512 Report on the Cultivation of Potatoes. 



the evaporation of moisture from the land, and enables Mr. 

 Knowles to be always at work with the plough deepening the 

 TOWS, and thus keeping the tubers high above the channels which 

 carry off the water. 



A careful perusal of this Report will show that, like Mr. 

 Myatt and Mr, Knowles, many growers attach great importance 

 to early planting as a means of preventing the potato-disease, 

 chiefly, however, because early planting, in the absence of severe 

 spring frosts, means early harvesting. Much stress is also laid by 

 many growers on the importance of effectually earthing-up the 

 plants, with a sharp ridge close to the haulm. Mr. Knowles also 

 especially insists on the importance of this practice.* It also 



* The following extract from the replies sent too late for insertion in the 

 body of this Eeport, by Mr. John Fryer, of Manor House, Chatteris, Isle of 

 Ely, confirm, in an important degree, Mr. Knowles's replies to queries 

 Nos. 14 and 23 :— 



" On looking back for nearly a period of 30 years over memoranda respect- 

 ing the treatment of the potato-crop, with special reference to ' the disease,' 

 I find only one set of experiments that have to any extent lessened the 

 amount of loss. These experiments have all been based on the fact, that 

 covering up the haulm to within a few inches of the ends greatly hindered 

 the progress of the bUght ; and ultimately it was found that the nearer to a 

 horizontal position the haulm was placed in, the greater was the immunity 

 from disease. 



" The first occasion on which the plan was tried was two or three years 

 after the first appearance of the disease, when a large field was operated upon, 

 the haulms being deeply moulded-up on one side only ; and the flattening 

 down of the earth upon them was completed by hand-labour. 



" In that season this field remained green and growing up to Michaelmas, 

 nearly every other field in the kingdom having been blighted in the latter 

 end of August. The plan was continued for a time, until the disease all but 

 disappearing, it was given up. Three years ago a trial of it was again made. 

 A small portion of a field was ' laid down,' and the results were so satis- 

 factory that last year nearly 50 acres Avere operated upon ; and with great 

 advantage, as will be shown by a detailed statement of results at the end of 

 this paper. 



" Careful observation brought to notice one important fact, viz., that those 

 rows yielded the most and finest tubers, which were laid down towards the 

 east, thus allowing the sloping side of the ridge to be exposed to the afternoon 

 and evening sim. 



" A plough has now been made suitable for 'laying down' all the haulms 

 in one direction towards the east. This plough is about to be introduced to 

 the public by Messrs. Howard, of Bedford. The theory as to the causes of 

 the benefit secured by this process I leave to others to suggest. Whether it 

 be that the descending spores of the fungus which produces the disease drop 

 from the flattened stalks on to the earth instead of descending to the root, 

 and thus lose their power of mischief, or whether the ' laying down' checks 

 for a time the too rapid and succulent growth of the tops, and thus i^revents a 

 weak growth of the tuber, it is difficult to decide ; at any rate, a large saving 

 is effected by the process. I now give details of results, carefully taken last 

 year from some plots of potatoes specially set aside for the experiment.^ 



