THE INFLUENCE OF SIZE AND CHARACTER 

 OF SEED ON THE YIELD OF POTATOES. 



By KEDC'LIKFE N. SALA.MAN, .M.A., M.D., 

 Barley, Ilerls. 



(With Four Text-figures.) 



The rosults of a preliiiiiuary iuvesligatiou ou tliis subject', in wliicli 

 single plots were used, which were pubUshed in 1921, tended to show 

 that the following inferences, in respect to the relation of size and type 

 of tuber-set to crop, might be drawn. 



1. The size of the crop varied directly with the weight of the set up 

 to a certain point, viz. 2 ozs., the crop then sinking slightly to a more or 

 less constant level, whilst the weight of the set increased. 



2. The crop residting from the planting of large sets with secondary 

 outgrowths exceeded that from all other types of sets and was as much 

 as 25 Y>eT cent, more than that derived from sets of equal size without 

 outgrowths. 



3. The proportion of heav}- ware in a crop varied inversely with the 

 size of the tuber-set, and was not materially affected by the existence or 

 otherwise of outgrowths on the set. 



4. The tendency to form outgrowths was not conveyed by tuber. 

 The problem was re-investigated in 1921. As in the previous year, 



the Potato used was the variety Barley Bounty^, the crop of which had 

 been grown in Scotland the previous season. The experimental plot was 

 situated on the writer's farm at Barley, on a piece of ground which sloped 

 gradually from east to west. The western end was shghtly more clayey 

 than the eastern portion, but on the whole the soil was of a uniform 

 type of loam and had been specially chosen on that account. The area 

 of the ground on which the experimental sets were planted was 17-5 feet 

 X 400 = 777 sq. yards. It was deeply cultivated: no stable manure was 



' Salaimin, R. N., Journ. of the Ministry of Agric. Vol. xxvni, April 1021. 

 - This is a wart immune variety raisi-il by the author in 1911 wliich is very resistant 

 to roll and mosaic and partially so to Phytophthora. It is not yet on the market. 



