m 



THE FARMER'S MAGAZINE, 



ON THE DISEASES OF CULTIVATED VEGETABLES, 



[translated from the FRENCH OF THE "JOURNAL OF PRACTICAL AGRICULTURE."] 



Sir and Honoured Colleague, — You have told me 

 that it enters into the plan of your useful journal to 

 announce useful publications; I therefore, for the benefit of 

 your numerous subscribers, am about to speak of a treatise 

 on the diseases of cultivated vegetables, the author of 

 which is M. Jules Kuhn, economic director of the comtal 

 domain of Egloffstein, in Silesia. This book, which calls 

 for all our forbearance, because it is wanting in agricultu- 

 ral science, bears for title Die KranMeiten der Kidlurge- 

 wwclise, Hire Ursachen mid Hire Virputung ; that is to say, 

 «' The diseases of cultivated vegetables : their causes, and 

 the means of preventing them." It is accompanied with 

 seven lithographic engravings, which represent all the 

 details of the rise and development of the vegetable parasites 

 60 injurious to our large culture. 



I have stated that the work of M. J. Kuhn fills up a 

 blank in agricultural science ; by this I do not mean that 

 everything it contains is absolutely new. Certainlj', as the 

 author himself acknowledges in his preface, we possessed 

 before it an agricultural literature rich in numerous facts ; 

 but those facts were scattered here and there, waiting a 

 skilful hand to unite and arrange them. No one was more 

 qualified to fulfil this task than the author of this vegetable 

 pathology. Prepared for a length of time by a profound 

 Study of inferior vegetables which live as parasites on culti- 

 vated plants, and for a long period having had the direction 

 of the working of a large landed property, he has had the 

 opportunity of making, at leisure, a long and continuous 

 application of his botanical knowledge, and thus combines 

 what is very rare — theory with practice. It is therefore the 

 fruit of his long experience and vast erudition that we shall 

 find in this book, the study of which we cannot too stronglj' 

 recommend to the agriculturist. M. Kuhn does not 

 pretend to exempt himself from that common law which 

 decrees all human works to be fatally imperfect; he 

 acknowledges, in the first instance, how much remains still 

 to be done to entitle him to a universal suffrage. In the 

 meantime, such as it is, I think that this treatise will ren- 

 der a great service to agricultui'e, above all when a good 

 translation shall have placed it at the doors of our cultivators. 



This is not the place to exhitit all the novelties we meet 

 with in it. I ask only to be allowed to make known a small 

 number which may be of practical utility. 



It was generally believed, before the experiments made 

 by M. Kuhn, but without any foundation, and upon simple 

 conjecture, that the seminules or spores of the nstilagoes and 

 uredoes of the cereals penetrate by the radicles of the plant 

 in order to arrive, creeping by degrees, to the leaves and 

 seeds of those vegetables. According to our learned agri- 

 culturist, it is not in this manner that thiugs proceed. He 

 shows us, in fact, by the help of the microicope, that valua- 

 ble instrument which the state of science renders indis- 

 pensable to every agriculturist, how the filaments, produced 

 by the germination of the spores of these fatal parasites, in- 

 troduce themselves into the tissue of the straw of the plant. 



while young, in order to produce the caries in the grain. He 

 has gone so far as to state, besides, that it is, above all, the 

 neck or the lowest knot of the plant of which the parasite 

 makes choice, in order to introduce its mycelium, doubtless 

 because that is the point nearest the earth in which its 

 seminules germinate. From thence the filaments, of which 

 he has followed the development, pass across the parietes, 

 still tender and delicate, of the cells, and not, as might be 

 supposed, by following the passage of the intercellulary 

 meatus, in order to raise itself, by little and little, with the 

 stem, and ascend to the grain, in which it ought to fructify. 

 In affirming the correctness of the fact, the author does not 

 attempt to say how it takes place ; that penetration, in fact, 

 is difficult to explain; but vegetable physiology presents 

 analogies to it. For myself, I find in this fact a sufficiently 

 plausible interpretation of the disease of the stems, which 

 consist?, as we know, in tlie accumulation of a mycelium in 

 the first internode or merithal of the straw of wheat. 



M. Jules Kuhn has cleared up another important point in 

 science. I am about to speak of the limits within which the 

 germinative faculty of the different ustilagines is restrained, 

 and of the conditions which favour or retard that operation. 

 Thus, he has discovered that, iu order to bud, besides the 

 necessary conditions of heat and moisture, these spores have 

 need of not being entirely withdrawn from the influence of the 

 atmospheric air. From his multiplied experiments on this 

 subject, it results that spores deeply interred in the soil do 

 not sprout ; but that as they preserve for more than a year 

 their germinative faculty, it ought necessarily to follow that 

 a field that shall be infested with it, remains disposed after- 

 wards to reproduce it, even though we should aow it with 

 grain perfectly free from the disease ; since, brought again to 

 the surface by labour, these spores are still found in conditions 

 favourable to their developement. Tlie observations of the 

 author teach us that those of the Tilletia caries {Tuf.) re- 

 quire from fifty-seven to sixty hours to bud ; that those of the 

 Carbon of oats and barley, sown ripe, require only six or 

 eight hours; and lastly, those of the Ustilago, or carbon of rye 

 and oats, may even germinate after the second year. 



As to the prophylactic means for opposing these parasites, 

 that which has best succeeded with him, and to which he 

 gives the preference, is the solution in 550 hectolitres of hot 

 water, of 467 grammes of sulphate of copper, very pure. It 

 is necessary that the immersion of the seed wheat should be 

 prolonged at least from twelve to fourteen hours, but it may 

 be continued without inconvenience even for twenty hours. 



I shall here close what I have to say of this work. The 

 short quotations that I have extracted from it will euffiee to 

 convince you of its importauQe to practical agriculture, which 

 receives so much lustre from your learned publication, so use- 

 ful and profitable to agricultural economy. 



Camille Montagne, 



Of the Institute of France, and of the Central 

 Society of Agriculture, 



