Note: Descriptions are shown in the official language in which they were submitted.
3~37
83-3-015 CM -1-
APPLïCA~rl~N OF spE~:rE~c IIGilTIMG TREATr~ENTS FOR PRO~OTION
_ ANTHOCY~NIM I~ ECOMOMTC~LLY IMPORT~NT CROPS
This invention relates to the use of specific
lighting treatments for improving anthocyanin formation in
economically important fruit and ornamental crops, without
affecting other produce quality features, and crop growth
and development. Accordingly, it is a general object oF
this invention to provide new and improved methods of such
character.
rrhe anthocyanins are water-soluble pigments which are
responsible for the attract:ive colors of flowers, leaves
and fruits. Apart from their biological role, they are
important aesthetically and economically, since their
formation and stability are of significance in the
marketability of p3ant products.
In the past, red color improvement of agricultural
produce in fields and greenhouses has been accomplished by
spraying or treating the crops and~or speci-fic crop parts
with chemical regul~tors. In some instances, geretic
selection and breeding methods have been used for color
improvement.
Chemical regulators that have been used by growers
for timely development of red color in certain ornamental
and fruit crops teilded to produce undesirable side effec-ts
(de~oliation, reduction in storac~e-life~ root inhibi~ion,
etc.~ and often e~hibited a pronounced variability in
responses. Cenetic selection and breeding approaches are
abor intensive and time-consuming.
It is kno-.Jn that anthocyanin s~nthesis in a wide
range of tissues ant1 plant species is promoted by ligh~.
The light promotion appears -to be mediated by at least iwo
photochemical reactions: 1~ a low energy, red/far-red
reversible, phytochrome-controlled reaction; and 2~ a hitfh
irradiante reac~ion (HIR~, mos~ effective at the blue and
far-red region oE the visible light spectrum. rrhe HIR of
tr~
~ 3~7
83-3-015 CN
anthocyanin accum~llation, in -the past, has been u~ually
investigated and interpretec1 either in terms o~
phytoehrome or of another, yet unknown, photoreeeptor.
The timely development of red color in certain
ornamental and fruit erops has importan~ economic bearing
in the produetion and marke-~ing of agricultural produce.
There are manv faetors which affeet anthoeyanin formation,
one of whieh is the influence of light. The influenee of
light on fruit and ornamental erops was investigated using
various approaehes. They are as follows: Whole green
mature apples and/or cranberries held in regular cold
storage were exposed to a combined treatment of blue
(0.82mW/cm2~ and red {0.30mW/em2) lights with maximum
emission peaks eentered around 448nm and 6~0nm,
respectively, at different time intervals. The results
showed a signi ieant improvement in anthoeyanin formation
(46% more on the average relative to either blue or red
light treatm~nt alone). Similarly, anthoeyanin formation
in s~;ins of mature apples by post-harvest irradiation with
red and blue lights at 10C was substantially improved
(35% more on the average relative to unlighted eontrol
groups).
Aeeordingly, the present invention provides a method
of improving anthocyanin formation in a product seleetecl
from the group eonsisting of fruit and crop eomprising
expos~ng said prod~et to a eombined treatment o~ blue and
red lights.
The cro2s ean be exposed up to 40 days prior to
harvest by high intensity discharge and/or VHO narrowband
fluoreseent lamps, having an intensity range of 1 to
.. ...
-' ~2~2~
~3-3-015 C~l --3~
200 ~/cm2 for a period oE one to four hours per day.
Apples prior to harves-t, preferabl~, are exposed to both
blue and red lights, while poinsettia should he exposed to
red light only. Following harvestl apples in cold st.orage
can be continuously exposed to red or red and blue lights
for a period of four days.
One embodiment of the invention will now be
described, by way of example, with reference to the
accompanying drawings in which:
FIG. l is an action spectrum for anthocyanin
formation in selected model crops in which disks were
- incubated in 0.1 molar sucrose and in light of various
wavelengths;
FIG. 2 is a chart illustrating the effect of light
intensity on anthocyanin formation in cranberry (C) and
apple fruit (A) disks;
FIG. 3 is a chart illustrating the effect of light
intensity on anthocyanin forma~ion in poinsetti.a leaf
disks;
FIG. 4 is a time course for anthocyanin synthesis in
poinsettia leaf disks; and
FIG. 5 is a time course of anthocyanin synthesls in
apple fruit disks.
