21* 



COMMON DISEASES OF CHOPS 



is to spray the trees, before they blossom, with Bordeaux 

 Mixture or with a weak solution of lime and sulphur. 



162. Molds are fungi that not only affect farm, orchard, 

 and garden crops, but which also concern the housewife, 

 especially in canning and baking. When a plant sub- 

 stance has died, molds destroy its body by producing 

 decay. Molds are everywhere present, especially in damp, 

 warm, dark places. This is why food soon "spoils "in 

 such places. If fruit or vegetables are to be preserved a 

 long time, they should first be sterilized by boiling for 

 thirty minutes, then sealed in air-tight vessels, and kept 

 in a cool place. We shall learn more about this subject 

 in Chapter XVII. 



163. Names of Fungous Diseases Attacking Common Crops. 



Apple 



Anthracnose 

 Black Rot 

 Blight 

 Brown Rot 

 Canker 

 Crown Gall 

 Leaf Spot 

 Powdery Mildew 

 Rust 

 Scab 

 Shot Hole Fungus 



Corn 



Damping-off 

 Downy Mildew 

 Smut 

 Wilt 



Bean 



Anthracnose 

 Blight 

 Damping-off 

 Powdery Mildew 

 Rust 



Potato 



Early Blight 

 Late Blight 

 Dry Rot 

 Scab 



Cherry 

 Black Knot 

 Brown Rot 

 Crown Gall 

 Witches' Broom 

 Leaf Spot 

 Powdery Mildew 

 Scab 

 Shot Hole Fungus 



Wheat 

 Ergot 

 Rust 

 Smut 



PRACTICAL QUESTIONS 



1. What an- the main agents causing diseases in plants? 2. Name 

 three plant diseases produced by bacteria. 3. What conditions are 

 most favorable for the multiplication of bacteria? 4. State two ways 



