FORTIETH ANNUAL REPORT. 163 



fill estimates indicate that the quantity of fruit annually harvested by 

 peach gi'owers in this tenntory is not less than 10,000,000 bushels Thus 

 the crop for 1910, although an unusually large one, was for the territory 

 mentioned, probably not less than 12,000,000 bushels, with a gross valu- 

 ation of about 112,000,000 to |10,000,000. , a a ^loss ^ am 

 Although many insects and parasitic fungi occur on the peach, com- 

 paratively few are of much economic importance. Of the diseases of the 

 . peach, the brown-rot (Sclerotinia fructigena (Pers.) Schrot.) and scab 

 or black-spot (CTajfospomm carpopUlmn Thiim.), are responsible for 

 practically all of the damage to the fruit crop and the insect iniury is 

 limited almost entirely to the attack of one species, the plum curculio 

 {Gonotrachelus nenuphar TLevh^i.) . ^ ' i 

 The brown-rot probably causes more loss to peach growers than all 



"tptln^T' ""f f- 1? 1 ^u^ ?^^'} combined, with perhaps the exception of 

 yellows," which kills the trees outright. In the South the brown-rot 

 often causes the destruction of half or even practically all of the crop 

 and throughout the territory under consideration the annual shrinkage in 

 yield IS i,erhaps 25 to 3.5 per cent of the crop, representing a valuation of 

 about 13,000,000 to |4,000,000. Although thV broVn-?ot Is^.l wayrpiLen^^ 

 lu the peach orchards of humid sections, causing a rotting of a certain 

 pmportion of the fruit, it becomes notably destructive only under cer- 

 tain weather conditions, when within a i>eriod of 10 days or two weeks 

 It will spread so rapidly as to rasult in the destruction of practically the 

 entire crop Such disastrous outbreaks are likely to occur during moist 

 humid weather as the fruit begins to rii>en. The brilliant prospectsof 

 the orchardists are thus within a few days obliterated as if by fire 



The peach scab is the only other destructive disease of the fruit in 

 the eagtem United States, and, while it does not occur in such sudden 

 and disastrous outbreaks, the sum total of the injuries caused by t ai^ 



$r^JX^nn\ nif'^T^^ ]" " '^""'^''^^^ ^^ ''^^ ^'^^^"^^ ^^ Perhaps 

 Jl 000,000 annually. This disease occurs all over humid America where 



Mountain. '%rT ""f ^' especially troublesome east of the Allegheny 

 Mountains. It not only renders much of the fruit unfit for market but 

 so mars the appearance of the marketed fruit as to reduce its value 



The plum curcuho is of scarcely less importance in its relation to 

 the successful production of the peach than the diseases above mentioned 

 By Its punctures of the frnit in feeding and egg laying and the iniury 

 resulting from the larvae, or grubs, within the f?uit it brings abouJa r7 

 ^3 7^Tnnn°/' ii''^ a valuation amounting to perhaps not less than 

 13 750,000 annually. The puncturing of the fruit also greatly favors the 

 brown-i.ot, and curculio control is a prime essential in preventing osses 

 from this malady. Although the plum curcnlio is very generally ^distrTb 

 uted eastward of the Rocky Mountains, it is especially abundant in the 

 f^Xl^""^ ^T^'™ ^*f "'• ^""^°§" ^^"^ ^^ f"" f ^^it ^rops its Lruries 



?roo is Ii?hrmtr.V'T'^ ^'"' "' ^"^^ ^^""^°S *^^ fruit; but when the 

 crop is light little fruit may escape its ravages 



rJ^^ ^r^v!"^^^ mentioned have more than kept pace with the develop- 

 r.nPPi.iL^ peach-gi-owmg industry, and the cultivation of this crop, 

 especially in the South, has become more and more hazardous. Practi- 

 cal means for their control have, therefore, been most urgently needed 

 and much attention has been given by investigators of the Department of 

 Agriculture and of the various agricultural Ixperiment stations to sup 



