CHAPTER ONE
1.0              INTRODUCTION
1.1       BACKGROUND  OF STUDY
The Avocado pear, Persea   Americana is a tropical and sub tropical  fruit tree, originated in central America or adjoining regions of North or South America.  It has now spread to much of the near tropical world.  The avocado is limited especially by its climatic requirements, with their race differences.  It is also highly susceptible to drought injury.  But excess soil moisture is equally fatal, encouraging the dread phytophthora root rot in most of the world, and where  the fungus is unknown. Despite the high water activity of  most fruits, the how PH leads to their spoilage being dominated by fungi, both yeast and moulds.  Other common diseases of pears include the black spot or scab caused by as comycetes
            Avocado fruits has being estimated that one fourth of all produced harvested is no consumed before spoilage (Salulche, 1974), spoilage of fresh fruits usually occurs during storage and transport and while wacting to be processed unlike many other foods fruits after picking and before processing are ‘a live’ of the products plus the normal ripering process complicate an independent discussion of the microbiological spoilage problems are really market diseases of these products:
            Shape, varies from slightly obligate to highly elongate, an intermediate oval or pear shape is preferred.  Yellow to purple or black.
            The composition of the fruit influences the likely type of spoilage.  thus bacteria soft rot is widespread for the most part among the fruits is limited to those that are not highly acid.  Because most fruits are somewhat acid are fairly dry at the surface, and are deficient in B vitamins, mold are the most common causes of spoilage.  The compositions too, must determine the particular kind of molds most likely to grow, thus avocado support a large, variety of fungal spoilage organisms and other kinds comparatively few.