Long-term effect of conservation agriculture on the composition and nutritional value of durum wheat grains grown over 2 years in a Mediterranean environment.

BACKGROUND: Given the interest in mitigating the consequences of soil deterioration and climate change impacts on durum wheat grain, the objective of our study was to evaluate the effect of two soil management systems - conservation agriculture (CA) and conventional tillage (CT) - on the grain composition and nutritional value of two durum wheat varieties (Karim and Monastir) grown over two cropping seasons (2018-2019 and 2019-2020). RESULTS: The soil management system had an impact on all studied parameters, namely 1000-kernel weight (TKW), proximate composition, energy value, total phenol content (TPC), antioxidant capacities (DPPH and ABTS) and mineral elements (K, P and Na), excluding hectoliter weight. CA resulted in high moisture content, crude protein, P, K, Na, TPC, DPPH and ABTS. However, TKW, crude fat, crude ash, energy value, and total carbohydrate were higher when using CT. CONCLUSION: A 2-year adoption of conservation agriculture after a long-term conversion enhanced some compositional parameters and nutritional value of durum wheat varieties. The interaction with year and/or variety was very influential. © 2022 Society of Chemical Industry.

Field Survey and Resistance Occurrence to ALS-Inhibiting Herbicides in Glebionis coronaria L. in Tunisian Wheat Crops.

Glebionis coronaria (L.) Cass. ex Spach is a troublesome weed in cereal cropping systems in northern Tunisia. Recently, failures in controlling this weed have been reported by farmers. Field surveys and farmers interviews were conducted to highlight the potential causes of G. coronaria occurrence and the associated yield losses in wheat. Survey results revealed a significant correlation between farmers' awareness of resistance occurrence and cultural practices, mainly sowing date and tillage, while G. coronaria abundance was related to the lack of herbicide rotation and the frequency of ALS-inhibiting herbicide use. High G. coronaria infestations (more than 20 plants/m2) caused a significant decrease in wheat grain yield, reaching almost 75% at a density of 100 plants/m2. Field and pot experiments showed low efficacies of ALS-inhibiting herbicides to control G. coronaria populations. The application of field rates of tribenuron-methyl and mesosulfuron + iodosulfuron failed to control the tested populations, and generally, G. coronaria dry weight increased compared to nontreated ones (potential hormetic effect). These findings were further investigated in two selected resistant populations through tribenuron dose-response experiments, plants from both populations exhibited high resistance factors (greater than 300), surviving up to 16-fold the recommended field dose. This is the first report for G. coronaria resistance occurrence to ALS-inhibiting herbicides in Tunisia and the second case worldwide.