Action or damage threshold – The level of a pest population at which control is initiated.

Acidity – pH below 7.

Acute toxicity – Injury that occurs soon after exposure to a pesticide.

Aerated – Contains plenty of air.

Alkalinity – pH above 7.

Ammonium – A form of nitrogen that is commonly found in the soil.

Aneorbic – Without oxygen.

Annuals – Plants that reproduce by seed and live for a single year.

Antagonists – Organisms that release toxins or otherwise change conditions so that activity or growth of the pest organism is reduced.

Aphids – Small soft-bodied insects with long, slender mouth parts with which they pierce stems and leaves to suck out plant fluids.

Azotobacter – A type of bacteria found in compost piles that can fix atmospheric nitrogen into a form plants can use.

Bacteria – Single celled organisms that require a host plant or some other organic material as a food source.

Bed planting – Growing vegetables in closely spaced rows that grow together at crop maturity.

Beneficial insects – Insects that are beneficial for crop production because they pollinate plants, attack insect pests or serve other useful purposes.

Biennial – A plant that lives for two years. It produces leaves in the first and flowers in the second.

Biodegradable plastic mulch – Plastic mulch that degrades in the environment.

Biological control – Any activity of one species that reduces the adverse effects of another.

Black plastic mulch – A plastic mulch that is black in color.

Blossom-end rot – A calcium deficiency in tomato and pepper fruit that causes the tip of the fruit to blacken and rot.

Bolting – The formation of a seed stalk instead of an edible portion of the plant.

Bone meal – Ground up animal bones that are an excellent source of phosphate, calcium and trace elements.

Broadleaves – Dicot weeds that have meristems at the terminal end of their branches.

Burpless cucumber – Mild-flavored and the skin is free of bitterness.

Butter and sugar corn – White and yellow colored kernels are mixed on the ear.

Cabbageworms – Caterpillars that attack cole crops.

Cantaloupe – A muskmelon of the round-to-oval, firm fleshed, no sutured, heavy-netted type.

Carbon to nitrogen ratio – The ratio of the amount of carbon in organic matter to the amount of nitrogen that it contains.

Casaba – A somewhat rounded melon with a smooth rind and white flesh.

Cation exchange – The ability of clay and humus to attract and exchange positive ions.

Chronic toxicity – Injury that occurs after long-term exposure to a pesticide.

Clay – A constituent of soils that consists of particles less than 0.002 mm in size.

Clear plastic mulches – Plastic mulch that is clear and allows light to penetrate.

Cold frame – An unheated structure used to start transplants.

Companion planting – Plants that protect neighbors by repelling pests.

Compost – Decayed organic matter that contains nutrients and organisms, which enrich the soil.

Cool season vegetables – Plants that grow best when temperatures are cool.

Cover crop – A vigorous fast-growing plant that covers the soil surface and improves the soil.

Crookneck squash – Fruit are elongated with slim, long, slightly to very curved neck.

Crop rotation – Planting different crops in the same place two years in the row.

Cultivars – Plants within varieties that breeders have developed and are distinct from each other.

Cultural weed control – Cropping practices that optimize vegetable growth.