TRINEXAPAC-ETHYL REDUCES PLANT HEIGHT AND SEED YIELD IN FORAGE SORGHUM

Forage sorghum presents tall plants, what makes mechanicalseed harvesting a difficult task. Plant hormones can reduce plant height andfacilitate the harvesting. Thus, the objective of this study was to evaluatethe effect of the growth regulator trinexapac-ethyl on plant height and seedyield in forage sorghum. This research was carried out at Embrapa Maizeand Sorghum, in two seasons (2017 and 2018), in a randomized completeblock design, four replications and three varieties (BRS Ponta Negra, 1141574and 0947216) under application of Trinexapac-ethyl in two stages of the plantgrowth (V8, V12, V8 + V12). The characteristics evaluated were: plant height,seed yield and mass of 1000 seeds. The effect of the hormone was significantin both stages of growth, with a significant reduction in plant height. Thehormone applied twice at growth stages V8 + V12 had a greater effect inreducing plant height. However, the hormone reduced seed yield in the threevarieties, what implies the need for further studies comparing the advantageof plant height reduction and the loss in seed yield.

SILAGE PRODUCTION, BROMATOLOGICAL COMPOSITION AND ECONOMIC VIABILITY OF INOCULATION OF VARIETAL MAIZES WITH

In the western region of the State of Goias family farmers that depend onthe raising of livestock as one of their main sources of income are predominant. These farmers periodically grow maize for the production of silage in order to compensate their incomes. Considering the high cost of hybrid seeds and nitrogen fertilization, technologies that contribute to the reduction of silage production costs are required. In this sense, the objective of this study was to evaluate the response of maize genetic materials (Feroz Hybrid VIP3 and varieties SCS 156 and SCS 154), regarding silage production, bromatological composition and economic viability when inoculated with Azospirillum brasilense. The experiment was carried out on strips using a completely randomized design with four replications. Each cultivar responded differently to inoculation. For the Feroz hybrid and SCS 156 variety, the use of Azospirillum provided increases of 13.1% and 42.1% in green stem mass and 11.2 and 30.3% in silage nitrogen content, influencing the nutritional composition of the bulky food produced. For the SCS 154 variety, there was no response to inoculation. As for the economic viability, the use of inoculated SCS 156 variety presents a better rate of rentability, proving to be more economically attractive and viable to farmers.