15 Oct., 1919. 1 Diseases of Plants New to ]'ictoria. 627 



certain centre in the United States of America. Part of on^e of these 

 consignments was sold to, and planted by the owner of a market garden 

 in a Melbourne suburb, and it was troni this garden that lettuce leaves 

 affected with tlie disease were obtained by Mr. Chas. French, jun., 

 Government Entomologist 



There is no doubt as to the source from which the disease was 

 brought here, as plants were raised in the garden from other seed, but 

 only those from the American seed were affected. Acting upon the 

 advice of officers of the Department of Agriculture the diseased planti^ 

 were destroyed, and u}> to the present no fresih outbreak of the disease 

 has been reported. 



Control. 



The disease first appears upon lettuce in the form of numerous 

 light brown or yellowish-brown spots more or less circular, but often 

 so numerous as to become confluent. The diseased portion driee, becomes 

 brittle and falls away, leaving the outer and a great number of the 

 inner leaves perforated. . To persons unacquainted with lettuce 

 anthracnose the injury might ba thought the result of attacks by insects. 

 Experiments show that spraying with Bordeaux mixture 6.4.80 will hold 

 the disease in check. Diseased plants .should be removed and destroyed 

 by fire, and not thrown on the headlands or rubbish heap. 



n. Botrytis and Sclerotinia Diseases of the Passion Vine. 



(d) JJotrj/tis cinerca (Bon) War. 



In the spring of 1916 numerous passion fruit vines were reported 

 to be affected with a serious disease. An exE^mination revealed the fact 

 that they were affected with Botrytis cinerea, and another disease caused 

 by a species of Sclerotinia. Cultural methods showed them to be 

 distinct, but the symptoms of attack were similar, i.e., from the general 

 appearance as exhibited on the vines. 



In the Botrytis it was noticed that the chief }>oint of infection 

 was where the vine was tied to the trellis wire. At these points the 

 vine is often slightly injured by friction, and these slight wounds offer 

 a ready opening for the fungus. The symptoms of attack in the case 

 of passion vines is similar to that in the case of other plants attacked 

 by Botrytis. The death of the plant cells is in advance of the fungus 

 hyphse. Wilting and death of the vine beyond the infection point is 

 rapid, and after death sclerotia are formed beneath the loose bark and 

 in the pith of the vine. In the latter case, if the vine be split it 

 will be found that the pith for several inches has been replaced by a 

 slender cylindrical selerotium, in appearance resembling the lead in 

 an ordinary pencil. In the cultural experin\ents made, conidia were 

 obtained from the sclerotia found internally and externally. These 

 were placed on the young tender shoots, and also at the collar of the 

 vine, but no infection took place. (Plate 2, Fig. 1.) 



A similar experiment was again carried out after slight punctures had 

 been made with a sterile needle, and infection resulted. (Plate 2, Fig. 2.) 

 Plants infected by conidia from culture on 14th November Avilted on the 

 ISth and died on the 21st of the same month. Another set of experiments 

 was carried out with the mycelium only. In this test, mycelium was 

 placed at the collar and on the young shoots, and covered with damp 

 cotton wool and oiled pa]>er. No infectioia took place. Later, the 

 experiments were repeated on plants that had been wounded with a 

 very fine sterile needle and infection followed, the mycelium, like the 



