CHE REFERENCE LIBRARY - ZetaTalk

CERTAIN ELEMENTS IN NURSERY PRACTICE 199fungus Cocco~~nyces /zie7r&is, and a similar fungus causes theyellow-leaf or shot-hole of plum. The fungus produces massesof spores that appear as small, white, velvety pustules on theundersides of the leaves, opposite the discolored spots. Thesespores are produced throughout the summer and being carriedby wind and rain to other leaves cause new infections. Thefungus lives over winter in the fallen leaves on the ground, andin the spring spe4al fruiting bodies (ascocarps) develop inthey old leaves. Spores discharged from the ascocarps pro-(1u~ t!le first infections that appear on the new foliage.hi trd. ---.- I, ime-sulfltr solution 1 to 50, or a dust mixtureof !G pa”‘ts filH?l)’ ,grourltl sulfur to 5 parts powdered lead arsenate,i.; &‘c&ve for the control of the yellow-leaf disease.‘1’1~ first application should be made when the first-year budsWC about six to ten inches high. As a rule, five to seven:qq4i&ons at inter\-& of about two weeks are sufficient.An attempt should be made to keep as much as possible of thefoliage protcc.tctl throughout the summer. It is usually notnecessary to treat m>-rob&n plum seedlings or the Japanesevarieties of plums sincbe the yellow-leaf disease seldom causes111UCll tlillUage Oil tllWt& trees.~'~~IVI'DERT-MILDEW cw CHERRY. - The mildew of cherry canbc recognizt4 1,~ the &aracteristic upward rolling of the foliage,actc~orklI.““~i~‘(1 by a shortening and an increased thickness ofthe internodes of the twigs. The curled leaves are covered011 tllch ullcler S\lrftl(‘t with a txngle of white felt-like threads.I ‘sutJly ;lfter miclsummer, small black specks ma,y be observedsc~attorrJ OYW the surf~e of the felt-like mass on the undersideof tlw ltd. ‘l’hc &3x is fht3 work of the fungus PodospA@rUcr.~~~frc~c~rrtIlrr~.(‘r~f~l. -- The trea.tments for the yellow-leaf disease ofdltW~~ id plwn are also suficient for the control of themildr~w.