436 The Profitable Culture of Vegetables. 



whole plant becomes a brown rotten mass. The fruit, of course, suffers 

 equally with the rest of the plant. Under conditions favourable to the 

 spread of the disease practically the whole of the crop may be lost. 



Treatment : As in the case of potatoes, the only safe course with this 

 crop is to include preventive spraying with a fungicide as part of the routine 

 of culture. In normal summers two applications of Bordeaux mixture, the 

 first in the middle of July and the second a fortnight later, will generally 

 be sufficient to ward off the disease, but in an unfavourable season the 

 sprayings should be continued at fortnightly intervals. The under surfaces 

 of the leaves should receive particular attention. When the fruit is 

 ripening cupram may be used instead of Bordeaux as it stains the fruit less, 

 but if disease is actually present, or if conditions are favourable to its 

 development, the use of Bordeaux should be continued even though its use 

 necessitates the wiping of the fruit. 



BLACK SPOT OF TOMATOES (Macrosporium Tomato). This fungus 

 generally makes its presence known w r hen the fruit is about one-half grown. 

 The point of attack is usually at the pistil (the point furthest from the stalk). 

 A small black spot develops first, gradually increasing in size until often 

 half the fruit is involved, the surface being sunken and the pulp below black 

 and decayed. The writer has observed that this disease has invariably 

 selected for attack the fruit on those plants which have had insufficient 

 moisture at the roots, whilst those under better growing conditions have 

 escaped. 



Treatment : Collect and burn diseased fruits. Spray regularly with 

 Bordeaux mixture or cupram. See that the plants have sufficient moisture 

 at the roots, and avoid planting in very dry situations. 



VIOLET ROOT ROT (Rhizoctonia violacea). Most cultivated plants 

 the grasses and cereals forming notable exceptions are liable to the 

 attacks of this fungus. Generally the attack is confined to the roots and 

 other underground parts, but in dull moist weather the disease may extend 

 up the stem to the leaves and fruit. It is easily recognised by the network 

 of red or purplish mycelium which grows closely round the organ attacked. 



The leaves of diseased plants become yellow and drooping. From the 

 mycelium are produced hard roundish bodies sclerotia which are masses 

 of closely interwoven mycelium, and which carry on the disease from year 

 to year. Carrots, beet, potatoes, beans, and peas are the garden crops 

 most likely to be attacked. 



Treatment : An acid condition of the soil is necessary to the proper 

 development of the fungus, hence the application of lime and proper 

 drainage will tend to keep it in check. 



All diseased roots, &c., should be carefully collected and burnt; on no 

 account should they be fed to stock without previous boiling. 



