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tosh only. The owner gave the entire orchard an oil spray when the buds were beginning to open. In this orchard, leafhoppers were very plentiful on the dusted plots so these plots were given an application of nicotine dust on June 2.
Prepink treatment (McIntosh only).....May 1 *Pink treatment.
May 7-8 *Calyx treatment.
Plots. The Platt orchard in Milford was divided into seven plots as shown in Table I. The first three rows (A, B and C) were sprayed; the next three (D, E and F) were dusted with 90-10 sulphur-arsenate dust.' The north half of rows G, H and I was treated with green copper dust, while the south half was treated with blue copper dust. The north half of rows J, K and L was treated as follows: prepink, pink and calyx, with spray; first and second after calyx, with 90-10 dust; third after calyx, with spray (combination No. II). The south half of the same rows was treated as follows: prepink and pink, sprayed; calyx and three other applications were of 90-10 dust (combination No. I). Rows M and N were left untreated for a check against the treated plots.
Plot 1 Plot 2 Plot 3 Plot 4 Plot 5 Plot 6 Plot 7
GHI GHI JKL JKL 90–10 Green Blue
McIntosh Prepink Spray dust
copper copper Spray SprayCheck variety dust dust
treated Pink Spray Dust Dust Dust Spray Spray Check All varie
All varieCalyx Spray Dust Dust Dust Spray dust Check ties 1st after
All variecalyx Spray Dust Dust Dust dust dust Check ties 2d after
All varie. calyx Spray Dust Dust Dust dust dust Check
ties 3d after
All variecalyx Spray Dust Dust Dust Spray dust Check ties
Plot 4-Blue copper dust Plot 2–90–10 sulphur-arsenate dust Plot 5-Combination Plot No. 2 Plot 3—Green copper dust
Plot 6—Combination Plot No. 1
Plot 7—Not treated-checks.
Nicotine in liquid spray.
DISCUSSION OF RESULTS. The sprayed plot gave the highest percentage of good fruit and the 90-10 dust plot came next. The copper dusts were not so good as the 90-10 sulphur-arsenate dust in control of scab. Neither of the combination treatments were as efficient as the spray, the sulphur or the green copper dusts, combination No. 2 being on a par with the poorest of the copper dusts. The plots receiving the combination treatments were at the lower edge of the orchard just east of a woodlot and the trees were in a copper dust plot last year where there was much scab, which may possibly account for the large amount of scab present this season.
RESULTS OF TREATMENTS ON BALDWIN.
9.65 Red bug.
2.2 Codling moth.. .01 Curculio.
.69 Other chewing
insects.... 1.7 Scab. Sooty blotch..
90-10 Green Blue Combina- CombinaSulphur- Copper Copper tion 1 tion 2 arsenate Dust Dust South North Dust
Check 87,2 86.5 86.5 79.0 85.5 No fruit 8.2 8.5 6.03 15.4 8.1 No fruit
.49 .2 .44 .6 1.42 No fruit
.52 .68 1.88 1.53 .35 No fruit 1.1 1.71 .89 1.47 2.2 No fruit
DISCUSSION OF RESULTS. There is very little difference in any of the plots of this variety. Combination plot number one was lower in the percentage of good fruit than the other plots; this was caused by a higher percentage of injury by aphids. The Baldwin trees in the check rows bore no fruit.
DISCUSSION OF RESULTS. In the Greening plots the sulphur-arsenate dust was a little better than the liquid spray. The copper dusts averaged a little more good fruit than the plots receiving a combination treatment. In the check plot the fruit was badly deformed by red bugs and aphids and most of this injury was scored as red bug work, but a good share.of it was undoubtedly caused by aphids; probably much more than the figures show. The variation in amount and control of scab was so small between the different treatments that a choice can hardly be made as can easily be done on the McIntosh.
DISCUSSION OF RESULTS. The Gravenstein trees are located on only one side of the orchard: therefore there were none in the green copper plot nor in the combination plot number two. The sprayed plot gave the lowest percentage of good fruit because the aphis injury was high on the fruit of this plot. Between the other three treatments there is very little choice, as they produced about the same amount of good fruit. In amount of scab, the sprayed plot was a little lower than the others, the highest percentage except for the check being in the blue copper dust plot. The blue copper dust and combination No. 1 plots showed a small percentage of sooty blotch and fruit speck.
MOUNT CARMEL ORCHARD. The old orchard at the Experiment Station Farm was divided into two plots. The first application in this orchard was the calyx treatment followed by three others. As there were no varieties in this orchard that were very susceptible to scab, we felt that the prepink and pink treatments could be omitted. Treatments
Dates of Applications
May 29 1st after calyx... Spray
June 13 90-10 2d after calyx.... Dust
July 9 90-10 3d after calyx.... Dust
August 7 The spray applications in this orchard were applied with an Arlington X. L. Sprayer, using two lines of hose with two nozzles at each rod. The duster was the same as used in the other orchard.
The applications of dust in both orchards were usually put on either in late afternoon or in morning before dew had dried or wind had begun to blow.
The check trees bore no fruit so no data was obtained.
MOUNT CARMEL ORCHARD,
Plot 1 16 trees 81.1 11.6
.56 5.27 1.66
Plot 2 4 trees 67.4 22.1
.16 1.02 8.17 3.5
DISCUSSION OF RESULTS. Plot 1 having first two treatments of liquid spray gave better control of all pests and therefore produced a higher percentage of perfect fruit.
RESULTS OF TREATMENTS ON GREENING.
Plot 2 6 trees
7 trees Good...
20.72 Red bug.
.14 Codling moth.
22.65 Other chewing insects. 2.78
2.84 Sooty blotch.
.01 Cedar rust.
DISCUSSION OF RESULTS. As in the Balwin plot in this orchard, the treatment on Plot 1 gave a higher percentage of good fruit than Plot 2. The percentage of aphid and curculio injury was much higher on this variety than on the Baldwin. Scab injury is also a little more evident.
SUMMARY. On the McIntosh, chiefly due to scab control, the liquid spray was 10 to 30 per cent. better than any of the other treatments, with 90-10 sulphur-arsenate dust a close second. The application of nicotine in the spray gave very good control of leafhoppers but the one application of nicotine dust gave in most cases better control of aphis than did the three applications of nicotine spray. This is shown by the fact that in every case where dust gave more perfect fruit than spray, the difference was due to aphis control.
On Baldwin, Greening and Gravenstein, aphids were the controlling factor in the production of perfect fruit. Where aphids were controlled by the treatment or were absent for some other reason, the per cent. of perfect fruit was correspondingly high and vice versa, a high per cent. of aphids lowered the per cent of perfect fruit. Other insects were controlled about equally well by all the treatments and due to the dryness of the season after June 1, fungi did not develop sufficiently to be important.
At the Mount Carmel orchard, the combination plot (having the calyx and the first treatment after the calyx with liquid spray) was the best on both Baldwin and Greening. Here as in the other orchard aphids were responsible for the largest amount of injury. Curculio ranks next in amount of injury in this orchard.