August, ’20] 
CHILDS: CALYX WORM CONTROL 
333 
fast that only a very small percentage sticks. The remainder passes 
on and is wasted for the most part. When the air is quiet these 
particles will hover for a long time over a tree and gradually settle. 
Air currents destroy the plan of the system and applications made 
under such conditions can only result in disaster. 
In order to avoid windy conditions it was found necessary to dust 
very early in the mornings; a calm usually occurs in most sections of 
the valley during this period of the day. However with us during the 
spring months it is not uncommon for a wind of varying degree to 
occur continuously for several days at a time. Many times in the 
carrying out of the experimental work the dusting had to be postponed 
for more favorable weather. We are all familiar with the fact that 
successful applications of spray cannot be delayed to any great extent 
and at the same time accomplish results. Several of our growers have 
used the dusting method; for the most part their work has been done 
regardless of air movement. In 1918 the condition of the fruit in one 
of these orchards was checked up; a 33 per cent injury from the codling 
moth was found. None of the growers of the valley have depended 
upon the system during the past year. On account of the many 
handicaps and difficulties encountered I do not recommend the method 
to our growers except those located on steep hillsides and in sections 
where sufficient water for spraying is difficult to obtain. 
The results, however, that have been obtained in calyx worm con¬ 
trol have a very decided bearing on the results that can be expected 
with the spray gun when properly used. For this reason I will discuss 
some of the results that have been obtained in seasons past with both 
dust and liquid applications. These results are summarized on the 
accompanying chart. In 1917 the unsprayed check trees in an orchard 
which had been quite wormy for several seasons, developed an infesta¬ 
tion of 65.13 per cent. Of this infestation 31.68 per cent were side 
worms and 68.32 per cent were calyx worms. (Exp. 5 in table.) The 
variety used in this set of experiments was Arkansas Black. This ratio 
did not hold true in all varieties. In an orchard of Spitzenbergs this 
ratio was 66.96 per cent side worms and 33.04 per cent calyx worms. 
In a Newtown block this ratio was 61.54 per cent to 38.48 per cent side 
and calyx worms respectively. In the block of Arkansas Blacks two 
dust experiments were checked against two blocks of trees sprayed with 
twelve foot rods. In Experiments 1 and 3 an early September 
application was omitted resulting in a much more wormy condition 
than occurred in Experiments 2 and 4 (see table). These different 
experiments are cited to show, that regardless of this marked difference 
in worminess, the general relation of side and calyx worms remains 
fairly constant, though with the increase in total worminess the chances 
