66 



NEW ENGLAND FARMER 



From the Book of the Farm. 



DISEASKS OF THE POTATO. 



The potato i.-? subject to disease at a very early 

 period of its existence, not merely after it has de- 

 veloped its steins anil loaves, but before the germ 

 has risen from the sots. The disease which affects 

 the plant, is called the curl, from the curled or 

 crumpled appearance which the leaves assume 

 when under the influence of the disease. What 

 the immediate cause of the disease is, it is diflicult 

 to say ; but the puny stem and stinted leaves indi- 

 cate weakness in the constitution of the plant, and, 

 like weak animals affecteil with constitutional dis- 

 ease, the small tubers [iroduced by curled potatoes, 

 when planted, propagate the disease in the future 

 crop. The curl is so well known by its appear- 

 ance, and the curled plant so generally shunned as 

 seed, that the disease is never willingly propaga- 

 ted by the cultivator; still there are circumstances 

 in the management of the tubers which induce the 

 disease therein. 



The experiments of Mr T. Dickson show, that 

 the disease arises from the vegetable powers of 

 the sets planted having been exhausted by over- 

 ripening, the sets from the waxy end of the potato 

 produced healthy plants, whereas those from the 

 best ripened end did not vegetate at all, or produc- 

 ed curled plants. It is the opinion of Mr Crich- 

 ton, "that the curl in the potato may often be oc- 

 casioned by the way the potatoes are treated that 

 are intended for seed. I have observed," he says, 

 " wherever the seed-stock is carefully pitted and 

 not exposed to the air, in the spring the crop has 

 seldom any curl ; but where the seed stock is put 

 into barns and outhouses for months together, such 

 crop seldom fails of turning out in a great measure 

 curled; and if but few curl the first year, if they 

 are planted again, it is more than probable the 

 half of them will curl next season." 



The other disease afTects the seeds or sets, and 

 is called the failure or <ani(, which consists of the 

 destruction of their vital powers. Many conjec- 

 tures have been h.nzarded as to the cause of the 

 failure, and most of them have ascribed it to the 

 fermented state of the dung, to the drought of the 

 season, to the heating of the sets, to the tuber be- 

 ing cut into sets, and other secondary causes ; but 

 all these conjectures leave untouched the principal 

 consideration in the question, viz: how these cir- 

 cumstances should induce failure now, and not in 

 bygone years ? Cut sets have been used for many 

 years without causing failure. Farm-yard dung, 

 in various states of decomposition, has been use"d 

 B8 long for raising potatoes. The extraordinary 

 drought of ISaO, caused no failure, while in com- 

 paratively cool seasons the disease has made great 

 havoc. Mr John ShirrefT takes a general and phi- 

 losophical view of the cause of disease in the po- 

 tato crop, and though, no doubt, his observations 

 are particularly applicable to the curl, still they 

 will apply equally well to the taint; for the con- 

 nection between the two diseases is so intimate, 

 that you have seen Mr Dickson's observation is' 

 that some sets "did not vegetate at all," that is, 

 failed, " or produced curled plants." Mr ShirrefT 

 adopts the general doctrine broached by Mr Knight. 

 " The maximum of the duration of the life of any 

 individual vegetable and animal," he says, "is pre- 

 determined by nature, under whatever circumstan- 

 ces the individual may be placed ; the minimum, 

 on the other hand, is determined by these very cir- 

 cumstances. Admitting, then, that a potato might 



reproduce itself from tubers for a great number of 

 years in the shady woods of Peru, it seems destin- 

 ed U> become abortive in the cultivated champaign 

 of Britain, insomuch that not a single healthy plant 

 of any sort cvf potato that yields berries, and which 

 was in culture 20 years ago, can now be produced." 

 Mr Shirrelf concludes, therefore, that the potato ia 

 to be considered a ehort-livcd plant, and that 

 though its health or vigor may be prolonged by 

 rearing it in elevated or in shady situations, or by 

 cropping the flowers, and thus preventing the 

 plants from exhausting themselves, the only sure 

 way to obtain vigorous plants and to ensure pro- 

 ductive crops, is to have frequent recourse to new 

 varieties raised from seed. The same view had 

 occurred to Dr. Hunter. 



The fact ascertained by Mr Knight deserves to 

 be noticed — that, by planting late in the season, 

 perhaps in June, or even in July, an exhausted 

 good variety may, in a great measure, be restored ; 

 that is, the tuber resulting from the late planting, 

 when again planted at the ordinary season, produ- 

 ces the kind in its pristine vigor, and of its former 

 size. 



It is obvious that all these opinions refer to the 

 possibility of plants indicating constitutional weak- 

 ness, and why may not the potato ? I have all 

 along been of the opinion, that the failure has aris- 

 en from this cause, nor does it seem to nie to be 

 refuted by the fact, that certain varieties of potato 

 have been cultivated for many years in the same 

 locality without fail ; because it is well understood 

 that every variety of potato has not indicated fail- 

 ure, and one locality may be mnre favorable to re- 

 tention of vigor of constitution than another ; at 

 least we may easily believe this, and discrepancies 

 in the case may arise, since we do not yet know 

 the circumstances which must of necessity produce 

 constitutional weakness. 



