THE DISEASE IN POTATOES. 



57 



they put the line across the furrows, and made 

 a rut on each side of the line ; turned out the 

 sod, put in the dung about 12 tons per acre, and 

 then returned the sod. I emploj^ed a boy with 

 a hoe after them, to blind any of the chinks; 

 and after the crop waa well brairded, I dug or 

 rather scraped with a spade betwixt the drills, 

 which were 28 inches wide, and about 20 days 

 alter I drew the scrapings to the plants with a 

 hoe. I measured several drills at lifting-time, 

 and the produce was nearly as possible 100 bolls 

 per acre — (a boll, ■we believe, is 400 pounds.) — 

 I planted one drill with Iri.sh Cup.s, and the crop 

 was good; one drill ^vith Buffs — th(;y^vere also 

 good ; one drill of Reds, from E.atlio (the low 

 countrj-), \vhich turned out a bad crop ; the rest 

 was from Biggar .shiel, all Don.s. My other Po- 

 tatoes -were planted in the field adjoining. — • 

 About the middle of May I gave them about 20 

 tons of dung per acre. I began about the first 

 week of October to lift them, and lifted the bog- 

 crop first, and they were all pitted on the same 

 plan ; the pits about 4 feet wide, and about 5 

 inches taken out of the bottom, the Potatoes put 

 in, covered with straw, and after\vards about 4 

 inches of earth. I put in wooden ventilators, 

 square boxes made of paling-rail, with open- 

 ings at the bottom, about 2 feet down amongst 

 the Potatoes, and the other end above the pit. 

 I let them (the ventilators) stand this way for 

 four or five weeks, and then put on about 10 

 inches of earth ; as soon as I sa^v an appeai'- 

 ance of frost I stopped them with straw. I 

 may add that the boxes ran short, and I finished 

 with straw, which seemed equally \vell to an- 

 swer the purpose. I have ju-st put the la.st of 

 the Potatoes in the barn to-day, to cut for seed. 

 Those from the new land and gi-eat crop do not 

 appear to be so good seed as my other Pota- 

 toes, which were not half the crop : there 

 seems to be more blind-eyes amongst them. 

 My going or cropping land has lain twice in 

 pasture during the last 15 years. I do not think 

 it possible that any of the seed which I planted 

 could be heated after cutting ; and I had no op- 

 portunity of knowing ^vhether those planted 

 had been heated before I received them : of 

 course they have not been heated this season. 

 I forgot to mention that the bog-land, before 

 draining, was all naturally ^^'et. The reason I 

 gave it so little manure was, that the cattle had 

 lain in that i>art of the field, and the land was 

 enriched from that circumstance. 



'■ I am, ice, JOHN CUNNINGHAME. 



" P. S. My brother at Kenleith got some seed 

 Potatoes from the west country — nine bolls from 

 new land, and one from going or cropping land 

 and he says that the latter is the best seed, hav- 

 ing fewer blind-eyes." 



The above completely confirms what I have 

 already advanced, viz., that a heavy or over- 

 grown crop of Potatoes, in any soil or situation, 

 will al%\'ays yield bad Seed-Potatoes; and that 

 over-cultivation is the sole or chief cause of the 

 degeneracy of the plant. 



It seems self evident, then, that the crop first 

 degenerated in the ricii and cultivated districts 

 of the lo\v country, producinar curl in the plant ; 

 that, as the cultivation of it increased, the curl 

 increased, and a change of seed was found ne- 

 cessary from the high country ; that within these 

 ten years past, in addition to curl, that blanks or 

 entire failure of the plant lias taken place in our 

 fields, and the disease of curl, and the complete 

 or partial failure, has kept pace^with the ex- 

 (10.=>| 



tended cultivation of ma plant, and in the exact 

 ratio of the quantity of stimulus or manure ap- 

 plied; and that the finst blanks in the fields have 

 appeared to have continued since the manure 

 has been so much increased to the crops, viz., 

 during the last ten years,Mie quantity of manure 

 applied to the crop having been increased one- 

 fourth generally all over the country, as the in- 

 creased quantity of manure (when the crop has 

 succeeded) has in a very remarkable degree in- 

 creased the return, to the extent, in many cases, 

 of one-third more Potatoes ; and in some in- 

 stances the crop has been doubled. But as the 

 crop is increased in quantity, so does it decrease 

 in quality ; and vary nearly in the same ratio. 



That the plant has continued longer in the 

 hill-districts, free of curl and failure, is no argu- 

 ment again.st my theorj', as it is the poverty of 

 the soil and the want of manure that have saved 

 it. It not only has received less manure— for 

 they have little to give it — but it has not re- 

 ceived at its roots so much of that heating and 

 stimulating article, horse-dung or stable-manure ; 

 which I attribute as the cause of assisting mate- 

 rially in the deterioration of the root. The crops 

 also, until of late years, have not been .so often 

 repeated on the same soil ; and a change of crop 

 is of great advantage to the health and well-be- 

 ing of any plant. 



I come now to the cure or remedy of the dis- 

 ease, or the best means of procuring and raising 

 good seed — as I do not yet despair of seeing 

 good seed, and the best that can be raised, to be 

 Ibund iJthe early and highly cultivated districts. 

 It must, of course, be obvious to all, that, if pos- 

 sible, .seed should be obtained from South Amer- 

 ica ; but as it would not be pos.sible to procure 

 more than a very limited quantity, we ought to 

 try what can be done to improve those of our 

 own country. I would recommend to select the 

 best varieties, and raise from the apple ; but, in 

 the mean time, to have the best and soundest 

 seed for present planting — always, of course, 

 avoiding the produce of a great crop, grown in 

 any situation or .soil. The land intended for 

 seed should be plo\ved deep in the autumn, and, 

 if possible, by the trench-plow. The drills to be 

 .'iO inches wide, and manured moderately with, 

 if possible, a mixture of earth ; and if eartli is not 

 previouisiy mixed with the manure, a little may 

 be drawn into the drills above the manure, and 

 before planting the seed. Mr. Dickson, Saugh- 

 ton, near Edinburgh, who has been very suc- 

 cessful in raising good crops of Potatoes, is very 

 judiciously, this year, mixing all the manure in- 

 tended for Potatoes with earth. The ground 

 intended for seed should be planted with whole 

 Potatoes, and about 14 inches apart ; or the Po- 

 tato cut in two, and planted at 10 inches — (both 

 may be tried ;) the plants to be placed near the 

 surface, and never highly earthed up by the 

 plow, as it is natural for the tubers of the plant 

 to run upwards; and the more of them, in ripen- 

 ing, that may be exposed to the .sun and air, 

 (greened.) they will make so much the better 

 seed. To be taken up rather green or unripe 

 than otherwise, but approaching to a ripe state. 

 To be placed in pits, (in an airy situation,) at 

 about 2^ feet at bottom : they may be carried 

 up pretty hiirh, and tile pits may be made of a 

 tolerable length. They should have first a little 

 earth thrown over them — saj- half an incli — and 

 then a good covering of straw, finishing witli a 

 few inches deep of earth, as it is the straw which 

 will defend them from frost ; and a few straw 

 fiinncl.s, at short distances, is all that is neces.sarj' 



