LOSSES FROM THE DISEASE. ID 



Goorgo Ncilson, chief iiispoctor under the veootation disoasos act of 

 that colony, states that peach loaf curl has })cen known in Victoria since 

 1856. This dates the presence of the disease iii Australia back to a 

 time Avhen its importation from America to that country would he 

 doul)tful. Its European origin, however, may not be improl)al)le. 



The severity of the disease in the gardens of China and the fact that 

 the peach proba])ly reached Europe and America from the East make 

 it still desirable to learn if the trouble is prevalent among the wild or 

 escaped peach trees in the interior of the Chinese Empire. 



It mav be pertinent to state, in view of the fact that Darwin holds 

 the peach to be derived from the almond, that none of the many widely 

 cultivated varieties of the almond in California, either of local or for- 

 eign origin, are subject to peach leaf curl, even when growing ))eside 

 peach orchards denuded b}- it. Trees which are apparently the result 

 of almond and peach crosses are somewhat aii'ected, however, and sev- 

 eral of the nectarines, which arc derived from the peach, arc ((uite 

 subject to it. Seedling peaches, as stated, are very connnoidy attacked, 

 but of some forty to fifty varieties of seedling almonds examined by 

 the writer none has thus far shown the disease. 



LOSSES FKOM THE DISEASE. 



The direct annual losses to the peacii interests of the United States 

 from peach leaf curl are very large, and are usualh^ nuich greater 

 than is suspected by the growers themselves, as the nature and action 

 of the disease are misunderstood ])y them, and its effects frequently 

 attributed to other causes. In case an orchard is so aii'ected that it 

 fails to hold the crop, or sets I)ut a partial crop, the grower has but 

 little ground for an opinion as to what the yield would have been had 

 curl not prevailed, hence the estimates of losses made by growers are 

 frequently ver}' unsatisfactory. In case curl occurs after a severe 

 cold spell in spring, as is quite commonly the case, the orchardist is 

 apt to charge the loss of fruit to the low temperature rather than to 

 the disease. The preventive spray work conducted b}^ the Depart- 

 ment has shown, also, that the loss estimates are nearly always too 

 low. 



By preventing the disease upon a portion of the trees of an orch- 

 ard the amount of injury sustained by the imtreated trees has l)een 

 determined most accurately by direct comparison. Such comparative 

 work has now been conducted for several years in many of the leading 

 peach-growing centers of the country, and these tests enable the 

 writer to state that the losses sustained by the peach industr}^ are 

 probably not overdrawn in the following estimates: Of a large num- 

 ber of peach growers who replied to a circular letter sent them in 

 1893, there were 251, living in 35 peach-growing States and Terri- 

 tories, who stated whether or not their orchards were affected by curl. 