I have no doubt, in my own mind, that were 

 seed potatoes securely pitted until they were about 

 to be planted — not over-ripened before they were 

 taken out of the ground — the sets cut from the 

 crispest tubers and from the waxy end — the dung 

 fermented by a turning of the heap in proper time, 

 carried to the field, quickly spread, the sets as 

 quickly dropped on it, and quickly covered — there 

 would be little heard of the failure, even in the 

 driest season, — at the same time, the precaution of 

 obtaining seed from an elevated and late district, 

 compared to that where the seed is to be planted, 

 should not be neglected. 



I own it is difficult to prove the existence of 

 constitutional weakness in any given tuber, as its 

 existence is only implied by the fact of the failure ; 

 but the hypothesis explains many more facts than 

 any other — than atmospheric influence, for exam- 

 ple, producing the failure, like epidemic diseases 

 in animals, for such influences existed many years 

 ago, as well as now. 



The longer the cultivation of the tuber of the 

 potato (which is not its seed,) is persevered in, the 

 more certainly may we expect to see its constitu- 

 tional vigor weakened, in strict analogy to other 

 plants propagated by similar means. 



This very season, 1843, contradicts the hypothe- 

 sis of drought and heat as the primary causes of 

 the failure, for it has hitherto (to June) been neith- 

 er hot nor dry, [in Scotland,] while it strikingly 

 exemplifies the theory of constitutional weakness 

 as the cause of the failure, inasmuch as the fine 

 season of 1812 had so much over-ripened the pota- 

 to, (farmers permitting the potatoes intended for 



AUG. 30, 1S43. 



seed to become over-ripened, unaware of any inju. 

 j ry resulting from it,) that the sets this sprinir, t( 

 1 repeat again the words of Mr Dickson, " did no 

 vegetate at all," even in the absence of heat am 

 j drought, and with the aid of moist weather. Hac 

 : the potatoes been a little less over-ripened in 1842 

 , the sets from them might have produced only cur 

 this season, though it is not improbable that thf 

 same decree of over-ripening may cause entire fail 

 ure now that would only have caused curl years 

 ago ; and as over-ripening was excessive last year 

 owing to the very fine weather, so the failure it 

 extensive in a corresponding degree in this, even 

 in circumstances considered by most people preven- 

 tive of its recurrence, namely, cold and moist 

 weather. And observe the results of both 184S 

 and 1843, as confirmatory of the same principle 

 illustrated by diametrically opposite circumstances, 

 The ujit/er-ripencd seed of the bad season of 1841 

 produced the good crop of potatoes of 1842, in 

 spite of the great heat and drought existinir at the 

 time of its planting in 184.J ; while the otjer-ripeii- 

 ed seed of the good season of 1842, has produced 

 extensive failure, in spite of the coolness and 

 moisture existing at the time of planting iu 1843. 

 How can heat, drought, or fermenting dung ac- 

 count for these results ? 



SILK CIRCULAR. 



To Silk Growers and Manufacturers in .Vtur 



England. 



At the first annual meeting of the New Engla-nd 

 Silk Convention held at Northampton, Mass., Sept. 

 28, 1842, the subscribers were appointed a commit- 

 tee to call the next meeting, at such time and 

 place as they should judge best. Notice is there- 

 fore given, that the second annual meeting of the 

 convention will be held at Northampton, on Wed- 

 nesday, Oct. 4th, at 10 o'clock, A. M. 



The object of the convention is to collect facts 

 for publication, and to discuss questions connected 

 with the silk business. A full attendance is ear- 

 nestly requested. Every gentleman is desired to 

 bring with him a brief written statement of his 

 own experience each year, together with such re- 

 marks and suggestions relating to any part of the 

 silk business, as he may deem important. We 

 hope especially for full statements respecting the 

 manner and measure of ventilation in each case. 

 Silk growers who cannot attend, are earnestly 

 urged to forward such a statement by mail, to the 

 chairman of the committee, or to D. Stebbins, 

 Northampton, in season for the convention. To 

 every person doing this, a copy of our report will 

 be sent as soon as published. 



The committee are happy to know, that a JVa- 

 lional Silk Convention is to be held in New York, 

 Oct. I2th, during the I6th annual Fair of the Amer- 

 ican Institute, and that the managers of the Insti- 

 tute are using special efforts to secure a full exhi- 

 bition of American silks and silk goods. It is 

 fully believed that the two conventions will collect 

 and spread before the public such an amount of 

 well attested facts as efl^ectually to remove all lin. 

 geriiig doubts in regard to the feasibility of the silk 

 enterprize. Gentlemen, come to the conventions. 

 At least, send us all the facts in your possession. 



I. R. 13ARU0UR, Oxford, Mass. ") 

 A. KOBBINS, Bellows Falls, Vt. j 

 D. W. DEXTER, Claremont, N. H. [ ^ 



L. SEVERANCE, Augusta, Me. { ^°"'- 

 D. BENEDICT, Pawtucket, R. I. 



II. PITKIN, Manchester, Conn, j 

 Editors who copy this will receive the report. 



