12 BULETIN 686, U. S. DEPARTMENT OF AGRICULTURE. 



secured when Rhizopus was inoculated into an area already infected 

 by Botrytis. 



During the experimental shipment between Monett, Mo., and 

 St. Paul, Minn., some berries attacked by Botrytis were kept in a 

 warm car, some were exposed to the air, and others were surrounded 

 by leaky berries on which RMzopus nigricans was fruiting. While a 

 few of the diseased berries became infected with Rhizopus, the per- 

 centage of such infections was smaller than in the case of uninfected 

 berries kept under similar conditions as checks. Most of the berries 

 infected with Botrytis, on the contrary, became brown in color, 

 firm in texture, and retained their shape for a week or more except 

 for some slight shriveling. 



At Hammond, La., on April 25, 1917, boxes of apparently sound 

 berries and also of berries infected with Botrytis were selected. 

 These were held at room temperature, without refrigeration, for 48 

 hours and then examined. Of the berries which had been apparently 

 sound, 79 per cent were now typical leaks and 9 per cent showed soft 

 spot^ due to Rhizopus infection. The berries which had shown 

 lesions of Botrytis, on the other hand, now contained only 19 per 

 cent of leaky berries and 9 per cent which showed small Rhizopus 

 infections. In no cases were the latter apparently associated with 

 the Botrytis infections. This seemed to indicate that the presence 

 of Botrytis inside the berry actually inhibited to some extent the 

 growth of Rhizopus. 



It is, of course, not impossible that Rhizopus may foUow in a region 

 infected by Botrytis. Since, however, the writers have not been 

 able to find a case of this sort or to produce it artificially, nt may 

 perhaps be fairly assumed that this type of infection is relatively 

 rare. 



SUMMARY. 



Leak, caused by Rhizopus nigricans, is by far the most important 

 rot of strawberries after picking. 



Losses from leak can be most effectively reduced by keeping berries 

 at low temperatures and by handling them carefully. 



Berries picked in the early morning are cool and less likely to 

 decay than those picked during the heat of the day. 



Adequate refrigeration greatly reduces the rate of growth of 

 RMzopus nigricans in transit. 



Washing strawberries to remove dirt may have a beneficial effect 

 if the berries are washed in clean water, handled with care, packed 

 in the crates while still wet, and refrigeration is not too long delayed. 

 Less bruising results if the berries are packed in boxes and then washed 

 by dipping the entire box or by running water through it than if 

 the berries are washed before packing and plating. 