E~periments, both in the field with various crops,
and studies using in vitro systems, have shown that red
color development can be enhanced through effective light
exposure.
.. , _ .... . .. . ., .. . . . , . . . . .. .~ , ,,
37
83-3-015 C~ ~4-
Laborator~ S udies
1. _ntroduction
Study oE anthocyanin formation was undertaken using
in vitro systems of selected model crops such as
cranberry, apple and poinset-tia in order to investigate:
a) the relative effectiveness of different spectral
regions and diLferent irradiance levels, b3 the
- red/far red reversibility and the reciprocity
relationship, and c) the involvement of phytochrome and
the probable contribution of photosynthesis to the
red-light mediated HIR response.
2. Materials and Method
The plant material included: cranberries, Vaccinium
macrocarpon AIT ~obtained from Ocean Spray Company,
Middleboro, Mass.); poinsettia, Euphorbia pulcherrima V-1
(obtained from Ecke Nurseries, Encinatas, CA); and
a~ples ~ cIntosh," Malus domestica (obtained from the
University of Massachusetts Horticultural Research Center, - -
Belchertown, MA and Standard Orchards, Hudson, MA). In
most cases, apple skin and poinsettia leaf tissue used for
experimental purposes were cut into uniform disks (0.5 cm
diameter) using a spring-loaded plunger. Disks cut from
each group of tissue were put directly into 0.1% HC1 in
me.hanol and were immediately frozen in liquid nitrogen,
and stored in a freezer.
Experiments were conducted in an environmental
cha~er (Con rolled Environments LTD., Winnipeg, Canada)
divided into five light--tight modules. Lamps were placed
across the top of each module and lighi intensities were
controlled by adjusting the distances between the lamps
and tissues. The tissues were maintained at 25C to 27C,
ancl exposed separately to narrowband liyht at nine
wavelengths between 371 nm and 740 nm (irradiance ranqe:
0.01mWtcm to 2mW/cm ) continuously each day.
Narrowband width-emitting fluorescent lamps, having
maxima at one of the following wavelengths: 371, 420,
. .
lZ~
83-3-0]5 CN -5~
44~, 467, 504, 550, 590, 660 and 740 nm (supplied by GTE
Svlvania Ligh~ing L~roducts, Danvers, ~1~), were covered ~in
all but the 371 nm lamp) with a 5-mil thickness of
Weatherable polyester film (Martin Processing Co.,
Martinville, VA)~ In addition, plastic filters
surrounding the UV prefilter were used to absvrb visible
mercury lines not~ in the immediate spectral region of the
narrowband emissions. The bandwidths and filters used for
each lamp source are known in the art. Anthocyanin was
extracted from all tissue using methanol-EIC1 (99:1 v/v).
The extracts were clarified by filtration, and dilutions
of the extracts were made within each set of plant tissue
with methanol-HCl until the absorbance of the solution
could be read in a spectrophotometer at 530 nm and 657 nm.
( 530 0.33 A657) was used to eliminate the
contribuiion of chlorophyll and its degradation products
in acid solution to the absorbance value at 530 nm.
- 3. Results
~",
The action spectra for anthocyanin formation were
measured with disks obtained from cranberry -and apple
fruit skins, and modified poinsettia leaves. The
measurements of the action spectrum were made during the
linear period of anthocyanin formation. Representative
results obtained in several action-spectr~lm experiments
are shown in Fig. 1 which depicts an action spectrum for
anthocyanin formation in selected model crops.
Disks were incubated in 0.1 molar sucrose and light
of ~ifferent waveleng-ths. Anthocyanin formation is
plotted as a function of the wavelength of light used for
each incubation. Each point in this plot represents an
avera~e OI 15 samples. Each sample consists of 50 disks.
Cranberry skin disks cultured in 0.1 molar sucrose
and in 'ight of different wavelengths showed two distinct
peaks of anthocyanin biosynthesis, a lower peak at 44~ nm
and a higher peak at 660 nm. The action spectrum for
anthocyanin formation in poinsetticl leaf and apple fruit
~. _ . .. . . . .. . .. . . ... . . . . .. ..... .. . . . . .. .
~ 37
83-3-015 C~ -6~
skin disks was esserltially the same as the ac-tion spec-trum
for cranberry. The most effective light ~avelength for
anthocyanin formation in apple disks, however, was blue
light with maximum emission peak at 448 nm.
