Analysis of yield, sowing and flowering dates of barley of field survey results in Spain

Abstract

Sowing dates, flowering dates and yields of barley ( Hordeum vulgare L.) of more than 500 sample plots (20×20 m) in Spain have been investigated, with the aim to obtain a better understanding of the consequences of sowing date and flowering date variation on yield. The results of this study may provide an indication of whether for Spain, and eventually also for other semi-arid areas in Mediterranean regions, one or more sowing dates should be used as input in the crop growth monitoring systems applied by the European Union (EU). Data for the seasons 1993–94, 1994–95 and 1995–96 have been studied. The association between sowing dates, rainfall and soil moisture status has been tested. For rainfall, observed and interpolated data were used. Soil moisture estimates were retrieved from scatterometter data of the European remote sensing (ERS) satellites. Analysis of the sowing date suggests that sowing is associated with the expected beginning of the rainy season. Variation in sowing dates as a result of rainfall variation could not be demonstrated. Yield variance analysis, grouping yield by sowing date and by flowering date, did not provide convincing evidence that sowing and flowering date variation influenced yield.