WISCONSIN HORTICULTURE 
167 
August, 1 1)19 
Efficiency of Common Insecticides 
(Continued from page 163) 
the powder to every 50 gallons ot 
water or Bordeaux mixture if the 
latter is used in disease control. 
This amount should cover about one 
acre. For codling moth and leaf 
feeding insects on fruit trees use 
one pound of t he powder or two 
pounds of the paste to 50 gallons of 
water. For “cabbage worms’’ and 
other chewing insects on cabbage 
plants use one pound to 50 gallons 
of water and add one pound of 
laundry soap to make it spread and 
stick to the foliage. 
Arsenite of Zinc: This material 
has come on to the market in recent 
years and next to Paris Green it 
seems to have a greater killing ef- 
ficiency than any of the other in- 
secticides given. However, it is 
somewhat variable in its action and 
more work is necessary to fully de 
termine its value. In our experi- 
ence it cannot be used with safety 
on fruit trees because of its ten- 
dency to burn or crimp the leaves. 
We have found it to be very effi- 
cient spray for potato bugs and 
have not noticed any injury to the 
foliage. It should be slightly 
cheaper per pound than arsenate 
of lead and would therfore make it 
a very desirable spray to use on 
potatoes and other plants with 
hardy foliage. 
How and When to Use: Arse- 
nite of zinc .sold mostly in the pow- 
dered form or in a paste form wheu 
combined with Bordeaux and 
known as zinc Bordeaux paste. For 
the Colorado potato beetle use 2 
pounds of arsenite of zinc powder 
to every 50 gallons of water or Bor- 
deaux mixture if the latter is used. 
Directions for using the zinc Bor- 
deaux paste are given on the pack- 
age. 
Calcium Arsenate : Calcium ar- 
senate is a material which has re- 
ceived some attention from time to 
time and the few early experiments 
in which it was used seemed to 
show that it was not a desirable 
spray because of its tendency to 
cause spray injury to tender plants. 
Investigations have also shown that 
although it contains a higher per 
cent of arsenic oxide than arsenate 
of lead still it does not have the 
corresponding efficiency. 
How and When to Use : Cal- 
cium arsenate may be used in the 
same proportions as arsenate of 
lead but in each case hydrated lime 
or unslaked lime should be added 
iu equal amounts to prevent burn- 
ing. When the lime is added 
it should be slaked in a small 
amount of water and poured into 
the spray tank before application. 
Calcium carbonate or air- slaked 
lime should not be used. For 
small gardens or garden plots 1 or 
2 ounces instead of pounds in a 
three gallon pail of water may be 
used. 
Garden Tractors 
We have had several inquiries 
about garden tractors but have 
been unable to get any first hand 
information. A writer in the 
Market Growers Journal for July 
1st writes in answer to a subscri- 
ber as follows : 
In the issue of May 15 I saw an ar- 
ticle in regard to garden tractors and 
am writing for further information. 
Do you consider them a practical ma- 
chine for garden work, price con- 
sidered? I have good ground for 
them to work in, a sandy soil. I 
would want to use one on Onions. 
Beans, Potatoes, Cabbage and Toma- 
toes. Can they be turned easily at 
the end of rows? What is about the 
Vife of one of them? They claim that 
the life of a large tractor is only two 
to three years, and if that is all the 
life of a garden tractor, it would be 
rather an expensive affair. — C. J. D.. 
Colorado. 
A significant incident has re- 
cently come to my attention in re- 
gard to the owner of the tractor 
of which I spoke in the Journal. 
An acquaintance of his, who 
bought a garden tractor last spring, 
has just sold it to Mr. Smith at i 
considerable reduction in price, 
after using it but very little. The 
former told me lately that the only 
good he could find in this tractor 
was that it would turn a grind- 
stone very nicely. Here are two 
men, gardening on much the same 
kind of land, and partly for the 
same market, who have widely 
different views with respect to 
this machine. The reasons for 
this situation will help answer 
some of your questions. 
Air. Smith does much of his work 
himself, or his own sons do it. He 
is a powerfully built man who is 
not worried by the labor of hand- 
ling a heavy machine. His whole 
family have considerable mechani 
cal ability; they have three or foil-' 
other gasoline engines around the 
place, and therefore are able to 
keep the tractor in good repair, 
spotting troubles before they be- 
come serious. The farm is rather 
stony, and this necessitates extreme 
care on the part of the operator, 
and, in the case of delicate seed- 
ings or breaking of the crust by 
means of hand implements, espec- 
ially when crops are small. 
Jones, on the other hand, grows 
crops on such a scale, and in addi- 
tion is involved in dairying to such 
an extent that his work is done en- 
tirely by employees. Tie tells me 
that he has known mm to stay 
away from work when he told them 
they would have to use the tractor 
next day. Men on his place knew 
too little about gasoline engines to 
keep the machine in order, and 
cared too little about the crops 
(Continued on page 176) 
