Response of ‘Hass’ avocado trees to irrigation management and root constraint

摘要: Abstract The performance of ‘Hass’ avocado trees grown in lysimeters under different irrigation regimes obtained by manipulating drip frequency and root volume was examined. experimental design comprised six treatments (3 × 2) with three frequencies two container volumes (100- 200-L). were: pulsed (10–20 min every 30 min) throughout the day (Irg1), one daily event beginning at night terminated morning (Irg2) days (Irg3). Irrigation management induced significant differences water availability zone subsequently, diurnal periodic uptake. Water uptake Irg1 treatment closely followed changes meteorological conditions (air temperature, pan evaporation vapour pressure deficit) while that Irg2 Irg3 depressed intermediate severe stress, respectively. had little effect on vegetative growth, flowering or fruit-set processes. However there were fruitlet abscission accordingly, fruit yield. Black spots initiated from seed became apparent some fruits June, about weeks later an intensive begun ended July. more intense 100-L than 200-L containers, following order: Irg3 > Irg2 ≫ Irg1 regardless volume. Net CO2 assimilation during periods growth decreased exposed to moderate stress (Irg2 Irg3, respectively) therefore, it is plausible resulted carbohydrate stress. Improvement nutrient availability, especially where activity system weak as a result low supply presumably played dominant role seeds function.