Columnar fruiting cacti as an effective technology in improving water use efficiency in the arid regions

One of the major steps in responding to imminent water shortages is improving water use efficiency. Drought-resistant crops would be an effective technology to curb rising demands of water. Columnar Cactus species characteristics fit with most of the requirements of a drought tolerant crop with very high water-use efficiency. Cacti have physiological and morphological methods of exploiting environments that would soon desiccate other plants. Some columnar fruiting cacti were introduced into UAE deserts and could be ideal for establishing crop plantations in the arid environment. Among the introduced fruiting cacti Carnegiea gigantean, Cereus hexagonus, C. pachanoi, C. peruvianus, C. validus, Myrtillocactus geometrizans, Pachycereus pecten-aboriginum, P. pringlii, Stenocereus griseus, S. stellatus and S. thurberi. Plants were propagated by cuttings in the greenhouse. Cuttings developed roots within 2–4 weeks of planting. The propagated plants were acclimatized and transplanted into the field in the desert. Cereus species were the most promising in the new environment in terms of its high adaptability and healthy growth in the new environment. C. pachanoi grew very fast, averaging up to a fifteen centimeter a month of new growth. On the other hand, Carnegiea gigantea showed very slow growth. Pachycereus pringlii and Stenocereus stellatus showed some yellowing on the side that faces the sunshines. S. griseus however, showed reddish rip edges that faces the sunshines. Over irrigation caused the stems to be cracked. However the introduced species showed differences in growth performance most of them found to be promising in the new environment.