Thinning of apple flowers with potassium bicarbonate (ARMICARB®) in organic orchard

Abstract

Flower or fruit thinning is the most important technique in apple growing for improving fruit quality. In organic fruit production the use of chemical-synthetic thinning agents or plant hormones for crop regulation is forbidden. In Poland the Armicarb® is registered as a fungicide. Being a caustic chemical, Armicarb® damages petals, pistils and anthers and prevents fertilization. In 2013 and 2014 potassium bicarbonate was used twice at the doses 10 and 15 kg∙ha-1 on trees cv. ‘Braeburn Mariri Red’/M.9 T337. The first spraying was done at the beginning of flowering (BBCH 61) and the second at the full bloom (BBCH 65). Trees of cv. ‘Šampion’/M.9 T337 in 2014 were sprayed twice at BBCH 61 and 65 at the doses 10 and 15 kg∙ha-1, but in 2015 the single application was done. In 2014 and 2015 on trees cv. of ‘Gala Must’/M.9 only one spraying with potassium bicarbonate was done at doses: 10,15 and 20 kg∙ha-1. Thinning of apple flowers with Armicarb® caused a decrease in the yield, especially of cv. ‘Gala Must’ and ‘Šampion’. However in all cultivars the fruit size distribution was much better than in control. Each variety responded by clear increase in the fruit size after thinning with Armicarb®. Mean fruit mass, the diameter and length of apples after using Armicarb® at all doses were much bigger than in control. Skin of apples was severe russeted after application of Armicarb®. However skin russeting was also affected by the weather. In 2014, at cold temperatures and high precipitation during the period of intensively fruit growth, the skin of apples was more russeted relative to others seasons. © Wydawnictwo Uniwersytetu Przyrodniczego w Lublime. Lublin 2016.

Full text

THINNING OF APPLE FLOWERS WITH POTASSIUM BICARBONATE
(ARMICARB®) IN ORGANIC ORCHARD
Szot Iwona1, Basak Alina2, Lipa Tomasz3, Krawiec Paweł4
1,3,4 University of Life Science in Lublin; 2 InHort in Skierniewice
Abstract. Flower or fruit thinning is the most important technique in apple growing
for improving fruit quality. In organic fruit production the use of chemical-synthetic thinning
agents or plant hormones for crop regulation is forbidden. In Poland the Armicarb® is
registered as a fungicide. Being a caustic chemical, Armicarb® damages petals, pistils and
anthers and prevents fertilization. In 2013 and 2014 potassium bicarbonate was used twice at
the doses 10 and 15 kgha-1 on trees cv. ‘Braeburn Mariri Red’/M.9 T337. The first spraying
was done at the beginning of flowering (BBCH 61) and the second at the full bloom (BBCH
65). Trees of cv. ‘Šampion’/M.9 T337 in 2014 were sprayed twice at BBCH 61 and 65 at the
doses 10 and 15 kgha-1, but in 2015 the single application was done. In 2014 and 2015 on
trees cv. of ‘Gala Must’/M.9 only one spraying with potassium bicarbonate was done at doses:
10,15 and 20 kgha-1. Thinning of apple flowers with Armicarb® caused a decrease in the
yield, especially of cv. ‘Gala Must’ and ‘Šampion’. However in all cultivars the fruit size
distribution was much better than in control. Each variety responded by clear increase in the
fruit size after thinning with Armicarb®. Mean fruit mass, the diameter and length of apples
after using Armicarb® at all doses were much bigger than in control. Skin of apples was
severe russeted after application of Armicarb®. However skin russeting was also affected by
the weather. In 2014, at cold temperatures and high precipitation during the period of
intensively fruit growth, the skin of apples was more russeted relative to others seasons.
Key words: crop regulation, fruit quality, yield, flower thinning
INTRODUCTION
Apple trees have evolved a system to control fruit load by a process called
physiological drop [Bangerth 2000]. In a normal season an apple tree set 5-10% of its
blossoms. Under favorable conditions too many flowers develop into fruit and tree cannot
feed all of them properly. Overcroping results in a very poor fruit size and leads to a poor crop
in the next year. Fruit thinning is one of the important practices in apple tree cultivation for
improving fruit quality and the regularity of yielding [Looney 1993]. Fruit thinning is
accomplished by hand, mechanical or chemical methods. Chemical thinners are separated into

