Análise de crescimento e seletividade a herbicidas em duas variedades da forrageira Festuca (Lolium arundinaceum)

Abstract

The fescue (Lolium arundinaceum) is a perennial winter grass that presents advantage in relation to the other temperate species by being persistent, providing some growth in the summer, producing forage earlier in the autumn and thus supplying the critical phase of forage vacuity. It is still little disseminated, but presents diverse adaptability, greater resistance to excess moisture and tolerance to cold. In order to know more about the species, the project aims to evaluate two varieties of fescue with precocious and late growth, in relation to the development in the region (test 1), as well as to identify the time of application and to select the herbicides that presents less phytotoxicity to the crop (test 2). Experiments were implanted in the experimental farm of UTFPR, Campus Dois Vizinhos - PR, in a completely randomized design. In the growth analysis, the two fescue varieties were analyzed in relation to the 9 variables evaluated, at different pickup times. The selectivity analysis was carried out in a two-factorial scheme (nine treatments x two varieties). The treatments consisted of eight herbicides, among which recommended and not recommended for pastures, and the control, on four replications. The results showed that the behavior of the two varieties of fescue in the growth analysis and herbicide application was similar. In the majority of the variables evaluated in the analysis of growth, the Aurora variety stand out in relation to Fortuna, but two presented exponential growth. The herbicides Paraquat + Diurom and Atrazine + Simazina presented high phytotoxicity to the crop. All herbicides tested showed a crop phytotoxicity up to 21 DAA, despite expressing low levels of symptoms in plants.