Differential effects of mulch on citrus and avocado.

摘要

Organic mulches were applied to two avocado and two citrus orchards ('Eureka' lemons on Macrophylla rootstock, and 'Navel' oranges on Troyer rootstock) over a four-year period (1994-98) in Los Angeles, California, USA. Soil moisture, weed suppression, tree canopy, root growth, soil/leaf nutrient status and fungal populations were measured. There was a pronounced effect of mulch on soil moisture (reduced evaporative loss) and weed growth (substantially reduced with mulch), but plant canopy and leafnutrient status changes were negligible during the time frame, although soil nutritional changes were noted. An important effect of mulches on root architecture was an increase in root length and spatial distribution in avocado, which was not observed incitrus. This change in rooting pattern may partially be responsible for improved resistance to Phytophthora spp. diseases in avocado.