Page 145 - FRUTAS DEL TRÓPICO

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INTRODUCTION

The two primary determinants of plant growth are genetics and plant adaptation to the envi-

ronment. Genotypic selection, through either conventional or molecular methods, to various
environmental stresses has already played an important role in increasing plant productivity.

However to maximize success, there needs to be a better understanding of the mechanisms

by which plants respond to their environment. Once these mechanisms are identified, plants

can be manipulated for optimum productivity.

There are three general methods to manipulate plants for improved growth and yield: 1) ge-

netic manipulation (i.e., breeding, tissue culture, molecular biology), 2) physical manipulation (i.e.,

pruning and girdling) and 3) environmental manipulation which includes plant selection for specific
sites or cultural management (i.e., bedding to avoid flooding, shading, windbreaks). All three of

these methods require an understanding of environmental physiology for maximum effectiveness.

Environmental plant physiology is often called “stress physiology” or whole-plant physio-

logy because the general goal is usually to relieve stresses on plants. Most agricultural plants

including subtropical and tropical fruit crops are not in their native habitats which often results

in many environmental stresses. There are two general types of plant stress, biotic due to

living organisms such as insects and diseases, and abiotic due to environmental factors such

as low light, wind, and flooding. Because biotic and abiotic stresses are complex and often

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