Page 8 



BETTER FRUIT 



April 



Spraying Economy and Insecticide Efficiency Important 



By T. H 



BY the average commercial fruit- 

 grower, insecticides and tlieir ap- 

 plication are understood to mean 

 but a necessary unit of expense in his 

 business, that is taken into considera- 

 tion in computing the cost of pro- 

 ducing the finished product. This is 

 comparable to the oijerating expense 

 needed in placing an\- finished product 

 on the market by the manufacturer 

 and which is figured in the selling price 

 necessary to be secured to offset all 

 such expenses which go to make up the 

 cost. Since the fruitgrower is not yet 

 able to control the market price of his 

 finished product to cover all cost of 

 production plus a compensation for his 

 services and a reasonable profit, he 

 must look the more toward lowering 

 his cost of production by applying bet- 

 ter business methods to his farm oper- 

 ations. 



The time is past when the only aim is 

 to increase the sui)ply of fruit to shove 

 upon an already glutted market, and 

 the grower is beginning to look to the 

 production of a superior quality of 

 fruit at as small cost as possible in 

 order to secure a reasonable interest 

 on his capital invested. This means 

 the application of business principles to 

 the spraying as well as other produc- 

 tion operations and reducing the ex- 

 pense of such spraying as much as pos- 

 sible without impairing their efliciency 

 and usefulness. It does not mean that 

 he need spray only once for codling 

 moth where he has been spraying two 

 or three times before, or spray for scale 

 only every other year instead of yearly, 

 but it iiuist be remembered that cost of 

 production includes also the costly re- 

 sult of hurried and careless work as 

 well as the actual outlay of expense for 

 labor and spray material, and it is this 

 side of the production expense that 

 presents the most room for improve- 

 ment. 



The fruitgrower cannot be blamed 

 for grasping at information emanating 

 from reliable sources and which prom- 

 ises to reduce the amount of work nec- 

 essary to produce a crop. His aim is 

 to simplify his spraying ojierations as 

 much as possible without impairing 

 their efficiency. He is especially apt to 

 make fewer codling-moth sprays, and 

 do the spraying less thoroughly during 

 a year when the crop is light than 

 w'hen it is heavy, because he does not 

 consider the crop worth so much. The 

 result is usually that the years of 

 wormiest fruit are years of light crop 

 when the worms are fwced to concen- 

 trate on the fruit that is present, and 

 the grower^often sees that he would 

 have had a' fair crop after all if he had 

 given the attention tp the .spray that he 

 had given in former years. This has 

 been brought to my attention in a num- 

 ber of cases, and instead of econo- 

 mizing on his sprays he has actually 

 been extravagant, flailing to save the 

 fruit that escapes the frost. The in- 

 creased supply of codling-moth larvae 



. Parks. Field Entomologist University of Idaho, 



will make the battle all the more difli- 

 cult next year. The degree of success 

 in si)raying for codling moth varies 

 with the relative abundance of the in- 

 sects in relation to the fruit crop, 

 'ffiis relative abundance will increase 

 directly as the supply of fruit de- 

 creases. Bearing in mind that reducing 

 the cost of spraying also includes the 

 prevention of loss from careless work, 

 how else can the grower reduce the 

 cost of his spray ap])lications? 



Co-operative Buying of Spray Mate- 

 rial. — The first cost of the spray mate- 

 rial is by no means the least, and co- 

 operative buying, whenever it can be 

 done, is to be recommended. In case 

 of lime-sulphur, where time and facili- 

 ties are at hand, it is often more eco- 

 nomical to make this on the ranch. 

 The individual grower will have to be 

 the judge of the economy of this. 