categories as bloom thinners and post bloom thinners. Early blossom thinning is currently
used in many apple producing areas to enhance return bloom and to reduce competition for
photosynthates between fruitlets [Fallahi and Fallahi 2004].
Organic products are becoming increasingly popular on the world markets of Europe
and North America, providing to further intensification of organic production. Growth of
organic fruit area exceeds the conventional fruit area and organic fruit area increases faster
than other organic crops. There is still a growing consumer response for organic fruit in
Europe, but marketing and competition from conventionally produced fruit are getting more
competitive [Granatstein et al. 2013]. Consumers expect organic apples to have comparable
size and quality to non-organic fruit and thinning is needed to achieve that goal [Weibel et al.
2013]. One of the main challenges in organic apple growing is the regulation of the crop load
to: prevent biennial bearing; improve fruit quality and save labor costs for hand thinning
[Link 2000]. In organic fruit production the use of chemical synthetic thinning agents or plant
hormones for crop regulation is forbidden. In most EU countries and in the US lime sulphur is
the standard thinning agent, however in Switzerland it is not allowed due to risks for the
operator [Weibel et al. 2012]. In Switzerland a formulated potassium bicarbonate product
(Armicarb®) is officially registered for thinning purposes in organic production [Weibel
2008]. In Poland the Armicarb® is registered as a fungicide. Being a caustic chemical,
Armicarb® damages petals, pistils and anthers and prevents fertilization. The objective of
these trials was to investigate the effect of Armicarb® on the thinning action and fruit quality
of apple cultivars: ‘Braeburn Mariri Red’, ‘Šampion’ and ‘Gala Must’. The cultivars chosen
for the experience are very important on European and Polish fruit organic market. Weibel et
al. [2013] reported that ‘Gala’ is the most popular cultivar in organic production (28% market
share) and ‘Braeburn’ is in fourth position (9%) after ‘Elstar’ (16%) and ‘Topaz (11%).
Šampion maybe is not so popular in the markets of Western Europe, but it is still a very
important cultivar on the Polish market.
MATERIAL AND METHODS
The trials were conducted on the two commercial organic fruit farms of family Lipa
and Buła, both situated close to Lublin. The experiments were performed in 2013 - 2015.
Each treatment (tab. 1) was tested on 10 trees (1 tree = replication) of similar height and
fruiting intensity, selected from trees distributed along the row. At the beginning of study the
experimental material were 6-year-old apple trees of cv. ‘Braeburn Mariri Red’/M.9 T337

rootstock, and 4-year-old apple trees of cv. ‘Šampion’/M.9 T337 rootstock, planted in
commercial orchards in Stryjno (52°6’67”N, 22°83’33”E). In other commercial orchard in
Świdnik Mały (51°26’67”N, 22°68’33”E), the experiment was conducted on 12-year-old
apple trees of cv. ‘Gala Must’/M.9 rootstock. Trees were planted in rows situated in the north
- south direction at distance: 3.0 x 0.8 m (‘Braeburn Mariri Red’), 3.3 x 1.2 m (‘Šampion’)
and 3.5 x 1.0 m(‘Gala Must’) and trained as slender spindles.
Flowering intensity of the trees cv. ‘Braeburn Mariri Red’and Šampion used for the
experiments was 90-100% and 75% (‘Gala Must’). In all studies a single spray was applied
with a knapsack sprayer at 1000 l of water per ha, up to “run off”. Usually the test agent were
applied twice during flowering stage BBCH 61 (at the beginning of flowering, about 10% of
flowers open) and BBCH 65 (at full flowering, at least 50% of flower open, first petal falling).
Only in the case of ‘Gala Must’ in 2014 and 2015 and ‘Šampion’ in 2015 (tab. 1) the spraying
was performed once (at the beginning of flowering, about 10% of flowers open). Armicarb®
(potassium bicarbonate; KHCO3) was applied at the rates 10 and 15 kgha-1 (‘Braeburn Mariri
Red’, Šampion’) and 10; 15 and 20 kgha-1 (‘Gala Must’). The Armicarb® should not be used
with the air temperature below 5°C and above 25°C. Since the test agent is a desiccant, the
application was done during warm days (air temperature about 15-20°C) from 8.30 to 9.30
a.m., with no rain announced for the following 24 h (tab. 2). Cultural practices other than
thinning were applied in a manner consistent with those of commercial apple orchards.
Crops of the experimental trees were harvested at commercial time. The harvest of
apple cv. „Braeburn Mariri Red’ in 2013 was conducted in 22nd of October and in 2014 in 28th
of October., ‘Šampion’ in 28th of September in 2014 and in 23rd of September in 2015. Fruit of
‘Gala Must’ were twice harvested: in 9th and 16th of September in 2014 and 10th and 17th of
September in 2015, so the data for ‘Gala Must’ are an average from two term of harvest.
For each experimental tree the total yield expressed in N°of fruittree-1 and kgtree-1
was determined. Size distribution – the fruits from every treatment were divided into three
class of fruit diameter: <65 mm; 65-75 mm and >75 mm.
A mean sample of 50 fruits per treatment was used to assess the fruit quality: Mean
fruit mass was determined with using digital scale (g). Diameter and length of fruits were
determined with using digital caliper (mm). Skin colour was specified in 1-5 scale (when 1:
no red colour, 2: 1-25% of skin coloured, 3: 26-50% of skin coloured, 4: 51-75% of skin
coloured, 5: 76-100% of skin coloured. Skin russeting was identified in scale 1-9 (when 1: no
net of russeting, and respectively 2: 1-12,5%; 3: 12,6-25%; 4: 25,1-37,5%; 5: 37,6-50%; 6:
50,1-62,5%; 7: 62,6-75%; 8: 75,1-87,5%; 9: 87,6-100% of skin fruit with russeting. Number

