| Material Information
||Field control of blackheart of celery
||Gulf Coast Station mimeo report
||2 leaves : ; 28 cm.
||Geraldson, C. M ( Carroll Morton ), 1918-
Gulf Coast Experiment Station (Bradenton, Fla.)
||Gulf Coast Station
||Place of Publication:
||Celery -- Diseases and pests -- Florida ( lcsh )
Celery -- Diseases and pests -- Control -- Florida ( lcsh )
||government publication (state, provincial, terriorial, dependent) ( marcgt )
non-fiction ( marcgt )
||Statement of Responsibility:
||Carroll M. Geraldson.
||Florida Historical Agriculture and Rural Life
The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
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site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University
Gulf Coast Station Mimeo Report 54-4
FIELD CONTROL OF BLACOHEART OF CELERY DEC 30 1953
/ Carroll M. Geraldson
Blackheart has been a serious problem of celery growers for more than 50
years. In Florida, individual growers have at times lost all or large portions
of a given crop, depending on the prevalence and severity of the conditions asso-
ciated with blackhoart. It is estimated that losses in Florida due to blackhearb
have often averaged about a million dollars annually.
Most investigators agree that blackhoert is a physiological disorder charac-
terizod by the break-down of the young leaf tissue in the heart of the plant. It
may eventually spread throughout the entire heart, cursing the affected tissue to
turn black, hence the name "blackhoart". A summary of the literature indicated
that blackheart is often associated with unbalanced moisture, over-fertilizationi,
high soluble salts, and certain practices or conditions that promote rapid growth.
Control of blackheart as suggested by various workers has been approached by the
use of measures alleviating such conditions as far as possible. These measures
have sometimes been helpful, but generally inadequate.
Recent work at the Gulf Coast Ekperiment Station aid in the Sarasota celery
area indicates that blackheart cni be completely controlled by applidhtion of a
calcium solution directly to the heart of the plant. Solutions containing 10 to
20 pounds of calcium nitrate or 5 to 10 pounds of calcium chloride per 100 gallons
of water applied at least once a week at a rate of about 150 gallons per acre hnve
been very successful. The frequency of, and quantity per application required for
prevention or cure of blnckheart is dependent on the prevalence and severity of th
contributing factors. Generally, treatment is not necessary until the celery be-
gins rapid growth and blackheart is suspected or has appeared.
A number of growers successfully utilized this method of blackheart control
the past spring crop season. The growers' spray machines were usually easily adap
ted for delivery of the calcium solution directly into the heart of the plant. It
should be emphasized that if the calcium does not reach the heart area, it is use-
less as a control for blackheart. The older foliage already contains relatively
large amounts of calcium which is not translocated to the younger tissue.
Greenhouse celery plants growing in nutrient solutions always develop black-
heart, regardless of the amount of calcium supplied to the roots, although the se-
verity varies inversely as the calcium content in the nutrient solution. However,
plants growing in similar solutions do not blackheart as long as calcium is sup-
plied periodically to the heart of the plant. Generally, since it is not a ques-
tion of the soil containing insufficient calcium, soil treatments are rarely help-
ful and are not recommended.
In addition to unbalanced moisture, excessive soluble salts and over-ferti-
lization, it appears that temperature and light may also be factors associated
with blackheart. It seems that when two or more of the many possible influencing
factors are involved, the incidence of blackheart increases accordingly. Invesrt-
gations are in progress on the means by which such conditions may affect the ce'.i
um uptake, translocation and assimilation. It is logical that in some cases, a
limited calcium supply or availability could be a-direct cause of blackheart.
It has been noted that the larger, more vigorous plants have the greatest
tendency to be affected by blackheart. The fact that calcium is taken up and
moved rather slowly in the plant may be important when considering that black-
heart is often most prevalent in rapidly growing celery plants. It would appear
that rapid growth makes the plant more sensitive to the effects of contributing
factors because per unit of time, the requirement for calcium is further extended.
It may be concluded, that regardless of the cause or causes, blackheart can
be controlled by supplying sufficient calcium at the proper time and to the proper
part of the plant'.