The spectral sensitivity of anthocyanin formation in
selected plant species exposed to continuous blue or red
radiation depended upon the irradiance and length of
exposure.~ In cranberry and apple fruit skin disks,
anthocyanin synthesis was fully saturated at an irradiance
of 0.82 mW/cm2 under blue, and 1.19 mW/cm2 under red light
(Fig. 2). Fig. 2 depicts the effect of light intensity on
anthocyanin formation in cranberry (C) and apple fruit (A)
disks. Disks cut from fruit skin were immediately
transferred to 'che incubation medium and exposed to red
tl) and blue (2) radiation at various intensities for 14
hr. The value for each point is an average of five
separate experiments done in triplicate ~ statistical
- error.
In poinsettia leaf disks, the blue light intensity
- 20 required for saturation of anthocyanin was the same as for
apple s~in disks. The saturation of red light intensity
for anthocyanin formation, however, was almost one-quarter
of that required in apple fruit skin disks, as indicated
in Fig. 3 which depicts the e~fec-t of light intensity on
anthocyanin formation in poinsettia leaf disks. Disks cut
from mod~fied leaves were immediately transferred to the
incubation medium and exposed to red and blue radiation at
various i~tensities separately for 120 hr. The value for
each point is an average of five separate experiments done
in triplicate ~ statistical error.
'~ith respect to the time courses of anthocyanin
synthesis under saturating blue and red radiation in
poinsettia leaf disks, it showed an initial lag phase of
about 12 hour during which practically no anthocyanin was
synthesized. Formation of anthocyanin be~an at the end o~
lag phase and reached steady state by 120 hours and 216
. . .
3~37
83-'-015 CN -7-
hours ur-der red and blue radiation, respectively, as shown
in Fig. 4, which depicts a time course for an-thoc~anln
synthesis in poinsettia leaf disks. Disks cut from
modified poinsettia leaves were immediately transferred to
the incubation medium and exposed to red (660 nm: 0.30
mW/cm2) and blue (~48 nm: O.S2 mW/cm ) radiation
separately at 0 hr, and harvested at indicated times for
estimation of anthocyanin content. The value for each
point is an average of five separate experiments done in
triplicate + statistical error.
In apple skin disks, anthocyanin synthesis showed an
initial iag phase of about 24 hours reaching a steady
state by about 1~4 hours and 196 hours under saturating
blue and red radiation, respectively, as indicated in Fig~
5 which depi~ts a time course of anthocyanin synthesis in
apple fruit disks Disks cut from fruit skin were
immediately transferred to an incubation medium and
exposed to blue (448 nm: 0.82 mW/cm2) and red (660 nm:
1.19 ~W/cm2) radiation separately at 0 hr and harvested at
indicated times for estimation of anthocyanin content.
The value for each point is an average of five separate
experiments done in triplicate + statistical Standard
error.
Since the action spectrum for anthocyanin formation
in apple and poinsettia showed the maxima around 448 nm
and 660 nm l ght wavelengths, the relative roles of thesP
wavelenyths in anthocyanin synthesis were examined. Data
in ~able 1 show the interactive effects of blue and red
radiation on apple anthocyanin synthesis. Apple fruit
skin disks exposed to continuous blue radiation at
~aturating light intensity formed more anthocyanin than
continuous red radiation. Continuous blue light, however,
when supplied simultaneously with continuous red radiation
formed about 36~ more anthocyanin than continuous blue
radiation alone. A similar effect was obser~Ted with
continuous b]ue radiation when it was provided with low
, .. . . . . . ... . .. . .. . . . . .
12~3~3~
83-3-015 CN -8-
f].uxes of red radiation throughout the irradiation period.
These resul.ts indicate that red ligh-t serves as a trigger
for the blue radiation actiny through the "Hiyh Irradiance
Reaction" rather vice versa since the pulses of blue light
superimposed on continuous red radiation were no-t equally
effective.
TABLE 1
EFFECT OF RED (660 nm) AND BLUE (448 nm) LIG~IT
TREATMENTS ON ANTHOCYANIN FOR~ATION IN APP~E
. (VAR. "McINTOSH'1) SKIN DISKS
. _ __ _
TREATMENT AMOUNT OF ANTHOCYANIN* .
