Page images
PDF
EPUB

than N1 and the net return per acre after deducting the cost of the fertilizer was $10.87 less for the fish plots than for the basal ration plots. Since the favorable results of the first two years are contradicted by the third year's results it would seem best to delay a decision until after further tests. At least ve can say that the fish ration compared very favorably with the basal and it was superior during two of the three years.

4. Can one half of the nitrogen be supplied in tankage? The answer is obtained by comparing the records of plots N7 with N1 during the three years. The average annual yield per acre of the N7 plots was 1,543 as compared with 1,520 for the N1 plots. In quality N7 was rated "good" in 1922 as compared with "excellent" for the N1 plots. The sorting records of 1923 show a higher percentage of light wrappers and seconds, a smaller percentage of fillers and brokes and a better fire-holding capacity on the N7 tobacco than the N1 plots. The situation is just reversed in 1924 when the average price per pound for the tankage tobacco was 2.2 cents less than Ni tobacco and the net return per acre was $35.55 less than where the basal ration was used. Here again, the results of the three years are contradictory and final decision must be reserved until after further trials have been made. The case does not seem quite as favorable for tankage, however, as for the substitution of fish.

PHOSPHORIC ACID SERIES. This series was begun in 1922 with the object of determining how much phosphoric acid should be used on tobacco. There is considerable difference of opinion on this point among tobacco growers. The only experiments dealing with this point on Connecticut Valley tobacco are those recorded by Jenkins which were conducted in co-operation with the United States Department of Agriculture.* In experiments on shade tobacco they found that by increasing the acre application of phosphoric acid from 210 to 310 pounds, the yield was increased by 25 pounds when precipitated bone was used, 55 pounds with double superphosphate and 88 pounds with acid phosphate. The burn and quality was good on all but best where precipitated bone was used to supply the extra hundred pounds of phosphoric acid. In another test, on broadleaf, they increased the phosphoric acid from 176 to 276 pounds by addition on successive plots of (1) acid phosphate (2) Thomas slag (3) double superphosphate and (4) precipitated bone. The addition of acid phosphate did not increase the yield, slag increased it by 108 lbs. per acre, double superphosphate by 144 lbs. and precipitated bone by 408 lbs. The burn was freer on the plots without added phosphoric acid but the leaf grown on added double super

* Jenkins, E. H., Studies on the tobacco crop of Connecticut. Conn. Agric. Expt. Station, Bulletin 180:28-30. 1914.

phosphate and on precipitated bone had better quality than the others. From these data one would expect that there would be a distinct advantage in raising the amount of phosphoric acid to about 300 lbs. per acre.

At the Windsor station during 1922, '23 and '24 four plots in triplicate received varying amounts of phosphoric acid according to the following formulas. The amount of ammonia and potash was the same in all. The plots were on the same field as the nitrogen series during these years and all treatment throughout the season after the application of the fertilizer was the same for all plots.

Plot Pl. BASAL RATION 225 LBS. P,05. SAME AS N1.
Plot P2. BASAL RATION BUT WITHOUT ACID PHOSPHATE OR PRECIPI-

TATED BONE. 75 LBS. P,0%.
Carrier

Plant nutrients per acre
Name
Pounds per acre

NH,
P:05

K:0 Cottonseed meal....

2,100

172.2 60.9 31.5 Castor pomace.

800

54.4
14.1

8.0 Vitrate of soda.

200

37.6 Sulf. potash. 400

200.0 Total.

3,500

264.2 75.0 239.5

Plot P3. 190.5 Lbs. P,O; IN PRECIPITATED BONE, COTTONSEED MEAL

AND CASTOR POMACE. Cottonseed meal...

2,100

172.2 60.9 31.5 Castor pomace.

800
54.1 14.1

8.0 Vitrate of soda.

37.6 Precipitated bone.

300

115.5 Sulfate potash. 400

200.0 Total.

3,800

264.2 190.5 239.5

200

Plot P4. 306 Lbs. P,O; IN PRECIPITATED BONE, COTTONSEED MEAL

AND CASTOR POMACE. Cottonseed meal....

