MISCELLANEOUS 



421 



Figure 169. Method of amputating mother-tuber from sprout. Left: plant grown 

 in pot buried in soil; right: plant inverted, placed upon board with slot from edge to 

 center used for support; pot then discarded. Note mother tissue being removed piece 

 by piece with scalpel; plant placed in soil after removal of mother-tuber. 



of the plant: (stage 1) when the plant was just emergmg from the soil; 

 (stage 2) when the germination was complete and the leaves were expanded; 

 (stage 3) when the plant was 10 mches above ground and tubers w^ere set; 

 and (stage 4) when the plants were at nearly maximum height and flower- 

 ing. The various stages of development when the mother-tubers were 

 removed are shown in Fig. 170. 



Removing the mother-tubers at stages 1 and 2 reduces the yield of both 

 Irish Cobbler and Bliss Triumph plants, and the reduction is greater witb 

 56- than with 14-grara seed-pieces. Removing mother-tubers of Irish 

 Cobbler at stage 3 reduces the yield when 56-gram seed-pieces are used 

 by 14 per cent, but not significantly when 14-gram seed-pieces are used. 

 Bliss Triumph plants are not affected significantly when the mother- 

 tubers are removed at this stage whether the seed-piece is 56 or 14 grams. 

 Removal of mother-tuber at stage 4 did not reduce the yield of either 

 variety for either size of seed-piece. In fact, a slight increase is shown 

 which Denny, in agreement with previous mvestigators, attributes to 

 toxic substances from some of the seed-pieces that rot late in the season. 



Chemical analyses were made of the mother-tuber seed-pieces at the 

 beginning and at the other stages of development. Table 48 shows these 



