ca, Mg and K ions. Means were compared by Tukey ́s and Dunnett tests (p<0.05). Applying Stimulate® increased the germination percentage and the germination speed index, while IAA application showed an opposite effect, increasing the electrical conductivity of crambe seeds. Calcium leaching decreased with IAA application, and all regulators reduced K leaching. We therefore infer that the application of plant growth regulators influences the physiological quality of crambe seeds.