. (A530 - ' 33A657~
. 72 hr 144 hr
Continuous Red (1.19mW/cm2) 0.054+0.003 0.126+0.006
Continuous Blue (0.82mW/cm2) Q.088+0.004 0.197+0.011
Continuous Red (1.19m~/cm2)+ 0.118+0.005 0.269"0.012
20 Continuous Blue (0.82mW/cm2)~ : ~ --
Continuous Red (1.19mW/cm2)+ ~0.056+0.002 0~163+0.006
10 min. Blue (0.82mW/cm2) ,
given every 4 hr ~.
Continuous Blue (0.82mW/cm2)t 0.112+0.006 0.264+0.013
1:0 min. ~ed ~1.19mW/cm2) -
given every 4 hr .
*Values are means of five separate experiments done in
tri~licate + statistical Standard error.
.. ,
The interaction of two light wavelengths on
anthoc~anin formation in poinsettia leaf disks was
somewhat different. As shown in Table 2, the most
effective narrowband region was red light peaking at 660
nm. Over si.Y-ty percent increase in anthocyanin formation
in leaf disks was observed when continuous blue radiation
was supplied wi-th continuous red light. Providing short
exposures of blue radiation with cont:inuous red radiation
- 1~43~37
83-3-0~5 CN -9-
result~d in a formation of an-thocyanin equal to that of
continuous blue plus red radiation.
-- - .
TABLE 2
. , .
EFFECT OF RED (660 nm) AND BLUR (448 nm) LIGHT
TREATMENTS ON ANTHOCYANIN FORMATION IN
POINSETTIA LEAF DISKS
. _
TREATl~ENT AMOUNT OF ANTHOCYANIN*
. (A530 - O 33A657
~ 60 hr 120 hr
Continuous Red (0.30mW/cm2) 0O119+0.006 0.262+0.01 l
Continuous Blue ~0.82mW/cm2) 0.065+0.004 0.15~+0.00 ¦
Continuous Red (0.30mW/cm2~+ 0.187+0.012 0.422-~0.02
Continuous Blue (0.82mW/cm2) ~
Continuous Red ~0.30mW/cm~)+ 0.166+0.011 0.410-~0.028
10 min Blue (0.82m~/cm2)
20 given every 4 hr
Continuous Blue (0.S2mW/cm2)+ 0.088+0.006 0.186~0.010
10 min Red (0.30mWtcm2)
~iven every 4 hr
*Values are means of five sepz rate experiments done in
triplicate + statistical Standard error.
The difference in a mode of action of red light and
blue light on anthocyanin appears to be related to the
stability of photoreceptor, possibly phytochrome. In
apple disks, photoreceptor seems to be relatively
unstable, since brief exposures to red radiation were
required throughout the blue radiation period. Red
radiation alone both activates phytochrome necessary Eor
the blue "High Irradiance Reaction" (HIR) and renders
possible, at a low level of efficiency, the HIR. In
poinsettia disks r the effect of blue radiation on
.
.. .. . . ... . . . ... .
~ z~3~
83-3-Ol5 CN -10-
anthocyanin fc,rmation, prohably, provides some precursors
required for anthocyanln foxmation. It is believed that
blue radiation reduces the level of certain speciic
inhibitors which interfere with phenylalanine
ammonia-lyase, a key enzyme involved with anthocyanin
biosynthesis
Well-establishea criteria should be satisfied,
however t before it can be claimed that phytochrome is
involved in a plant system. The fulfillment of these
criteria for anthocyanin formation is described in
Table 3.
I TABLE 3
_ I
EFFECT OF BRIEF IRRADIATION OF RED AND FAR-RED
LIGHT ON ANTHOCYANIN FORMATION IN POINSETTIA
LEAF DISKS
_
~MOUNT OF ANTHOCYANIN*
TREATMENT (A530 ~ 0-33A657
D~rk Control 0.001
10 min R/Day 0.02~
10 min FR/Day 0.001
10 min R -~ 10 min FR/Day 0.001 -
10 min FR + 10 min R/Day - 0.023
*Ext-action or anthocyanin was performed five days after
the first irradiation. Conventional induction-reversion
e~periments demonstrate the involvement of phytochrome
in light-mediated anthocyanin formation in poinsettia
leaf disks. Values are means of eight separate
experimen~s done in triplicate.