of seeds were recorded for each individual fruit from the probe of 25 apples per treatment and
determined as total number of seeds, which was divided for number of normal and
degenerated seeds. Fruit flesh firmness was measured on two sides of each fruit (the probe of
25 apples per treatment) with a hand held FT 327 penetrometer (EFFEGI, Italy), fitted with an
11.1 mm diameter head. Total soluble solids content (%) were determined using an Abbé
refractometer on the probe of 10 apples per treatment. Dry matter content (%) was determined
in three replicates per treatment with the oven-drying method. Total sugar content (%) was
determined according to the Loof-Schoorl method [Krełkowska-Kułas 1993]. Acidity (%) was
determined potentiometrically by titration with 0.1 N NaOH solution and was converted to
malic acid [Yermakov et al. 1987].
The data were subjected to analysis of variance and mean separation was by Tukey’s
test at P=0.05. Data were analyzed by STATISTICA for Windows version 5.5, Tulsa USA,
software.
RESULTS AND DISCUSSION
Armicarb® is a well-known product against scab and scooty blotch on apple [Tamm et
al. 2006]. Due to the limited number of preparations registered for fruit thinning, Armicarb®
is an interesting candidate for organic apple cultivation. Armicarb® showed quite good
thinning effect, when it was used during flowering period. It seems, that this product
deteriorates the stigma surface, preventing pollen germination there. The desiccation of the
stigma surface could be due to osmotic reactions induced by the high product concentration
[Weibel et al. 2008]. In the present research both doses of Armicarb® influenced the
significant decrease in total yield of ‘Braeburn Mariri Red’ determined in N°of fruits·tree-1 as
compared to the control. However, there was no significant decrease in total yield determined
in kgtree-1. It was caused by distinct increase in mean fruit mass, diameter and length of fruit
from trees treated by Armicarb®, as compared to the control (tab. 3). At the both rates of
Armicarb® stated significant decreasing in total yield of cv. ‘Šampion’ determined in N°of
fruitsha-1and kg·ha-1. It was clearly reflected in the quality of the fruit. The mean fruit mass,
the diameter and length of fruits were much bigger in the treatments with Armicarb® than in
control (tab. 4). In the study on cv. ‘Gala’ beside the doses of Armicarb® 10 and 15 kgha-1,
the dose 20 kgha-1 was additionally applied. Significant decrease in total yield determined in

