2. 



about 2 weeks before the desired harvest date 

 of 2 2/3 pints per acre should be applied.** 



A total 



Within 2 days after the ethephon application, use a 

 ar spray of 2,4,5-TP at 20 ppm. 



foli- 



**It may be possible to enhance red color development with a lower 

 concentration of Ethrel* and thereby reduce the loss of fruit 

 flesh firmness. We plan to investigate the effects of lower con- 

 centrations this fall. 



*************** 



BLUE MOLD APPLE STORAGE ROT 



C.J. G i 1 g u t 

 Department of Plant Pathology 



Blue Mold probably causes more rot of apples in storage than 

 all the other rots together. In some years, the loss may be sub- 

 stanti al . 



The rot is caused by the fungus, Peni ci 1 1 i um expansum , which 

 attacks all parts of the apple and causes a brownish, soft, wet, 

 mushy rot with a musty odor. It may affect part or all of the apple, 

 At times there is some growth of white mold on the rotted surface 

 and usually the surface is covered with bluish-green tufts which 

 consist of masses of fungus spores. A sound apple against a rotten 

 one becomes wet and has a musty odor. Often it also rots and this 

 results in "pockets" of rotten apples in a box. 



The blue mold fungus grows and produces an abundance of spores 

 on all kinds of dead organic matter in shady places where it stays 

 damp or wet. It grows on dead wood on the tree or in the orchard, 

 on old boards and new boards, on picking boxes and crates, on rot- 

 ting fruit under the tree, on rotting and mashed fruit in dump 

 piles outside of the storage, discarded apples in boxes in the 

 packing room and, of course, on wet boards, boxes and rotting ap- 

 ples in the storage. 



Blue mold spores are present everywhere the fungus grows. 

 They are air-borne and are in the air of storages and packing rooms, 

 on room surfaces, on grading and handling equipment, on the hands 

 of workers, in water in tanks used for fruit dumping, washing or 

 dipping. All apples dipped in a contaminated tank will have spores 

 on them. Blue mold spores are tough! They can live at least 2 

 years under dry conditions and are not killed by most fruit fungi- 

 ci des . 



The rot affects only ripe apples or apples approaching maturity, 

 As apples stay in storage longer, they become more mature and more 

 susceptible and there is more rot. Rot starts from a spore which 

 germinates on the apple and grows into the flesh. The most common 

 places of entry early in storages are injuries or breaks in the 