The formation of anthocyanin was induced by a brief 10 min
exposure to red (R) light given every day and this effect
was completely counteracted by immediate and subsequent
exposures to 10 min of far-red (FR) li~hts. The induction
by a sinyle, hrief, low irrad ance treatment and
re-l/far-red reversi~le reaction provided ~vidence that
~3~
83-3-0l5 CN -11-
phytochrom~ was at least one of the pho-toreceptors
involved in an-thocyanin formation~
As indicated iII Table 4, by reciprocal changes of the
.irradiance and duration of irradiance, it is demonstxated
that anthocyanin formation in poinsettia disks obeys the
reciprocity relationships and this response is a function
of the dose lIxt~ rather than that of the irradiance
alone. The validity of khe reciprocity relationships
indicates the involvement of only one photoreceptor in
photocontrol of anthocyanin synthesis.
TABLE 4 _ _
RELATI~NSHIP BETWEEN IRRADIANCE AND TIME REQUIRED
FOR PHOTOPROMOTION OF ANTHOCYANIN FORMATION IN
POINSETTIA LEAF DISKS
.
RED LIGHT AMOUNT OF ANTHOCYANIN*
IRRADIAN~E (I) (A530 ~ A-33A657
.. AFTER IRRADIATION FOR:
. _
20_______. 240 hr 120 hr 60 hr
600 0.256 + 0.013- - 0.268 + 0.015~ 0.262 + 0 014
300 ~ 0 249 ~ O.0~5 ~ O.265 + 0.011 -0.119 + 0 006-~
150 -~ O 251 + 0 012 ~0.123 + 0.005 ~ 0.062 + 0.00~
~*Values enclosed in dashed lines represent equal light
doses, i.e., Ixt = constant, where I is irradiance and t
is time. Values are means of five separate exper.iments
done in triplicate + s.e. _
The quantity of anthocyanin formed in response to a
brief irradiance is relatively sma]l and maximum
production requires prolonged exposure to red light
.... . . .. . ... . , . . .... . . . . . , . ... .~ . .. .
~Z~3~
S3-3-015 CN -12-
(Table 5). The former response was identified as the low
enerqy red/far-red reversible phytochrome reaction, while
the latter was considexed as the high energy reaction,
also called high irradiance reaction system of plant
photomorphogenesis. The latter response suggested light
duration dependence of phytochrome interaction or the
possible existence of a secon.d photochemical system
besides phytochrome, particularly photosynthesi.s.
TABLE 5
EFFECT OF DURATION OF RED LIGHT EXPOSURE ON
ANT~OCYANIN FOR~TION IN POINSETTIA LEAF DISKS
.
TREATMENT : ~OUNT OF ANTHOCYANIN*
_ - - (A530 ~ 0'33A657
10 min R/Day** 0.024 + 0.001
(660 nm: 0.30 mW/cm2)
120 hr R 0.265 + 0.010
20 (660 nm: 0.30 mW/cm2) .
*Values are means of eigh : separate experiments done in
triplicate T statistical Standard error.
**E~traction of anthocyanin was performed five days after
the first irradiation treatment.
In order to determine if photosynthesis contributes
to reQ-light mediated HIR response in the enhancement of
a~thocyanin formation in poinsettia di.sks, studies were
conducted using various inhibitors of photosynthetic
photophosphorylation and chlorophyll synthesis. Table 6
shows the effect of cyclic and noncyclic photosynthetic
inhibitors on anthocyanin syn-hesis. Poinsettia leaf
disks were incubated with four inhibi-ors separately over
a period of ti~e under 660 nm light. None of the
inhibitors, such as 3- (3, -4 dichlorophenyl) -1,
dimethylurea (DC~IU), ammonium sulphate (N~l~)2SO4 of
1 ~ 7
83--3-015 CN -13-
noncycl,ic photophospho:rylation and dinitrophenol lDMP) arld
antimycirl-A (ANT-A) inhlhited the light-medi.atecl
anthocyanin formation.
TABLE 6 _~
. _ __
EFFECT OF PHOTOSYNTHETIC INHIBITORS ON ANTHOCYANIN
. FO~TION IN POINSETTIA LEAF DISKS
T~EATMENT - ¦ - AMOUNT OF ANTHOCYANIN8
CONCENTRATION¦ (A530 ~ O33A657 _
(M) ¦ DCMU (NH4)2SO4 DNP ANT-A .
O 0... 26Ba o.261a 0.249a 0.253a
10-5 0.261a 0.267a 0.256a 0.254a
10 3 0.264a 0.259a 0.252a 0.249'
*DCMU, 3-(3, -4 ~chlorophenyl)-1, DimethyIurea; DNP,
Di'nitrophenol; (NH 7 2SO~, A~onium sulfate; ANT-A,
Antimycin A.
