Impact of irrigation during flowering and fruit growth on fruit yield and quality of the cactus Opuntia spp.

peer reviewedMost plantations of cactus pear are not irrigated in Morocco and fruits are tiny. The impacts of irrigation during flowering (FLO) and fruit growth (FRG) on fruit yield and quality were monitored along two years on three varieties of cactus pear. In 2011, irrigation treatments were: T1 (0 mm), T2 (30 mm during FLO and 30 mm during FRG) and T3 (30 mm during FRG only). In 2012, irrigation treatments increased to 60 mm during FLO and FRG. The irrigation treatments were applied in 8 (T3) or 16 (T2) watering, once every three days. Interactions between varieties and treatments were significant for fruit yields and for yield components. In 2011, T2 and T3 irrigations had a negative effect on ‘Aissa’ and ‘Moussa’ (-2.8 kg/ plant) and T2 had a positive effect on ‘Achefri’ (+2.7 kg/plant). Fruit quality was not affected by irrigation. In 2012, all the varieties responded positively to irrigation: ‘Achefri’ and ‘Aissa’ yielded very significantly more with T3 (plus 63 % and 30 % resp.) and ‘Moussa’ with T2 (+30 %). All irrigations increased fruit number and size. Irrigation had no significant effect on the fruit quality or slightly decreased the content of total sugars and titratable acidity

Improving yield and water use efficiency of sugarcane under drip irrigation in the Gharb region of Morocco

Au Maroc, la rareté de l’eau liée au changement climatique, constitue le facteur limitant principal du développement agricole. Depuis 2008, un programme de reconversion à l’irrigation localisée a été entrepris par l’état pour mieux valoriser et économiser l’eau d’irri-gation. Un essai a été conduit durant deux années sur la canne à sucre dans le Gharb sous un climat méditerranéen avec un sol argilo-limoneux. Les objectifs étaient de déterminer les besoins en eau de la culture, d’optimiser l’EUE et d’évaluer la réponse de la culture à différents apports d’eau en mode d’irrigation localisée. L’expérimentation a été conduite en utilisant la variété “CP70-321” avec un dispositif en blocs aléatoires randomisés, quatre répétitions et cinq régimes hydriques. Les résultats ont montré un effet hautement significatif du régime hydrique sur les rendements en tiges et en sucre et sur la hauteur de végétation. Les besoins en eau d’irrigation sont de 7500 m³.ha-1, mais 5000 m³.ha-1 équivalent à 67 % ETM serait un volume suffisant pour optimiser l’EUE (132 à 157 kg de tiges ha-1.mm-1 et 22,2 à 24,2 kg de sucre ha-1.mm-1). L’irrigation localisée pourrait donc conduire à: i) économiser environ 50 % d’eau apporté comparativement à l’irrigation par aspersion, ii) presque doubler le rendement en tiges et iii) améliorer le rendement en sucre d’environ 8 à 23 tonnes/ha.Mots clés: Canne à sucre, Efficience d’utilisation de l’eau, Gharb, MarocOne of the most limiting factors for agricultural development in Morocco is water scarcity linked to climate change. Since 2008, an important program promoting drip irrigation was undertaken by the state to achieve water saving and productivity. An experiment on sugarcane was conducted in the Gharb region under Mediterranean climate with a silty clay soil during two cropping seasons. The objectives were to assess the sugarcane water requirements, optimize WUE and test the crop response to variable irrigation water supplies under drip irrigation. The experiment was conducted using ‘’CP70-321’’ sugarcane cultivar in an experimental station using a randomized block design with four replications and five water regimes. The results showed a highly significant effect of the water regime on sugar and stems yields and also on height of stems. Water requirements for sugarcane were estimated at 7500 m³.ha-1, but 5000 m³.ha-1 equivalent to 67 % ETc, was sufficient to optimize WUE (132 to 157 kg of stems ha-1.mm-1 and 22.2 to 24.2 kg of sugar ha-1.mm-1. This means that drip irrigation on sugarcane could potentially i) save about 50 % of the irrigation volume, comparatively to sprinkler irrigation, ii) almost double the stem yields and iii) increase the sugar yields from 8 to 23 tons/ha.Keywords: Sugarcane, Water use efficiency (WUE), Gharb, Morocco