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1. The developing time of the mealybug from catalpa exceeded that of the mealybug from apple. 2. In no experiment did cross-breeding of the mealybug from apple and from catalpa take place. 3. Each mealybug was able to live successfully on both hosts. 4. The parasites, Clausenua purpurea Ishii, from the mealybugs from catalpa parasitized the mealybugs from apply failed to parasitize mealybugs from catalpa. 5. Some female mealybugs may overwinter in the adult form if fully protected from the weather and if the temperature does not drop below 45 °F. 6. Under optimum conditions, several mealybugs lived exceptionally long lives, passing a maximum of 145 days. 7. A color differentiation of the females of the two mealybugs was noticeable. / Master of Science

Rooted stool-bed layers of Malling Merton (MM) 111 apple trees were container-grown in a greenhouse and trained to a single shoot. When shoot length averaged 73 cm, the following treatments were applied: a) check, untreated (CK); b) tipped (shoot apex removed) and top 1/2 of shoot disbudded (T-DB); c) top 1/2 of shoot disbudded and defoliated (UT-DB-DF); d) tipped, and top 1/2 of shoot disbudded and defoliated (T-DB-DF); e) pruned at mid-shoot (P); or f) pruned at mid-shoot and disbudded (P-DB). Treatments UT-DB-DF, T-DB-DF, P, and P-DB delayed the eventual decline in net photosynthesis (Pn) and total chlorophyll content exhibited by the check. The delay in the decline of Pn and total chlorophyll content was maintained for the longest period in the UT-DB-DF, T-DB-DF, and P-DB treatments. Maintenance of Pn and chlorophyll levels following pruning or defoliation appears to result from an increased root : shoot ratio at treatment rather than an increased demand for photosynthates by subsequent growth. Treatment responses of Pn and total chlorophyll content were similar so that Pn per unit chlorophyll showed no treatment differences. Removal of leaves by either pruning or defoliation reduced total dry weight of the tree whereas tipping had no effect. Final dry weights of the basal stem, roots, and shank were reduced by pruning or defoliation. Lateral shoot growth induced by pruning caused an initial decrease in the shank diameter and root and shank dry weights of potted apple trees. / Master of Science

M.S.

These experiments have proved conclusively the effect of cedar rust on the normal processes of the apple leaf. The diseased leaves use more oxygen and give off more carbon dioxide than the healthy leaves, and at the same time less starch and sugar is made than in the healthy leaves. When transpiration is reduced, the food supply - the soluble plant food - is accordingly reduced. The difficulty of diseased trees not being able to get sufficient food through insufficient transportation, by water, may be overcome by either of two methods - (1) irrigation or (2) fertilization, with neutral or slightly acid fertilizers, manure being an excellent material to use. The first and most important method of cedar rust control is to cut the cedars for a distance of at least a half mile from the orchard. Second in importance is by timely sprayings, and third, is by feeding the trees. In order that cedar rust control is to be realized, cooperation in a community is essential. “Team work" is necessary in all lines of work and the orchardist should not forget this fact. / Master of Science

In an economy characteristics by keen competition among commodities for consumers' disposable income, the per capita demand for a product may shift over a period of time. With a decline in demand (a shift to the left of the demand curve) for a commodity, the total consumption may be less than in previous years even with an expanding population. In the past four decades the trend in per capita consumption of apples has been downward. This downward trend is evident when the per capita rates of apple consumption are compared for various time periods during these years. In fact, the trend in per capita consumption of apples has been steadily downward from 1909 to 1953 as shown by the averages for each five-year period beginning with 1909¹. The trend in total yearly consumption of apples in the United States has likewise been downward. However, this decline has been less pronounced than per capita consumption declines because of the counteracting influence of population increases in this country. Shifts in demand for a commodity create economic problems in both production and marketing. These problems are especially acute for products such as apples, which require large fixed investments of capital for production and handling. Apple production initially requires large outlays of capital for land, labor, and nursery stock. It is approximately eight years before an apple tree is brought into production and the orchardist begins to realize a return on his investment. During these formative years, and more especially in later years, the land planted in trees is not easily and readily shifted into production of other commodities. Likewise, the special equipment and storage facilities necessary for efficient marketing of apples represent a sizable investment of capital of a specialized nature that is not easily and readily adaptable for other uses. In order to make production and marketing decisions that are economically sound, people in the apple industry need adequate information on changes in consumer reactions to apples. To be adequate, this information must not only reflect the changes in the movement of apples moving into consumption, but must also provide information concerning the effectiveness of current merchandising practices on apple sales. The best source of this information is the market place where consumer preferences are registered. / Master of Science