Page Eight 



BETTER FRUIT 



February, 1922 



Orchard Spray Prog-ram for 1922 



THE orchard man must fight for his 

 crop against a considerable number 

 of pests and diseases that are always 

 on the job, and it is a fact, demonstrated 

 every season, that the fruit grower cannot 

 win in this fight unless he is likewise ever- 

 lastingly on the job. His orchard enemies 

 are fiendishly efficient, taking advantage of 

 every opportunity offered to make their 

 attack, and it is necessary to plan the spray 

 campaign with the greatest care and execute 

 it effectively so as to head off every thrust 

 of the opponent. 



The spraying program is a program of 

 prevention. It aims to prevent the activities 

 of these orchard pests and diseases almost 

 entirely by covering the fruit, leaves or 

 frame-work of the tree with a material 

 poisonous to them, so they will have no 

 avenue of entry. Failure is due in many 

 instances, to lack of understanding of the 

 proper weapon to employ and the proper 

 time to employ it. 



A spray calendar, such as the one appear- 

 ing here, is intended as an aid to the grower 

 in these particulars, but there are a few 

 pointers that may be added as aids to 

 complete effectiveness. 



Iron Sulfate as Indicator — With the 

 dilute lime-sulfur sprays it is rather difficult 

 to determine just how thoroughly the foli- 

 age is being covered or the fineness of the 

 droplets reaching the tree. By adding 

 iron sulfate at the rate of half a pound, 

 dissolved in water, for each gallon of con- 

 centrated lime-sulfur used, the spray is 

 turned black without the effectiveness be- 

 ing destroyed and the operator can tell at 

 a glance just how well his work is being 

 done. Many growers use this method in the 

 scab sprays with satisfying results. 



Amount of Spray Required — It takes 

 a certain amount of spray to give satis- 

 factory protection to a tree. LeRoy Childs, 

 of the Hood River Branch Experiment 

 Station, has determined by a survey of some 

 of the best orchards in his section that it 

 takes, on the average, about 4 gallons of 

 spray to cover a healthy eleven-year-old tree 

 and about seven gallons for a seventeen- 

 year-old apple tree. 



If the apple grower will figure up his 

 spray tank average for last season he can 

 determine whether he was using a safe 

 amount per tree. One must always remem- 

 ber that it is just as important to cover the 

 leaves, upper side and lower side, as it is 

 to cover the fruit, for clean fruit is an 

 impossibility in a tree filled with scab 

 spots on the foliage. 



The Tree Top — -The average orchard 

 will show more scab and worms in the tops 

 of the trees than in the portions more 

 easily reached by the sprayer. More 

 thorough covering of the tops will repay 



By H. P. Barss and A. L. Lovett 



many times over the extra exertion and 

 skill required. 



Spray Guns — The spray gun is a great 

 time and labor saver, but must have suffi- 

 cient power behind it if it is to equal the 

 results secured by the old spray rod equip- 

 ment. Furthermore no little skill is 

 required to sweep the spray thoroughly 

 through the tree from top to toe without 

 missing some of the branches, drenchmg 

 others, or actually causing injury to the 

 surface of the fruit and to the foliage by 

 the force of the powerful, direct drive of 

 the coarse adjustment of the gun. 



Dry Lime-Sulfur — Dry lime-sulfur is 

 now being used by a good many fruit 

 growers in place of the usual liquid lime- 

 sulfur, on account of its greater convenl- 



Time for the delayed dormant spray for 



scab, mildew and aphids. Should never 



be omitted in commercial orchards. 



ence in handling and storing. When it is 

 used in strengths sufficient to give the 

 dilute solution practically the same equiva- 

 lent strength as the usual dilutions of 

 liquid lime-sulfur, the results seem to be 

 equal to the latter. 



Chemical analysis indicates that it takes 

 about four pounds of dry lime-sulfur to 

 equal the sulfur content of a gallon of com- 

 mercial liquid lime-sulfur of 32 degrees 

 Baume test. The Experiment Station still 

 feels that the grower is taking some risk in 

 using the dry material at dilutions very 

 much under those called for by the usual 

 spray schedule. 



Notes on Spray Calendar 



DORMANT Spray — The blister mite 

 spray (pear) and the twig miner spray 

 (prune and peach). It is effective for 

 scale. 



It is seldom advisable to omit this ap- 

 plication on pears and, with the advent of 

 blister mite in the apple orchard, it is 

 equally important there. There is too 



much blister mite injury in most of our 

 fruit sections, warranting more serious con- 

 sideration of the timeliness and thorough- 

 ness of this application. 



Generally speaking, this spray cannot 

 be safely omitted on prunes, because the 

 twig miner is generally present and fre- 

 quently wreaks serious havoc in unsprayed 

 trees. 



In the absence of these pests spraying 

 for San Jose scale and red spider mites 

 may be deferred until the delayed dormant 

 stage, but in such cases the strength of lime- 

 sulfur should be increased to the dormant 

 strength of 12-100. 



Oil sprays may be substituted for the 

 standard lime-sulfur applications only for 

 the control of scale and leaf-roller. For 

 best results from the use of oil sprays it is 

 essential that several days of settled weather 

 follow the application. 



The ideal time for the application of 

 the dormant spray is about the middle of 

 February if suitable weather for spraying 

 occurs then. This application is not ef- 

 fective for the control of our principal 

 fungous diseases, although peach leaf curl 

 may be often checked considerably if it is 

 not delayed too long. For this disease 

 earlier winter spraying with Bordeaux is 

 safer. 



Delayed Dormant Spray, Apple and 

 Pear — The first scab spray, the aphis spray. 

 In Western Oregon satisfactory scab and 

 mildew control cannot be expected where 

 this application is omitted, poorly timed or 

 indifferently done. Much mildew damage 

 on the fruit starts at this early stage and 

 scab gets under way promptly after the 

 winter buds burst. Mildewed twigs should 

 be pruned out during the winter. The 

 old fallen pear and apple leaves should be 

 turned under before this time since they are 

 responsible for carrying the scab over from 

 the previous season and, in most orchards, 

 considerable benefit in scab control will 

 result from this practice. 



For apples, the addition of nicotine 

 (Black Leaf 40) is advisable at this time 

 for aphis control. 



Pink Spray, Apple and Pear — The 

 second scab spray required to afford pro- 

 tection during bloom. Important for mil- 

 dew control. 



Where fruit worm injury to mature 

 fruit was apparent last season lead arsenate 

 should be added, excellent control being 

 possible from this application. 



Pre-Blossom Spray, Prune, Plum and 

 Cherry — On stone fruits this spray is 

 required only where blossom blight, due 

 to the grown rot fungus, is troublesome, or 

 where bud moths and aphids were preva- 

 lent the previous season and measures for 

 their control are advisable. 



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