Effect of Vegetative Application of Herbicides on the Quality of Silage from Sorghum vulgare var. technicum [Körn.]

Abstract

On the basis of field experiments carried out during the period 2017 - 2020 in the experimental field of the Institute of Forage Crops –- Pleven, Republic of Bulgaria to establish the phytotoxic effect of a group of herbicides for postemergence application in broomcorn and the biochemical analysis carried out at the Institute of Animal Science, Skopje, Republic of North Macedonia, a comprehensive assessment of the influence of herbicide selectivity on the quality of broomcorn silage was made. It was found that the physico-biochemical parameters (dry matter content, pH, lactic acid, and butyric acid) in the forage mass are directly related to the fermentation parameters and the quality of the broomcorn silage and are significantly influenced by the selectivity of the herbicides at the culture. Obtaining silage from broomcorn with good silage qualities can be ensured by using above-ground fresh biomass from the crop with an established phytotoxic effect of no higher than 2.5 score as a result of the application of vegetation herbicides. The silage of above-ground biomass from broomcorn in the growth stage BBCH - 47 with established moderate-strong (EWRS - 4.5 score) to strong phytotoxicity (EWRS - 8.5 score) when applying herbicides, deteriorates the quality of the silage as a result of lowering the content of dry matter and compensatory processes related to reducing the content of lactic acid and increasing the share of acetic and butyric acids.