Apple rust . s later Treturned to Crawfordsville for a visit and went out again tosee the cedar trees from which I had, during my senior year,gotten such large quantities of galls. To my astonishmentthey were practically free from infection, while others nearbythat had borne no galls before were now badly covered withthem. What the explanation of this phenomenon is I do notknow. It occurred to me, however, that a serious infectionof the trees one season might have rendered them more orless immune for a time That the infection was on differenttrees in these two years is certain, as I was very f
Apple rust . s later Treturned to Crawfordsville for a visit and went out again tosee the cedar trees from which I had, during my senior year,gotten such large quantities of galls. To my astonishmentthey were practically free from infection, while others nearbythat had borne no galls before were now badly covered withthem. What the explanation of this phenomenon is I do notknow. It occurred to me, however, that a serious infectionof the trees one season might have rendered them more orless immune for a time That the infection was on differenttrees in these two years is certain, as I was very familiar withthe different trees with which I had worked. CONTROL OF RUST BY SPRAYING. Ever since spraying for orchard diseases became widelyadopted there have been occasional attempts to control applerust by this method. The varying successes of these trialshave been mentioned under historical notes. *This statement is from unpublished records made by Prof. Whetzell, inconnection with some o£ his early 46 W. Va. Agrl. Experiment Station [Bul. 154 J The incidents directly responsible for our taking up ex-periments along this line were a very severe outbreak of therust in the eastern part of the state in 1910, and a case inwhich a few trees were kept free from it by means of spray-ing. These controlled trees were part of a row along oneside of a large orchard. The owner had some atomic sulphuron hand and, incidentally applied it to these apple trees tosee how effective it would be. It was at once assumed bynearly everyone in that section that this spray would controlrust, while others would not. Inquiry failed to locate anyother apple trees sprayed on the same date, and a belief wasexpressed that lime-sulphur, or Bordeaux mixture, wouldcontrol this disease just as effectively as the atomic sulphur, ifit were applied at the right time. During the season of 1911 the rust was not very severe,but no orchards were seen in which spraying had effectivelycontrolled it. Field Expe
Size: 1252px × 1996px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookidapplerust154, bookyear1915
