Temporal and spatial diversity of the occurrence of atmospheric drought in Poland (1966-2005) and its effect of yield of pickling cucumber (Cucumis sativus L.)

Counteracting the negative effects of drought in vegetal production should include drought monitoring, determination of drought tolerance and, thus, the assessment of risk, limitations and losses of yield for various species of cultivated plants. The aim of the work was to assess temporal and spatial variability of the occurrence of atmospheric drought in Poland and to determine the risk of cultivation of pickling cucumber caused by this phenomenon. To carry out the task, starting data concerning the marketable and total yield of cucumber, durations of cucumber development stages and also daily atmospheric precipitation totals, collected respectively from 28 experimental stations and 51 meteorological stations through 1966-2005, were used. Atmospheric drought of different intensity: moderate, severe and extreme, in four analysed cucumber development stages was determined on the basis of the standard precipitation index. On the other hand, relationship between cucumber yield and precipitation deficiency in the period of the highest demand for water was determined by means of curvilinear regression analysis. In Poland, drought occurred mostly in the central-western part of the country. In this area, an average decrease in the cucumber total yield amounted to over 12% every 2-3 years, and the marketable yield over 15% every 2 years. The results obtained in the present work can be used in the research concerning the assessment of drought influence on growth, development and crop productivity of other cultivated plants.