52 EXPERIMENT STATION RECORD. 



Potato diseases in New Jersey, M. T. Cook and G. W. Mabtin {'New Jersey 

 Stas. Circ. 33, pp. 2If, figs. 13). — A description is given of some of the more 

 common diseases of potatoes, with suggestions for their control. 



Leaf roll of potato, O. Appel and O. Schlumberger {Mitt. K. Biol. Anst. 

 Land u. Forstic, No. 12 {1912), pp. 14, 15). — No conclusions are drawn from the 

 variable relations observed between weight of crop obtained and weight of 

 tubers planted in case of seed potatoes showing leaf roll. The experiments 

 have been continued. 



Colocasia blight caused by Phytophthora colocasise, E. J. Butler and G. S. 

 KuLKARNi {Mem. Dept. A^/r. India, Bot. Ser., 5 {1913), No. 5, pp. 233-261, 

 pis. 4). — The authors describe a widely distributed disease of Colocasia, or 

 tare. 



The disease is said to be found practically wherever the plant is cultivated 

 and also occurs on wild specimens in moist localities. In severe attacks all the 

 leaves may be destroyed and the plant killed, or in milder attacks the older 

 leaves are more or less destroyed by the fungus, in which case the corms may 

 be entirely lacking or if any are formed they will be small and shrunken. 

 Infection of the corm was noticed comparatively recently, while the attack on 

 the leaves had been known for a number of years. On the corm a dry rot of 

 rather soft texture is formed. Microscopic characters of the fungus, results 

 of inoculation experiments, etc., are given. From the inoculation experiments 

 it is found that Colocasia is the only representative of the family Aracese that 

 serves as a host for this fungus. The systematic relationship of the fungus is 

 discussed at some length, after which suggestions are given for prevention of its 

 attack. The means suggested include spraying, removal and destruction of 

 spotted leaves, and selection of sound corms for planting. 



The mosaic disease of the tomato and related plants, L. E. Melchers {Ohio 

 Nat., 13 {1913), No. 8, pp. 1.^9-175, figs. 3). — The author presents a review and 

 bibliography of the essential literature of mosaic disease of plants and gives 

 brief description of his investigations on the mosaic disease of tomato and 

 potato. 



The disease is said to be quite prevalent on tomatoes, especially when grown 

 under glass, and frequently appears in Ohio on the main crops. It was noticed 

 In February, 1913, on potatoes grown in the greenhouse, the first symptoms 

 appearing when the plants had attained a height of approximately 18 in. 

 The disease appeared spontaneously without pruning, mutilation, or artificial 

 stimulation, but thus far has not been observed on potatoes growing in the field. 

 Histological studies were made of the tissues and no characteristic abnormali- 

 ties were observed on the tomato. In potato leaves sections of the mottled 

 areas were readily distingushed by the shape and size of the palisade cells. 

 Their length was from one-half to one-third that of normal cells and their 

 thickness was usually somewhat increased. The spongy parenchyma was some- 

 what abnormal in appearance in the yellow regions which contained fewer 

 chloroplasts. 



An extended discussion is given of the characteristics of the mosaic disease 

 on different plants, theories regarding its cause, and preventive measures. 



Root knot in the tomato, H. A. Wager {So. African Jour. 8ci., 10 {1913), 

 No. 3, pp. 51-53, pi. 1, fig. 1). — A description is given of a nematode disease of 

 tomatoes, which the author believes is due to a si^ecies differing from Hctero- 

 dera radicicola as described in the United States and elsewhere. 



Preliminary report on a disease of melons and cucumbers, Z. Kamerltnq 

 {Bui. Min. Agr., Indus, e Com. [Brazm, 2 {1913), No. 4. pp. 157-161, pis. 2).— 

 The author reports briefly the partial study of a cucumber and melon disorder, 

 in connection with which Heterodera radicicola was noted. 



