Fruiting and Kernel Production Characteristics of Ten Mediterranean Carob Cultivars Grown in Northeastern Spain

Abstract

The carob ( Ceratonia siliquaL.) is a leguminous fruit tree commonly grown in Mediterranean coastal areas. Carob bean gum is extracted from the pod seed and is a valuable stabilizer and thickener for the food industry. The identification of carob cultivars that produce high seed yields in northeastern Spain, and similar environments, would be of interest to growers. Vegetative, fruiting and pod characteristics were examined for ten carob cultivars with six cultivars originally from Spain (‘A-19’, ‘Bugadera’, ‘Gastor-1’, ‘Gaucin-1’, ‘Sayalonga’ and ‘Rojal’), three from Portugal (‘Aida’, ‘Galhosa’, and ‘Mulata’) and one cultivar from Italy (‘Albarcara’), in a replicated trial in northeastern Spain (Catalonia). This rainfed trial (500 mm of average rainfall) was planted in 1991 using seedling rootstocks budded in 1992. The trees were trained to free vase at a 8 x 9 m spacing (139 trees/ha including 12% pollinizers). ‘Aida’, ‘Rojal’ and ‘A-19’ were the most precocious cultivars. Significant differences were observed for cumulative pod production 13 years after budding. With respect to the cumulative kernel yield, ‘Albarcara’ and ‘Aida’ gave the highest production (over 33 kg/tree). The lowest tree vigour (as estimated by trunk-cross sectional area) was observed in ‘Sayalonga’ and ‘A-19’. ‘Rojal’ and ‘Mulata’ trees produced the largest pods (over 20 g of fruit weight) and lowest kernel content (10-12%) while ‘Gaucin-1’ and ‘Albarcara’ produced the smallest fruits (weighting 13.0 g and 14.1 g respectively) with the highest kernel content (14.8% and 20.6% respectively). Thus, regarding kernel and pod production, ‘Aida’, ‘Albarcara’, ‘Galhosa’, ‘Gaucin-1’ and ‘Mulata’ seem to be the best performing female cultivars for planting new carob orchards.