ABSTRACTS. 



1191 



Trabut). This parasitic fungus was first observed attacking Beetroot at 

 Rouiba, near Algiers. On this plant it produces irregularly -wrinkled 

 tumorous outgrowths, which, when mature, contain numerous irregularly 

 shaped cavities filled with the dark-coloured resting spores of the fungus. 



" On the Potato, the fungus does not cause the tumour-like out- 

 growths, but a continuous rough or nodulose, black, scab-like, thick 

 crust, which commences at one or several distinct points, and finally 

 covers the entire surface of the Potato." 



The disease was first received from the neighbourhood of Liverpool in 

 1901 ; subsequently from several widely separated localities in England. 



Preventive Pleasures. — "Diseased roots and tubers should be very 

 carefully collected and burned or deeply buried, because, if allowed to 

 rot on the ground, resting spores of the fungus would be liberated into 

 the soil, and future crops thereby endangered." 



" The temptation to feed stock with diseased Potatos must also be 

 resisted, otherwise the resting spores of the fungus, after passing through 

 the intestinal canal of some animal, would eventually be returned to the 

 land along with the manure." * A dressing of gas-lime or of ordinary 

 lime, is also recommended. 



ii. Bacteriosis of Potatos (Bacillus Solanacearum, E. F. Smith). 

 This bacterial disease has been recorded from several localities in this 

 country during the past season. 



u The earliest indication of the presence of the parasite is the sudden 

 wilting of the leaves, which soon hang limp and shrivel up. This is 

 followed by discolouration and collapse of the stem. If a stem is split 

 down at this stage, brown streaks, corresponding to the position of the 

 vascular bundles, will be seen. These brown streaks are the vessels 

 crowded with bacteria, which gradually descend the stem and finally pass 

 into the tubers, where they first manifest their presence by a more or 

 less interrupted pale-brown zone, situated some little distance from the 

 outside of the Potato. This zone corresponds to the position of the 

 vascular bundles in the tuber, which eventually become rotten, the skin 

 alone resisting the disintegrating action of the bacterium." 



Preventive Measures. — " The important point to attend to is the 

 destruction of insects that feed on the leaves of the Potato. This can be 

 accomplished by spraying with Bordeaux mixture to which an insecticide 

 has been added." 



" If Potatos are dug as soon as the disease is indicated by the wilt- 

 ing of the leaves, a considerable portion of the crop may be saved by 

 storing the tubers in a cool dry place. If allowed to remain in the 

 ground, not only do the tubers become rotten, but the soil is also badly 

 infected." 



"Potatos or Tomatos should not be planted in soil that has produced 

 a diseased crop, nor should Potatos from a diseased area be used for ' sets.' " 



iii. Sclerotium disease of Potatos (Sclerotinia sclerotiorum, Massee). 

 " In this instance the tubers are not directly attacked by the fungus, but 

 their growth is either checked or entirely arrested, owing to the entire 

 destruction of the leaves of the plant." 



* Boiling the tubers (a method frequently adopted by farmers and cottagers) 

 would effectually destroy the fungus or its resting spores. — R. N. 



