Pruning guide for blackberries in Central America

Although the cultivated blackberry (Rubus fruticosus) has been grown in the highlands of Central America for decades, it is relatively new as an export crop. There are many types of commercial cultivated blackberries in the world. According to growth habit, the types vary from erect to semi-erect to trailing. There are also the thornless and the thorny types. Then there are varieties developed from inter-specific and inter-varietal hybrids. Finally, varieties are developed for different sets of climatic and edaphic conditions. Blackberry variety trials principally in farmers" fields initiated by PROEXAG in Central America have demonstrated, so far, that the varieties developed in Texas (such as Brazos, Rosborough, and Brison) are better adapted to the Central American Highlands (within the range of 1,000 to 2,000 meters above sea level) than the other varieties tried such as the Arkansas developed varieties (Shawnee, Cheyenne, Comanche, and Cherokee) and the thornless varieties (such as Chester). At lower elevations, the berries are not sweet and disease problems are more acute. At much higher elevations, frost problems become more severe and production declines during the cold months. The pruning systems described in the present work are, therefore, practices recommended (for now, based on the limited experience so far) for the Texas developed erect varieties when planted in the Central American highlands. (Author abstract)