Weather observations in Zafra during the period 1750 to 1840 have been compiled and studied. Zafra was the capital of the Duchy of Feria, located in the southwest of the Iberian Peninsula. The documentary sources used in this work are weekly reports submitted to the Duke (who lived in Madrid)...

During a three-year period, we evaluated the profitability of a deficit-irrigation (DI) treatment in mature `Lane late' navel orange (Citrus sinensis (L.) Osb.) trees grafted on two different drought-tolerant rootstocks, `Cleopatra' mandarin (Citrus reshni Hort. ex Tanaka) and `Carrizo' citrange...

Ridge regression has been widely applied to estimate under collinearity by defining a class of estimators that are dependent on the parameter <italic>k</italic>. The variance inflation factor (VIF) is applied to detect the presence of collinearity and also as an objective method to obtain the value of <italic>k</italic> in ridge...