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BOOKS AND BULLETINS. 



made studies there in the same direction. These early 

 investigations gave rise to a very general impression that 

 the trees under experiment were not 

 Maynard on afflicted with the true yellows. Pro- 



Peach Vellow/s. fessor Maynard, "having the above 

 trees under his care then and up to the 

 present time, and having made a careful study of the 

 peach for nearly twenty years, can say positively that 

 many of the trees were badly diseased with the yellows, 

 notwithstanding the statement by parties not conversant 

 with the facts that it was doubtful if the true yellows had 

 made its appearance in this section at that time. Many 

 visitors familiar with the disease also pronounced it the 

 typical yellows." The doubts concerning the affliction 

 of these trees did not arise from any feeling that the e.\- 

 periments were ill-advised, but wholly from the fact that 

 the descriptions of the disease in the College orchard did 

 not seem to identify the disease as it exists in the great 

 peach regions. Professor Penhallow's characterization 

 of the disease before the Massachusetts Horticultural 

 Society in 1882, was wholly inadequate to a diagnosis. 

 The characterization is condensed as follows : ' ' We first 

 of all observe a sickly yellow color in the leaves, which, 

 later, generally extends to the branches, and thus gives 

 to the entire tree the yellow color, on account of which 

 the disease was very appropriately given the name it 

 now bears. The fruit ripens prematurely (from two to 

 four weeks before its season), often becomes abnormally 

 velvety, possesses a high, unnatural color, which is usu- 

 ally likened to the hectic flush of a consumptive person, 

 and has an insipid, unnatural flavor." Whatever may 

 have been the ailment of the trees, this description is 

 not characteristic of the yellows. 



Neither is Professor Maynard's characterization diag- 

 nostic. It is as follows: " i. A sickly yellowish-green 

 color of the foliage. 2. Small leaves, often clustered 

 and tinged with red, with a small amount of chlorophyll 

 in the cells. 3. The new shoots are small and wiry, and 

 grow in clusters or tufts, especially if they come out on 

 the trunks or main branches. 4. The fruit ripens pre- 

 maturely, is small and of a high color, and insipid or bit- 

 ter to the taste. Trees may present the yellow, sickly 

 appearance from want of food or from injury, but if the 

 fine wiry shoots, the prematurely ripened, high colored 

 and bitter fruit are present, the trees have the ' ' yellows. '' 

 The first symptom certainly conveys the idea that the 

 first indication of yellows is a general yellowing of the 

 whole foliage. As a matter of fact, this yellowness is 

 usually a late symptom, and it rarely happens that the 

 disease at once affects the foliage of the whole tree. The 

 disease is usually first apparent in one or two portions 

 of a tree, often in only a single fruit. The small leaves, 

 "clustered and tinged with red" indicate general debil- 

 ity rather than yellows. The third symptom usually 

 designates yellows, but the description of the "new 

 shoots" is not full enough to be satisfactory. The ten- 

 dency of these adventitious shoots — if such shoots are 

 meant — to branch the first year is one of the crucial 

 tests of the disease. Premature fruit, "small and of a 



high color," is by no means characteristic of yellows. 

 Many conditions may give such fruits. The diagnostic 

 point in this connection is the presence of definite red 

 spots or blotches upon the fruit, and these blotches ex- 

 tend into the flesh, and usually to the pit. These spots 

 are conspicuous and characteristic, and they constitute 

 the most important symptom for the determination of 

 the disease. It is unusual, also, that yellows fruit is 

 bitter until the disease is far progressed. But bitter 

 fruits are often found upon debilitated trees. 



We do not mention these points for the purpose of dis- 

 crediting Professor Maynard's observations, but simply 

 to show that more complete diagnoses must be made be- 

 fore peach growers can feel assured of results. The 

 trees may have the yellows, but the description does not 

 prove it. Professor Penhallow's description of the dis- 

 ease at Houghton Farm is no more characteristic, yet 

 the trees must have had the yellows, for a visit to the 

 Farm last summer revealed the fact that very few of the 

 trees upon the place are alive, and these are in the last 

 stages of true yellows. 



Professor Maynard thinks that "the causes which are 

 productive" of yellows are the following: insufficient 

 food supply ; too much nitrogenous manure applied late 

 in the season ; injury by cold ; injury by borers ; injur- 

 ies by accident. It is even supposed that the breaking 

 of the tissues or structure of the tree by frosts " in such 

 manner that they cannot be repaired during the next 

 season's growth," and which causes "dead places often 

 on the trunk and main branches," may be productive of 

 the disease. It is singular that so many of these old and 

 loose notions should still be held to account for the dis- 

 ease, even indirectly. The experience of growers upon 

 the new and fertile soils of the west proves beyond all 

 cavil that trees upon the best soils and receiving the best 

 of care, both in youth and age, in all seasons, in all treat- 

 ments, are liable to the attack of yellows. 



Professor Maynard has done a service in giving the 

 behavior of trees in the college orchards, although we 

 wish that the statements and discussions had been fuller. 

 The observations suggest the old question in a new form, 

 Does peach yellows behave differently in Massachusetts 

 than in the large peach growing sections of the country ? 

 It is not impossible that it may do so, and such records 

 as this may bring out the facts. It is certain that the 

 following observations will not apply to all parts of the 

 country : "In the college orchard of some nine hundred 

 trees, careful examination of all the trees was made 

 during the past season. Of these, about fifty in different 

 parts of the orchard gave unmistakable evidence of the 

 'yellows,' and in every case the trunks or main branches 

 were found to be injured from 10 to 60 per cent. In no 

 case could we find any indications of the disease where 

 the branches or trunk were not injured in some way. 

 The same disease, apparently, although we have made 

 no careful study of the tissues, often destroys the wild 

 cherry, the wild plum, the sweet birch (Betula lenta) and 

 other trees. " 



The following conclusion is drawn: "While we do 



