摘要
The study was carried out in northTunisia(36.5?N, 10.2?E) in order to get a comprehensive view of the growth dynamic of young olive orchards (Olea europaea L.,). The experiment involved irrigated trees of cultivars Chétoui, Manzanille, Meski and Picholine, planted at 6 ×6 m2spacing. Tree height, shoot length and canopy, fruit and trunk diameters were monitored regularly after plantation on 12 trees per variety. Root development was analyzed on Chétoui trees, only. Growth patterns were established annually for each variety before proposing an average model for each growth parameter. Results showed that tree height, shoot length and trunk diameter grew following an S-shaped curve with maximum annual increases occurring on the 4th year for tree height and a year later for canopy. The minimum gain coincided with the highest fruit load year, indicating that competition for assimilates concerns also young trees. Average growth patterns for tree height and shoots showed sustained rates all over the growing season with seven distinct periods of growth. Rapid growth occurred in April, July, and September, with similar growth trends observed for productive and less productive cultivars. However, the studied varieties behaved differently. Picholine cv., provided the most important increases and was the best water user. Results also showed that most roots were confined to the top soil layers and developed nearby the trunks. High root densities and important water depletion were observed in this area and thus, water and fertilizers should be supplied for young trees at these depths and distances from trunks. Root and canopy development were highly correlated (r = 0.94) and interfered with fruit growth. When trees set their first productions, the root-canopy ratio approximated the unit. An optimum ratio between root length and leaf area was found (2.3 km·m?2) for the 6-year-old tree, indicating good equilibrium between the above and the underground parts. On the basis of these results, a mathematical model was developed allowing a precise estimation of water requirements of olive trees during a period, where ground cover rarely exceeds 30%. We can conclude that all these models, graphic and mathematic give precise information on the occurrence of the various phenophases of young olive trees and may be used for a quantitative appraisal of the performance of olive varieties under a given environment. However, some aspects would be probed deeper and particularly the influence of climatic data on growth dynamic.
The study was carried out in northTunisia(36.5?N, 10.2?E) in order to get a comprehensive view of the growth dynamic of young olive orchards (Olea europaea L.,). The experiment involved irrigated trees of cultivars Chétoui, Manzanille, Meski and Picholine, planted at 6 ×6 m2spacing. Tree height, shoot length and canopy, fruit and trunk diameters were monitored regularly after plantation on 12 trees per variety. Root development was analyzed on Chétoui trees, only. Growth patterns were established annually for each variety before proposing an average model for each growth parameter. Results showed that tree height, shoot length and trunk diameter grew following an S-shaped curve with maximum annual increases occurring on the 4th year for tree height and a year later for canopy. The minimum gain coincided with the highest fruit load year, indicating that competition for assimilates concerns also young trees. Average growth patterns for tree height and shoots showed sustained rates all over the growing season with seven distinct periods of growth. Rapid growth occurred in April, July, and September, with similar growth trends observed for productive and less productive cultivars. However, the studied varieties behaved differently. Picholine cv., provided the most important increases and was the best water user. Results also showed that most roots were confined to the top soil layers and developed nearby the trunks. High root densities and important water depletion were observed in this area and thus, water and fertilizers should be supplied for young trees at these depths and distances from trunks. Root and canopy development were highly correlated (r = 0.94) and interfered with fruit growth. When trees set their first productions, the root-canopy ratio approximated the unit. An optimum ratio between root length and leaf area was found (2.3 km·m?2) for the 6-year-old tree, indicating good equilibrium between the above and the underground parts. On the basis of these results, a mathematical model was developed allowing a precise estimation of water requirements of olive trees during a period, where ground cover rarely exceeds 30%. We can conclude that all these models, graphic and mathematic give precise information on the occurrence of the various phenophases of young olive trees and may be used for a quantitative appraisal of the performance of olive varieties under a given environment. However, some aspects would be probed deeper and particularly the influence of climatic data on growth dynamic.