N°of fruitsha-1and kgha-1 after using Armicarb® at all used doses was stated. All doses of
Armicarb® influenced on significant increasing in mean fruit mass, the diameter and length
of fruit as compared to the control (tab. 5).
A significant improvement in fruit size, especially of cv. ‘Šampion’ an ‘Gala Must’
may result from early reduction of crop load. Based on the results of long term experiment on
apple flower and fruit thinning Link [2000] stated that mean fruit weight was negatively
correlated with crop load. Armicarb® is blossom thinners, which has a caustic effect on floral
parts. Early removal of potential fruit is currently used in many apple producing areas to
enhance return bloom. It also results in reduced competition for photosynthates. Many
researchers [Bound and Wilson 2004, Stopar 2008, Bound and Klein 2010, Milić et al 2011]
found that fruit from the trees, where thinning has been performed at the time of flowering,
have a higher quality than fruits from trees where thinning practices were done later. This is
due to the fact that after removal of the part of the flowers, these that developed into fruitlets,
have better conditions for growth.
Fruit size can be viewed as the result of cell number, cell size and intercellular spaces
[Goffinet et al. 1995]. Early blossom thinning increases fruit size by enhancing the rate of cell
division in the cortical tissue and cell size [Pearson and Robertson 1953]. But cell number is a
more important contributor to fruit size than cell size. Bergh [1990] stated that the cell
division period lasted 4 weeks after full bloom. A decrease in cell number of fruits from trees
thinned after a period of intense cell division was accompanied by larger cell, but these larger
cells did not compensate for the reduction in cell numbers, and average size of fruit was
reduced [Bergh 1985].
Fruit size distribution corresponds to a normal distribution curve. Every effective
thinning treatment shifts the curve from the lower size categories to the higher ones [Link
2000]. In the first year of study on ‘Braeburn Mariri Red’ the use of the Armicarb® reflected
in increasing of percentage of fruits with diameter between 65-75 mm and bigger (fig. 1). The
percentage of fruits with diameter below 65 mm after using Armicarb® in the dose 10 kgha-1
was almost twice lower than in the control. In the second year of the study all apples were
bigger, because even in the control there were no fruits with diameter below 65 mm (fig.2). At
both doses of Armicarb® the amount of fruits cv. ‘Šampion’ with diameter above 75 mm
increased as compared to the control (fig. 3, 4 ). In the case of ‘Gala Must’ in every year of
study thinning by Armicarb® influenced on decreasing in percentage of small fruits with
diameter below 6.5 mm (fig. 5, 6). From the thinning trials of single year it may by concluded
that the yield of large apples is about doublet, especially in the case of cv. ‘Šampion’ and

‘Braeburn Mariri Red’. However the opportunity to increase the quantity of middle to large
sized fruit is rather restricted. It was clearly shown, that it is depending on the cultivar and the
year. In 2015 none of the thinning practices influenced on the increasing in size of apple cv.
‘Gala Must’. There were no apples with diameter above 75 mm. It could be connected with
unusually high temperatures and drought in August (tab. 7). Tukey [1970] stated, that thinning
does not change a potentially small fruit into a large fruit, but rather insures that a potentially
large fruit will size properly. Fruit thinning can quickly reach the point of diminishing returns.
Rather than a high percentage of large fruits, the objectives of thinning should be elimination
of the smallest fruits and improved fruit quality [Forhey and Elfving 1977]. In addition, a low
yield of small and of oversized fruit is also expected.
The number and quality of seeds could have a decisive influence on the fruits,
especially their size and form (symmetry), persistence, physical properties (firmness, juiciness
etc.), moreover the rustiness of the skin and weight loss in the store [Barbier 1983, Mantinger
1997]. Not all seeds in the fruit are well developed. It was postulated that some of the seeds
stop growing at different phases of the growing season, up to then, they may function as
sources of growth substances as well, and participate in the stimulation of the growing fruits,
and later, by their failure, they contribute to fruit drop. Racsko et al. [2009] founded that the
number of empty (degenerated) seeds was low in all studied phases than the number of stout
(normal) seeds. For some cultivars i.e. ‘Golden Delicious’, as many as 8 seeds per fruit are
considered to be necessary to obtain high quality fruit, which means, the fruits are sensitive to
the diminished number of seeds. Fewer than the critical number of seeds may cause russeting
of the skin and appearance of ribs on fruits [Gautier 1983]. In the fruits of ‘Red Delicious’, a
lower number of seeds per fruit (4-5) are expected. There was no influence of Armicarb® on
the number of total and degenerated seeds in fruits of ‘Braeburn Mariri Red’ as compared to
the control (tab. 3). Only application 15 kgha-1 of Armicarb® influenced on significant
increase in the number of normal seeds relative to the control. Apples of ‘Šampion’ from trees
treated with Armicarb® had much more seeds than control ones and these were normal
shaped seeds (tab. 4). Significant increase in the number of normal seeds and in total number
of seeds in the apples of ‘Gala Must’ after using Armicarb® at the dose 20 kgha-1 was stated
(tab.5). The individual varieties differed in the total number of seeds. The highest mean
number of total seeds was noted for cultivar ‘Šampion’. Apples of ‘Braeburn Mariri Red’ and
‘Gala Must’ were characterized by the lower mean number of total seeds (5.9 and 5.4
pieces·fruit-1). Racsko et al. [2009] determining the differences in the seed production during
the subsequent phases of the growing season stated at Gala’s mutants had the greatest number

