THE PEACH ROT AND LEAF CURL. 



or where the fruit is densely shaded by 

 leaves in contact ; and in case of warm, 

 April showers at the time of blossom- 

 ing, these spores from the mummy 

 peaches may enter through the blossoms 

 and cause sad havoc in the form of twig 

 blight. It may be a matter of surprise 

 to some to hear that this rot fungus 

 destroys the twigs and blossoms of the 

 peach. But close observers in the 

 orchard at harvest time have often called 

 my attention to the death of the twigs 

 and branches bearing rotten fruit. Yet, 

 even these observers have usually missed 

 the early spring blighting of twigs and 

 destruction of blossoms. Unquestion- 

 ably this fungus is responsible for the 

 injuries just named. Therefore, in deal- 

 ing with it we must know where and 

 when to strike. 



It is first to be observed that the loss 

 of fruit from the monilia is much more 

 a matter of weather conditions than is 

 even usually supposed. We are accus- 

 tomed to find much rot among early 

 varieties like Hale, Alexander and Craw- 

 ford's Early, and are consequently likely 

 to call these susceptible varieties. The 

 large grower sometimes finds that Smock 

 and Salway show the greatest losses. 

 A large amount of rot in any variety 

 may be expected during hot, wet weather 

 at ripening time, and there seems no 

 sufficient reason to regard early sorts, on 

 the whole, as more liable to rot than 

 late sorts. As before stated, the favor- 

 able conditions determine the amount 

 of rot, though it may also be true that 

 these conditions more commonly occur 

 about the ripening time of the early 

 varieties. Late varieties succumb when 

 met by hot, rainy weather at ripening. 

 To induce rot, the spores of the fungus 

 must gain entrance into the peach, and 

 a decided difference in the texture of 



the peach skin would have some effect. 

 This difference, however, may be given 

 too much weight. The pin punctures 

 of the curculio with early peaches as 

 with plums are a fertile source of rot 

 infection. 



THE PREVENTION OF PEACH ROT. 



As shown above the rot fungus sur- 

 vives the winter in the mummy peaches ; 

 and the same holds true for mummy 

 plums and cherries, since the same fun- 

 gus is found in all the stone fruits. To 

 what extent it may survive in twigs can- 

 not be stated. The resting forms of the 

 fungus are shown above, Fig. 1591, 2, 

 &, c. All that is needed to induce their 

 growth is a period of warm, rainy 

 weather, such as commonly comes in 

 April and May of each year. So long, 

 therefore, as the mummy fruits are per- 

 mitted to remain on the trees, we must 

 expect an abundance of rot fungus and 

 the losses it causes. All rotted peaches 

 should be removed from the trees as 

 soon as they appear, and before the 

 advent of spring rains. This is the first 

 step in preventing rot. If these* are per- 

 mitted to remain on the trees over win- 

 ter, they should be burned when gath- 

 ered ; the better plan is to remove the 

 rotten fruits as they appear in the fall, 

 or ifi early winter, when they may be 

 dropped on the ground. 



Without this destruction of the mum- 

 my fruits, other methods will not be 

 likely to succeed, though the disease 

 may not succumb to this alone. Ches- 

 ter* has conducted experiments in 

 spraying peach trees for the prevention 

 of rot. Results of the second season 

 show a three to four fold increase of 

 sound fruit on sprayed trees of Hale 

 and Early Rivers. In this work Bor- 

 deaux mixture and Paris green is recom- 



•Bull. Del. Exper. Station, 34. 



l8l 