Di,sks were exposed to red light at 660 nm (0.30 mW/cm2)
for five days. Controls kept in 0.lM sucrose solution.
Va~lues are means of five separate experiments done in
triplicate. Me~ns followed by identical postscripts
within each column are not significantly different for
.¦ nthocyan,in values.p,'~0'.05. - - - ~ .
Similarly, streptomycin (STM) and chloramphenicol
iCHP), inhibitors of chloroplast development and
chlorophyll syn'hesis at two different (10 ppm and 100
ppml concentrations had no effect on anthocyanin synthesis
(Table 7).
, . ... . . . .. . . . .. . . . ... . .. ... . .. .. .. .. .
83~3-015 CN -:l4-
¦ TAB].E 7
ACTION OF STREPTOMYCIN (STM)
AND CHLOR~MPHENICOL (CHP) ANTIBIOTICS ON
ANTHOCYANIN SYNTHESIS IN POINSETTIA LEAF DISKS
; AMOUNT OF ~NTHOCYANIN*
TREATMENT - : (A530 ~ 0-33A657
CONCENTRATION : .. :
STP~ ~._ .
. 0 0.265a 0.258a
0~ 259a O. 267a ,
100 0.268a 0.2S2a
*Disks were exposed to red light at 660 nm (0.30 mW/cm2
for five days. Control disks were incubated in 0.1M
sucrose solution. Values are means of five separate
experiments done in triplicate. Means followed by
idelltical postscripts within each column are not sig-
.. nif.icantl.y..different.for anthocyanin values, p<0.05.
The basic features of phytochrome response such as
the relative eEfectiveness of different irradiance levels,
red/far-red reversibility and the validity of the
reciprocit~ relationships of the response were not
affected by antibiotics. The ratios of the levels of
anthocyanin produced after a ten minute red, and a ten
minute redilO minute far-red treatment were the same in
the incubation medium containing inhibitors as was
observed with the control (Table 8). These findings
indicate that photosynthesis does not play any role in
red-light dependent anthocyanin formation, and the effect
of red radiation on anthocyanin synthesis and
photosynthetic development are independent of each other.
"
. . . ~ - . -- . . . . .
~1.2~ 37
83-3-015 CN -15--
TABL~ 8
______ _ _ . __
INFLUENCE OF STREPTOMYCIN (STM) AND CHLOP~MPHENICOI,
(CHP) ON THE R-FR REVERSIBILITY OF ANTHOCYANIN
FORMATION IM POINSETTIA LEAF DISKS
_
AMOUNT OF ANTHOCYANIN*
TREATMENT (A530 ~ 0-33A657~
Control STP CHP
(0.lM sucrose) (100 ppm) (100 ppm)
Dark Control 0.001 0.001a 0.001
10 min R/Day 0.024b 0.025b 0.024b
10 min FR/Day 0.001 0.001a 0.001a
10 min R + 10 min 0.001 0.001a 0.001
FR/Day
10 min FR + 10 min 0.023b 0.024b 0.023b
R/Day
*Extraction of anthoc~ anin was performed five days after
the first irradiation. Values are means of three
separate experiments done in triplicate. Means followed
by nonidentical postscripts within each column differ
significantly for anthocyanin values, p~0.05.
4. Discussion
The action spectra for anthocyanin formation in
cranberry, apple fruit skin and poinsettia leaf disks
shows two m~xima, one in the blue and the other in the red
region of the visible spectrum (Fig. 1). The spectral
sensitivity and -the irradiance dependence of anthocyani
synthesis in tissues exposed to continuous irradiation
depends upon the length of exposure (Figs. 2 through 5).
Thus, anthocyanin synthesis is controlled by high
irradiance reactions, operated throu~h the interactions of
phytochrome with other HIR photoreceptors.
Red light was effective in stimulating anthocyanin
formation and this effec-t was nullified when red light was
- - - . .
83-3-015 CN 16-
followed i.l~nedi.ately by far-red light. Such reversibility
was obtained with short ligh-t periods clearly indicati.ny
the involvement of phytochrome (Table 3)
Field Studies
1. Apples
a. Night-break liyht treatment
Apples tvar. "~cIntosh", "Red delicious")
on trees exposed to night-break light treatment (high
intensity discharge and/or VHO narrowband fluorescent
lamps: 1~/cm2 to 200~W/cm2, one quarter hour per day) for
40 days prior to harvest show improvement in anthocyanin
formation as compared to control (not receiving
nigh-t-break exposure) groups.
