The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1904-03-30
Professor C. w. Woodwork
Tells How to Deal Death
to the Destroying Insect
FAVORS PARIS GREEN
Advises 0rchardiStS of Cali
fOrnia of Time to Apply
Deadly Arsenite to Trees
Berkeley Office San Francisco Call,
214s Center Street, March 2s.

-l4e AEHlEI OAltEAs 01dICn
Full directions for destroying the
cooling moth, the enemy of the apple
! trees of California, are contained in a
bulletin issued at the University of
/ California to-day by Professor c. W.
] Woodwork Of the chronological de-
partment Of the College Of Agriculture.
/ Professor Woodwork directed the war
with sprays against the tenacious lit
/ tie insect all of last season in the Pa
! jaro Valley and is therefore qualified
to tell the orchardists of the State the
way out OF loss and ruin.
The campaign demonstrated to Pro-
| fessor Woodwork one thing and that is
! that arsenical sprays are the only real
remedy for the codling moth. There
/ fore he lays considerable stress on this
point in his bulletin. OF all the many
suggestions that have been made for
4 controlling the insect, none but the
arsenical sprays have yielded any re-
suits worth mentioning. The others
have been tried and found wanting.
His advice 10 the orchardist is that he
not attempt TO experiment with any
thing else, unless il be on a small scale.
Paris green, Professor Woodwork
finds is the most effective arsenite in
dealing with the moth. 1t is true that
there are some places where paris
green is likely to injure the tree, an
injury that might result in greater loss
than any that the moth might inf1ict,
and even affect the crop Of the follow
/ ing year But in most Of these regions
the danger Of injury can be avoided by
the addition Of lime. On this point Pro-
: fessOr Woodwork says:
The amount added to the spraying
mixture should be the greater the more
susceptible the trees are 10 injury. The
regions in which the trees are most LA
bic TO injury are those where dews and
fOgs are most prevalent. Five or ten
times as much lime as paris green is
the proportion recommended in the
most moist regions. The amount Of
paris green commonly used and found
very satisfactory is one pound for 100
gallons.
In the lower portion of the Pajaro
/ Valley the danger of poisoning the To-
/ liage is so great, even when the maxi
mum Of lime is added that we cannot
( recommend the use Of paris green at
I all, but suggest the substitution of the
1 lime or lead arsenite."
When and how TO spray are questions
which Professor Woodwork says must
/ be answered by the orchardist himself
/ California is Of such diversified climate
that no precise rule will obtain in any
two parts Of the State at the same
time. Every part requires a different
kind Of campaign, differently timed
and differently executed. Here is what
/ Professor Woodwork says:
All the spraying operations should be made
I o depend upon data determined for each
region as 70 certain essential facts in regard
: the trees These facts not difficult TO OBJ
I tain and there Is reason why any grow er
I OF apples might not make the necessary OBJ
I serFations 70 determine the proper time for
Z these spraying operations
Under the worst conditions there will be
/ the necessity Of making three campaigns each
season against the insect In many regions
one or two OF these might be omitted. How
much may be omitted VIII have TO be de-
Z termined by the conditions and the locality.
The first campaign is intended for the poison
ine OF the cslyx cup OF the apple and re-
4 Qrires spraying from above and more than
I one application. X the blossoms are not uni
I form IN time Of opening. The second cam
/ psign Is timed by the appearance Of the moth
/ IN the spring ard requires method of spray
/ ing different from that OF the first cam
! paign. the idea being to cover every part
! q the leaf and fruit with poison. The third
]
I times Of beginning and closing this attack
/ are determined by the production of pupae
! from which moths viii hatch that season and
I lay eggs for another brood of worms. The
danger 10 foliage by poison is greatest during
I this period
The aid Of orchardists of the State is
solicited by the College Of Agriculture
in the study Of the moth, by making
/ observations in their own localities OF
the facts upon which the timing of the
/ applications in each of these cam
paigns must be based.