Asparagus yields as affected by severity of cutting

THE UNIVERSITY

OF ILLINOIS

LIBRARY

G3CX7

Y\

UWVERSHY OP

i 'TURE LtBRARY

HQN CIRCULATING

CHECK FOR UNBOUND
CIRCULATING COPY

ASPARAGUS YIELDS

As ASected By Severity
of Cutting

By E. P. LEWIS

UNIVERSITY OF ILLINOIS

AGRICULTURAL EXPERIMENT STATION

BULLETIN 401

(April, 1934)

RESULTS IN BRIEF

SEVERE CUTTING of asparagus is injurious to both
yield and market quality of spears. The injury increases
in proportion to the severity of cutting, especially in the
early life of the plantation.

Cutting the asparagus bed during the first year after
setting was not profitable under the conditions of this ex-
periment. Even Plot 5, which was cut only two weeks the first
year, gave lower total yields for the seven-year period than
plots which were not cut until the second and third years.
More severe cutting caused injury which, from all indications,
was permanent. The experimental plantation was of average
vigor, but even under very favorable conditions first-year
cutting would not be advisable. The lower grade of spears
resulting from severe cutting reduces the yearly income from
an asparagus plantation.

Light cutting of asparagus the second year and medium
cutting the third year gave the highest yield and quality of
the six different treatments used in this experiment. Cut-
ting for four weeks the second year after setting reduced the
yields. Under conditions of average vigor, such severe cut-
ting would not seem advisable.

If a plantation has made a very poor growth during the
first and second years after setting, it may be advisable to
delay cutting until the third year or at the most cut very
lightly the second year, tho ordinarily there is no need for
delaying cutting until the third year.

Urbana, Illinois April, 1934

Publications in the Bulletin series report the results of investigations

made by or sponsored by the Experiment Station.

Asparagus Yields As Affected By
Seventy of Cutting

By E. P. LEWIS, Associate in Olericulture

ASPARAGUS ranks as one of the important truck crops in Illi-
nois, tho the areas devoted to its production are centralized in
a few counties. The value of the crop is greatest in Cook
county (Table 1).

In cutting asparagus there are two problems to be considered: (1)
the length of cutting season for an established plantation that will give
the most satisfactory yields over a period of years; and (2) the most
desirable length of cutting season for a new plantation and the age of
crowns when cutting should begin! Some growers cut the plantation
as long as the market price for asparagus is high, without regard to
future yields, while others are more conservative and stop cutting at
the end of the normal cutting season. In Illinois the normal cutting
season extends over a period of 8 or 9 weeks which, in northern sec-
tions, would end about July 4. In a new plantation many growers
start cutting the field the second year after setting while others do not
start cutting until the third year.

During the summer and early fall the green tops manufacture the
food supply, a large proportion of which is translocated to the fleshy
storage roots in late fall. This reserve is used to produce the next crop
of spears. Shortening the growing period of the tops by excessive
cutting would therefore restrict the supply of food that could be stored
and consequently would reduce yields the following year.

The experiment reported in this bulletin was conducted at the Cook
County Experiment Station maintained by the University of Illinois
near Des Plaines, Illinois. The object of the experiment was to de-
termine the effect of severe cutting upon asparagus yields, especially
during the early years of the plantation, and to determine the exact age
of crowns when cutting should begin.

OTHER EXPERIMENTS

During the past few years, several experiments have been con-
ducted in other states to determine the effect of severe cutting on the
yield and quality of asparagus. Most of this work has been along the

27

28

BULLETIN No. 401

[April,

TABLE 1. — ACREAGE AND VALUE OF ASPARAGUS CROP IN LEADING
ILLINOIS COUNTIES IN 1929m

County

Number of acres

Crop value

Union

1 Oil

$ 98 288

Cook

755

148 353

Madison

516

126 000

Pulaski

492

26 121

Jackson

397

31 437

La Salle

215

42 473

Other counties

1 278

204 256

Total

4 664

$676 928

•U. S. Census.

line of extending the normal cutting season of an established planta-
tion. In Iowa, Haber1 has shown that cutting until July 15, which is
approximately two weeks longer than the normal season, reduced the
yield and quality of spears. In California, Jones2 studied the effect of
extending the normal cutting season two weeks. Results showed that
yields were somewhat reduced even under the conditions of a long
growing season.

