ABSTRACT The use of growth regulators as a technique that can reduce plant height and thus strengthen stalks, which may be an option to eliminate or reduce plant lodging, thereby avoiding crop loss. However, there is a lack of information on the subject. The purpose of this study was to evaluate the effect of the dose (0; 37.5; 75.0; 112.5 e 150.0 g ha-1 active ingredient) and the application times of trinexapac-ethyl (sixth, seventh and eighth leaves), in a randomized complete block, in a 5x3 factorial scheme, with four replicates. The field experiment was performed during the 2016/17 crop season, in the experimental farm located in Selvíria, Mato Grosso do Sul State, Brazil, at Universidade Estadual Paulista- UNESP, Ilha Solteira, São Paulo State, Brazil - Campus. It is not recommended to apply the trinexapac-ethyl at eighth leaf, especially in the doses of 75.0; 112.5 and 150.0 g ha-1, since they generated the lowest values for yield parameters, thus reducing productivity, and providing greater number of unfilled grains. Taking into account the reduction in plant height, the minimization of lodging and grain yield, trinexapac-ethyl should be applied to the seventh leaf of the BRS Esmeralda rice at the dose of 75 g ha-1.

Resumo O uso de corantes verdes em gramados esportivos é uma prática comum, tendo como principal objetivo, a manutenção do aspecto da grama, com intuito maximizar a qualidade estética. Os corantes são utilizados para fornecer cor verde as gramas durante períodos de estresse e dormência, sendo considerados uma alternativa para gramas de clima quente durante os meses de inverno. A recente popularidade do uso desse artifício ocorreu devido aos esforços para conservação da água, bem como à redução dos custos das operações, como o “overseeding”. Assim, objetivou-se avaliar a durabilidade e doses de corante orgânico na qualidade visual de grama bermuda DiscoveryTM. O experimento foi instalado a campo, subdividido em parcelas de grama bermuda DiscoveryTM, sendo os tratamentos: 0 ml L-1 (Testemunha), 33 ml L-1, 50 ml L-1, 66,6 ml L-1 (recomendação do fabricante), 83 ml L-1, 100 ml L-1 do corante comercial orgânico específico para gramados. A cada 10 dias foram avaliados os índices de coloração verde, reflectância, vegetação por diferença normalizada (NDVI) e imagem digital. Os resultados indicaram doses entre 66,6 e 83,3 ml L-1 podem ser recomendadas, visto o tempo da durabilidade do produto.

Abstract The painting of sports turfs with colorants is a common practice, with the main objective to maintain grass appearance for maximum aesthetic quality. Colorants are used to provide green color to grasses during periods of stress and dormancy and are considered an alternative for warm weather grasses during the winter months. Recent increases in the use of colorants is due to water conservation efforts as well as lower operating costs compared to winter overseeding. The objective of this study was to evaluate durability and doses of organic colorant in terms of visual quality of DiscoveryTM bermudagrass. The experiment was installed in the field, subdivided into plots of DiscoveryTM bermudagrass treated with lawn-specific commercial, organic colorant as follows 0 ml L-1 (Control); 33 ml L-1; 50 ml L-1; 66.6 ml L-1 (manufacturer’s recommendation); 83 ml L-1; 100 ml L-1. At 10 day intervals the green color index, reflectance, normalized difference vegetation index (NDVI), and digital images were measured and assessed. The results indicate that, given the durability of the product, doses between 66.6 and 83.3 ml L-1 are recommended.