of seeds (from 1138.3 to1510.4 n°/tree). Seed production for Šampion was on the level 859.9
n°/tree and for Braeburn mutans from 123.5 to 161.2 n°/tree.
A wide range of possible thinning effects on fruit firmness at harvest is to be expected,
because fruit firmness is determined multifactorially by positive and negative effects caused
for instance by fruit size, number and size of cells, volume of intercellular space, dry matter
(pectin) and mineral content [Link 2000]. Johnson [1994] noted increase in fruit firmness at
harvest, especially by thinning during the period from the five to fifteen days after full bloom
with no increase when thinned at twenty-five days after full bloom for ‘Cox’s Orange Pippin’.
On the other hand, firmness is often negatively associated with other thinning effects, such as
mean fruit weight and calcium content of the fruit [Siddiqui and Bangerth 1995, Kacal and
Koyuncu 2012]. The thinning of ‘Braeburn Mariri Red’ flowers with Armicarb® did not
influence on significant differences in flesh firmness between studied treatments (tab. 3).
Flesh firmness of the ‘Šampion’ apples after treating with Armicarb® at the dose 10 kgha-1
had significantly higher flesh firmness that the control ones (tab. 4). In the case of ‘Gala
Must’ after spraying with Armicarb® at the doses 10 and 15 kgha-1 the significant decreasing
in flesh firmness was stated (tab. 5).
An overall tendency is that fruit thinning decreases the percentage of green fruit and
increases yellow background colour of yellow cultivars and the extent and intensity of skin
blush in red cultivars. The number of leaves per fruit appear to enhance anthocyanin
accumulation. This may be due to a result of more photosynthate being available per fruit and
thus more sugar delivered for anthocyanin production. There was no significant influence of
Armicarb® application on skin colour of ‘Braeburn Mariri Red’ (tab. 3). Apples of. cv.
‘Šampion’ from trees treated with Armicarb® were much better coloured relative to the
control (tab. 4). Apples of ‘Gala Must’ from control trees treated with Armicarb® in the doses
15 and 20 kgha-1 were better coloured than the control ones (tab. 5).
When the growth rate of fruitlets is low, small cracks develop in the epidermis leading
to fruit russeting [Skene 1982]. Hand-thinning usually increases the growth rate of fruitlets
and thus reduces the amount of fruit with russeted skin. However chemical thinning is
practiced during the most sensitive phases of fruit development, for example during
flowering, so it is expected that thinning compounds might influence fruit russeting
specifically [Stopar 2004]. For example the use of ATS to thinning flower caused sometimes,
particularly at high concentration, more severe skin russeting [Irving et al. 1989, Noé N.
1996]. At apples cv. ‘Braeburn Mariri Red’ from trees treated with Armicarb®, skin was more
russeted than in the control (tab. 3). In the case of Šampion’ after using Armicarb® more

severe skin russeting was observed, as compared to the control (tab. 4). Thinning practices
with Armicarb® at the dose 15 kgha-1influenced on significant increasing in skin russeting,
as compared to the control (tab. 5).
The improvements in fruit size and colour by thinning are accompanied by higher
contents of soluble solids and titratable acid. In the case of ‘Braeburn Mariri Red’ thinning
practices had no significant influence on soluble solids content, but Armicarb® at the dose 15
kg·ha-1 caused that fruit had distinct higher acidity and lower sugar content than in control
(tab. 3). Apples of cv. ‘Šampion’ from trees treated with Armicarb® characterized by higher
soluble solids, dry matter content and lower acidity (tab. 4). There were no significant
differences in chemical composition of apples cv. ‘Gala Must’ after using Armicarb®. Only
treatment at the dose 10 kgha-1 caused significant decreasing in soluble solids content and at
dose 15 kgha-1 decreasing in acidity, as compared to the control. However apples from trees
treated with Armicarb® at dose 20 kgha-1 had much more dry matter content then the control
ones (tab. 5).
Besides thinning practices the weather conditions had significant influence on fruit
quality of studied cultivars. Fruit growth and development are influenced by different
environmental factors. A general temperature effect in plants involves the ratio between
photosynthesis and respiration. Higher than normal temperatures affect the photosynthetic
process through the increase of enzyme activity. The growing season in 2014 characterized by
the most favorable conditions for apple growth and development. The high air temperatures in
April accelerated flowering of all cultivars in relative to the 2013 and 2015. Beside the
temperature, the precipitation could affect the growth of fruit. In 2014 there were no month
with the drought. In the May, when fruitlets growth intensively, the precipitation was much
higher relative to multi - year mean (tab. 7).
Apples of cv. ‘Braeburn Mariri Red’ characterized by much higher mean fruit mass,
diameter and length of fruit, better colouring, had more normal seeds and soluble solids
content in 2014 than in 2013 (tab. 6). Apples of cv. Šampion’ in 2014 were significant bigger
than in 2015. They have much higher mean fruit mass, diameter and length of fruit and were
better coloured. However, these apples had significant less normal and total seeds and their
flesh firmness, soluble solids and dry matter content were lower than in 2015. Apples of cv.
‘Gala Must’ in 2014 were significant bigger than in 2015 because of higher mean fruit mass,
diameter and length of fruit. They had also significant higher flesh firmness. However, these
apples were more severe russeted, had significant less normal and total seeds and their soluble
solids and dry matter content were much lower than in 2015.

