February 4, 1891.] 



Garden and Forest. 



59 



less variable result than propagation by seeds.' And yet there 

 are instances in which plants do not come true from cuttings 

 or grafts. As a philosophical question, the presumption is 

 that varieties propagated by buds wear out sooner than those 

 propagated by seeds, for the experiments of Darwin and others 

 have shown that the special office of seed propagation is to 

 increase the vitality of the species through cross fertilization. 

 It must follow, therefore, that in the absence of cross fertiliza- 

 tion vitality must be less.* 



" But as a matter of practice we do not need to consider this 

 phase of the question, for we are concerned with variation 

 rather than with ultimate longevity. And it is also probable 

 that any tendency toward weakness through lack of fertiliza- 

 tion is fully counterbalanced by protection which such varie- 

 ties receive under cultivation. 



"The question comes simply to this: If buds are taken from 

 parts which possess stable characteristics they will give stable 

 products under similar conditions. But if the buds are taken 

 from parts which have been developed into abnormal condi- 

 tions, and which tend to vary, they must tend strongly to de- 

 part from the parent, especially when the means by which the 

 high development was produced and is maintained are re- 

 moved. Bud variation may therefore be said to be indetermi- 

 nate. The best example of running out in plants propagated 

 by buds is the potato. It is a matter of general observation 

 that varieties of potatoes disappear. And Bealf has per- 

 formed experiments which show that in eight years varieties 

 which gave good crops so far ran out as to produce nothing. 

 These varieties were grown in the same garden throughout 

 the experiment, but they were constantly shifted over an area 

 of from five to eight acres, so that potatoes were not grown 

 two seasons upon exactly the same ground. And during the 

 time when these potatoes were decreasing in yield the garden 

 was each year producing better crops of other kinds, and the 

 newer varieties of potatoes did well. In this case it may be 

 argued that the plants showed signs of wearing out rather than 

 running out by variation, but there is no evidence to show that 

 the plants were in any way weaker or less able to perpetuate 

 themselves after they had run out than before, for it is proba- 

 ble that seed production increased as tuber production de- 

 creased. At all events, we cannot determine if the varieties 

 wore out, so long as we have no record of their seed produc- 

 tion. It seems, rather, that the plants returned to a compara- 

 tively tuberless condition. Large Potato-tubers are abnormal 

 to begin with, and it is not strange if their characters are tran- 

 sitory. 



" At present I see no reason for supposing that fruits propa- 

 gated by buds run out so long as equal conditions of culture 

 and soil fertility exist ; but if the buds were to be taken from 

 parts which are abnormally or unusually developed, as they 

 are in the potato, I should expect that we could not long hold 

 the offspring to their assumed character. 



" The conclusion of the whole matterissimply this : Varieties 

 grown from seeds tend to vary or run out. Varieties grown 

 from buds tend to remain permanent, or nearly so, unless the 

 parts which are propagated possess abnormal, or what we 

 might call fictitious or unstable, characters, in which case fur- 

 ther variation or running out may be expected." 

 BACTERIA AND GREEN MANURING. 



Professor Caldwell delivered an unusually instructive ad- 

 dress on this subject. About four-fifths of any crop plowed 

 under is water ; one-fiftieth of it, or what would remain after 

 burning, is called ash, and the rest is organic matter which 

 mostly comes from the air. There are twelve pounds of this 

 in every hundred of the crop turned under, and this addition 

 to the soil improves it in many ways. In the first place, it 

 adds humus, which makes the soil more porous and warmer, 

 and is a constant source of carbonic acid, which does good 

 work in making soluble the food already in the soil. Besides 

 this, it has been clearly demonstrated by recent research that 

 organic matter in some kinds of plants contains much nitro- 

 gen, the costliest of plant foods, which it has gathered from the 

 air. The crops which are known to have this faculty are 

 Clover, Peas and other leguminous plants. On the roots of 

 these plants are nodules formed by bacteria, and somehow, 

 in the formation of these swellings, the free nitrogen of the 

 air in the pores of the soil is taken up by the plant. It has 

 been proved that Peas or Lupins will grow in sand which is 

 entirely free from nitrogenous food of any kind if there is only 

 added to the sand a sufficient quantity of the other constitu- 

 ents of plant food with some of the bacteria to secure the 

 nitroo-en. Professor Caldwell concludes as follows : 



* See also Gray, /. c. 

 tRep. Mich. Bd. Agr., 18 



"But the bacteria have still another part to play in the prepara- 

 tion of green manure in order to convert it into assimilable food 

 for the following crop. Green vegetable matter is not food im- 

 plants. It must first undergo decay, or, to use a less elegant 

 phrase, it must rot. Now another set of bacteria come in here 

 and carry on this work of decay. They live and multiply in 

 the green vegetable matter, and in connection with their life 

 and growth this matter is converted into humus. There is still 

 another valuable piece of work done by the bacteria besides 

 making the humus, which is the conversion of the nitrogen 

 into nitric acid, or the very important process of nitrification. 