Do not use a stronger strength of 

 spray than recommended. This is often 

 done, especially with arsenate of lead 

 used as a codling-moth si)ray. Many 

 growers have the impression that 

 doubling the anif)unt of spray material 

 called for by the directions will give 

 better results. Consequently they use 

 5 pounds of arsenate of lead to 50 gal- 

 lons of water instead of 2 or 2% 

 pounds, in the hope of getting better 

 results and possibly with fewer 0]5era- 

 tions. The less successful grower is 

 liable to ascribe the worms to too weak 

 a spray and next year he will double 

 the strength in the hope of getting bet- 

 ter results. This phase of the insecti- 

 cide efliciency has been thoroughly in- 

 vestigated and excellent results have 

 been secured with strengths of 1 iiound 

 of arsenate of lead to 50 gallons of 

 water (one-fifth of the above strength), 

 but only with very thorough applica- 

 tions. There is little necessity of the 

 grower using over 2% pounds of arse- 

 nate of lead to each 50 gallons of water, 

 as experiments and practical demon- 

 strations have shown this to be equally 

 as eflicient as stronger sprays and the 

 possible danger of injury from arsenic 

 residue about the roots of the tree is 

 thereby much lessened. 



Thoroughness of Apiilication. — More 

 attention should be ])ai(l to thorough- 

 ness of application, es])ecially of the 

 first or "calyx" spray for the codling 

 moth. This cannot be overemphasized, 

 and it is here that the best results can 

 be secured with a little extra attention, 

 especially if it is done at the proper 

 time. It should be remembered that the 

 calyx cu]) well filled in May is a ileath- 

 Iraj) to larvae trying to enter that calyx 

 in August and SeiJtember. The work of 

 thoroughness here includes also the use 

 of a high-pressure power outfit, a tower 

 on the top of the outfit to enable the 

 operator to reach the topmost branches, 

 and the use of a driving spray from 

 angle nozzles and hose fitted with ex- 

 tension rods at least eight feet long. 

 None of these can be omilled without 

 afl'ecting the thoroughness of the work, 



and along with t!ie outfit should go the 

 owner of the orchard or the highest- 

 paid man on the ranch. It is no exag- 

 geration to say that !»0 per cent of the 

 men handling spray rods do not know 

 how to spray a tree, and usually the 

 highest-priced man on the place is the 

 cheapest in the end. Poor spraying is 

 more expensive than a thorough job, 

 even though the time required may be 

 double, provided the orchard is not too 

 large to be covered by the outfit in the 

 proper time. 



L'se of Combination Sprays. — Combi- 

 nation sprays have a place and are 

 coming to be more and more used. By 

 the combination of an insecticide and 

 a fungicide spray, or a contact and 

 arsenical spray, the cost of keeping the 

 orchard clean is greatly reduced over 

 the expense of separate applications. 

 This is especially true with reference 

 to the codling moth and the apple scab 

 in North Idaho, and possibly will be 

 used more fretiuently for the codling 

 moth and apple mildew in South Idaho. 

 The combination sprays which are de- 

 signed to reach codling moth and green 

 aphis are to be encouraged and can be 

 used to good advantage, especially 

 during the early applications of spray 

 for the codling moth. This saves the 

 expense of making a separate spray for 

 the aphis and the only extra cost is the 

 cost of materials. The following list 

 contains most of the common sprays 

 that can be safely used in combination 

 for both insects and fungus diseases. 

 Some of these combinations are already 

 being used successfully in Southern 

 Idaho, and the cost of separate applica- 

 tions thus reduced: 



Ai-senate of lead and Lime-sulphur 



(neutral) (summer strength i 



Tobacco and soap 

 "Black Leaf 10" 

 Bordeaux mixture 

 Atomic sulphur 

 Ii'on sulphide 



Arsenate of zinc and Iron sulphide 



Atomic sulphur 

 Lime 



Lime-sulphur and "Black Leaf 40" 



Arsenate of lead 

 (neutral) 



Kerosene emulsion and Siilplun- (powdered, or 

 lime-sulphur) 



In passing I may state that no combi- 

 nation spray used later in the season 

 can take the place of the lime-sulphur 

 spray applied early in the spring for 

 San .lose scale, and the one recom- 

 mending using arsenate of lead and 

 lime-sulphur (summer strength) is rec- 

 ommended for its fungicidal value 

 rather tlian its effectiveness against 

 scale, though it would have some value 

 against scales which have escaped the 

 action of the dormant lime-sulphur 

 spray. Every orchard is entitled to the 

 annual "house cleaning" given by the 

 aiiidication of lime-sulphur spray, pref- 

 erably when the buds are swelling. A 

 great deal has been said about the num- 

 l)er of sjirays, but 1 do not think that 

 we can afford to economize here. Few 

 successful growers feel that they can 



Continued on page 37 



