Group Title: Mimeo Report - University of Florida Everlgades Experiment Station ; EES64-20
Title: Studies on the development of pith in Everglades celery
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00067439/00001
 Material Information
Title: Studies on the development of pith in Everglades celery
Series Title: Everglades Station Mimeo Report
Physical Description: 6 p. : ; 29 cm.
Language: English
Creator: Burdine, Howard W., 1909-
Everglades Experiment Station
Publisher: Everglades Experiment Station
Place of Publication: Belle Glade Fla
Publication Date: 1964
 Subjects
Subject: Celery -- Growth -- Florida   ( lcsh )
Genre: non-fiction   ( marcgt )
 Notes
Statement of Responsibility: H. W. Burdine and V. L. Guzman.
General Note: "May, 1964."
 Record Information
Bibliographic ID: UF00067439
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 62862970

Full Text






Everglades Station Mimeo Report EES64-20 *



STUDIES ON THE DEVELOPMENT OF PITH IN EVERGLADES. CELERY

H. W. Burdine and V. L. Guzman


A great deal of work was done between 1925 and 1940 on the
development of pith in stored celery, but there seems to be little
or no published data on factors affecting the development of pith
in the field. There are large variety differences in tendency to
develop pith. Many celery growers also believe that environmental
factors such as fluctuating temperatures, soil moisture supply, heavy
rains, etc., have an effect on pith development. Field observations
indicate that any factor that slows growth during the last two weeks
or 10 days before optimum maturity may accelerate the development of
pith formation, beginning at the base of the oldest and outer most
petioles, and proceeding rapidly up to the petiole and into younger
petioles in age sequence. Under severe conditions it may extend all
the way into the heart petioles.

Microscopic studies have revealed that the development of pith
in celery is due to breakdown of the cells of certain type of tissue
in the celery petioles. Why this occurs has been one of the mysterious
aspects of the phenomenon.

Another problem has been the method of determining severity of
pith development. The older method of rating for severity was slow
and laborous. With the usual variation between plants within plots,
several petioles in age sequence on each of several plants were rated
to get a good estimate of the amount of pith present in a given
treatment. Our first attempts to estimate pith was by the older rating
method, which was eventually shortened to cutting off.the..petioles at ..
the base of the plant and counting the number of petioles with white
pith showing. In order to obtain yield and other data this was further
shortened to counting the number of pithy petioles after field trimming.
The number of pithy petioles counted with this method is not6 as great
as counting the pithy petioles on an untrimmed plant as the pithy plant
tends to be more severely trimmed than the plant with less pith, but
as pith development is progressive it was felt that it would show
treatment differences.

A. Tables 1 and 2 show changes in growth of the celery plant
as the plant approaches maturity.


I 1 "










Table 1. Total weight in pounds per plot of three celery varieties
harvested at seven day intervals.
Summer Pascal Emerald Utah 52-7 Av.
Days % Change cChange % Change-
from from from from
Trans- Total Previous Total Previous Total Previous %
planting Weight Week Weight Week Weight Week Wt. Change

Exp. No. 1 grown on Station. Harvested December 13 to January 2.

70 89 82 101 91
77 104 + 1% 101 + 23% 107 + 6% 104 + 14%
84 130 + 25 139. + 38%' 145 + 36%. 138 + 33%
91 134 3% .132 5% 132 10% 133 --4%

Exp. No. 2 grown on the farm of Mr. Billy.Roger,: South Bay, Harvested Jan. 14
to March 3.
70 54 57 54 55
77 65 + 20% 64 +12% 66 + 22 65 + 18%
84 84 + 29% 82 + 28% 81 + 23% 82 + 26%
91 101 + 20% 107 + 30%5 108 + 33% 105 + 28%
98 111 + 10% 108; + 1% 124 + 15fo 114 + 9%
105 100 10 109 + 1% 117 -6% .109 5%
112 101 +1% 101 -7% 103 12% 102 6
119 108 + 7% 107 + 6%. 123 +19% 113 + 11


Average decreases in weight from 98 through the 112th day in Experiment
No. 2 are significant and the increase between the 112 to 119th day is also
significant. It is believed that the plants were going through a resting
stage" between the 98 and 112th day in the second experiment, after which
they began to grow again. In the first experiment they seem to be entering
this stage between the 84th ind'91st day. .







