68 
F. & F. NURSERIES 
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 beetle 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 weakened from some other cause. 
Borers infesting herbaceous 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 REPELLENT 
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 flowers 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 preventives 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 purposes. 
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-sulphur 
solution diluted 1-9 is the most commonly used dormant disinfecting 
spray. Some sprays and dusts prevent infection by depositing a protec¬ 
tive coating poisonous to fungous spores on the plant surfaces. Lime- 
sulphur 1-49, Bordeaux mixture, sulphur dusts and wettable sulphur 
sprays are the most generally known and used protective sprays. 
