Nurserymen and Fruit Groovers on Fumigation 



THE question of fumigating nursery slock 

 is one of increasing importance. San 

 Jose scale is spreading in tlie province 

 of Ontario. It will extend the area of 

 its depredations if adequate steps are not taken 

 to control it. The value of fumigation as 

 a means of doing this is a point upon which 

 there is a diversity of opinion. To learn the 

 conclusions of practical men regarding the mat- 

 ter, The Canadian Horticulturist submitted 

 the following list of questions to leading nursery- 

 men and fruit growers: "Do you consider fumi- 

 gation of nursery stock to be a necessity ? Does 

 it kill all the insects and scale that it is claimed 

 to do? Can you cite instances where it has 

 injured the trees? What do you think of dip- 

 ping the trees in a lime-sulphur wash as a sub- 

 stitute for fumigation?" Here are some of the 

 replies: 



OPINIONS OF NURSERYMEN 



"Do I consider fumigation of nursery stock 

 a necessity?" writes E. D. Smith, M.P., Winona, 

 Ont. "If it were not for the excessive cost of 

 an absolutely thorough inspection, I should say 

 the inspection, accompanied by the destruction 

 of all trees on which scales were found, would 

 be more satisfactory to the nurserymen. At 

 any rate, it would to me, as our losses under 

 that system would be nothing. The objection 

 to depending upon that system, however, en- 

 tirely, is that no inspection can be thorough, 

 no matter what the cost. Inspectors have told 

 me that no matter how often they may go over 

 a block of trees, whether it is fruit trees or 

 nursery stock, if scale is there at all they are 

 never sure they have found the last one, and 

 I can well believe this, as it is such an infinites- 

 imally small thing it may be so easily hidden. 

 The objection to fumigation lies chiefly in the 

 delay that it causes in the handling of the trees, 

 making it necessary that they shall be out of the 

 ground greater lengths of time than they would 

 be without it. An exhaustive experiment, con- 

 ducted on my grounds by W. N. Hutt, formerly 

 of the Dept. of Agric, Toronto, convinced me 

 that there is no damage done by fumigation. 

 Mr. Hutt was furnished by me with a large 

 quantity of nursery stock of almost every 

 variety of fruit trees and bushes. Some of 

 these were not fumigated at all. Some were 

 fumigated with the ordinary strength, some 

 with double strength, and some with treble 

 strength. Others were fumigated wet, as it 

 was supposed that the damage was caused by 

 fumigating the stock wet. These trees were 

 planted in a row on my grounds, and the growth 

 watched during the season. In the fall a certain 

 synopsis was made of the results, and it showed 

 that there were no greater losses in one lot 

 than in another. The trees that were fumigated 

 even vrith treble strength, and those that were 

 fumigated wet showed no greater percentage 

 of loss than those that were not fumigated at 

 all. Consequently, although I was a firm be- 

 liever up to that time that fumigation was 

 disastrous, I could not but conclude that fumi- 

 gation did no damage to the trees of itself. 

 Nevertheless, we have had very much greater 

 losses since fumigation started than before, and 

 I can only account for it on the assumption 

 that the trees were damaged by the greater 

 length of time they are obliged to be out of 

 the ground." 



"As to dipping the trees in lime and sulphur 

 •wash," continued Mr. Smith, "it would be out 

 of the question. The quantities that are handled 

 and the disagreeable nature of the operation 

 •would make it impossible. I have often thought 

 that something of that nature might be done, 

 dipping in whale-oil soap, for instance. I am 

 not sure whether this would damage the roots 

 or not. If it would not damage the roots, a 

 whole load of trees might in some mechanical 



manner be lowered into a large vat, and, after 

 becoming saturated, lifted and allowed to drain. 

 Experiments would first have to be made as 

 to whether these solutions would damage the 

 roots or not. If so, then this method would be 

 impracticable, and every tree would have to 

 be taken by the roots and dipped individually, 

 which would be too expensive and too nasty an 

 operation." 



C. W. F. Carpenter, Winona, Ont.: "The 

 fumigation of nursery stock is a decided benefit 

 to the trees in the eradication of the San Jose 

 Scale or other scales, I cannot say definitely 

 that it will kill every single scale, as I have not 

 personally made any tests along this line. I 

 do not think it necessary where there is not any 

 scale in a radius of several miles of nursery stock, 

 to have same fumigated, especially when in- 

 spectors have gone over the stock and pro- 

 noimced it free from scale. There is no doubt, 

 however, that fumigation is a thorough insecti- 

 cide. The only stock that fumigation will in- 

 jure are peaches and cherries, which in the last 

 few years, since fumigation has been in force, 

 have been injured from said procedure. It is 

 almost impossible, especially in the case of 

 sweet cherries, to get them fumigated in the 

 spring in a perfectly dormant condition, as the 

 buds of this stock swell very early. This is 

 where the danger lies in fumigation. If trees 

 are in a proper condition and perfectly dormant, 

 there is not the slightest injury done to them, 

 but a decided benefit, as it frees the tree from 

 insects. Dipping trees in sulphur solution is 

 almost out of the question from a nurseryman's 

 standpoint. It would be possible for the planter 

 to do this; but where we handle tens of thousands 

 of trees yearly it would be impossible." 



Joseph Tweedle, Fruitland, Ont.: "Fumi- 

 gation does pretty thorough work, but the 

 fumigated trees make a very feeble start into 

 growth. I planted fumigated peach trees last 

 spring, and they did not start to bud for 6 

 weeks to 3 months, although they were in an 

 excellent condition when planted. I pointed 

 this out to the nurseryman who paid me a 

 visit in midsummer and examined my trees. 