In regard to the degree of cutting of a new plantation, there is
little information. Experiments in California by Jones and Robbins3
showed that if asparagus made a very vigorous growth the year of
setting, it might be cut the following year for a short period without
injury. However, in Illinois, where the growing season is shorter,
some injury might be expected.

PLAN OF ILLINOIS EXPERIMENT

In the experiment reported in this bulletin, crowns of the Mary
Washington variety of asparagus were grown during the season of
1925 and set in the permanent field in the spring of 1926. There were
18 plots, each consisting of a single row 375 feet long with 150 crowns.
The rows were 4 feet apart with the crowns spaced at intervals of 2j/2
feet. The depth of planting was 8 inches.

During the first year, the customary cultivation was given and the
furrows gradually filled in around the plants. No fertilizer was ap-

'Haber, E. S. Effect of size of crown and length of cutting season on
yields of asparagus. Jour. Agr. Res. 45, 101-109. 1932.

'Jones, H. A. Effect of extending the cutting season on the yield of aspara-
gus. Calif. Agr. Exp. Sta. Bui. 535. 1932.

'Jones, H. A., and Robbins, W. W. Influence of cutting asparagus the first
year after planting on production the following year. Amer. Soc. Hort. Sci.
Proc. 23, 23-25. 1926.

1934}

ASPARAGUS YIELDS AS AFFECTED BY CUTTING

29

plied the first year. In all subsequent years the plots were disked in
the spring and fall, 500 pounds of 4-8-4 fertilizer applied at the end of
the cutting season, and ordinary cultivation practised during the cutting
season. For three or four weeks after cutting, cultivation was con-
tinued and a cover crop of oats was seeded each year about August 1.
The cutting season started approximately May 5 each year and ex-
tended for a definite number of weeks according to the outline shown
in Table 2. Six different degrees of cutting were made in triplicate.

TABLE 2. — NUMBER OF WEEKS EXPERIMENTAL ASPARAGUS PLOTS WERE CUT

EACH YEAR, Six DEGREES OF SEVERITY BEING REPRESENTED BY

THE DIFFERENT SCHEDULES

(Plants set in 1926)

Plots'

1927

1928

1929

1930

1931

1932

1933

Cut third year
1, 7. 13

0

0

4

6

8

8

8

Cut second year
4, 10, 16

0

2

4

8

8

8

8

2, 8, 14

0

4

6

8

8

8

8

Cut first year
5. 11. 17

2

4

8

8

8

8

8

3, 9. 15

4

6

g

8

g

8

8

6. 12. 18

6

8

8

8

8

8

8

•The plots were arranged in series of triplicates, as indicated here. In all subsequent tables the
figures given for each plot are averages of the three replications.

Plots were cut beginning the first, second, and third years after setting
and for various lengths of time. Plots were harvested at intervals of
one to two days depending on the rapidity of growth. The spears from
each plot were graded and records taken as to number and weight for
each grade. Three sizes were arbitrarily taken in establishing grades.
No. 1 consisted of all spears over y^ inch in diameter, No. 2 from 1/4.
to Yi inch, and "Strings" under 14 inch. All measurements were made
close to the butt. In spears which were not circular in cross-section
the greatest diameter was measured. Weight of spears was recorded
on total length as cut and not after trimming.

RESULTS OF DIFFERENT DEGREES OF CUTTING
Long-Time Yields Reduced by Severe Early Cutting

The severe cutting of asparagus during the early life of the planta-
tion reduced subsequent yields, as shown by the figures in Table 3
reporting the yields each year for the entire seven-year period. The

30

BULLETIN No. 401

[April,

economic returns from the six treatments were lowest where the most
severe cutting was done (Table 4).

