Determination of the Irrigation Regimen for an Avocado Plantation in Spring and Autumn

摘要

An irrigation experiment was conducted with three cultivars (Hass, Ettinger and Fuerte) in the avocado nplantation of the Akko Experiment Station, Israel, during 1974-80 to determine the effect of irrigation nregimen in spring and autumn on tree growth and productivity. nTwo treatments (wet and dry) were tested in the spring and in the autumn. In spring the trees nreceiving the wet treatment were irrigated when the tension at a soil depth of 30 cm reached 25 char n(250 MPa), while those in the dry treatment were irrigated at 40 cbar tension. The same wet treatment nwas also applied in the autumn, while in the dry treatment the trees were not irrigated until the fruit nreached elasticity at noon. nThe water regimen in the spring affected tree growth slightly, but in cvv. Hass and Ettinger the nabsolute and relative growth was higher in the spring dry treatment than in the wet. Trees grew faster nunder the autumn wet regimen than with the autumn dry regimen. nThe effect of irrigation regimen on yield, fruit size and export quality was light. Only with cv. nEttinger were higher yields recorded from trees irrigated with the dry-wet regimen. The autumn water nstress sometimes decreased fruit size, but size was affected much more by the tree yield than by the nirrigation regimen. nIt seems that the regimens in spring and autumn do not increase the productivity of avocado trees. nHowever, equivalent yields of the same quality can be obtained with reduced water amounts, by using nthe water more efficiently.