Citrus: vitamin C in many shapes and sizes
Citrus are a varied and versatile family of fruit. Oranges are the most widely grown and eaten fresh or juiced, but the smaller, easy to peel, tangerines, mandarins, clementines and satsumas have become more popular in recent years. However, there are many other citrus which collectively are the number one fruit in international trade. Besides lemons, limes and grapefruit, try calamondins, citrons, pomelos or ugli fruit sometime.
In tree crops such as citrus, emphasis should be on the management of weeds rather than their permanent removal. Maintaining a particular balance of weeds in the citrus grove is important for sustainability by providing habitats for predators of insect pests and minimising soil erosion through the anchoring effect of plant roots.
Other facts about citrus
Using paraquat as part of an integrated weed management programme helps to achieve these goals in citrus groves. Paraquat is very fast acting, rainfast and safe to citrus trees for several reasons. First, it is immobilised on contact with the soil meaning that it cannot move to roots and be taken up into plants. Second, it is sprayed around the citrus trees which are protected by their bark which paraquat cannot penetrate. Third, even if small amounts of paraquat land on citrus leaves there is little or no damage because paraquat does not move through plants systemically like the alternative non-selective herbicide glyphosate. Paraquat has a very robust environmental profile. It does not leach because it is extremely tightly bound to soil particles immediately on contact, so it cannot move into groundwater, or to surface waters by run-off.