Because disease pests are so small, most home gardeners tend to underestimate their importance and may not know much about them. Consequently, more emphasis is often placed on insect and weed control, and gardeners sometimes fail to carry out an effective disease control program. There's time to work out a game plan for controlling disease pests for the 1999 season, but you'll do a better job if you know more about your opponents. When the latter occurs, the symptoms of disease are produced on the host plant. When diseases are bad enough, poor quality vegetables and fruit, along with reduced yields, are the end result.
Many fungi are mold-like organisms existing in the form of microscopic threads.
Most are transmitted from plant to plant by tiny seed-like bodies called spores, which are carried by air currents, splashing water, or tools. Bacteria are microscopic one-celled organisms. The forms causing plant diseases are rod-like or cylindrical in shape and reproduce by fission. This means that one bacterium can divide to form two new cells, and these two can spit to form four cells. In this manner, millions of bacteria may be produced in a short period of time unless controlled.