COCLUSIONS
1. Thinning of apple flowers with Armicarb® caused fruit set decrease, especially of cv.
‘Gala Must’ and ‘Šampion’. However at all cultivars the fruit size distribution was
much better than in control.
2. Each variety has responded by clear increase in the fruit size after thinning with
Armicarb®. Mean fruit mass, the diameter and length of apples at all doses of
Armicarb® were much bigger than in control.
3. Skin of apple was more severe russeted after application of Armicarb®. However skin
russeting was also affected by the weather. In 2014, at cold temperatures and high
precipitation during the period of intensively fruit growth, the skin of apples was more
russeted relative to others seasons.
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thinning in organic apple growing with optimized strategies including natural spray
products an rope-device. Europ. J. Hort. Sci., 73, 4, 145-154.
Weibel, F.P., Daniel, C., Tamm, L., Willer, H. (2013). Development of organic fruit in
Europe. Acta Hort., 1001, 19-34.
Weibel, F.P., Lemcke, B., Monzelio, U., Giordano, I., Kloss, B. (2012). Successful
blossom thinning and crop load regulation for organic apple growing with potassium-
bi-carbonate (Armicarb®): results of field experiments over 3 years with 11 cultivars.
Europ. J. Hort. Sci., 77, 4, 145-153.
Yermakov, A.I., Arasimovic, V.V., Yarosh, N.P., Peruanskij, J.V., Lukovnikova, G.A.,
Ikonnikova, M.I. (1987). Methods of biochemical analyses. Agropromizdat,
Leningrad, 431.
PRZERZEDZANIE KWIATÓW JABŁONI W UPRAWIE EKOLOGICZNEJ
ZA POMOCĄ WODOROWĘGLANU POTASU
Streszczenie. Przerzedzanie kwiatów lub owoców jest jedną z ważniejszych metod
stosowanych w uprawie jabłoni dla poprawy jakości owoców. W uprawie ekologicznej
zabrania się stosowania syntetycznych preparatów chemicznych oraz hormonów
roślinnych w celu przerzedzania. W Polsce Armicarb® jest zarejestrowany jako
fungicyd. Stosowany na kwiaty ma właściwości parzące, niszcząc płatki, słupek,
pręciki i w ten sposób zapobiegając ich zapyleniu. W latach 2013 i 2014
wodorowęglan potasu użyto dwukrotnie w dawkach 10 i 15 kg·ha-1 na jabłonie
odmiany ‘Braeburn Mariri Red’/M.9 T337. Pierwsza aplikacja została wykonana na