-3-


Table 2. Pith Severity


Exp.
Exp.


No. 1 Rated 1 = no pith, to 8 = very severe pith.
No. 2 Number of pithy petioles per plant after field trimming.


Days from Summer Pascal Emerald Utah 52-70 Average
Transplanting ECp. 1 Exp. 2 Exp. 1 Exp. 2 Exp. 1 Expt. 2 Exp. 1 Exp. 2

70 1.6 1.2 1.0 0.1 1.0 0.3 1.0 0.5
77 2.3 1.7 1.0 0.2 1.0 0.8 1.4 0.9
84 5.1 1.7 5.1 0.2 4.2 0.6 4.8 0.8
91 8.0 1.3 6.3 0.3 7.0 0.4 7.1 0.6
98 0.2 0.8 0,8 0.6
105 32 1.. 2.0 2.2
112 32 2.0 1. ..., 2.2
119 343 115 0.9. 1.9


The above two tables taken together indicate that after 70 days the
celery plant grows very rapidly to 90-98 days, or longer during prolonged
cool temperatures until it reaches a point where growth rather suddenly
stops. At about this point pith begins to occur in significant amounts.

B. Following are data indicating that nutrition and fertility of the
plant also affects the development of pith. In all of the following experiments
the variety Utah 52-70 was used.

1. Exp. No. 1, grown on the farm of Mr. C. A. Thomas, South Bay,
Florida. The plot was harvested February 1, 8, and 15. The pH at harvest
was 6.01. Soil tests following all broadcast, P and K applications indicated
28 lbs. H20 soluble P and 292 Ibs. 0.5 N acetic acid soluble K/A.


Table 3. Exp. No. 1.


Number pithy petioles per plant after field trimming,
total and trimmed weights in pounds per plot.


No pithy petioles
Days from per plant Total Fresh Wgt. Trimmed Weight
Transplanting Rate of N, lbs./A. Rate of N, Ibs./A. Rate of N, lbs./A.

o 75 150 Avg. 0 75 .150 Avg. o 75 150. Avg.
88 3.4 3.0 2.3 2.9 110 124 .126 120 72 81 83 78
95 6.3 5.7 4.9 5.6 145 144 148 146 100 98 99 99
102 7.1 5.9 4.8 5.9 156 164 :64 161 98 105 106 103


5.6 4.9 4.0


137 144 146


90 95 96 -





-4-


B. Experiment No. 2. Grown on the farm of Mr. Billy Rogers, South Bay,
Florida. The experiment was harvested December 20 and 27, and
January 2. The pH at harvest was 6,71, 435 Ibs. PO0 and 580 lbs.
K20 per acre was applied in the broadcast and sidekrss.
2


Table 4.


Exp. No. 2. .Number of pithy petioles per. plant after field trimming,
and total, and trimmed weight in pounds per.plot.


No. pithy petioles
Days from per plant Total Fresh Wgt.: Trimmed Weight
Transplanting Rate ofN bsA Rate of N, Ibs./A. Rate of N, Ibs./A.
0 75.150 Avg. 0 75 150 Avg. '0 75 150 Avg.
83 .5.0 3.5 2.8 2.7 79 88 88 85 59 65 64 63
90 7.2 6.6 6.2 6.7 84 101 108 98 61 72 75 69
97 7.3 6.4 5.8 6.5 91 107 117 105 63 74 79 72

Avg. 6.5 5.5 4.9 85 99 104 61 70 72


Weight data differences, at the last harvest date on the no nitrogen
treatment seem to indicate a heavier trimming on plots with more. severe pith,
indicating differences in pith development were greater than the data
indicates.

