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.

Allelopathic bioactivity of fresh and infused aqueous extracts of Brazilian cherry (Eugenia uniflora L. ) on lettuce and maize / Bioatividade alelopática de extrato aquoso fresco e infuso de pitangueira (Eugenia uniflora L. ) sobre alface e milho

This study aimed to analyse the allelopathic bioactivity of fresh and infused aqueous extracts of Brazilian cherry leaves on the germination of lettuce and the initial development of maize. Brazilian cherry leaves were used to prepare a fresh aqueous extract (200 g L-1) and an infused extract (100 g L-1), which were diluted to concentrations of 0.4, 0.8, 1.2, 1.6 or 2.0% w/v. The variables evaluated in lettuce were the germination rate (GR), germination time index (GTI), germination speed index (GSI) and root length (RL). To determine the effect on the initial development of maize, we measured the shoot (SL) and root (RL) length. The experimental design included a factorial 2 × 5 design (two extracts and five concentrations), in addition to a control treatment (no extract). In general, the allelopathic bioactivity differed between the fresh and infused extracts. The fresh extract was more phytotoxic for the GR and RL of lettuce. Some beneficial results were observed for the infused extract, including an increase in the RL of lettuce and SL of maize. These effects were dependent on the extract concentration. Thus, there is evidence that Brazilian cherry extracts have allelopathic bioactivity.

O presente trabalho tem por objetivo em analisar a bioatividade alelopática do extrato fresco e infuso de pitangueira sobre a germinação de alface e no desenvolvimento inicial de milho. Para tanto, utilizaram-se folhas frescas de pitangueira para preparação de extratos aquosos fresco (200 g L-1) e infuso (100 g L-1), diluídos em 0,4; 0,6; 1,2; 1,6 e 2,0% p/v de concentração. Os parâmetros avaliados em alface foram porcentagem (PG), tempo médio (TMG) e velocidade média de germinação (VMG) e comprimento de raiz (CR). Já no desenvolvimento inicial do milho, obteve-se o comprimento de raiz (CR) e parte aérea (CPA). Os experimentos foram conduzidos em esquema fatorial 2x5 + tratamento controle (ausência de extrato), com dois tipos de extratos e cinco concentrações. De modo geral, a bioatividade alelopática dos extratos frescos e infusos foi diferente, sendo que o extrato fresco mostrou-se fitotóxico sobre a PG e CR de alface. Alguns resultados benéficos foram observados com o extrato infuso como aumento no CR de alface e no CPA de milho. Os efeitos desses extratos dependem das concentrações onde são testados. Dessa forma, há evidência de que os extratos de pitangueira possuem bioatividade alelopática.

Biochemical behavior of bean seeds and grains during storage / Comportamento bioquímico de sementes e grãos de feijão durante o armazenamento

The development of researches about vigor provides greater insight about the physiological behavior of seeds over storage periods. The aim of this study was to evaluate the biochemical changes which occurred in beans stored for 360 days. Analyses were performed at 0, 30, 90, 180, 270, and 360 days after receiving the seeds (S1 and S2) and grains (G1 and G2) of BRS Splendor. The following tests were conducted: water content, electrical conductivity, and chemical composition of the soaking solution, where sugars and ions Fe2+, Zn, Ca2+, Mg2+ and K+ were quantified. The experimental design was completely randomized split-plot and means were compared through Tukey test (p>0.05). Water content decreased after 90 days, and after 180 days reached an average of 16%. The electrical conductivity showed the greatest loss of solute after 90 days. Larger amounts of soluble sugars were found in S1 and G1. The quantities of potassium and calcium decreased after 360 days, while magnesium increased after 90 days of storage. The electrical conductivity test showed no direct relation to the quantification of the investigated ions. The amount and behavior of amino acids and studied ions did not showed relation to the decrease in vigor of beans.

O desenvolvimento de pesquisas sobre vigor proporciona maior conhecimento sobre o comportamento fisiológico das sementes ao longo do armazenamento. O objetivo desse estudo foi avaliar as mudanças bioquímicas ocorridas em feijões armazenados por 360 dias. As análises foram realizadas aos 0, 30, 90, 180, 270 e 360 dias, após o recebimento das sementes e grãos da cultivar BRS Esplendor. Foram realizados os testes de teor de água, condutividade elétrica, e a composição química da solução de embebição, onde os teores de açúcares e íons Fe2+, Zn, Ca2+, Mg2+ e K+ foram quantificados. O delineamento foi inteiramente casualizado em esquema de parcelas subdivididas e as médias comparadas pelo teste de Tukey (p>0,05). A condutividade elétrica apresentou maior perda de solutos aos 90 dias. As quantidades de potássio e cálcio diminuíram até os 360 dias, enquanto o magnésio teve aumento após 90 dias de armazenamento. O teste de condutividade elétrica não apresentou relação direta com a quantificação dos íons investigados. A quantidade e o comportamento dos aminoácidos e dos íons estudados não demonstraram relação com a queda do vigor dos feijões.