NOTES ON PLANT PESTS.
Prepared by Section of Insect Pests, A. G. Ruggles, and by Section of Plant Diseases, E. C. Stakman, University Farm.
The first real spraying of the apple orchard should be given just as the center bud of the flower cluster begins to show pink. The material to use in the spraying compound is lime-sulphur (1 to 40) plus arsenate of lead, 1-1/2 pounds of the powder, or three pounds of the arsenate of paste to fifty gallons of the made-up lime-sulphur. If done properly this will get the scab of the apple, blossom blight or the brown rot in the plum, and is the most important spray for plum pocket. The arsenate of lead in the mixture will control the young of leaf eating insects and precocious plum curculios.
The second most important spraying of the year is given within a week after the blossoms fall, the same spraying compound being used. This spraying kills many of the germinating spores of such things as apple scab and also is the important spray for codling worm as well as for the plum curculio and for leaf eating insects.
Watch carefully for the hatching of plant lice eggs. The ideal time to spray for these is just after hatching, and before the young lice become hidden in the bud scales or in the curl of the leaves. The spraying material to use at this time is a sulphate of nicotine.
Plow the plum orchard as soon as possible in order to turn under mummied plums, which are responsible for much of the primary infection of brown rot.
Plowing the apple orchard early to turn under the old leaves is also essential in preventing scab spreading to the flower stalks.
Cultivate the vineyard in order to turn under the mummies. Practice clean cultivation from the very beginning in order to help control black rot and downy mildew. If the rot or mildew was very bad in the previous years, early spraying with the Bordeaux mixture 4-4-50 is very important.
Keep the radishes, cauliflowers, and cabbages covered with a poison spray from April 30 to May 20 to prevent the ravages of the cabbage maggot. This should be applied once a week in fair weather, and twice a week in rainy weather. The spray is made as follows: