Potential of cowpea [Vigna unguiculata (L.) Walp.] and guar [Cyamopsis tetragonoloba (L.) Taub.] as alternative forage legumes for the United Arab Emirates

Investigations were conducted with an objective to identify alternative crops, especially legumes with low water requirement to replace the water intensive conventional species in forage production systems in the United Arab Emirates (UAE). Thus, the performance of 23 accession of cowpea (Vigna unguiculata) and 10 accessions of guar (Cyamopsis tetragonoloba) was evaluated over a growing period of 120 days during summer in 2009. In cowpea, the dry matter yield, averaged over the accessions was 18.1 t ha^-1 with accession TVu 9480 producing the maximum yield of 24 t ha^-1. Seed yield varied from 1.1 t ha^-1 (accession TVu 9604) to 4.9 t ha^-1 (accession TVu 9510) among accessions with an average of 2.4 t ha^-1. In guar, while the average dry matter yield of the 10 accessions was 9.5 t ha^-1, accession PI 323083 produced the highest yield (12.8 t ha^-1). Seed yield varied between 2.5 t ha-1 (accession PI 263891) and 1.4 t ha^-1 (accession PI 263877) with a mean of 2.2 t ha^-1 over accessions. The results show that both cowpea and guar have great potential and because of their low water requirements, they could be excellent alternatives for the water-thirsty forage species such as alfalfa in the UAE. Both these crops are salt-tolerant and in addition, they are fast-growing high quality forages and have other economic uses, especially as vegetables.