First-Year Cutting Compared With Third-Year Cutting
Cutting on Plots 5, 3, and 6 was started in 1927 and is designated
thruout the discussion as first-year cutting since the plantation was set
in 1926. A comparison of yields on these three plots with yields on
Plot 1, on which cutting was delayed until the third year, is shown in
Table 3 and Fig. 1.

TABLE 3. — YIELDS OF ASPARAGUS DURING SEVEN-YEAR PERIOD
(Each plot consisted of ^29 acre)8

Plot

1927

1928

1929

1930

1931

1932

1933

Total

Weight of spears

1

Ibs.

Ibs.

Ibs.
10.58

Ibs.
49.97

Ibs.
97.33

Ibs.
158.5

Ibs.
151 5

Ibs.
467 86

4

5.90

14.37

72.61

98.83

170.5

169 4

531 53

2

12.27

15.47

55.78

80.53

135.8

134.3

434 . 2 1

5...

2.1

14.13

27.05

48.85

73.95

132.3

133.1

431 51

3

5.7

14.77

20.33

41.87

61.58

108.0

110.8

363.12

6

7.4

16.30

18.37

31.99

52.30

92.7

101.0

320.09

Number of spears

1

383

936

1 508

2 172

2 290

7 289

4...

212

439

1 310

1 510

2 186

2 393

8 051

2

479

562

1 109

1 314

1 899

2 012

7 374

5...

91

552

991

1 147

1 371

1 932

2 035

8 119

3

249

667

733

960

1 146

1 642

1 764

7 161

6

355

786

712

811

1 027

1 424

1 626

6 742

•Plots were 375 feet long with 150 crowns; rows 4 feet apart: crowns spaced at 2 H-foot intervals.

Plots 5, 3, and 6 received respectively, light, medium, and heavy
cutting for the first and second years, while Plot 1 had two full years
to become established before cutting began (Table 2).

Weight and Number of Spears. — Each of the three plots on which
cutting was started the first year ( Plots 5, 3, and 6) gave a lower total
yield for the seven-year period in weight of spears than Plot 1, which
was given two full years to become established (Table 3). Plot 5
gave a greater total number of spears for the seven-year period than
Plot 1. Differences in yield, however, are more significant for weight
of spears than for number of spears. Furthermore the income from
asparagus is more dependent upon weight of crop harvested than on
number of spears.

1934]

ASPARAGUS YIELDS AS AFFECTED BY CUTTING

31

TABLE 4. — GROSS INCOME ON ACRE BASIS, ACCORDING TO GRADE OF ASPARAGUS,

FOR SEVEN-YEAR PERIOD FROM PLOTS CUT WITH VARYING

DEGREES OF SEVERITY

Plot

Number of crates per acre*

Gross income per acreb

No. 1

No. 2

No. 1

No. 2

Total

1

706

825
648

611
503
321

278

299
265

285
224
241

$ 948

1 105
868

820
674
430

$311

335
297

319

2S1
270

$1 259

1 440
1 165

1 139
925
700

4

2

5.. .

3

6

•The number of crates in each grade are calculated on an acre-basis at a weight of 12 pounds per
crate. A 10 percent deduction in weight was made for the butts, which were cut off in trimming for
market. Each plot equaled !i» acre.

*>The prices are taken from Chicago South Water Market for 1927-1933: No. 1, $1.34 per crate;
and_No. 2. $1.12 per crate.

An analysis of Fig. 1 shows the following facts:

1. The number and the weight of spears on all plots for the first
two years were in direct proportion to the number of weeks cut.

2. In the third year, Plot 5, which had been cut the lightest of the
three plots cut the first year, surpassed Plots 3 and 6, the less severely
cut first-year plots, in both number and weight of spears.

3. By the end of the third year, Plots 5, 3, and 6 gave higher total
yields for the first three years than Plot 1, which was not cut until the
third year. This difference in yields would be expected, of course,
since the yields from Plot 1 represent only one year's cutting and the
cutting was for a shorter period than on the other plots.

