Chemicals for Tomatoes

Acids and Bases

• Often, the soil or growing medium that the tomato plants are destined for is not optimally pH-balanced. Because the amount of nutrients given to a tomato differs from growing medium to growing medium, the necessary pH also differs. In soil, tomato plants prefer a soil pH level between 6 and 7. This is slightly more acidic than some other plants but is not terribly acidic. If the soil is too basic, the tomato gardener can add chemicals such as calcium carbonate, also known as limestone, or calcium silicate. Extremely acidic soil, on the other hand, requires basic chemicals such as soil sulfur, calcium chloride or sodium sulfate, also known as gypsum.

Fertilizer

• Like all living things, chemical nutrients are essential for the tomato plant’s growth and development. While chemical compounds such as nitrates, phosphates and elements such as potassium are required in large numbers, tomatoes also require trace amounts of chemicals such as magnesium, calcium, and keratin. Commercial fertilizer mixes often contain all of these chemicals, but their proportions in a particular fertilizer will determine if the product is good for tomato growth. Start young tomato plants in a balanced chemical mixture of 3 percent nitrogen, 3 percent phosphorus and 3 percent potassium. When blossoms appear, lower the amount of nitrogen, which stimulates plant growth and increase the amount of phosphorus, which stimulates fruiting.

Pesticides

• A host of insects and larval plant predators also enjoy a good tomato as well as tomato plant leaves, stems and roots. Calcium hypochlorite, sodium hypochlorite and tetramethylcyclopropanecarboxylate are all inorganic chemical compounds used for killing insects that feed on the crops. Dimethoate, malathion, neem oil and methyl bromide are all organic insecticides.

Fungicides

• Mold spores and fungus travel on the air, looking for nutritious places to land. Fungicides ensure that tomato plants are not nutritious for fungus and mold. Chemical fungicides include copper hydroxide, chlorothalonil, kaolin, and metam-sodium. These chemicals are often combined with fertilizers to prevent fungus from attacking young plants or root structures.

Herbicides

• Also used often in conjunction with fertilizers, herbicides ensure that tomatoes are the only plants able to enjoy the nutrients of the soil. Common herbicidal chemicals include ammonium sulfate, glyphosate, or potassium salt, and carbaryl. Methyl bromide is also used not only as a pesticide but also as an herbicide.