Management Options for Macadamia Orchards with Special Focus on Water Management and Ecosystem Services

Abstract

Abstract South Africa is the World’s largest producers of macadamia nuts, with about 51,000 ha of land covered by macadamia. This leads to major farming challenges, as the expansion of orchards is associated with the loss of habitat and biodiversity, the excessive use of and resistance to insecticides, and an increased pressure on water resources. More frequent and severe droughts and heat waves are projected to worsen the situation and have already negatively affected harvests. Here we review current literature and recent work conducted in the subtropical fruit growing area of Levubu, South Africa, which include catchment-scale assessments of ground water, landscape-scale studies on pest control and pollination services, through to evaluations of tree-level water use. Several biological control options are being developed to replace pesticides. Results suggest that bats and birds provide large and financially measurable pest control services, and interventions should therefore focus on maintaining functional landscapes that would be resilient in the face of global climate change. This would include a landscape matrix that includes natural vegetation and minimize water consumption by optimizing irrigation schedules.