What is Horticultural Mineral Oil (HMO)

What is Horticultural Mineral Oil (HMO) Horticultural Mineral Oil (HMO) is an oil used in horticulture and agriculture to control the pests and diseases of plants. Safe to use on most plants when applied correctly, it is a highly refined petroleum product. Mainly, it works by smothering the pests, such as aphids, scale insects, and mites, as they are covered with oil that clogs the respiratory openings. Thus, it kills the pests.Horticultural oil can also kill spores of fungi causing diseases such as powdery mildew and rust by suffocation. It is applied in organic and conventional farming because it degrades fast in the environment and does not remain in the soil.Several formulations of horticultural oils are available: dormant oils are applied in late winter when plants are dormant, and summer oils can be exterminated when plants are actively growing. Harmless to all the other environmental factors and of negligible toxicity to humans and all other animals. Compatible with the natural enemies of the pests (beneficial insects) Easy to use and safe. Lower in cost compared to the traditional pesticide chemicals No record has been made about development of pests resistance: Since the mode of action is mechanical rather than chemical there is actually a very little chance of the insects developing resistance against the oils. Types of HMOs 1. Dormant oils 2. Summer oils Dormant oils: Horticultural oils are called “Dormant” oils only when they are applied during dormant stage of plant growth (delayed dormancy stage) or simply while trees are resting. The term “dormant” refers to the seasonal timing of the application and not to the type of oil that we use. Summer oils: Also called “superior oils” and are sprayed during growing season. These oils are applied at much lower concentration compared to dormant oils. These are more volatile in nature and have less residency time on sprayed plants compared to dormant oils. In what way should oils be put on? All plant surfaces, above all in the case of the under-sides of the leaves, and in the crevices of the branches and stems that harbor pests. How do horticulture oils work? Horticultural oils control insects through direct contact, meaning the pests must be present for the oil to work. Complete coverage of the insect population is essential, for the oils to be effective. Pre-cautions for application You must read and follow the instructions before applying any material on the label. Oils must not be applied in combination with sulfur or sulfur containing pesticides such as Captan or Karathane since they may react with oils to form phytotoxic compounds. Elemental sulphur, being persistent for long periods, prohibits label directions on most oils to use within 30 days of sulfur application. Avoid mixing insecticide with the HMO. Horticultural Mineral Oils are applicable as an efficient pest management method, allowing suffocation for removal of chemical action. Proper timing and thorough application with well-