PORTO RICO KXl'EKIMKNT STATION. 467 



digestive agent that it is claimed is ecjual to or superior to animal 

 pepsin. Unfortunately, the plant seems rather subject to diseases. 

 Besides the two troultlcs mentioned below, it is attacked and injured 

 by red spiders during the dry season, and Professor Barrett has 

 ol)served a bud rot that kills the plant by destroying the terminal bud 

 and the soft tissue at the apex of the stem. No cases of this disease 

 were observed. 



Papmr ncaJe. — A scale insect, proba))ly Diaspis pentarfona., attacks 

 the papaw very seriously and is killing a great many of the trees. 

 No parasites were observed, and spraying will have to be resorted to 

 to save the trees. So far as 1 know nothing is known as to the resist- 

 ance of papaw foliage to kerosene or other insecticides, and experi- 

 ments would ha\'e to be made to determine what treatment would be 

 safest and most effective. 



PdjKiir Je(ifl>J'Hi1it. — A fungus {Pacciniopsiscart(';r)''y\{ii^ observed in 

 the neighborhood of San Juan. It forms small (1 millimeter) erumpent 

 black masses on the under side of the leaves and causes more or less 

 yellowing of the surrounding tissues. The attacked leaves fall pre- 

 maturely. It seems more abundant on young seedlings, but was also 

 observed on bearing trees. The damage done by it is usually of minor 

 importance, but when combined with the attacks of the scale it hastens 

 the death of the trees. Spraying with Bordeaux mixture is the indi- 

 cated remedy. 



BEANS AND COWPEAS. 



Beans are extensively grown in Porto Rico and constitute an 

 important element in the food supply. The conunon bean rust (Uro- 

 m3'ces) was observed, and a few cases of two wilt diseases were found. 

 Still a third wilt occurs on the cowpea. Neither of these wilts seemed 

 to be caused by Neocosmospora, the conunon wilt fungus of the 

 Southern States. They have not been sufhcicntl}' studied for further 

 comment at this time. As they are probably of considerable economic 

 importance, they should be fully investigated. 



Doubtless many other diseases of economic plants occur that were 

 not observed during the short time at my disposal. On the whole, the 

 more important crops do not seem to be unusually subject to serious 

 diseases. In fact, their production is less heavily handicapped in this 

 way than in many competing countries; still enough is recorded above 

 to indicate the need for a careful study of the diseases that do occur. 

 The diseases of tropical plants have received com])aratively little atten- 

 tion and the held is a wide and important one, sinct' tropical products 

 seem destined to play an ever-increasing part in the world's commerce. 



«Bul. New York B(»t. (Jard., 2 (1902), p. 340. Depi-ribed si)eciniens sent from 

 SaiiilH'l Island, Florida, by S. M. Tracy. 



