-8- 



spores float or are carried by air currents to the blossoms of the peach, 

 producing blossora blight. Close observation shows that this infection 

 extends from the blossom into the tivig. Closer observation shov:s iTinuto 

 tufts of conidia (sumi.ier spores) on the surfaces of the blossom andiy/ig. 

 These spores may infect more blossoms. Each time it rains or becomes 

 humid for any leni;;th of time (about four hours) a n'-:v: crop of conidia 

 is produced on the surface of these cankers. At first infection is 

 evidenced by the blighting of the blossom. The second syriipton vdiich 

 appears about shuck fall is tv^ig dieback, VjT'ierever a blossom has blighted, 

 the tv.'ig infection or canker girdles the tv/ig and starves everything be- 

 yond the canker. Blighted tvvigs are evident in orchards nov/-, V.'ith 

 severe infestations of curculio, it r;ill be -difficult to control conidial 

 infection on the young peaches. To reduce brov«ii rot in the peach orchard, 

 it is going to be necessary to control blossom blight. Orchards in v.hich 

 twig dieback occurs contain the necessary inoculum for severe preharvest 

 brovai rot infection. Frequent use of fungicides through the sunra'jr is 

 therefore suggested," 



CONTROL OF THE PEACh TRIJE BORETi V.ITIi DDT . (From Storrs Horticultural Notes 

 by' phiTip Carman"JI 



According to work done in Connecticut and N'jvv Jersey, there 

 is considerable promise in control of poach tr-^^e borers vdth DDT, Unlike 

 treatments fonnerly recoimended (paradichlorobenzene or ethylene di- 

 chloride) DDT must bo applied when the moths are flying and depositing 

 eggs, June and July and possibly August, in Connecticut, According 

 to experiments by Mr* Y/allaco of the Connecticut Station, only one 

 application made on June 23 gave excellent control in nurs';ry stock. 

 The material v;as applied as an emulsion in Velsicol, a mixture of mono 

 and dim^jth.yl naphthalenes. Concentrations varied from 3/4 poiond to 3 

 pounds actual DDT in 100 gallons, but controls were best at l--g- and 

 3 pounds. Apparently 5/4 pound per 100 v:as not enough under the condi- 

 tions of his tests. The mixture used by Mr, Yfallace should be kept off 

 the foliage particularly in hot (30 degrees F.) weather as should most 

 comi.iercial DDT emulsions. 



In Kev; Jersey, Dr. Driggers of the New Jersey Experiment 

 Station reports control of the peach tree borer with one spray applied 

 to control Japanese beetles aiid the Oriental f ruit moth. His obs-.rva- 

 tions also include results from tv;o sprays. The figures given shovv a 

 difference of .4 borersper tree from one spray to ,05 borers por tree 

 from two sprays and 2,20 borers per tree from no spray. This moanR 

 five times as many bor?^rs in check trees as in those receiving one spray 

 and 45 times us msavj borors in check trees as in those receiving two 

 sprays, 



DDT acts by killing the moths and presumably the young larvae 

 before entering the trunk, Hoths are on the wing in the state beginning 

 in late June and continuing through July and into August, Mr. v.'allace's 

 experiment v;as designed primarily to kill young larvae and his cmuision 

 probably was effective for two to three months. The wettable DDTs are 



