Oil Spray for Citrus Trees
Oil spray for citrus trees, usually called horticultural oil spray, helps kill diseases and pests on citrus trees. Research also shows that oils can improve the color of citrus fruits. It makes the trees more attractive, prevents damage and keeps their fruit harvests bountiful. Gardeners can use oil spray for a variety of problems, and it is easy to find and apply.
Effects on Pests
Horticultural oils kill insects that eat citrus trees and spread pests. According to the National Gardening Association, oil sprays work by smothering bugs, especially small mites and bug eggs. The Western Australian Department of Agriculture and Food recommends horticultural oils to kill citrus leafminers, weevils and scales.
Effects on Diseases
Horticultural oil also helps get rid of mildew and other plant fungi, according to the National Gardening Association and the University of Florida. Fungi do not grow as well in the presence of oils, and the oils also help prevent fungal and viral problems by killing the bugs that spread them.
Types
Different types of horticultural oils exist, but they all serve to reduce pests and diseases. According to the National Gardening Association, most horticultural oils come from refined crude oil. However, some oil sprays come from vegetable oil or neem oil. Dormant oil is a type of oil that works well on citrus trees during their dormant seasons.
Use
To use horticultural oil, spray it all over the leaves of the infected citrus tree. Make sure to thoroughly cover the leaves, especially in infected areas. Reapply the oil after a rainfall, because much of it will wash away.
Warning
Although some beneficial bugs, like lacewings and beetles, can fly away before horticultural oils kill them, gardeners should keep in mind that horticultural oils may kill beneficial bugs. The National Gardening Association warns farmers against using oil spray when they rely on beneficial mites, which can help keep away other pests on citrus trees.