The impact of dry, wet and heat episodes on the production of vegetable crops in Polabi (river basin)

This work evaluated the impact of meteorological extremes' variability on the growing of vegetables in the Labe river basin (Polabi), one of the Czech Republic's traditional vegetable growing regions. We analysed data for the majority of market vegetable crops cultivated in Polabi and their relationships with dry, wet and heat episodes. A higher number of tropical days caused reduced yield for the majority of vegetable crops, and the negative effect was especially significant for onion (r = -0.69), pea (r = -0.44), cabbage (r = -0.31), cauliflower (r = -0.32) and Savoy cabbage (r = -0.32). We found negative correlations between longer heatwaves and yields of pea and onion (r = -0.50), cauliflower (r = -0.42), carrot (r = -0.30) and celeriac (r = -0.40). Long-lasting extreme rainfall caused lower yields of garlic (r = -0.36), cucumbers (r = -0.30), and carrots (r = -0.44). Longer dry spells, meanwhile, caused lower yields in the majority of root vegetables (from r = -0.21 to r = -0.32). Nearly all vegetable crops (root, bulb and leaf vegetables) are sensitive to dry and wet spells during two periods: after sowing (planting) and the last 3 weeks before harvest. A tendency toward increased frequency of dry and heat episodes in Polabi leads to decreased yields and increased yield variability.