MARYLAND. 157 



The entonnological project on parasitic Hymenoptera was continued 

 during the year, and many facts with reference to the life history 

 of certain species were worked out. 



Work on the projects in plant physiology consisted of investiga- 

 tions regarding the effect of chemicals injected into plants on their 

 physiology and structure, the effect of chemicals on weeds to deter- 

 mine methods for their destruction, and the relation of chemicals 

 to mutations in plants. The effect of chemical treatment of pollen 

 was also studied and observations were further made on the use of 

 fertilizers in relation to mutation and changes in cell structure in a 

 large number of varieties of fruits, vegetables, and flowers. 



The station also had in progress under the Hatch and other funds 

 a large number of other experiments. The work in the horticultural 

 department was divided among the workers, each one being placed 

 in entire charge of certain lines of work. Under this arrangement 

 C. P. Close worked extensively on nut trees, especially walnuts and 

 pecans, and worked out a successful method of bench grafting. In 

 addition, attention was given to peanut and mushroom culture, orch- 

 ard heating, apple breeding, fertilizers, and cover crops for apple 

 orchards, and experiments with the sweet cherry. In the orchard- 

 heating work, carried on in the spring of 1910, the temperature of 

 the orchards was raised 8 degrees over the adjoining regions. Breed- 

 ing work with geraniums and pears, culture tests with strawberries, 

 raspberries, tomatoes, and muskmelon, testing preserving fluids for 

 fruits, propagating apple and pear by cuttings, feeding plants with 

 copper solutions for disease resistance, the study of reciprocal in- 

 fluence of scion and stock, and experiments with peaches were in 

 charge of W. R. Ballard. T. H. White conducted experiments with 

 asparagus, cabbage, celeiy, potatoes, sweet potatoes, and onions, made 

 observations on the variation of plants due to excess of plant food in 

 various forms, made fertilizer tests with gooseberries and currants, 

 and devoted some time to the study of carnations, chrysanthemums, 

 sweet peas, roses, and violets. 



In agronomy the work was grouped under three heads: Soil and 

 fertility tests, experiments with cereals, forage and green manuring 

 crops, and tobacco experiments. Tests were made of different forms 

 and sources of j^hosphoric acid and of various nitrogenous fertilizers, 

 different forms of lime were compared, and a study was made of the 

 use of gi-een manure, deep ploAving, and of farm manures for renovat- 

 ing soils and maintaining their fertility. The particular crops used 

 for green manures included coAvpeas when followed by wheat and 

 corn, and crimson clover when followed by corn. In this connec- 

 tion some nonleguminous crops were grown for the purpose, and the 

 value of lime was tested when used for growing green manuring 

 crops. Breeding work, variety testing, and culture experiments were 