4. Beginning with the fourth year, Plot 3, the medium-cut first-
year plot, produced each year a greater number and weight of spears
than Plot 6, the most severely cut first-year plot.

5. For the last three years of the experiment Plot 1 gave higher
yields than Plots 5, 3, and 6 in both number and weight of spears and
a greater total yield in weight for the entire period.

Plot 1 will probably continue to outyield Plots 5, 3, and 6 both in
number of spears and in weight of spears per crown, since the yields
have run almost parallel during the last three years of the experiment.
Altho the differences in favor of third-year cutting do not appear
great, more significant differences would result if they were expressed
as acre-yields.

It is evident that unless a plantation makes a very vigorous growth,
cutting for even a short period the first year after setting is detrimental
to yield of spears.

32

BUI.I.F.TIN No. 401

160

1927 I92S 1929 '930 1931 1932 1933

FIG. 1. — EFFECT OF FIRST- YEAR CUTTING ON WEIGHT AND NUMBER OF
ASPARAGUS SPEARS, 1927-1933

Of the three plots cut the first year, Plot 5 was given light cutting; Plot 3,
medium cutting; and Plot 6, heavy cutting. Plot 1 was not cut until the third
year. Both weight of spears and number of spears are in inverse proportion to
the number of weeks the plots were cut, except for the first two years. All
three plots cut the first year gave lower yields, as measured by weight of spears,
over the seven-year period than the plot cut for the first time the third year.

1934]

ASPARAGUS YIELDS AS AFFECTED BY CUTTING

33

200

1927

1928

1929

1930

1931

1932

1933

FIG. 2. — EFFECT OF SECOND-YEAR CUTTING ON WEIGHT AND NUMBER OF
ASPARAGUS SPEARS, 1927-1933

Plots 2 and 4 were cut for the first time the second year, while Plot 1 was
not cut until the third year. Plot 4, which was given lighter cutting than Plot 2,
produced the largest yield of spears as measured by weight and the largest num-
ber of spears over the seven-year period.

34 BULLETIN No. 401 [April,

Light Second-Year Cutting Superior to Third-Year Cutting

The effects of starting the cutting of an asparagus plantation the
second year after setting as compared with the third year are shown
in Table 3 and Fig. 2.

Cutting on Plots 2 and 4 started in 1928 and is designated thruout
the discussion as second-year cutting. Plot 1 was not cut until the
third year after setting (Table 2).

Weight and Number of Spears. — The plots most severely cut dur-
ing the second and third years showed a permanent reduction in yield,
as measured by both weight of spears and number of spears, compared
with the plots cut more lightly during these years (Table 3 and Fig. 2).

The weight of spears cut from Plot 2, which was cut heavier than
Plots 1 and 4, was less after the fifth season than the weight of spears
from either of the other two plots. Tho a higher number of spears
was cut from Plot 2 than from Plots 1 and 4 for the first three years,
owing to the longer period of cutting, after the third year Plots 1 and
4 produced the highest yields.

Plot 4, which was cut for only 2 weeks the second year, yielded a
heavier total weight of spears and a larger total number than Plots 1
and 2 for all seven years of the experiment. Plot 1, on which cutting
was delayed until the third year, gave a lower number of spears than
either of .the second-year cutting plots until after the fourth year of
the experiment, when it exceeded Plot 2.

An analysis of the total seven-year yields in pounds per plot shows
that Plot 4, which received light second-year cutting, gave an increase
of 22-percent over Plot 2, which received a heavy second-year cutting,
and a 13-percent increase over Plot 1, which was not cut at all until
the third year.

Quality of Spears Reduced by Severe Cutting

The market quality of all spears was influenced to a great extent
by the various degrees of severity of cutting during the early life of
the asparagus plantation. The size of spears, as indicated by individual
weight and by diameter, decreased in direct proportion to the severity
of cutting (Table 5 and Fig. 3). The figures represent the average
performance of the six treatments for the seven-year period.

