Title : Weed biocontrol with alternative natural compounds
Abstract:
Over the last decade, about 6.1 billion kilograms of the herbicide glyphosate [N-(phosphonomethyl) glycine] have been applied worldwide. Despite being the most heavily applied herbicide in the world, in 2015 glyphosate was classified as ‘probably carcinogenic to humans’ by the International Agency for Research on Cancer. The strong pressure form consumer associations and green organizations on European regulatory bodies could cause in a relatively short time the ban of glyphosate. Moreover, among the concrete targets to transform the EU food system, the objective in reducing the use and risk of pesticides by 50% is one of the most ambitious measures that will require the development of alternative and effective solutions. In this context, the aim of the present research was to identify some possible alternative treatments for weed control by using less harmful compounds for the human being and the environment than glyphosate based herbicides. Weed control trials were carried out in a completely randomized experimental design with 3 replications. During the experiment, data were collected considering a monocotyledon (Lolium perenne L.) and a dicotyledon (Vicia sativa L.). In the first trial, 5 acetic acids (concentrated natural vinegar, glacial acetic acid, lactic acid, citric acid, and acetic acid from food processing waste) were compared applying a volume of 300 L/ha. Images of the weed cover were collected 4 and 7 days after treatment (DAT). Results showed that total weed control ranged from 13,5 ± 5,7% for citric acid to 74,8% ± 9,0% for acetic acid from food processing waste. In addition, specific data were collected on the optimal dose to improve treatment efficacy and persistence. Finally, the effect of adjuvants was also considered. In conclusion, results confirmed the potential of acetic acids as bioherbicide. However, additional research efforts are needed to fine-tune product distribution and agronomic management of the crop.
