How the Management and Environmental Conditions Affect the Weed Vegetation in Canary Grass (Phalaris canariensis L.) Fields

Canary grass (Phalaris canariensis L.) is a versatile crop with global significance; it is primarily cultivated for its small elliptical seeds, which are used as bird feed and for human consumption. This crop is adapted to various climates and soils, so it can be grown successfully in Hungary. However, challenges such as weed control, climate change impacts, and soil factors require strategic management for sustained success in canary grass cultivation. Our study investigated the impact of management and environmental (as seasonal and soil) factors on pre-harvest weed vegetation in canary grass fields in Southeast Hungary between 2017 and 2020. In addition to showing the weed vegetation of the canary grass, the aim of our work was to promote more effective weed management of canary grass by revealing correlations between soil, seasonality, and management variables, influencing weed diversity and coverage. Using the analysis of covariance (ANCOVA) and correlation tests, we tested significant variables, providing insights into the complex interactions affecting weed composition. A redundancy analysis (RDA) further unveiled the relationships between explanatory variables and weed species' composition. The findings offer valuable information for effective weed management strategies in canary grass cultivation. Our comprehensive study on canary grass fields in Southeast Hungary sheds light on significant factors influencing weed composition and abundance. The average weed coverage was 10.8%, with summer annuals and creeping perennials being the most prevalent life forms. Echinochloa crus-galli, Cirsium arvense, Xanthium italicum, and Setaria viridis were among the dominant species. ANCOVAs revealed the impact of soil, management, and seasonal factors on weed cover, species richness, diversity, and yield levels. Soil properties like texture, pH, and nitrogen content showed varying effects on weed parameters. The vintage effect, tillage systems, and farming practices also played crucial roles. The redundancy analysis highlighted the influence of the year, soil sulfur content, and winter preceding crops on weed composition. In conclusion, the herbaceous vegetation in the studied area is dominated by summer germinating and creeping perennial species. Despite slight differences in average coverage and occurrence, a well-defined set of significant species is evident. Multicollinearity among variables suggests limitations to further increase the number of variables that can be included in the analysis. The ANCOVAs showed that the soil, seasonal, and farming variables significantly influence overall weed vegetation and crop yield, with a lesser impact on species richness and diversity. The reduced RDA model highlights the strong influence of the year on species' composition, emphasizing the inherent factors during canary grass cultivation that are challenging to modify through farming practices.