48 MASS. EXPERIMENT STATION BULLETIN 398 



Rust varies with seasonal conditions, but some selected strains showed only 52 

 percent infection as compared with 83 percent for the commercial strain. Rust 

 of sufificient severity to cause any injury to the plant occurred on only a fourth of 

 the total population. This compared with 14 percent on the old asparagus plants 

 growing alongside, from which the strains under comparison were derived; and 

 67 percent for a row of the Paradise variety, known to be more susceptible to rust. 



Vegetable Breeding for Improvement of Quality. (Robert E, Young, Waltham.) 

 During the year breeding and general varietal studies were conducted with a 

 number of the common vegetables including tomato, Summer Pascal celery, 

 lettuce, rutabaga, beet, greenhouse cucumber, broccoli, and carrot. While there 

 has been an extensive accumulation of information concerning the possibilities 

 and habits of these several vegetables, the results are not sufficientlj' conclusive 

 to justify detailed discussion, except in a few cases. 



Trellis Tomato. The breeding program to improve the internal quality of the 

 two strains of trellis tomatoes developed here was continued with a very satis- 

 factorj' crop. Since most of the tomatoes that have better internal quality are 

 later maturing, some of the desirable F2 population has been back-crossed to 

 Trellis No. 22 to get earlier 3'ield. A small early tomato, Denmark, has also been 

 used for some of the back crosses. Some new hybrids were made in the green- 

 house and planted for the summer crop, to determine what varieties could be 

 combined with Trellis No. 22 to take advantage of the hybrid vigor. 



The most productive hybrid tried this year was Trellis No. 22 X Maine No. 

 85. This produced an early yield 44 percent greater than Trellis No. 22, with an 

 11 percent greater total yield, although the percentage of No. 1 fruits was only 

 slightly larger for the hybrid. Work with this hybrid will be continued. There 

 were other first -generation hybrids that produced an increase in yield, and the 

 second generation hybrids were above average in early yield. 



Greenhouse Tomatoes. The spring crop of tomatoes was used as a test crop in 

 the use of a hormone spray to produce fruit without seed. Every other plant 

 was treated by spraying the cluster about the time two to three blossoms had 

 opened. Three applications were made one w'eek apart, and some of the buds 

 on the second cluster were small at the time of the last spray. The use of the 

 hormone spray almost doubled the average set of fruit on the first cluster. The 

 spray did not make so much difference in the set of the second cluster — 52 per- 

 cent for the sprayed, compared with 39 percent for the unsprayed. For both 

 clusters, the three sprays produced a set of 64 percent compared with 38 percent 

 for the untreated plants. There was no noticeable difference in flavor between 

 the seedless fruit and that having seed. 



The disadvantage of this spray is that it must be confined to the flower cluster 

 because it affects the foliage about the same as severe mosaic. The labor of 

 putting on the spray, where it has to be applied several times, is considerable; 

 and further trials are necessary before its practical value can be determined. 



Rutabaga or Cape Turnip. As reported last year, three distinct types of Ruta- 

 baga have been developed and were ready for trial, and six lots of these three 

 types were distributed in Bristol and Barnstable counties. 



No. 1 has typical Cape turnip foliage and root shape. The chief distinguishing 

 feature is the absence of green coloring matter in the exposed shoulder, which, 

 however, develops a purple color when exposed to the sun. When grown with 

 sufficient foliage to furnish shade, the shoulder as well as the bottom of ithe root 

 is white. 



No. 2 is a uniform type having white flesh and a green shoulder, and in general 

 resembles the White Cape strains. 



