104 VEGETABLE GROWING IN NEW SOUTH WALES. 



soil by steam or fire (see page 132) before the sowing is made. The fungus 

 attacks the seedlings at or near the surface of the ground, the stem shrinking 

 and the plants falling over. Thinning out seedlings, reducing the water 

 supply, and allowing the free access of air and sunshine to the fungus \\ ill 

 check the further development. 



Downy Mildew. The fungus which causes this disease attacks the leaves, 

 producing felt-like patches which become dense and whitish to greyish in 

 colour and spread rapidly in moist weather. The spores can live from one 

 season to another in any decaying parts of the plant. The destruction of all 

 plant refuse, the reduction of the moisture on the plants by the access of 

 sunshine and the free circulation of air will check the disease. Spraying 

 with weak Bordeaux mixture (see page 128) is recommended. 



Powdery Mildew. This disease which is caused by a fungus is very 

 common. On peas ia moist seasons it may form a dense mass of fungus 

 matter, covering stems, leaves, and pods. When mildew attacks young plants 

 the crop is generally a total failure. The fungus may hibernate in the seed 

 derived from affected pods. 



Spraying with weak Bordeaux mixture (see page 128) is recommended. 



Pea Spot. 



This disease attacks French, and haricot beans, and garden psas. The first 

 indication of attack is the appearance of pale green spots of variable size and 

 irregular shape on the pods. These spots continue to increase in size, and 

 eventually become whitish, bounded by a dark line, and dotted with minute 

 black points. The fungus may grow through the pod into the seed and 

 reduce its germinating power as well as carrying the fungus over to the 

 succeeding crop, thus furthering its distribution. Similar spots may occur 

 on the leaves and stem, and often penetrate through the woody part, causing 

 wilting of the plant. 



On young plants the disease often assumes the character of a "damping- 

 off " disease. Spraying with weak Bordeaux mixture (see page 128) on the first 

 appearance of the disease checks its spread. As the disease is also distri- 

 buted in affected seed, careful attention should be given to the selection of 

 good seed, free from any disease spots. 



Powdery Mildew of Pumpkin, Melon, &c. 



This fungus disease appears as a whitish, flour-like growth on the leaves and 

 stems, at first forming circular spots, which soon enlarge. It is distributed 

 by wind and rain, and its effect is to render the fruit bitter and to distort it. 



All old plants and parts affected should be collected and burnt, and if the 

 attack is severe, rotation should be made, or the crop grown on fresh ground. 

 As in the case of most powdery mildews, sulphur and its compounds are the 

 best checks. On small patches, dusting with dry, powdered slake lime and 

 sulphur is effective. On a larger scale, spraying with weak Bordeaux 

 mixture (see page 128) must be resorted to. 



