THE MON^TIILY BULLETIN". 371 



ORCHARD SANITATION. 



By n. S. Fawcett, Whittier, Cal. 



The timeworn saying that "prevention is better than cure" holds true 

 with as great force in the control of diseases of trees as it does in the 

 control of diseases in the human species. It is also true that prevention 

 is easier and cheaper than cure. ]Much extra labor and many thousands 

 of dollars would be saved annnally if greater care were exercised at all 

 stages of the tree's life from the time it is in the seed and the bud till it 

 is beyond the age of usefulness to the orchardist. There probably 

 always will be used for effective remedies for attacks of fungi in trees 

 just as in case of attacks of bacteria in man. Some tree diseases come 

 to us at first unawares, and measures for their control are necessarily 

 delayed until after the trees are suffering. It will not be the purpose 

 of this paper, however, to treat of remedies and cures, but to emphasize 

 strongly the necessity for using preventive measures when possible ; to 

 emphasize the value of getting in on the ground liefore the enemy 

 {irrives, or to put up barriers to develop such vigorous resistance that 

 the fungi will have little chance to get in their work. 



The Fungi. 



The fungi are not mysterious kinds of organisms generated out of 

 nothing, but they are real live plants growing from spores just as weeds 

 or trees grow from seeds, each kind of fungus producing its special kind 

 of spore, just as each kind of tree produces its special kind of seed. The 

 spores rise to mold-like growths, many of them too small to be seen, even 

 under the hand lens. 



A Fight Between Tree and Fungus. 



"When a parasitic fungus attacks a tree there is, in a sense, a fight 

 between two kinds of plants, the fungus-plant and the tree-plant. We 

 have on one hand the resistance of the self-sustaining tree, which when 

 healthy and vigorous is often very great, and on the other hand the 

 attack of the dependent fungus. Conditions surrounding both the tree 

 and the fungus have much to do with whether the tree can resist success- 

 fully or whether the parasite becomes established in sufficient amount or 

 numbers to materially injure the tree. This explains why fungus diseases 

 vary so in severity during different seasons, and why, at times, a disease 

 may be attributed entirely to weather conditions, when it is due in reality 

 to the attack of a fungus which has been encouraged in its growth by this 

 particular kind of weather. 



In order not to give a wrong impression in regard to these fungi it may 

 be mentioned here that there are, living on the dead and even on the 

 outer surface of living parts of trees above or below the ground, many 

 kinds of fungi that the tree does not have to fight that are not parasites, 

 that are never aggressive and possibly distinctly useful. As soon as any 

 part of the tree dies or is killed, as by frost or dry winds or insect attack, 

 these harmless fungi grow into the dead cells and live there. The pres- 



