48 



HORTICULTURAL SOCIETY OF NEW YORK. 



the Department of Agriculture in comparison with over forty other varieties, 

 and during the past two years has been the only kind to withstand the wilt 

 fungus. In other varieties the loss on the infected land has been from two- 

 thirds to the whole of the crop, while in the adjoining rows of Iron it was 

 difficult to find a single affected plant. (PI. IV.). Other trials of the 

 variety in a number of places where common cowpeas had failed to succeed 

 resulted in a satisfactory crop. The experience of farmers who have grown 

 this cowpea on a larger scale confirms our observations. In addition to its 

 resistance to the wilt fungus it withstands drouth remarkably well, and holds 

 its leaves late in the season, when other varieties have become defoliated, 

 showing in these and other respects its unusual hardiness. 



The most noteworthy quality of the Iron cowpea, however, is its re- 

 sistance to the root-knot worm, or nematode {Heterodcra radicicola) . This 

 was brought out by the experiments of the Department of Agriculture a 

 year ago,* and another year's work has given similar results on a somewhat 

 larger scale. The Iron pea was planted beside a number of other varieties on 

 land infested with nematodes, and careful comparisons made by examination 

 of the roots of each lot. The Iron was uniformly free from nematode attacks 

 and remained green and healthy till late in the season. All other kinds were 

 much diseased and died before maturing much seed. Their roots were much 

 knotted and deformed by the nematode galls, while the roots of Iron were 

 uniformly smooth and clean. 



This attribute of the Iron cowpea, if maintained in other localities and 

 through later years, will make it of very great value as a rotation crop 

 throughout the wide areas in the Southern States where nematodes are 

 prevalent. In these sections the use of the common cowpeas is often injuri- 

 ous because of their extreme susceptibility to root-knot, since a crop of them 

 will so greatly increase the number of the parasites in the soil that succeeding 

 cotton or other crops will be injured more severely. No other leguminous 

 crop equals the cowpea as a soil renovator in the Southern States, and if 

 this variety can be safely used on nematode infested land it will have a w'de 

 range of usefulness. 



Another point of interest to us as plant breeders in connection with the 

 resistance of this variety to nematode attacks lies in the encouragement it 

 gives us in our efforts to produce nematode resistant strains of other plants. 

 If such forms of peaches, cotton, tomatoes and other vegetables can be pro- 

 duced they will be extremely valuable, not only in America, but also in other 

 countries where nematodes cause injury. 



The Watermelon Wilt. 

 This disease, caused by the fungus Neocosmospora vasinfecta var. nivea 

 Erw. Sm., is similar in nature to the two preceding, but is more widespread 

 in our southern and central States. Its action is also more rapid and the 

 destruction it causes more complete. In sections where it is prevalent seven 

 to ten years must elapse after land has been planted to watermelons before 

 the same crop can with safety be put there again. We have had some diifi- 



•Webber, H. J., and Orton, W. A.— Some Diseases of the Cowpea, Bui. 17, pp. 

 23-35. Bureau of Plant Industry, U. S. Dept. of Agric, Washington, D. C, 1902. 