2,100

172.2 60.9 31.5 Castor pomace.

800
4.4 14.1

8.0 Vitrate of soda .

200

37.6 Precipitated bone.

600

231.0 Sulfate potash.. 400

200.0 Total..

4,100

264.2 306.0 239.5

During 1922 the plots were carefully watched for any signs of earlier maturity. The triplicate plots, P4, almost from the start showed a marked tendency to early ripening and the buds appeared on the plots of this series fully a week before the others. This plot, P4, had received a very high application, 306 lbs., of phosphoric acid per acre. On none of the other plots of this experiment (on which phosphoric acid was applied in amounts ranging from 75-225 lbs. to the acre) was there noted any such tendency to early maturity. All the tobacco was harvested at the same time in spite of the early maturity of the plants in plots P4. In the following table will be found the amounts of phosphoric acid applied per acre and the resulting yields with Chapman's notes as to quality.

TABLE VII. Effects of DIFFERENT AMOUNTS OF PHOSPHORIC ACID ON

THE YIELD AND QUALITY OF PRIMED HAVANA–1922. Plot Pounds of P:05 Yield of cured leaf

General No. per acre lbs. per acre

Quality P1 225 1,419

Excellent
P2

75
1,425

Good-Greenish
P3
191
1,156

Excellent P4 306 1,386

Poor-double colors

Within the limits of this experiment, varying the amounts of phosphoric acid had little effect on the yield. Only one treatment, P4 (with an excessively high application of phosphoric acid) showed any appreciable effect and this was on the quality rather than on the yield. The tobacco from P4 was inferior and showed many double colors, probably due to the fact that it was harvested over-ripe. The colors of P2 were inclined to be more green than the other plots but the tobacco was of fine quality otherwise.

In 1923 tests of plots P1-4 and replicates were conducted just as in 1922, the location of the plots and treatment being the same. The unfavorable effect of high application of P20; was apparently the same as in 1922 but the notes are scanty. The tobacco was primed. Records were taken from sample hands of leaves as in the case of the nitrogen series. Burn tests were made. Table VIII includes all records taken.

These data do not indicate that there has been a reduction in yield from omission of all mineral carriers of P205. The fireholding capacity is strikingly best on the plot which received the least P205. In view of the fact that acid phosphate is believed to be detrimental to the burn of the leaf, it is puzzling to find that Pi which received acid phosphate had a longer fire-holding capacity than P3 or P4 which received no acid phosphate, and that Pl also had the highest yield.

During 1924 no wide differences in growth and maturity were observed. Plot P2 might possibly have been slower and Plot P4 more rapid in developing buds and flowers than the other plots of this series.

The tobacco was taken down, stripped, sorted and weighed at the same time as the nitrogen plots. The sorting results are given in Table IX.

TABLE VIII. SORTING DATA ON PHOSPHORIC ACID PLOTS FOR 1923.

Data taken by C. M. SLAGG.

Number of leaves

Plot
No.

Av. lbs.
per acre

Total No.

leaves sorted

No. of priming

Treatment of Plot

Fire-holding capacity (seconds)

Lt. Wr.

Med. Wr.

Dark Wr.

Secs.

Fil. and Br.

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small]
[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small]

6

9
6.7

4
7

9
6.6

0 1 0 .3 1 0 0 .3

pi P1*

Pi**

Av. %
P2.
P2*
P2*
Av: %
P3.
P3*
P3
Av. %
P4
P4*
P4**
Av. %

[blocks in formation]

5
6

3
4.7

5
4

5
4.7

9
6

3
6.0

4
6

4
4.7

100 100 100 100 100 100 100 100 100 100 100 100 100 100 100 100

8

8
7.3

3
9

7
6.3

1
0
.7
0
0

0
0.0

« PreviousContinue »