Desempenho das gerações F1 e F2 de canola sobressemeada à soja

Abstract

Oversowing is a technique aimed at enabling the intensification of cropping systems, allowing more crops in an agricultural year, by sowing the successor crop over the predecessor crop at the end of the cycle. The use of saved seeds for the production of canola grains has been an alternative used by farmers aiming at lower production costs. However, saved seeds have lower hybrid vigor in relation to certified seeds. Therefore, the loss of productivity using saved seeds can be greater than what is saved by not buying certified seeds. Thus, the objective of this work was to verify if there is feasibility in the technique of oversowing canola on soybean, at the R7 stage of development, using certified seeds and saved seeds in order to determine which progeny presents the best performance in the field. As well as, define the most suitable sowing density. The study was carried out in 2021, in the municipality of Cerro Largo, RS. A completely randomized design was used in a 2 x 6 factorial scheme, with 4 replications, with the seeding density factor established at 3 kg ha-1 (recommended for canola cultivation) at broadcast, 3 kg ha-1 in the row, 6 kg ha-1, 9 kg ha-1, 12 kg ha-1 and 15 kg ha-1 and the factor certified seeds of canola Diamond (generation F1) and saved seed of canola Diamond (generation F2). During the canola development cycle, evaluations of seedling emergence, plant height, number of leaves per plant and the determination of the phenological stages of the crop were carried out. After the canola harvest, the yield components of the crop, the dry mass of aerial part of each plot and the productivity determined were measured. There was a significant difference in the canola yield components, impacting the final productivity. The F1 generation showed superior results compared to the F2 generation in the silique components per plant, thousand seed weight and grain yield. For the other variables evaluated, there were no significant differences between generations. As for the evaluated sowing densities, the highest productivity in the F1 and F2 generations of canola was obtained at the density of 12 kg/ha-1.