Referring to Table I, which tabulates the effect of
night-break light treatment on apple red coIor development
at the time of harvest, there is listed various data
comparing control vs. lighted crops for McIntosh apples
for t.he years 1977 and 1978, Red delicious apples for
1978-1980 for Washington State and California. Note that
in 1977/ with trees exposed to night-break lighting for 30
days prior to harvest, the percent red color for the
apples showed an improvement, from 73.8 percent to 78.3
percent (a 4.5 percent increase). In 1978, with a 30 day
exposure, the lighted group showed an improvement over
control of 62.8 percent vs. 53 percent (a 9.8 percent
increase).
The disparity among annual data is due, in part, to
the fact that two annual seasons are not identical, as to
temperature, humidity, rainfall, insect infiltration, and
the like.
The light applied was a combination of continuous
blue and continuous red lights having maximum emission
peaks centered around 448 nm and 660 nm, respectivPly.
The Red delicious apples were in Wenatchee,
Washington in 1978 and in Linden, California in 1979 were
exposed over a 45 day period, one-quar-ter hour per night,
. . - - : . .
. lL29~3~3~7
83-3-015 CN -17-
showing an improvement, over control, of 9.2 and 7
percent, resp-ectively. The tests were repeated the
followins year, with 40 day exposure showing an
improvement of 9.2 percent and 12.5 percent, respecti~Tely.
~3~3'7
83--3-015 -18-
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~ .~
a . ~ P ~
~ ~ ~ ~ .c
H E~ . 1~! ~ a~ C~ . 1
z o b
~j H ~ U ~ ~ O ~1 0
HX !~ _ ~) 2
I¢H l¢ ~ H ~
mlo ~ ~ ~
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12~ 3~
83-3-015 CN -19-
The eEfec-ts oE night-break treatment on apple (var.
"Red Delicious") harvest growth and quality in 1979 at
Wenatchee, Washington is tabulated in Tab].e II below.
Comparison is shown among control, apples treated with
alar, and night~break treatment at two different dosage
values.
In particular, the results show that night-break
lighting improves percentage red color over both control
and alar groups. The percentage of total solids, and the
dry weight of the apples, also showed improvement.
.;24L3~37
83--3--015 --20--
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3~37
83-3-015 CN -21-
Ethrel, a chemical growth regulator which is
commercially us2cl for red coloration of apples, produce~
apples having poor storage characteris-tics. In contrast,
apples exposed to night~break light treatment of blue and
red lights yield good storage quality characteristics, as
shown in Table III below:
TABLE III
_ ,
EFFECT OF NIGHT-BREAX LIGHT TREATMENT ON HAP~VEST APPI,E
FRUIT (VAR. "RED DELICIOUS" - TOP RED) QUALITY
~ (LINDEN, CA) 198Q
_ l
Treatment Av. Color Avo Firmness Av.% Storage ~uality
(%)(lbs.) ¦Solids Characteristicc
.,
Control 47O5 18.70 11.93 Good
Lighted 60 18.79 11.5~ Good
20 Ethrel* 50 17.04 13.77 Poor
California
Apple grower's 18 to 19 11 to 12
"Standards
*Ethrel is a chemical growth regul ator, us ed commercially
or red coloration of apples.
Night-break light treatment of apples (var. "Red
Delici~us") prior to harvest had VàriOI1S benefits compared
to "control" app]es which were not provided with
night-break lights. The lighted apples, as shown in Table
IV were more likely to be of consumer grade, (U.S. Extra
Fancy or Fancy)have a higher percentage of solids, be
heavier, longer, have a higher percentage of red color,
and have an increase in tree trunk growth.
~ 12~3~37
8 3- 3 - O 1 5 - 2 2 -
_ ___ R
U~ H ~ . . .
H ~i i~ ^ Lo c5~
~'C W ~ ~ ~ ai~ o -1 o
Z Q W ~ ~ o l~o
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a~ ~ ~ 0~o ~
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I
~ ~L2~3~
~3-3-015 C~' -23-
The night break light treated apples retained the
firmness of "control" apples, retained the good storage
characteristics of control apples, had a higher percentage
of solids than control apples, and had a higher percentage
of red color. In contrast, ethrel treated apples were
less firm, less solid, and had poor` storage
characteristics, as shown in Table V.
