PESTS OF GAKDEN VEGETABLES. 



809 



thickened about the apex, surmounted by an obtuse hyaline wart or 

 papilla. Externally the spores are smooth (26-35 x 20-26 /u). 



It is recorded in France, Belgium, Netherlands, Germany, Switzerland, 

 Austria, Hungary, Italy, Portugal, and North America. 



Spraying with potassium sulphide solution should be commenced as 

 early as possible after the manifestation of the disease, to be of any 

 service. There is no hope with the uredines when firmly established 

 and the mycelium permeates the host plant. 



Sacc. Syll. vii. 1926 ; Mass. PI, Dis. 230 ; Cooke, M. F. 211 ; Cooke, 

 Hdbk. No. 1543 ; Plowr. Br. Urcd, 122. 



French Bean Anthracnose. 

 Colletotrichum Lindemuthianum (Sacc. and Mag.), PI. VII. fig. 108. 



This disease appears on the legumes of French Beans and Peas, while 

 still living, and often before they are mature, giving them a very unsightly 

 appearance. The spots are roundish, becoming brown, with a reddish 

 margin. The pustules appear in the centre of the spots, raising the 

 cuticle, so that it seems inflated, and then splitting it. 



The conidia are produced at the tips of threads collected in little 

 bundles, the threads being nearly three times as long as the conidia, 

 which latter are oblong, either straight or curved, rounded at the ends, 

 and granular within (15 19 x 4-5 /j). 



The disease is very prevalent in the United States, where it is reported 

 that " the young fruit is most subject to attack, and if the parasite gains 

 a footing, it is very disastrous, as growth is checked, even when the pods 

 are not conspicuously diseased." A favourable condition is dampness of 

 soil and atmosphere, which seems to be more necessary to the development 

 of this disease than in the majority of others. An airy dry situation for 

 the plants is recommended as the best means of preventing an attack. 

 The application of sulphur is said to check the disease somewhat. 



Sacc. Syll. iii. 3747 ; Mass. PI. Dis. p. 208 ; Grevillea, x. p. 48 ; U.S.A. 

 Rep. Agri. 1887, p. 361, pi. vi. ; Tubeuf, Dis. 486, fig. 



Pea Pod Spot. 

 Ascochyta Pisi (Lib.), PI. VII. fig. 109. 



This spot occurs sometimes upon the leaves but most commonly on 

 the legumes of the Garden Pea, and was first called Depazea concara on 

 account of the concave little spots on the pods. 



The spots are round and yellowish, with a definite brownish margin 

 in the centre of which nestle the small brown receptacles in which the 

 sporules are produced. When mature these latter issue in a short thick 

 reddish tendril from the mouth of the receptacle, and sometimes become 

 confluent. When dissolved by moisture the sporules separate and flow 

 over the matrix. They are oblong, divided in the centre into two cells, 

 usually with a small nucleus in each cell (14-16 x 4-6 n). 



This disease is recorded in Belgium, Germany, Portugal, and Italy. 



No experiments have been recorded on the treatment of this disease, 

 but it has been recommended that Bordeaux Mixture should be tried if the 

 affection should become troublesome. 



