SCIENCE AND INDUSTRY. 
DUSTING VERSUS SPRAYING. 
The conclusions arrived at by the Virginia Agricultural Experiments 
Station regarding the relative efficiency of dusting as compared with | 
spraying are that neither in the case of apples nor peaches can dusting 
be regarded as giving a satisfactory general control. Recent experi- 
ments demonstrated that dusting, as compared with spraying, saves 
time and labour, especially where rough ground hampers the use of the 
heavier liquid outfits, but it has several limitations in practice in the 
ease of both peaches and apples. The following formule were used 
in dusting experiments (the parts being by weight) :—For peaches, sul- 
phur and lead arsenate 90-10, and sulphur, filler and lead arsenate 
50-40-10; for apples, a Bordeaux dusting mixture and an 80-10-10 mix- 
ture of sulphur, filler and lead arsenate. In peach orchards both the 
dusting mixtures produced a satisfactory control of scab (Cladosporium 
carpophilum), and probably curculio (Conotrachelus nenuphar), but. 
were of only slight value in the control of brown rot (Sclerotinia 
cinerea); consequently though they may be used for the first two 
summer applications, they cannot be relied on for the third or sub- 
sequent ones. In apple orchards both mixtures produced a satisfactory 
control of the codlin moth (Cydia pomonella), and the Bordeaux dust 
gave excellent results against blotch (Phyllosticta solitaria) and frog- 
eye (Sphaeropsis malorum) ; but they were little better than no treat- 
ment at all against bitter rot (Glomerella cingulata). As a result it 
would seem that neither in the case of apples nor peaches can dusting 
be regarded as giving a satisfactory general control; and as its use 
must therefore necessitate duplications of equipment, the best results 
will probably come from the methods and materials the value of which 
has already been proved. ; : 
A SUBSTITUTE FOR NICOTINE. 
A decoction of the stems and leaves of the tomato plant, especially 
if prepared with the household washing lye made with wood ash, is a 
very potent insecticide that may be diluted with water and used for 
spraying in the same way as nicotine. The active principle in the 
tomato stem is more injurious than that in tobacco leaf. The leaves 
of Digitalis grandiflora yield digitalin, which is as powerful as nicotine 
and serves admirably against the beet aphis (Aphis rumicis), the hop 
aphis (Phorodon humuli), fruit tree Aphids (Haltica ampelophaga, &c.) 
It is in June and July, when the plant is in flower, that the leaves are 
richest in alkaloid. To prepare the decoction, 30 Ibs. of stems, with 
the leaves, are boiled for 30 minutes in 20 gallons of water. The 
solution must be stored in labelled containers, as it is a violent poison, 
and it is diluted for use with an equal part of water. It is less liable 
to scorch than nicotine. Petroleum; at the rate of 1 part by weight per 
100 parts of spray solution, is another substitute for nicotine. The 
following is a tested formula :—Petroleum, 5 lbs.; panama bark, 1 lh.; 
water, 8 gallons. The bark is crushed and: boiled in the water until 
about 24 gallons of liquid is obtained; this is strained through a fine 
cloth and the petroleum is added by degrees with constant beating until» 
a perfect emulsion results. This is diluted with 50 gallons of water.— 
Journal d’Agriculture, Pratique, Vol. XXXTV., No. 27.) 
708 