. ~ . . " . . ,
~ 3~37
83--3-015 -24-
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a ~ ~ In ~
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~ .~ .~ .
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_ _ _. . . _ .
3~"3~
83-3-015 ~N -25-
b. After harves-t con-tinuous lighting
Table VI tabulates the percentaye of red
color of "Red delicious" apples at Linden, Cali~ornia in
1979 under control conditions and lighted conditions.
Prior to harvest, the lighted apples were exposed to four
hours (from 10 pm to 2 am) of continuous red (peak
emission at 660 nm) and blue (peak emission at 448 nm) at
about 100~W/cm2. After harvest the lighted apples were
continuously exposed to 660 nm light (about 100~W/cm2) for
four days, while the apples were held in cold storage.
¦ _ TABLE VI _ _
¦EFFECT OF NIGHT-BREAK LIGHT TREATMENT ON APPLE RED COI.OR
- DEVELOPMENT, "RED DELICIOUS", LINDEN, CA., 1979
PERCENT RED COLOR
-28 35 HARVEST ~AFTER H~RVEST 4 DAYS
TREATMENT DAYS -DAYS 50 DAYS IN REGULAR COLD
~ ~ STORAGE*
CONTROL30 33 53 55
LIGHTED--40 46 - 60 - 85
- Night-~ ,reak treatment was co mmenced on July 3, 1979
Trees were exposed to red (660 nm) and blue (448 nm)
iights (-100~W/cm2) for 4 hrs (10 p.m. to 2 a.m.) per
nigh,.
*After harvest, fruits were held in regular cold
l10C) storage. The lighted group were exposed
immediately to con-tinuous 660 nm light t~l00~W/cm 2) for
four days. Fruits were graded for color after four days.
2. Grapes
Grapes (var. "Emperor") on vines were exposed
to night-break light treatment (HID and naxrowband
fluorescent lamps: l~W/cm2 to 200~W/cm2 for one to four
237
83 3-015 CN -26-
hours yer clay ror 40 clays prior to harvest. Impro~jremen-t
in anthocyanin format.ion was shown, as compared to contro:L
(not receiving night-break treatment), as shown in Table
VII.
Fruit growth (si~e) and quality (flesh firmness,
solids and storage-life) at the time of harvest were not
affected adversely by night-break light treatment.
Similarly, the terminal shoot growth and fruit bud
development was normal.
-
TABLE VII
EFFECT O~ NIGHT-BREAK LIGHTING TREATMENrT ON SUGAR :
ACCUMULATION AND ANTHOCYANIN FORMATION IN GRAPES
(VAR. "EMPEROR")
_
: AVERAGE .
TREA~MENT PERCENTAGE ANTHOCYANIN .
_ SUGAR IN~ENSITY
Control 14 +
Ethrel : 15.~ ~++~+_
Red Light 15.9 . ++~
Blue Light 15.4 ++
Red & Blue Light 15.3 +++
Red Light & Ethrel 16.93 : ++++_
~lue Lisht & Ethrel 16.23 ++++_
Red & ~lue Light & Ethrel 16.30 +~++-
_________________________ _______________ _____________.
Data Collection - two weeks prior to harvest
-~ Indicates (10-20%) pink colo.r of berries
++ Indicaces (30-45%) pink color of berries
+++ Indicates t50-75%) pink color of berries
++++ Indicates (S0-99%) pink color of berries
30- Indicates softening and deep brown red coloration
.of berries (not corNmercially desirable features~
. I . . ~ ~ ..... .. . . . ........ ... .. ..... . .
. ~
.
~3~37
83-3-015 CN -27-
Conclusions
~ se oE a specific lighting system should help
considerably in improvement of color of fruit and
ornamental crops (either exposure of produce under s-torage
or yreenhouse and field conditions) without causing either
any phytotoxicity or adverse effects on normal growth and
development of trees.
Through the practice of this invention, color of
fruits under regular cold storage greenhouse, and field
conditions can be improved using specific light treatments
without causing any adverse effects on plant grow-th and
development. The integrity of fruit storage quality
features can be maintained, and the environment kept free
from hazardous chemical residues. APP1QS taken from
regular cold storage can be light-treated at any time
before and after harvest with no subsequent fading of
color.
! i
