768 PROCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 



experiments conducted at the College an exposure of 24 hours at the 

 rate of one pint to every 200 cubic feet of space is found sufficient to 

 kill the larvae and 90 per cent, of the pupae. 



2. Prevention of Injury to the skin of the Potato. To protect the 

 potatoes from superficial injuries it is found extremely necessary to 

 desist from handling them until their skin gets hardened. Two weeks 

 must elapse after their harvest before any attempt is made to fumigate 

 them, as this necessarily entails rough handling. It is again possible 

 by waiting two weeks to discard the potatoes which develop signs of 

 bacterial and Fusarium rots already noted. Once the potatoes are 

 fumigated they are carefully selected to remove the rotting and injured 

 ones. If this selection is thorough and if it is made by one who under- 

 stands the signs of rots the potatoes may be kept for four months or 

 more without any danger of rotting and this obviates all further necessity 

 of repeated selections. 



3. Thorough selection before Storage. Bacterial rots can be avoided 

 to a large extent if the potatoes are examined carefully before storage. 

 The blackening of the eye should always be taken with distrust. Blister- 

 like swellings just under the skin is an evidence which cannot fail to 

 attract attention. They are bound to rot the earliest. Small pinhole- 

 like, black depressions are also signs which ultimately develop into the 

 wet rot and must therefore be looked for. Fusarium dry rot can also 

 be identified by concentric depressions on the surface and these are 

 very often found beginning at the stock end of the potato. They may 

 also be found in the eyes or other parts. This rigid selection means 

 the examination of every potato and it has been found that no more 

 than five hundred pounds of potatoes are capable of being selected in 

 one day of eight working hours by one man. Insect-attacked potatoes 

 need not be rejected because of the insects, but if they show any of the 

 two rots they should be discarded. 



4. Experiments conducted to determine various methods of sub- 

 sequent treatment in store have shown that if the potatoes are kept 

 in gunny bags, they remain perfectly sound and that this prevents further 

 infection from moth attack even although there may be moths freely 

 moving about in the godoivn. The godown should have as far as possible 

 thick walls and a high roof, so as to secure a cool atmosphere round 

 about the bags. The windows should be opposite to each other to 

 establish free circulation of wind in between the bags. If these 

 precautions are taken and if the bags are not kept one above the other 

 the rots are diminished to the extent that it does not require any further 

 selection for at least three months. 



