Using Vetiver in Arboriculture

At Pepiniere Naac Baal we grow fruit trees (Mango, mandarin, grapefruit, lemons, papaya and oranges). For the last three years we have used vetiver extensively to support these trees. We surround each tree with a ring of vetiver grass. This has a range of advantages:

• It retains soil moisture, important as we have low rainfull and rely on piped water for 8 months of the year. As we extend the circle each year, the vetiver is harvested and the replanted in a wider circle. The roots from the previous seasons vetiver remain in the soil and improve its quality and produce a 'sponge' like texture which retains water.
• We have seen trees develop at a better rate when surrounded with vetiver than those without, and seen increased yields. Whilst there could also be other factors, it is our belief, and evidenced from documentation from elsewhere in the world, that this is due in part to the use of the grass and the ability of its deep roots to bring up nutrients from the soils to the trees.
• We use the grass, when cut, as a mulch around the base of the tree, again increasing water retention and reducing evaporation.
• As our trees are organic, we use compost and cow dung around the base of the trees, the vetiver hedges around the trees prevent heavy rain and flooding from washing away this valuable resource.
• We have found that vetiver helps reduce pest attack. We used to suffer from a serious termite problem but have found that vetiver acts as a trap crop during the dry season, attracting the termites into the vetiver and away from the trees. Overall since planting the vetiver we have seen an overall reduction of termites on the farm. Although anecdotal, we has not seen any attacks of 'white fly' on our fruit trees since planting with vetiver.