Efficacy of pyraclostrobin on the production and chemical composition of forage and silage of wheat (Triticum aestivum cv. BRS Umbu) and oats (Avena strigosa cv. Embrapa 139) preceded by successive cuts in the hard dough grain stage

Abstract

The objective of the experiment was to evaluate the productivity, nutritional value and degradability of forage and silage of wheat (Triticum aestivum cv. BRS Umbu) and black oats (Avena strigosa cv. Embrapa 139), preceded by successive cuts, harvested at the hard dough stage, subjected or not to treatment with pyraclostrobin fungicide. Plants were harvested manually with a height of 0.08 m from the ground surface, at the hard dough stage, after two cuts at the vegetative stage; two applications of pyraclostrobin, 0.6 L ha-1 were made, before the first and the second cut. Pyraclostobin decreased the dry matter losses from 21.1% of the control system to 7.7% for the system with pyraclostrobin, reduced the neutral detergent fiber from 70.05% to 66.73%, decreased detergent fiber acid from 43.37% to 39.96%, decreased lignin from 14.37% to 10.13% and increased the relative value of the food from 75.27% to 82.72%, all in the forage, which resulted in changes in silage, with a decrease in neutral detergent fiber from 64.00% to 58.46%, acid detergent fiber from 38.76% to 35.87%, lignin from 10.11% to 6.78% and an increase in the relative value of the food from 85.87 to 97.26. In the evaluation of the forages, wheat presented the best productivity, with 10,068 kg ha-1 vs. 8,238 kg ha-1 black oats, lower neutral detergent fiber (60.32% vs. 76.46%), lower acid detergent fiber (34.49% vs. 48.84%) and higher relative value of the food (96.04 vs. 61.95), these data were from the forage, which were reflected in the resulting silage. It is recommended to use pyraclostrobin as it reduces losses during fermentation, changes fiber composition and improves the degradability of the food. Among the forages, the wheat was more promising, than black oats, due to its productivity, combined with its better chemical composition and degradability.