166 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
[ August 24, 1893. 
2, Cereal crops.—Corn mildew (Puccinia graminis), about which 
we know very little more than Felice Fontana published in the 
year 1767, and certainly no more than resulted from the movement 
set on foot by Sir Joseph Banks in 1804, the harvest that year 
being alarmingly blighted, and given in pamphlet, with capital 
illustrations, by M. F. Bauer. Without setting the Berberry 
theory aside, we may just look the simple fact in the face that 
“ rust ” always appears conspicuously on the blades of cereals 
towards the end of May or early in June, and in localities where 
there are no Berberry bushes for miles around. Spray the cereal 
crops, especially Wheat, the end of April or early in Mav in the 
south, later in the north, and repeat in a fortnight or three weeks. 
Remember that the “ rust ” attacks the “ grass,” and that is fosterer 
of the grain. 
3, Potato Crops.—Spray these, each row on both sides, up one 
side and down the other, the first week in July, again the third 
week in July, and a third time the second week in August. Early 
varieties left for seed will only require one, second early two, and 
late crops three dressings. 
Arsenate of copper, called Scheele’s green, after its discoverer, 
a celebrated chemist, “his own instructor” at Upsal in 1773, 
attained some repute as an insecticide on the Continent long before 
Paris green, alias emerald green. Schweinforth green was employed 
in America, but did not become popular on account of its poisonous 
nature. It was first used as a destroyer of black fly on Beans, the 
Bean aphis (Aphis rumici.s) being “ hard ” to kill, and became 
famous in America through being found effectual in saving the 
crop of Potatoes from the Potato or Colorado Beetle (Doryphora 
decemlineata). Then it came into use as a remedy against the 
canker worm, Codlin moth, and other insects destructive to fruit 
trees in America, and during the past five years in this country 
against larvje eating the foliage and blossom of fruit trees. All 
about Paris green as a remedy for caterpillar infections will be 
found in the last ten volumes of the Journal of Horticulture. 
There is one thing about Paris green that I cannot understand— 
namely, a coat of it on foliage or growths will not kill sucking 
insects—aphides, chermes, and red spider ; why house flies have to 
imbibe very little of the stuff (arsenic) smeared on “ fly papers ” 
before death ensues. Of course aphides and chermes are fixed, or 
provided with a skin that throws off the mixture intended for their 
destruction ; the fact being that the Paris green mixture never is 
interposed between their suckers and the epidermis—or is their 
immunity due to their never being reached by the spray ? Spray 
upwards for to reach aphides on the under sides of the leaves, and 
what happens then ? The Paris green mixture kills red spider, the 
Ivy and Gooseberry acari (Bryobia speciosa), gall mites also, only 
get it on the buds before they enter them, or on the leaves in 
advance of their becoming snug in the galls. 
It is not, however, about mixtures that contain a little of 
everything in the hope of killing something, but of Paris green 
as a combined fungicide and insecticide that I desire to draw 
attention. 
Orchardists in America and in this country have found that 
where Paris green has been used for the prevention and destruction 
of insects that the scab fungus (Cladosporium dentriticum) has not 
plagued Apples and Pears. In Paris green we have copper, 32-11 
per cent., for funguses, and arsenic, 28-56 per cent., with carbon, 
6-09 per cent., for insects or their larvae. Here we have all that is 
required to kill every parasite preying on crops above ground. 
That is the thing—spray our cereal crops with Paris green, 1 lb. of 
the paste to 200 gallons of water, adding enough lime to make it 
correspond to skim milk, at the latest time it may be used in May 
with the Strawsonizer. Turnips can be done the same way, and the 
“ fly ” will not eat more than one meal afterwards. Later applica¬ 
tions can be made with the knapsack pump Eclair, which will serve 
for all garden and allotment requirements. The lime must be fresh 
slaked, and when cool added to the Paris green mixture slowly 
through a hair sieve, stirring the mixture whilst the limewash is 
being added. The object of the lime is twofold. 1, To admit of 
the better application of the mixture ; 2, cause the mixture to 
adhere better and longer to the plants. Instead of the lime 4 lbs. 
of flour may be added to the mixture to retain the poison on the 
foliage, but it is not equal to the lime, which serves other useful 
purposes, the chief being absolute safety to the foliage from the 
copper of the arsenite—Paris green—and it suffices if the Paris 
green mixture has enough lime stirred in to render it slightly 
milky. Care must be taken not to use it over vegetable crops that 
will be required for table before the parts dressed have been 
allowed time to be washed clean by rains, and the “ paste ” only 
should be employed for the mixture, dry Paris green being not 
only difficult to mix but dangerous to handle. 
