Estudio del efecto de dosis y momento de aplicación del regulador de crecimiento (moddus) en producción de semilla de Festuca y Raigras

Fescue (Festuca arundinaceae) and annual Ryegrass (Lolium multiflorum) are forage crops with very good productivity, used in Uruguay mainly under grazing for livestock: meat, milk and wool. The seed production of these species is relevant in the development of the main agricultural activity in the country. Therefore, the demand for forage seed in Uruguay will depend mainly on the demand for forage by the most intensive livestock systems, with fescue and ryegrass being the most widely used species.

It is considerate that the seed production historically average yields obtained are low in relation to the potential of these species. This could be attributed, among other factors, to the fact that under certain growth conditions the plant lodge under its own weight. There are changes in crop management that include strategies to improve production efficiency and reduce the gap between potential yield and yield obtained in the field. Within these changes in management is the use of new technologies such as growth regulators.

The work was carried out in the field in different commercial crops of producers and the samples were analyzed in the Seed Analysis Laboratory of INIA (Instituto Nacional de Investigación Agropecuaria) belonging to the experimental station La Estanzuela located in the department of Colonia, Uruguay. Three trials were carried out, two on Festuca Arundinacea cv. Rizar, one with irrigation and one without irrigation, and one on Lolium Multiflorum cv. INIA Escorpio with irrigation. In all cases, four treatments were carried out based on the Moddus growth regulator: control (without application), 400cc, 400cc + 400cc and 800cc. Three repetitions were made for the case of Festuca Arundinacea and two for Lolium Multiflorum (pivot operation).

The objective was to evaluate the effect of the use of Moddus in fescue and annual ryegrass seed fields, dose and time, on seed yield, yield components, seed quality and seed losses in the harvest process.

The results obtained indicate an excellent yield potential of the crops studied, in comparison with previous studies in Uruguay and in some cases, in comparison with regions with better environmental conditions for the production of seeds of these species. An effect of the use of the growth regulator on the reduction of the height plants was obtained for two of the three trials evaluated.

Despite this, the tests carried out did not allow the detection of effects of the applied treatments of the TE growth regulator on seed production in the Rizar fescue and the INIA Escorpio ryegrass.