 He said he was very dissatisfied, as it was the 

 general complaint; and he thought with myself 

 that dipping with lime and sulphur is much 

 better for the health of the trees, as this treat- 

 ment has been so effectual in the orchard. It 

 would be a wise move if the Government would 

 legislate to make the change, or at least give 

 us an option to use either method we might 

 choose. I much prefer to use the lime and 

 sulphur as a substitute for fumigation, it being 

 just as effectual and much safer for the trees." 

 A. G. Hull & Son, St. Catharines, Ont. : "Fumi- 

 gation of nursery stock is a wise precaution. It 

 is effective when thoroughly done. No injury 

 is done to apple, pear or plum trees, but cherry, 

 peach and ornamentals are more or less injured 

 when so treated. There is a difference of opin- 

 ion, however, regarding the question. Some 

 planters prefer stock that has not been fumi- 

 gated. Dipping the trees in the lime-sulphur 

 wash would be the surest and safest method. 

 It would cover every doubt," 



Morris & Wellington, Fonthill, Ont. : " Dipping 

 trees in lime and sulphur wash would not be 

 practicable for large nurserymen, as the short 

 season for handling large quantities of stock 

 would not give them time to perform the work 

 thoroughly. Fumigating would, perhaps, injure 

 peaches and other stock with tender roots, if 

 applied full strength. To avoid this, we fumi- 

 gate such stock in our frost-proof cellars during 

 the winter, while the roots of the trees are heeled 

 in the soil In this way we have not noticed 

 any injurious effects from fumigating." 



Brown Brothers Company, Ltd., Browns' 

 Nurseries, Ont.; "There can be no doubt as to 



the necessity for fumigation where scale or 

 other pests actually exist; but there is a great 

 amount of work done in this line where there 

 was not even a suspicion of a scale. There is 

 no way of determining absolutely beforehand 

 whether or not the work is necessary. Fumi- 

 gation of stock coming from the States, which 

 has already been fumigated and is so certified 

 by certificate on the package or car, should be 

 prevented. Could not provision be made for 

 the acceptance of authentic foreign certificates 

 of fumigation? 



"Certain classes of stock are much more sus- 

 ceptible to injury by fumigation than others; 

 but it is difficult to see how the dose can be 

 adjusted to suit certain stocks. Dipping trees 

 in lime-sulphur wash seems to be an entirely 

 impractible process, especially where many 

 thousands of trees are handled. It would be 

 extremely disagreeable and dirty, on account 

 of the nature of the mixture, and it would be 

 difficult to procure men for such work, even if 

 it were practicable. The present process, aside 

 from possible damage to stock, is the most 

 thorough, effective and expeditious." 



WHAT FRUIT GROWERS SAY 



A. O. Telfer, Ilderton, Ont.: "Fumigation of 

 nursery stock should be certain death to all 

 insects. The lime-sulphur wash might be safer 

 but not as sure a remedy." 



W. H. MacNeil, Oakville, Ont.: "I am of the 

 opinion that dipping trees in the lime-sulphur 

 wash to kill insects would also kill the buds." 



Milton Backus, Chatham, Ont.: "For several 

 years I have imported young stock from New 

 Jersey, and its vitality has been badly injured 

 by fumigation. Coming from there it gets 

 fumigated twice. By the best American author- 

 ities the practice is considered injurious to 

 young stock in particular. Dipping the trees 

 in the lime-sulphur is preferable." 



C. M. Honsberger, Jordan Station, Ont.: 

 "Fumigation does not do all that is claimed for 

 it, except at the risk of killing the trees or 

 plants so treated. My opinion is that dipping 

 in lime and sulphur before the trees are pre- 

 pared for planting is preferable to fumigation " 



F. S. Wallbridge, Belleville, Ont.: "The fumi- 

 gation of nursery stock is more a question for 

 chemical experts than for fruit growers. Fumi- 

 gation can be, and sometimes is, overdone, the 

 stock being subjected to a longer fumigation, 

 with probably a greater quantity of fumigating 

 material than should be the case. There would 

 be no bad results from fumigation if it were 

 done carefully and properly, but the danger is 

 that it may not be attended to in that way. 

 Fortunately we are not troubled with the San 

 Jose Scale in this locality, and we do not know 

 what effect fumigation has upon the scale. 

 Dipping the trees in a lime and sulphur mixture 

 is, I believe, far preferable to fumigation. The 

 danger from the lime and sulphur is practically 

 nil, and it certainly has a cleansing effect upon 

 the trees. If the experts at the Experimental 

 Farm consider it ju,st as effective for the scale, 

 it should be adopted without hesitation in lieu 

 of the fumigation." 



Geo. E. Fisher, Burlington, Ont.: "Fumiga- 

 tion is more reliable for destroying insect life 

 than any other treatment. While it is not an 

 absolute necessity, except with the San Jose 

 Scale, it is always desirable if carefully con- 

 ducted. No animal life can resist an exposure 

 of 40 minutes in a gas-proof compartment 

 containing gas from one-quarter of a gramme 

 of cyanide of potash to each cubic foot enclose (i 

 at which strength it is used in fumigatiii',; 

 nursery stock. It is questionable, however, if 

 the gas has any effect upon eggs. The propor- 

 tions and quality of chemicals recommended 

 by the Dept. of Agric. will give satisfactory 