Experiments in the treatment of Apple scab were carried on by 
Prof. E. S. Goff with Paris green mixture in 1891,and though several 
other fungicides and insecticides were tried it proved “ more efficient 
in preventing scab and more effective against insects than any of the 
other preparations used singly or combined.” This is good news 
—too good almost—only it is confirmed by all who have used Paris 
green mixture in two or three consecutive years. Spraying, there¬ 
fore, is a paying concern, for it is better to prevent than to provide 
a cure for fungal and insect plagues. Fruit trees are beset by 
other fungoid growths besides scab on Apples and cracking in 
Pears. Mildew often attacks Apple blossom and its young leaves, 
the fungus (Oidium farinosa) preventing the young fruit swelling 
and crippling the growths. When a crop of fruit appears certain 
caterpillars emerge—not borne on the wings of east winds—from 
the eggs. The Codlin moth deposits its eggs at or near the eye of 
Apples and Pears before they turn down, and many other depre¬ 
dators commence their attacks as soon as the buds, foliage, blossoms, 
and fruit are sufficiently advanced fox their food. The duty of every 
cultivator is to place a barrier between the spoilers and the object 
aimed at. Paris green paste, 1 lb. to 320 gallons of water, is gene¬ 
rally strong enough to use over Apple trees just after the petals 
fall, as the foliage is then tenderer than that of Pear trees. Cob Nats 
and Filberts, 1 lb. of Paris green to 265 gallons of water, sufficing 
for the latter while the foliage is young. Plum and Damson trees. 
Currant and Gooseberry bushes bear the mixture full strength, 
Paris green 1 lb. to 200 gallons of water, with sufficient fresh made 
limewash added to give it a slightly milky appearance, from the 
first, and all the foliage after it is fully developed. At the strength 
last named it should be sprayed on trees liable to fungoid or 
insectal parasites by the time the buds commence swelling in 
spring, say at the end of March, earlier or later by a week according 
to the season, and it ought not to be used after the flowers expand, 
on account of the bees, as well as being dangerous to the fructi¬ 
fying organs. This is a precautionary measure, but not the least 
important of the series. The second spraying should take place 
directly the fruit is set and commences to swell, say the first or 
second week in June for Apples, but be guided by the condition of 
the trees and the infestation, for in case of a severe and early 
attack of caterpillars it may be desirable to spray the trees just 
before the flowers open, otherwise the pests devour, the flowers— 
everything, and repeat the spraying directly the petals have fallen. 
This will only be required in exceptional years of caterpillar 
infections. Usually four sprayings are sufficient—that is, the two 
before mentioned—1, at the end of March ; 2, early in J une, and 
a third a fortnight after the second, with a final one the second 
week in July. The latter spray may interfere with the early 
Apples and Pears, therefore cultivators must exercise their judg¬ 
ment and discretion, for it must be understood that no fruit treated 
with an arsenical or copper preparation is safe to eat until it has 
been washed by rain. 
Raspberries are the most susceptible of damage from copper or 
arsenite mixtures. Paris green mixture must not be used on them 
at a greater strength than advised for the tender foliage of the 
Apple tree. They have many enemies, which may be accounted 
for from the fact that the latter are allowed to have their “ own 
sweet will ” on Raspberry plants. The “ minim ” Bordeaux mix¬ 
ture may be employed safely against fungal pests, which are not 
particularly troublesome in this country ; but foliage biting and 
eating creatures are best destroyed by Paris green mixture not 
stronger than for Apples, and not applying it later than the full- 
sized flower buds appear. 
Strawberry plants are sometimes plagued by blight caused by 
a fungus (Oidium Balsami, a stage only in the development of 
some Erysiphe). The plants subject to the attacks of the parasite 
may be sprayed with the “minim” Bordeaux mixture just before 
or when the flowers show colour, and repeat directly the fruits are 
set ; but it is rare that more than one treatment is necessary. If 
Paris green mixture is used it must not be stronger than advised 
for Apples trees, and not be applied later than the first “ peep ” of 
white blossom in the trusses.—G. Abbey. 
THE VALUE OF TREES. 
Though it looks as if Brother Jonathan threatened to take 
possession ultimately of these happy islands with his corn, his beef, 
his millionaires, his redeemed Irish patriots, and his “notions” 
generally, it is scarcely likely that we shall ever introduce the 
American festival “ Arbor Day ” into the British calendar. The 
four national holidays in the United States are, “ The Glorious 
Fourth of July,” “Washington’s Birthday,” “ Decoration Day,” 
and “ Arbor Day.” “ Decoration Day ” is that consecrated to the 
embellishing of the graves of those who fell on both sides during 
the Civil War of 1861-65; “Arbor Day” is that on which old 
and young go out in parties and plant whole districts of barren 
public land with infant timber. In our own colonies similar con¬ 
ditions have suggested the adoption of so reasonable a custom, and 
