490 Report on the Cultivation of Potatoes. 



tops is eminently unfavourable, and early planting in well-drained 

 lands is several times insisted upon. The evidence as to early 

 or late harvesting is again contradictory, and seems to be based 

 on various experiences with regard to the land, the state of the 

 crop at the time of lifting, and the weather subsequent to the 

 earlier potato-harvest. 



Mr. Richard Spencer, previously quoted, sends the following 

 additional notes : — 



" The Eegent potato we are now using, and have been for the last eight 

 years, was obtained from a London salesman, and I believe came originally 

 from the North. I believe that we increase yearly in our diseased tubers, but 

 as compared with fresh seed I think our old sort is the best. 



" The potatoes have always commanded top prices in London. 



" In 1871 we obtained throiigh the same salesman some seed from the 

 fen-land near Wisbeach, but they were so attacked by the disease that we 

 immediately discontinued using them. 



" There is no doubt that it is best to harvest your crops as early as 

 possible, but at the same time you would have to sacrifice them, as the potatoes 

 would not be matured, and would therefore not yield so great a quantity. 

 Last year we harvested some in August (Regents), and the disease had not 

 then set in. Some of the setts were kept by themselves, and at the present 

 time not a diseased tviber can be found amongst them. These are planted by 

 the side of the trial setts ; I shall therefore be able to give some information 

 whether they will resist the disease to any extent. 



" There are certain essential points which ought to be more studied as 

 regards the disease. The following are some of them : — Selection of seed ; 

 temperature of soil ; cultivation of land, and drainage. 



" In the first place I believe that one sort of potato is able to resist the 

 disease more than another, in the same way that one animal or human being 

 in a certain state of health is able to do so under varying circumstances, and 

 therefore I am making experiments with potatoes selected from roots upon 

 which not a trace of disease was to be found (of which the proportion was 

 very small indeed). These are planted by the side of the trial setts. 



*' In the year 1871 the Regents obtained from the Wisbeach district were 

 planted in a field upon each side of our own original sort ; both of them grew 

 well together until the disease appeared, when the bine of the Wisbeach lot 

 went in a most rapid manner, and when taken up those from the fen-land 

 were diseased to the extent of 75 per cent., whilst our own sort went only to 

 the extent of 25 per cent. This was upon a gravelly soil. But it did not 

 rest here, for upon a light sandy soil on our farm at five miles distant it was 

 visible to the same extent, even to a part of.a row where the one sort began and 

 the other ended, with the same result at the time of harvesting. This, I think, 

 clearly shows that it is not entirely atmosjiheric. 



" Also Myatt's Early Prolific planted upon a soapy clay soil by the side of 

 another Kidney gave similar results ; the Myatt's Kidney going at the rate 

 of about 30 per cent., whilst the other went at the rate of at least 90 

 per cent. 



" Temperature of Soil. — As regards the temperature of the soil, I fancy that 

 the more the temperature is reduced the greater the chance of the disease ; 

 and therefore after a great amount of wet, and when land has been worked in 

 a bad season, like the last two or three, when it has been left in a cold and 

 raw condition underneath and heat has succeeded, rapid evaporation has gone 

 on and a great difference of temperature has been produced between the 

 atmosphere and the soil, which is not at all beneficial to the tender potato plant. 



