The impact of dry, wet and heat episodes on the production of vegetable crops in Polabí (River Basin)

This work evaluated the impact of meteorological extremes’ variability on the growing of vegetables in the Labe river basin (Polabí), one of the Czech Republic’s traditional vegetable growing regions. We analysed data for the majority of market vegetable crops presently cultivated in Polabí 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. Important for fruit vegetables is that a wet period during June causes their yields to decrease. A tendency toward increased frequency of dry and heat episodes in Polabí is leading to decreased yields and increased yield variability. That, in turn, means rising costs for vegetable growing and economic losses for farmers