Abstract: Molecular iodine, or a composition or ionic iodine complex which comprises, generates, or chemically or ionically releases molecular iodine, is used alone or mixed with a carrier for use as a plant and crop protectant. Secondary active ingredients, fertilizers, nutrients, phytosterols, micronutrients, promoters, polyaspartates, biomass, surfactants, emulsifiers, oils, odorants, waxes, salts, preservatives, herbicides, fungicides, nematicides, insecticides, bactericides, virucides, fumigants, iodides, rainfastness agents, adhesive extender agents, and tackifying extender agents are optionally added to the carrier for additional plant benefit. The molecular iodine and the desired beneficial additive(s) is applied, directly or indirectly by various methods, to agricultural substances, such as plants and crops, in order to protect the plants and/or crops from pests, such as fungi, nematodes, viruses, bacteria, and weeds which are harmful to plants or crops.