ANNUAL REPORT, 1939 77 



of Carolina Hemlock {Tsiiga caroliniana), ten trees to the plot, which will receive 

 different treatments in 1940. 



Factors Influencing the Hardiness of Evergreens. (Harold S. Tiffany, 

 Walthani.) Winter injury to evergreens is a serious problem both in nurseries 

 and in ornamental plantings, particularly of those species which are injured at 

 infrequent intervals only, and at such times to an extreme degree. Cultural 

 treatment sfeems to be one of the factors involved. Accordingly three plots of 

 the spreading English Yew, Taxus baccata repandans, have been started as 

 suitable material for study, since the spedes baccata is outstanding in the list 

 of plants affected. By 1940 the plants should be sufficiently established to allow 

 the beginning of the treatments to be tested. 



DEPARTMENT OF OLERICULTURE 



Grant B. Snyder in Charge 



Shape Index Studies of Tomatoes. (W. H. Lachman.) It has been dem- 

 onstrated in past years that shape indices are quite reliable in making quantitative 

 comparisons among varieties of tomatoes. These studies have been continued 

 with the idea of ascertaining the influence of season upon the form of fruit in 

 several tomato varieties. Under unfavorable growing conditions the polar diam- 

 eter of the fruit is greater in proportion to the equatorial diameter than under 

 more desirable conditions. 



Sweet Corn Breeding. (W. H. Lachman.) This project was initiated three 

 years ago in an effort to isolate inbred strains of sweet corn which excelled in 

 earliness, productivity, disease resistance, and quality. Moie than 1600 plants 

 of eight early commercial varieties were self-pollinated and have since been 

 carried in pedigreed lines. From this early work 300 lines have been selected 

 as the best of the progenies. 



The planting has been made on the same plot each year. The soil in this 

 plot is evidently thoroughly contaminated with root, stalk, and ear-rot diseases 

 of corn. In addition to this, each plant has been inoculated with the bacterial 

 wilt disease. Approximately 200 of the lines show a moderate to high degree of 

 resistance to all of these diseases. Most inbreds of Golden Gem, however, seem 

 to be particularly susceptible. 



Many of the lines showed a remarkable degree of uniformity the past year 

 and will be combined in the hybrid condition to further test their usefulness. 



Hybrid Sweet Corn Trials. (W. H. Lachman.) Thirty-five hybrid varieties 

 of yellow sweet corn were planted for trial during the past season. Many of these 

 performed very well but were a little too late in maturity for general usefulness 

 in Massachusetts. Four of the varieties were especially noteworthy: Spancross 

 C4.13, which w^as exceptionally early; Marcross C13.6, an early sort with an ear 

 of good size; Marcross 13.39, a second early with an ear of good size and 

 exceptional quality; and Golden Cross Bantam, a midseason variety with a 

 large ear, high productivity, and excellent quality. 



Tomato Breeding. (W. H. Lachman.) The primary object of this project 

 is to incorporate the uniform ripening character into otherwise desirable com- 

 mercial tomato varieties. Most commercial varieties of tomatoes have a green 

 to yellow-red coloration of the shoulders when firm ripe. This character is un- 

 desirable from the market viewpoint. 



By cross-pollinating a variety of little importance possessing the uniform ripen- 

 ing character with six commercial varieties of tomatoes, many promising seg- 

 regates have been noted and selected for further study. Although the work has 



