Phytophthora Rot of Tofiiato 299 



PHYTOPHTHORA ROT OF TOMATO, EGGPLANT, AND 



PEPPER/ 



James B. Kendrick, Purdue University Agricultural Experiment Station. 



A Phytophthora rot, apparently identical with buckeye rot of toma- 

 to appeared in epidemic form in an experimental plot of tomatoes at 

 Lafayette, Indiana, August 1-3, 1921. The disease continued through- 

 out the summer and destroyed about 40 per cent of the tomato fruits. 

 A few weeks later, a very similar disease developed on eggplant and 

 sweet pepper fruits growing adjacent to the tomatoes, and from all of 

 these, the same Phytophthora was repeatedly isolated. With the Phy- 

 tophthora isolated from tomato, successful inoculations were secured on 

 eggplant and pepper fruits. The organism was repeatedly isolated from 

 inoculated eggplant and pepper fruits. So far as has been determined, 

 this disease has not been previously reported in Indiana under field 

 conditions. 



History. — The genus Phytophthora contains a number of species 

 which are separated by apparently minor and none too stable differences. 

 Rosenbaum- made an extensive comparative study of nine described 

 species of Phytophthora and presented a tentative table for the separa- 

 tion of species based on his studies. 



SherbakofP working in Florida, described a buckeye rot of tomatoes 

 in 1917 which he attributed to an undescribed species of Phytophthora 

 to which he gave the name, P. tcrrestris. Using the fungus isolated 

 from tomato, he inoculated tomatoes, sweet peppers, watermelon fruit, 

 lemons, and tubers of Irish potatoes and secured infection in every case. 



Late blight of potatoes, caused by Phtjtophthora infestans, has been 

 reported on tomatoes in West Virginia by Giddings.' It occurred on 

 leaf, stem and fruit, causing a rot of the fruit. He reports serious 

 losses due to blighting of the plants before many fruits were set. The 

 organism, according to Giddings, is morphologically identical to P. in- 

 festans which causes a serious blighting of potatoes. 



In 1915, Haskeir while stationed in Dutchess county, New York, 

 observed a disease on eggplant fruit pedicles and calyces and a decay 

 of a few of the younger fruits. The eggplants were growing adjacent 

 to a field of potatoes which were badly infected with P. infestans. A 

 comparison of the organism causing the disease on the eggplants with 

 P. infestans from the potatoes showed that the two were identical. 



1 Contribution from the Botanical Department of Purdue University Agricultural 

 ExDcriment Station, Lafayette, Indiana. 



The writer wishes to express his appreciation to Dr. Max W. Gardner for helpful 

 suggestions and criticisms. 



2 Rosenbaum, J. Studies of the Genus Phytophthora. Jour. Agr. Res. 8:233-276, 13 

 fig.. 7 pi., 1917. 



= Sherbakoif , C. D. Buckeye rot of tomato fruit. Phytopath. 7:110-129. 5 fig., 1917. 



* Giddings, N. J. Potato and tomato diseases. West Virginia Agr. Exp. Sta. Bui. 

 165, 18-19. 1917. 



'- Haskell, R. J. Phytophthora infestans on eggplant in the United States. Phyto- 

 path. 11:504-505. 1917. 



"Proc. 38th Meeting, 1922 (1923)." 



