Chaim Kurtz and Isaac Guil - Ministry of Agriculture, Israel
An irrigation trial was conducted during 1984-1988, to evaluate the optimal water dose required for early and high production of avocado (Persea americana, cvs. Ettinger, Fuerte and Hass, grafted on seedlings of West Indian root-stocks). The trial was carried out in a silty-loam soil along the coastal plain of Israel. Irrigation treatments included a gradual increase of water dosage, adjusted to tree age, in a pre-determined ratio of 70%: 100%: 130%. Data was collected on water and nutrient inputs, soil and leaf analysis, soil matric potential, growth, yield, and fruit size. The 130% irrigation increased significantly the yield of 'Ettinger' and 'Fuerte' by 32% and 15%, respectively. The yield of 'Hass’ was not affected. The higher rate of irrigation raised fruit size of 'Ettinger' but only in the first year of production when the crop load was light. Fruit size of the three cultivars was not affected by irrigation rate in the following years, when record yields were obtained. Water uptake took place mainly from the 0 to 60 cm soil layer, although root activity could be detected at 90 cm as well, mainly at the lower rates of irrigation. With the exception of 'Hass' which showed reduced trunk growth at the higher irrigation rate, tree growth increased as irrigation rate was raised. The average electrical conductivity of the 0 to 90 cm soil layers at mid-summer was 1.8, 1.6 and 1.3 dS/m in the 70%, 100%, and 130% irrigation treatments, respectively. The electrical conductivity was proportional to the chloride concentration of the soil. The 'Hass' had higher %N, %P and %K in the leaves as compared to 'Ettinger' and 'Fuerte'. Leaf %K was raised proportionally to the cumulative K fertilization from year to year, with notable interaction with irrigation treatments. Higher leaching in the intensive irrigation resulted in lower soil and leaf K. The present irrigation experiment pointed out the importance of intensive irrigation for rapid tree growth to achieve full canopy coverage for early production.
Chaim Kurtz and Isaac Guil - Ministry of Agriculture, Israel
An irrigation trial was conducted during 1984-1988, to evaluate the optimal water dose required for early and high production of avocado (Persea americana, cvs. Ettinger, Fuerte and Hass, grafted on seedlings of West Indian root-stocks). The trial was carried out in a silty-loam soil along the coastal plain of Israel. Irrigation treatments included a gradual increase of water dosage, adjusted to tree age, in a pre-determined ratio of 70%: 100%: 130%. Data was collected on water and nutrient inputs, soil and leaf analysis, soil matric potential, growth, yield, and fruit size. The 130% irrigation increased significantly the yield of 'Ettinger' and 'Fuerte' by 32% and 15%, respectively. The yield of 'Hass’ was not affected. The higher rate of irrigation raised fruit size of 'Ettinger' but only in the first year of production when the crop load was light. Fruit size of the three cultivars was not affected by irrigation rate in the following years, when record yields were obtained. Water uptake took place mainly from the 0 to 60 cm soil layer, although root activity could be detected at 90 cm as well, mainly at the lower rates of irrigation. With the exception of 'Hass' which showed reduced trunk growth at the higher irrigation rate, tree growth increased as irrigation rate was raised. The average electrical conductivity of the 0 to 90 cm soil layers at mid-summer was 1.8, 1.6 and 1.3 dS/m in the 70%, 100%, and 130% irrigation treatments, respectively. The electrical conductivity was proportional to the chloride concentration of the soil. The 'Hass' had higher %N, %P and %K in the leaves as compared to 'Ettinger' and 'Fuerte'. Leaf %K was raised proportionally to the cumulative K fertilization from year to year, with notable interaction with irrigation treatments. Higher leaching in the intensive irrigation resulted in lower soil and leaf K. The present irrigation experiment pointed out the importance of intensive irrigation for rapid tree growth to achieve full canopy coverage for early production.