Potential of Cytisus and allied genera (Genisteae: Fabaceae) as forage shrubs .1. Seed germination and agronomy

The potential adaptability of 19 shrubby legume species belonging to the genus Cytisus and allied genera (Cytisophyllum, Chamaecytisus, and Genista sect. Teline) for arid regions was studied. Twenty-eight accessions were assessed for germination level, field survival, height and diametrical growth, and dry matter yields. All accessions had high germination, often over 80%, when seeds were scarified with sulphuric acid for 40 min. Two germination temperatures were tested: constant 16 degrees C and alternating 21/16 degrees C. Optimum temperature varied according to the different species. Cytisophyllum sessilifolium, Cytisus purgans, Cytisus villosus, and Chamaecytisus sp. pi. had more rapid and higher germination at 21/16 degrees C compared with at 16 degrees C. In the field, Genista canariensis and G. monspessulana had the highest growth, and survival around 80%. Chamaecytisus accessions showed the highest survival and an intermediate growth. Cytisophyllum sessilifolium, Cytisus heterochrous, Cytisus villosus, and G. linifolia presented intermediate growth as well, and survival around 75%, whereas the rest of the Cytisus accessions as well as G. tenera, presented very low survival rates.