436 



DISEASES OF CULTIVATED PLANTS 



spots are more or less circular, and surrounded by a well- 

 developed, blackish border, hence the American name of 

 bird's-eye rot. When the fungus produces fruit on the 

 diseased spots they are greyish in colour, due to the masses 

 of conidia present. There are generally several diseased 





1 IG, i^. -Glo >sporium ampelophagum. i, appearance of 

 u in. leaves, and tendrils of vine ; 2, i I grapes ; 



3, section of pustule "I fungus on young grape; 4, conidia. 

 Figs, i .mil 2 natural size ; remainder mag. 



spots scattered over the fruit. When one grape in a bunch is 

 infected, the disease spreads rapidly until every grape is 

 attacked, the spores being washed by rain from one fruit to 

 another. I I d fruit often becomes contorted and much 



cracked, exposing the pips, and finally shrinks and becomes 

 mummified, still remaining hanging on the vine. 