początku kwitnienia (BBCH 61), a druga w pełni kwitnienia (BBCH 65). Drzewa
odmiany ‘Šampion’ były opryskiwane dwukrotnie w roku 2014 w stadium BBCH 61 i
65, natomiast w roku 2015 zastosowano jednokrotną aplikację preparatu. W latach
2014 i 2015 jabłonie odmiany ‘Gala Must’ traktowano wodorowęglanem potasu
jednokrotnie, na początku kwitnienia, w dawkach: 10, 15 i 20 kg·ha-1. Przerzedzanie
kwiatów za pomocą Armicarbu® obniżyło plon jabłoni, zwłaszcza odmian ‘Gala
Must’ i ‘Šampion’. Jednakże w przypadku każdej z odmian zanotowano wyraźną
poprawę w rozmieszczeniu owoców w poszczególnych klasach wielkości w stosunku
do kontroli. Każda z odmian zareagowała znacznym zwiększeniem rozmiaru owoców.
Średnia masa pojedynczego owocu, średnica i długość jabłek po zastosowaniu
Armicarbu® były znacznie większe, niż w kontroli. Skórka owoców z drzew, gdzie
zastosowano Armicarb®, była silniej ordzawiona. Jednakże zaobserwowano, że
pogoda miała też wpływ na stopień ordzawienia. W 2014 roku, gdy w okresie
intensywnego wzrostu zawiązków panowały niskie temperatury powietrza i było dużo
opadów, skórka jabłek była bardziej ordzawiona w stosunku do owoców uzyskanych
w pozostałych sezonach.
Słowa kluczowe: regulowanie plonowania, jakość owoców, przerzedzanie kwiatów
Corresponding author – Adres do korespondencji: Iwona Szot, Department of
Pomology, University of Life Sciences in Lublin, ul. Leszczyńskiego 58, 20-068
Lublin, Poland, tel.: (+48) 81 524 71 08, e-mail:szoti@autograf.pl

Table 1. Treatments with Armicarb® tested in 2013-2014
Cultivar Concentrations
kgha-1)
Frequency and period of application Year
‘Braeburn Mariri Red’ 10 2 x at BBCH 61 and 65 2013, 2014
15 2 x at BBCH 61 and 65 2013, 2014
‘Šampion’ 10 2 x at BBCH 61 and 65 2014
15 2 x at BBCH 61 and 65 2014
10 1 x at BBCH 61 2015
15 1 x at BBCH 61 2015
‘Gala Must’ 10 1 x during flowering period (BBCH 61) 2014, 2015
15 1 x during flowering period (BBCH 61) 2014, 2015
20 1 x during flowering period (BBCH 61) 2014, 2015
Table 2. Weather conditions in the period of Armicarb® application
Weather
feature
‘Braeburn Mariri Red’ ‘Šampion’ ‘Gala Must’
2013 2014 2014 2015 2014 2015
BBCH
61
BBCH
65
BBCH
61
BBCH
65
BBCH
61
BBCH
65
BBCH
61
BBCH
61
BBCH
61
Application
date
14th of
May
16th of
May
6th of
May
14th of
May
25th of
April
6th of
May
1st of
May
29th of
April
6th of
May
Average
temperature
13.2 18.4 8.7 10.2 13.8 8.7 10.2 13.2 15.7
Max
temperature
17.7 23.4 14.6 14.2 18.4 14.6 17.3 20.3 20.7
Min
temperature
8.9 12.6 2.0 6.2 9.4 2.0 4 7.8 11.3
% relative
humidity
77 69 64 89 71 64 72 74 88
Average
wind speed
(kmh)
10.2 7.8 7.8 9.6 12.2 7.8 7.4 7.2 10.4
Precipitatio
n totals
(mm)
000000000

Table 3. The effect of using Armicarb® on yield and some chemical and physical
characteristics of apples cv. ‘Braeburn Mariri Red’ (mean from two years 2013-2014)
Studied features Treatment
Control Armicarb® 10 kg·ha-1 Armicarb® 15 kg·ha-1
Total yield (N°of fruittree-1) 126.0 b* 102.7 a 100.6 a
Total yield (kgtree-1) 20.7 a 19.9 a 19.5 a
Mean fruit mass (g) 173.1 a 200.7 b 201.8 b
Diameter of fruits (mm) 71.9 a 75.7 b 75.7 b
Length of fruits (mm) 66.2 a 69.6 b 70.7 b
Skin colour (scale 1-5) 4.82 a 4.85 a 4.83 a
Skin russeting (scale 1-9) 1.09 a 1.40 b 1.34 b
Number of normal seeds (N°of
seedsfruit-1)
3.66 a 4.40 ab 5.09 b
Number of degenerated seeds
(N°of seedsfruit-1)
1.87 a 1.27 a 1.30 a
Total number of seeds (N°of
seedsfruit-1)
5.53 a 5.67 a 6.39 a
Flesh firmness (kGcm-2) 9.78 a 9.88 a 9.77 a
Soluble solids content (%) 12.79 ab 13.11 b 12.27 a
Dry matter content (%) 15.25 a 15.59 a 15.60 a
Sugar content (%) 6.57 b 6.47 b 6.15 a
Acidity (%) 0.56 b 0.53 a 0.57 c
*Means marked with the same letter in a row did not differ significantly at =0.05
Table 4. The effect of using Armicarb® on yield and some chemical and physical
characteristics of apples cv. ‘Šampion’
Studied features Treatment
Control Armicarb® 10 kg·ha-1 Armicarb® 15 kg·ha-1
Total yield (N°of fruittree-1) 167.25 b* 97.65 a 101.95 a
Total yield (kgtree-1) 23.46 b 16.44 a 17.17 a
Mean fruit mass (g) 141.87 a 168.79 b 169.61 b
Diameter of fruits (mm) 69.92 a 76.23 b 76.55 b
Length of fruits (mm) 61.95 a 67.30 b 67.40 b
Skin colour (scale 1-5) 3.04 a 4.10 b 4.08 b