1. Other fertility effects on the development of pith in :celery.
All these experiments are single harvest at near estimated optimum
*maturity. This series of experiments are not completed:and the data
presented should be taken only to point out fertility effects on pith
at a particular harvest date, not for recommendations as to fertilizer
rates.

a. Experiment No. 1. Grown on the farm of Billy Rogers, South Bay,
Florida, harvested January 11-13. The average pH 6 weeks after broadcast
fertilization was 6.50. The experiment was designed to test for response
of the crop to.3 levels of phosphorus, 3 levels of potassium and 3 levels
of nitrogen applied sidedress in all combinations.- Amount of materials
used.according: to designated symbols are as follows:


= no. additional N
= 50 Ibs. N/Acre
= 100 Ibs. N/Acre


K- = 344 lbs. K20/A.
K2 = 544 lbs. K20/A.
K. = 744 lbs. K20/A. .


* 1 140'"lbs.
P2 340 lbs.
- P 540 Ibs.
P3'


Table 5. Number of pithy-petioles/plant after field trimming.


P1
"~' I~ ~-KI5


P2 P 3
'K K- ~~-' K6_ 1 c. xi KI


No .. 7.1 7.3 7.51 7.9 ,7.7 7.5.. 8 0- .: _-7-5
-N -..... 6.5 6.8 '6.6 7.8 7.3 6.4 7.1 6.9 6.1
N2 6.4 6.0 5.6 7.2 7.0 5.8 7.2 6.7 6.3


P205/A.
P205/A.
P205/A.







Average P and K effects:


o.t asm pPhosphorus Effects Avg
Potassium -. ..Avg. K
Effects PI P23 PEffect
K1 6.7 7.6 7.4 7.2
K2 6.7 7.3 7.2 7.1
K3 6.4 6.6 6.6 6.5

Avg. P effect 6.6 7.2 7.1


Average nitrogen effect


No = 7.6
N = 6.8
N = 6.5
2


b. Experiment No. 2. This experiment was done on the farm of A. Duda
and Sons. It was harvested May 3 and 4. The average pH at harvest was 6.02.
Treatments are as follows:


NO = No additional N
N1 = 50 lbs. N/A.
N2 = 100 lbs. N/A.


= 60 lbs. P 0 /A.
= 260 lbs. P205/A.
= 460 lbs. P205/A.


= 260 lbs.
= 460 lbs.
= 660 lbs.


Table 6. Number of pithy petioles/plant after field trimming.

N 1 2 3
Treatment K2 K3 Kl K3 K1 K2 3
NO 7.0 3.2 3.3 1.6 5.3 5.3 6.6 5.4 3.0
N 5.1 4.0 3.9 6.9 7.0 3.1 5.1 4.1 4.7
N2 5.1 4.4 3.0 5.7 4.0 4.7 5.0 4.1 4.0


Average P and
Potassium


K Effects:
Average for


Treatments P P2 P3 Potassium
K1 5.7 6.7 5.6 5.5
K2 3.9 5.0 4.6 4.5
K3 3.4 4.4 3.9 3.9

Av. for phosphorus 4.3 5.4 4.9


Average nitrogen effect:


0
NO =
N1
21


6.0
4.7
4.5


K20/A
I20/A
K20/A








-6-


It will be noted that there was less pith at higher nitrogen
and potassium levels.

Yield and growth data due to P and K treatments in the two last
experiments are not given as differences were not significant. However,
it can be said that growth and yield were good in all treatments. It
could be expected that differences in pith would probably have been
greater if growth differences had been significant..

The above data indicate major element supply, particularly that of
nitrogen and potassium, also has an effect. It is believed that this
effect may be one of keeping the plant vegetative. Studies are
continuing on the effects of these materials.

The role of minor elements, particularly boron and manganese
have not yet been evaluated, but these studies will be initiated this
coming year.

It is believed that one of the dominating factors regulating
pith formation in this normally biennial plant- may be a mechanism
within the plant, that during the period of extremely rapid growth;
observed in Table 1, between about 70 days after transplanting and
maturity, any factor checking or limiting growth results in a rapid
movement out of the older and outer petioles of-elaborated organic
materials, and nutrient elements (this has been shown in our chemical
studies), which causes the cellular breakdown, known to growers as
pith. The thick fleshy petioles of the celery plant seem to function
as temporary storage organs. In this respect, this mechanism must
operate to conserve stored materials for the reproductive processes
of the plant.

Adequate supply and balance of nutritional-elements to keep the
plant vegetative and growing for a long a period as possible seems
to be an additional means of pith control.



EES66-20
400 copies




University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs