Page 78 - ORNAMENTALES DEL TRÓPICO

78 Ornamentales del trópicO

Symptoms of viral diseases include mottling and mosaic patterns in the color of leaves,
flowers, and fruit, yellowing and/or crinkling of leaves, misshapen leaves, and shortened inter-

nodes, which make the plants appear abnormally small.

Disease Diagnostic Information and Submission of Samples

There are several steps the one should follow when attempting to diagnose disease problems
in the plants brought into the extension office. It is very helpful to get as much information as

possible. It is important to find out from the person bringing in the plant how many plants are

affected, when symptoms appeared, the pattern of development in the field or garden, the

severity of the disease, any recent cultural practices (e.g., use of pesticides or fertilizers), and

any weather conditions that might have affected the plants.

Some helpful web sites:

Managing Plant Diseases

Failure to adequately manage a disease can often be traced back to a failure to correctly diag-

nose the problem. Once a disease is properly diagnosed, many resources (books, fact sheets,

the Web, extension professionals, etcetera.) can be consulted to help outline a reasonable

disease control program.

In order for a disease to develop in a plant, there must be three things present: the patho-

gen; the host, and an environment favorable for disease development. This is called the disea-
se triangle. All three parts of the triangle must be present for the disease to occur. In order to

control a disease, it is necessary to remove one of these three parts.

Plant disease controls include crop resistance, cultural and physical methods, pesticides,

and regulation.

Universidad Autónoma de Chiapas