THE GARDENERS' CHRONICLE OF AMERICA. 



57 



SPRAY EVERY YEAR FOR PERFECT FRUIT. 



Spraying is done by tlie average fruit grower for but 

 one purpose, — that of preventing injury to the fruit, 

 whereas there is a secondary reason for spraying, 

 which escapes ordinary observation. This second 

 reason is for the purpose of maintaining healthy fohage 

 on the trees, without wdiich the tree dies. Spraying 

 really has for its object the production of fruit which is 

 free from damage by fungi and insects, and for the 

 protection of the leaves from damage by the same 

 agencies that destroy the fruit. 



Healthy leaves on trees are of as much importance 

 as healthy roots. They are organs which are essential 

 to the life and fruitfulness of a tree, and are comi)ar- 

 able to the stomach and lungs of animals. The roots 

 do only half the work of nourishing a tree, and the 

 leaves perform the other half. The roots supply the 

 soil moisture with the mineral salts which are dissolved 

 in it, while the leaves gather the carbon and oxygen 

 which enter into the various compounds making up all 

 parts of the plant. 



To perform their functions i)niperly, leaves must be 

 healthy, and must be exposed to the sunlight, for if 

 they are not they will turn yellow and drop of¥. Leafy 

 plants which are grown in a dark place sicken and die, 

 because light is essential to the maintenance of their 

 vital functions. They are unable to digest, or to as- 

 similate the gases of the air and the juices which are 

 supplied by the roots, unless exposed to sunlight. 



If the leaf of a plant is examined closely, such as an 

 apple or plum leaf, or of an onion, lily, or any other 

 green plant, there will be found on the upper and 

 lower surfaces a thin skin which can Ije torn oil, leav- 

 ing a spongy, green substance. This spongy matter 

 gets its green color from a material called "chloro- 

 phyll," and it is upon this chlorophyll that the activity 

 of the leaf depends. Under the intUience of sunlight 

 it collects a gas from the air which is combined with 

 the moisture supplied by the roots and starch is made. 

 This is stored in the leaves temporarily in a form iden- 

 tical with commercial starch. 



But starch is insoluble in the sap of the plants or in 

 cold water, and is of little use to the plant while it 

 remains in that form. However, in the mystery of the 

 leaf, by an obscure process, the starch is changed into 

 another very common substance which is very soluble, 

 and which is nothing more than a form of sugar. As 

 soon as this change takes place the starch, which is, the 

 real food substance of the plant, can be transported to 

 the fruit, branches, leaves and nmls ami then liy nther 

 processes be converted into other substances. In this 

 way, then, the leaves of a tree act in essentially the same 

 manner as the stomach of an animal, for the reason 

 that it is here the food material wdiich gnes to supply 

 the various tissues is digested and made over into 

 substances which can be used. 



But leaves also act in a similar manner as the lungs 

 (jf an animal, that is they take in oxygen from the air 

 and give off a gas called "carbon dioxide." This is 

 exactly what is done by the lungs of an animal, but 

 this process goes on very slowly in the leaves. This 

 exchange of gases takes place through very minute 

 holes in the skin covering the leaves, and when these 

 holes become choked up, or the channels in the leaves 

 through which the gases and fluids ])ass, become 

 broken or in any manner intermitted, then the func- 

 tion of the leaf does not take place normally, and it 

 soon dies. 



This is what happens wdien leaves are badiv muti- 

 lated by insects or invaded by the threads of \ari'ius 



fungi. Spray materials frequentl}- damage the tender 

 tissues of leaves to such an extent that they cannot 

 l)roperly perform their function, with the result that 

 they drop. Everyone is familiar with this condition 

 who has ever tried spraying peach or plum trees with 

 strong bordeaux mixture. Then, too, most every one 

 who grows tree fruit knows how the leaves will fre- 

 quently fall from the trees about the time the fruit is 

 beginning to ripen, because of attacks of leaf destroy- 

 ing fungi. 



In this case the channels in the leaves through which 

 the sap circulates either becomes so plugged with the 

 fungous threads that there can be no passage to or 

 from the crude and elaborated sap, or else the food 

 material in the leaves is consumed by the fungous 

 parasite. 



This early defoliation of trees is of such a common 

 occurrence that many fruit growers have almost come 

 to take it as a matter of course, and fail to associate 

 with it anv ill c( Jiisecjuences. However, as soon as the 

 leaves are shed, the tree becomes dormant, and cannot 

 store up within its buds, branches and roots, the food 

 material on which it must depend for its early growth 

 the following year, and the development of its fruit 

 crop. 



A tree which dr()])S its foliage, even half its leaves, 

 before the fruit is gathered or before the arrival of the 

 first frost is more or less weakened, and is not in the 

 best of condition for the next year. Trees which are 

 well sprayed throughout the summer and on which 

 the foliage is maintained in healthy condition by spray- 

 ing, can not only ijroduce finer fruit, but make strong, 

 vigorous fruit buds as well for the next season's crop. 

 One of the things which goes a long way toward 

 having annual crops (.)f apples is the maintenance of 

 healthy foliage which will remain on the tree bright 

 and green until killed by frost. 



It is as much (if a crime to let the foliage on a tree 

 driip abnormally early through the agency of fungi 

 cir insects, as it is to [iroduce wormy or fungous in- 

 fested fruit. Keeping the trees healthy in foliage by 

 spraying is just as important as is the production of 

 perfect fruit. The tree is not only then able to make 

 nmre fruit buds for the next year, but it has the ojipor- 

 tunity to store up in its tissues food materials which 

 make it stronger and more vigorous and fruitful the 

 next year. 



The man who fails to spray his trees in years when 

 the frost destroys his crop is only half converted to the 

 xalue (if spraying, for he is allowing the foliage of his 

 trees tn ])ecome the prey of various pests and its effects 

 will surely be felt directly or indirectly the following 

 year. The secret of getting eighteen crops of apples 

 ill twenty years lies as much in maintaining healthy 

 fnliage (111 tlie trees as in any other orchard practice. 

 — Fruit Grozi'cr. 



The Service Bureau 

 National Association of Gardeners 



Is maintained for the purpose of providing opportunities for efficient 

 nnd ambitious men engaged in the profession of gardening. 

 This department of the Association is at the disposal of those who 

 may require the services of capable superintendents, gardeners or 

 assistant gardeners. Address 



M. C. EBEL, Sec'y, 



National Association of Gardeners, 



Madison, N. J. 



