SPRINGFIELD, N. J. 
109 
Dormant sprays are usually used for the control of the eggs 
of plant lice, spider mites and other stages of insects that might 
hibernate on the trees or shrubs. 
INSECTS INJURING THE ROOTS OF PLANTS 
The most common forms are various plant lice, wire worms, 
various kinds of white grubs, such as the Japanese bettle grubs, 
weevil grubs of several kinds and nematodes. Plant lice may 
sometimes be controlled by mulching with % to % inch of 
tobacco powder or by watering the plants with a nicotine solution 
at the strength used for spraying plant lice. Root infesting plant 
lice are often attended by ants; therefore, control of the ants 
will help in getting rid of the root aphis. 
BORING INSECTS 
There are many insects that bore on the inside of the trunk, 
stem, twigs or even the foliage of plants. Usually they cannot 
be reached with either a contact spray or a stomach poison 
spray. When they occur in woody plants and make a distinct 
opening to the outside through which the borings are pushed they 
may be destroyed by poking with a flexible twig or by poking a 
small rag dipped in free nicotine into the hole or by injecting a 
nicotine paste material into the hole. A second type of wood 
borers tunnel in the cambium layer of the bark or in the sap 
wood. They are usually not found until considerable damage has 
been done. Stimulating plant growth by watering and the use of 
fertilizers will help to prevent their occurrence as they usually 
attack trees that have been transplanted or that have been weak¬ 
ened from some other cause. 
Borers infesting herbacious plants such as the common stalk 
borer, the iris borer, etc., often pass the winter in the egg stage 
on the foliage of dead plants. The raking up and burning of 
these dead plant remains will help very much in keeping down 
infestations of these borers. 
RABBIT AND RODENT REPELLANT 
Sulphonated oil is a new remedy for the protection of fruit 
and shade trees from the ravages of rabbits, mice and other 
rodents, which often do much damage in winter. Trees sprayed 
or painted with the oil are entirely avoided by all rodents unless 
they become extremely hungry and if they do attack the trees 
they speedily die. 
The mixture is prepared by heating linseed oil until it is 
smoking hot—about 470 degrees Fahrenheit. The mixture should 
be set outdoors and flow'ers of sulphur added, one part to nine 
parts of oil by weight, making a 10 per cent solution. It is best 
to sift the sulphur slowly into the hot oil and stir. The mixture 
will become hotter until all the sulphur is dissolved. When it 
cools it will be ready for use; but if it is to be sprayed on the 
tree trunks, thinning with turpentine may be necessary to put it 
through the spray pump. 
BORDEAUX MIXTURE 
4 lbs. copper sulphate crystals 
4 lbs. storelime 
50 gallons water 
Plant Diseases of Ornamentals 
FUNGICIDES 
Satisfactory control measures for the diseases of ornamental 
plants are preventatives rather than cures. Control measures 
must, therefore, to be most effective, be initiated before the 
appearance of disease. When a plant is once infected there is 
often no cure, and the removal of such individuals and their 
destruction should be a general sanitary practice in all growing 
operations. 
Disinfecting and protective fungicides serve two distinct pur¬ 
poses. A disinfecting spray is used as a dormant and summer 
spray to destroy the spores of fungi which cause disease, and 
which may be lodged on the bark or about the buds of deciduous 
trees and shrubs. Lime-sulfur solution diluted 1-9 is the most 
commonly used dormant disinfecting spray. Some sprays and 
dusts prevent infection by depositing a protective coating poison¬ 
ous to fungous spores on the plant surfaces. Lime-sulfur 1-49. 
Bordeaux mixture, sulfur dusts and wettable sulfur sprays, are 
the most generally known and used protective sprays. 