All plots cut the first year (Plots 5, 3, and 6) gave the smallest
proportion of No. 1 spears and the largest proportion of the lower
grades. Heavy second-year cutting (Plot 2) gave lower quality of
spears than third-year cutting ( Plot 1 ) ; while light second-year cutting
(Plot 4) gave higher quality than third-year cutting (Plot 1).

1934]

ASPARAGUS YIELDS AS AFFECTED BY CUTTING

35

TABLE 5. — EFFECT OF VARIOUS DEGREES OF CUTTING UPON MARKET QUALITY OF
SPEARS HARVESTED DURING SEVEN-YEAR PERIOD"

Plot

Percent of total spears in each grade

Average
weight
per spear

Average
diameter
of spears

Based on number

Based on weight

No. 1

No. 2

Strings

No. 1

No. 2

Strings

1

45.8

48.7
42.8

38.7
38.0
35.9

39.6

39.1
41.4

41.9
41.6
44.5

14.6

12.2
15.8

19.4
20.4
19.6

69.6

71.8
68.8

65.4
64.0
60.6

27.4

25.7
28.1

30.4
31.1
34.6

3.0

2.5
3.1

4.2
4.9
4.8

gms.
29

30
27

24
23
22

He inch
7.28

6.96
6.51

6.31
6.05
5.76

4.. .

2

5...

3

6

•During the first two years all spears were measured, while during the last three years, a repre-
sentative sample consisting of half the spears was measured on alternate harvest days.

14253
NUMBER 1 GRADE

142536
NUMBER 2 GRADE

4253
STRINGS

FIG. 3. — EFFECT OF DEGREE OF CUTTING ON NUMBER OF SPEARS IN EACH GRADE

Severe cutting of asparagus early in the life of the plantation reduced the
quality of spears as measured by grade. The six plots are arranged in the above
graph in order of increasing severity of cutting. The percentage of No. 1 spears
decreased with more severe cutting while the percentage of the two lower
grades increased.

Growth of Tops Permanently Stunted by Severe Cutting

Prolonging the cutting season of asparagus, since it lessens the
growing period of the tops and thus restricts the food supply that is
manufactured in the top and stored in the fleshy roots, tends to reduce
the yield the following season. In order to insure high yields of
asparagus, a full growing season is necessary.

36

BULLETIN No. 401

The effects of severe cutting upon the growth of tops were deter-
mined by growth records and measurements taken in September, 1929,
the third year of the experiment, and early in October, 1933, the
seventh year (Table 6). Every third crown in each plot was taken as
a representative sample. Each stalk was measured just above the

TABLE 6. — EFFECT OF VARIOUS DEGREES OF CUTTING UPON GROWTH OF TOPS

Plot

Height of stalk

Average diameter
of stalks

Average number of
stalks per crown

1929

1933

Aver.

1929

1933

Aver.

1929

1933

Aver.

1

inches
49.8

51.5
49.2

45.3
47.0
42.9

inches
58.7

59.8
58.3

59.5

57.5
57.5

inches
54.3

55.6
53.8

52.4
52.2
50.2

M« inch
5.13

6.28
5.17

5.25
4.85
4.90

Hs inch
6.70

7.10
7.00

7.20
6.80
6.80

H-> inch
5.93

6.69
6.09

6.21

5.84
5.87

6.9

5.7
6.0

4.7
5.3
4.6

9.8

9.6
8.6

8.3
8.3
8.5

8.35

7.63

7.27

6.50
6.80
6.55

4

2

5. .

3

6

ground. Stalks, which were somewhat oval in cross-section, were
measured thru the smallest diameter. Growth records showed that
severe cutting restricted the growth of tops in 1929. The height of
stalk, the number of stalks per crown, and average diameter of stalks
were reduced somewhat in proportion to the severity of cutting. The
results in 1933 were quite similar in that the most severe cutting during
the early years of the plantation still showed up in reduced vigor of
tops.

The 1929 results indicate that severe cutting during the first three
years of growth of an asparagus plantation retards the growth of tops
at the end of the third year ; the records of 1933 show that this stunt-
ing is permanent.