500 Rei^rt on the Cultivation of Potatoes. 



Mr. S. D. Shirreff observes on this point : " Whenever the 

 crop is ripe or ready for lifting, let it be done. When lifted dry, 

 the crop is safer in the pit than in the ground." 



Applications of lime, sulphur, &c., to the haulm, find no 

 favour in this district, nor does the practice of pulling up or 

 cutting off the haulm for the purpose of arresting the disease. 



Mr. James Skirving sums up his experience as follows : — 



" On the whole my firm belief is that until we acquire the art of controlling 

 the elements we must just fight the potato-disease as we learn from experi- 

 ence, and my experience leads me to adopt the following rules : — 



" 1. Don't manure excessively. 



" 2. Change your seed everj^ second year at least. 



" 3. What are early lifted sell otf at once. 



" 4. Those for late sale allow to reach full maturity, and never touch them 

 after being stored until they are dressed for sale." 



Mr. Scot Skirving has appended the following note to his 

 replies, in illustration of the difficulty of the subject : — 



" After having planted from 50 to 100 acres of potatoes for the last 20 

 years, and having read anything I thought worth reading on the subject, I 

 profess utter ignorance of the subject of potato-disease. 



" Like cholera in man or grouse-disease among birds, it seems to have as 

 yet baffled human research. It is easy to say it is caused by the weather — 

 that close, warm, misty weather, and, above all, thundery weather, when there 

 is much electricity in the air, brings it on. But all these conditions of the 

 atmosphere existed long ago, and yet no disease came. The first thing I 

 would inquire into would he to find out the state of the iveather in 1845 and 

 1846, when the disease may be said to have been pro(?;<ced* Since then we 

 have only had weakened tubers ever ready to take disease, and unable to 

 resist any unfavourable conditions. 



" Take one example : Previous to the great outbreak of disease it was the 

 common practice in Scotland to store the cut tubers (i.e. the potatoes cut for 

 seed) in large masses. These heaps were left for days, often in large piles 

 in outhouses, and no evil came of it. Now, if cut potatoes are left a day in a 

 large heap, they heat and lose their vitality altogether. 



" Once, a land steward I had (an old man) followed the old practice, and the 

 consequence was that not one sett in twenty vegetated. 



" Referring to the question, ' Is your district open or wooded?' of course, 

 every one knows that potato-disease is worst (as a rule) when shaded by 

 trees or high hedges ; also all ground that has been much trod and trampled 

 on by horses. Dry, free soils resist the disease best ; clay worst : I have 

 seen, however, moss as bad as any, but it was damp." 



The replies from Lothian growers are, as will have been 

 gathered Irom the summary given in this report, generally in 

 accordance with Mr. James Skirving's four rules ; but in contra- 

 distinction to Rule No. 1, Mr. Shirreff repeats his opinion that 

 farmers had better limit their acreage of potatoes if they cannot 

 apply as much as 30 tons of farmyard manure, 4 cwt. of guano, 



* On this point compare IMr. Carruthers's statement on p. 445, as to the recent 

 appearance of a new fungus extensively aft'ecting Hollyhocks and other plants 

 belonging to the natural order Malvacem (Mallows;.— H. M. J. 



