. The more important fruit tree diseases of Ontario [microform]. Fruit; Pulvérisation et poudrage en agriculture; Spraying and dusting in agriculture; Fruits; Exploitations agricoles. 24 inner or central portion have begun to show the disease. If the centre of the tree looks healthy but the outer branches because of a reddish-yellow colour look dis- eased, it will nearly always be found that such trees are not affected by Little Peach or Yellows, but are suffering from lack of nourishment. Care must of course be taken both with Yellows and Little Peach not to confuse the foliage symptoms of th
. The more important fruit tree diseases of Ontario [microform]. Fruit; Pulvérisation et poudrage en agriculture; Spraying and dusting in agriculture; Fruits; Exploitations agricoles. 24 inner or central portion have begun to show the disease. If the centre of the tree looks healthy but the outer branches because of a reddish-yellow colour look dis- eased, it will nearly always be found that such trees are not affected by Little Peach or Yellows, but are suffering from lack of nourishment. Care must of course be taken both with Yellows and Little Peach not to confuse the foliage symptoms of these diseases with those caused by winter injury or by borers at the base of tree or by cankers on a branch or elsewhere. A little study and experience will soon enable a person to recognize injuries from these causes. It is also worth remem- bering that the foliage on the Crawford type of trees differs from that on the Elberta, and the latter again from that on the Smock or Triumph or St. John; so that to study Yellows and Little Peach one should first familiarize himself with the different kiiids of foliage to be found on the different varieties. This is especi- ally important as the amount of curling and clustering due to the diseases depends largely upon the sort of leaf characteristic of the particular tree Leaves from Little Peach tree, showing the character- letic flattening and curling. (Original.) li Cause. The cause of Yellows or of Little Peach has not been discovered. Tliere are, of course, several theories, but none are satisfactory. No organism, whether bacterial or fungus, so far as the microscope or as cultures are able to reveal it is present. It has been shown both in our own experiments £ 1 in those of several investi- gators in the United States, that the disease can be produced in hcdlthy trees by budding them witli buds from diseased trees. We have done this in many eases, both on large and small trees, and in the majority of instances, th
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