" For the best results, then, in green manuring, take for your 

 crop some leguminous plant, such as Pea, Bean, Vetch, 

 Clover, Lupin, Alsike, or others, and select the one that will 

 give you the largest quantity of green matter before the mid- 

 dle of August at the latest. Have your soil well drained and 

 fertilize it well with phosphate and potash, buying no fertilizer 

 that is claimed to contain any nitrogen. For if such a claim is 

 made you have to pay more for manure on that account, and 

 one of the objects of your green manuring is to get your nitro- 

 gen for nothing. Plow the crop in even by the 1st of August 

 if you have the ground well covered with a luxuriant growth 

 by that time. Avoid plowing it in deep, and, if practicable, 

 loosen up the ground before the cool weather sets in. This is 

 just the sort of treatment required for putting in a grain crop. 

 Soon after this crop is turned in the bacteria will begin their 

 arduous labors of humufication and nitrification. 



" Finally, letmegiveanaccountfromoneof the German jour- 

 nals of the successful use of green manuring in a vineyard. 

 On a German experimental vineyard thirty-five pounds of clo- 

 ver-seed [Trifolium incarnatuni) were sown per acre, with 

 Thomas' phosphate added for mineral fertilizer. The roots of 

 the plants from a small plat were carefully taken up, and found 

 to be well covered with tubercles. The gain in nitrogen was esti- 

 mated to be about 118 pounds to the acre. ' This would have 

 required 20,000 to 25,000 pounds of stable manure for the same 

 quantity of nitrogen. The whole cost of this crop was about 

 126 marks, while the cost of the stable manure to accomplish 

 an equal result would have been 200 to 300 marks." 



DISEASES OF THE GRAPE IN WESTERN NEW YORK. 



A carefully prepared paper on this subject was made by 

 David G. Fairchild, of the Department of Vegetable Pathology 

 at Washington. What he said in reference to the various mil- 

 dews, rots and anthracnose, with their remedies, it is not 

 necessary here to repeat. These matters have been already 

 treated in this journal. We present, however, some facts in 

 reference to a new disease of the grape, which may prove a 

 serious matter in our vineyards : 



"About the 1st of September, 1890, complaints reached the De- 

 partment from numerous localities through western New York 

 of a disease which was threatening the grape in that region. 

 Specimens were received from various parties, and, although 

 carefully examined, revealed no parasites upon them. Accord- 

 ingly, although so late in the season that many of the vine- 

 yards had been touched by the frost, an examination was made 

 of numerous vines in different localities through the infected 

 region, and notes taken of the varying conditions under which 

 the disease appeared. From a study of the trouble in October 

 the following diagnosis may be made : The leaves first show 

 the disease manifesting at the outset irregular, somewhat star- 

 like red blotches between the veins, which gradually enlarge 

 and run together, at the same time becoming browner until 

 they fill up the spaces between the main veins with a deep 

 red-brown tissue, giving to the leaf a pronouncedly striped 

 appearance. This striped look is quite characteristic and may 

 often be seen from a distance of several rods. Upon those 

 vines diseased the berries are of an insipid flavor, often intensely 

 sour, and drop from their stems in the later stages on the slight- 

 est touch. Badly diseased veins may often be distinguished by 

 the layer of shriveled berries covering the earth beneath them. 



"The trouble is not entirely confined to cold, heavy soils, 

 although apparently worse upon such land, nor is it connected, 

 so far as can be ascertained, with the use or absence of any fer- 

 tilizers. The shade which is afforded by the foliage of trees and 

 by houses, although in one or two cases seeming to afford pro- 

 tection, cannot be surely connected with it. Examinations of 

 the roots of many diseased and healthy plants, while revealing 

 the fact that the young fibrils had almost entirely rotted away 

 in the diseased ones and were only partially decayed upon the 

 healthy ones, have shown no parasite of a nature adequate to 

 cause the injury. In some respects the disease resembles that 

 which lately appeared in California and threatened the grape 

 interest of that state, and until one or both are more fully 

 worked out must stand in the same general category. 



