Insects and fungi cause Iowa fruit growers and gardeners a loss which in the aggregate amounts to hundreds of thousands of dollars annually. They cause fruit and vegetables to rot and to be wormy and knotty or scabby; they damage blossoms and blossom buds and so interfere more or less with the setting of the fruit; they, destroy a vast amount of foliage or injure it in such a way as to interfere with its work of building up the special kinds of food which the plant must have in order properly to sustain its life, to support its growth, to form fruit buds for the following year, and to store away in its roots, trunk, and branches the reserve supply which it needs to support its active growth during the spring until the new leaves are fully developed and ready for work. Fortunately many of the worst of these insects and diseases may be kept well under control by proper, treatment as outlined in this spraying calendar. It is not best always to follow these general recommendations exactly. The strength of the mixtures and the number of treatments should be varied to fit special cases. It must be left for the manager of the work to decide this matter, but let him remember that, as a rule, the Iowa fruit grower who would be most successful under present conditions must spray systematically and thoroughly every year.