DEVELOPMENT OF WILT-RESISTANT TOMATOES. 17 



tion and produced a heavy crop of fruit. Cuttings were made from 

 this superior plant and transferred to the greenhouse. By repeat- 

 edly making cuttings during the winter from this greenhouse ma- 

 terial enough seed was obtained by spring to make an acre field test. 

 The results were so good that the entire crop was saved for seed and 

 used for making extensive field trials in 1917. This new strain was 

 equal to the original strain in quality and quantity of fruit and 

 much superior to it in wilt resistance. This is one of the cases in 

 which a second selection gave further improvement, the other cases 

 being selections from Merveille des Marches. 



The Norton produces a heavy yield of large, smooth, solid red 

 fruit (PI. X), which ripens slowly and therefore ships well. It is 

 similar to the Stone in time of maturity, but usually produces heavier 

 yields and more solid fruit. It is highly resistant to tomato wilt 

 (Fusarium lycopersici) and possesses a little resistance to tomato 

 leaf-spot {Septoria lycopersici) . It has frequently been commended 

 by growers for resistance to drought, but its apparent drought re- 

 sistance is probably due largely to its resistance to wilt. 



It is an excellent tomato for canning, for home gardening, and for 

 late trucking, as it not only produces an excellent crop of fruit, but 

 begins to ripen about midseason and continues to bear heavily until 

 killed by frost. 



Variety, very productive, late, highly resistant to tomato wilt {Fusarium 

 lycopersici) and somewhat resistant to leaf-spot {Septoria lycopersici). 



Plant large, erect, vigorous ; branches many, long, stout ; internodes long. 



Foliage type, standard; leaves large, smooth, dark green, deeply divided, 

 shading the fruit. 



Flowers large ; fruit clusters small, many, scattered. 



Fruit large, smooth, oblate, bright red, very solid, comparatively free from 

 cracks ; stem-end cavity shallow, smooth to smooth ribbed ; blossom-end basin 

 medium small, shallow ; stylar scar small, circular to linear ; skin thin ; vertical 

 section medium long, oval ; cross section round to oval, smooth ; walls thick, 

 firm, juicy, evenly colored ; cells many, small, irregular, well filled ; seeds few, 

 medium large ; pulp thick ; core not defined ; flavor pleasantly acid. 



SUMMARY. 



Tomato wilt {Fusarium lycopersici) causes in the United States 

 an annual loss of more than 115,000 tons of tomatoes. By the use 

 of wilt-resistant varieties this loss can be overcome at the mere ex- 

 pense of handling the extra crop. 



Three varieties of tomatoes developed by the writer and one de- 

 veloped by Mr. J. B. S. Norton and the writer produce heavy crops 

 of excellent fruit on land so heavily infected by wilt that ordinary 

 tomatoes can not be grown on it. They are selections from the 

 Greater Baltimore, Stone, and Merveille des Marches (Marvel of the 

 Market), three of the best commercial varieties of tomatoes grown, 

 and possess in addition to wilt resistance all the good qualities of 

 their parent varieties. Moreover, extensive field tests have shown 