Skin russeting (scale 1-9) 1.88 a 2.28 b 2.18 b
Number of normal seeds
(N°of seedsfruit-1)
6.1 a 7.9 b 8.1 b
Number of degenerated seeds
(N°of seedsfruit-1)
0.1 b 0.0 a 0.0 a
Total number of seeds (N°of
seedsfruit-1)
6.2 a 7.9 b 8.1 b
Flesh firmness (kGcm-2) 6.55 a 6.76 b 6.51 a
Soluble solids content (%) 12.45 a 13.70 b 13.53 b
Dry matter content (%) 14,79 a 16,23 c 15,79 b
Sugar content (%) 9.04 a 9.24 a 9.43 a
Acidity (%) 0.35 b 1.30 a 1.29 a
*Explanations as in table 3.

Table 5. The effect of using Armicarb® on yield and some chemical and physical
characteristics of apples cv. ‘Gala Must’
Studied features Treatment
Control Armicarb® 10
kg·ha-1
Armicarb® 15
kg·ha-1
Armicarb® 20
kg·ha-1
Total yield (N°of fruittree-1) 279.80 c 223.95 b 208.65 b 174.4 a
Total yield (kgtree-1) 32.57 c 29.26 b 28.73 b 25.44 a
Mean fruit mass (g) 120.81 a 138.00 b 150.27 c 161.57 d
Diameter of fruits (mm) 64.85 a 68.45 b 69.51 c 70.32 c
Length of fruits (mm) 60.68 a 63.81 b 65.09 bc 65.84 c
Skin colour (scale 1-5) 2.73 a 2.91 a 3.26 b 3.51 b
Skin russeting (scale 1-9) 1.58 a 1.54 a 1.81 b 1.72 ab
Number of normal seeds
(N°of seedsfruit-1)
4.5 a 4.7 a 4.9 a 6.1 b
Number of degenerated seeds
(N°of seedsfruit-1)
0.4 b 0.4 b 0.13 a 0.2 ab
Total number of seeds (N°of
seedsfruit-1)
4.87 a 5.03 a 5.01 a 6.31 b
Flesh firmness (kGcm-2) 7.55 c 7.11 a 7.31 b 7.58 c
Soluble solids content (%) 12.45 b 11.90 a 12.55 b 12.28 b
Dry matter content (%) 14.28 ab 14.03 a 14.50 b 14.92 c
Sugar content (%) 6.89 ab 6.71 a 7.07 b 6.83 a
Acidity (%) 0.270 bc 0.267 ab 0.257 a 0.280 c
*Explanations as in table 3.
Table 6. The comparison of yield and some chemical and physical characteristics of apples cv.
‘Braeburn Mariri Red’, ‘Šampion’ and‘Gala Must’ between years of study
Studied features ‘Braeburn Mariri Red’ ‘Šampion’ ‘Gala Must’
2013 2014 2014 2015 2014 2015
Total yield (N°of fruittree-1) 131.20 b* 88.33 a 113.9 a 130.67 b 183.15 a 260.25 b
Total yield (kgtree-1) 19.66 a 20.41 a 19.77 b 18.28 a 28.36 a 29.64 a
Mean fruit mass (g) 151.57 a 232.11 b 176.90 b 143.27 a 157.89 b 127.44 a
Diameter of fruits (mm) 68.14 a 80.70 b 77.75 b 70.73 a 72.09 b 64.48 a
Length of fruits (mm) 62.01 a 75.67 b 68.79 b 62.31 a 67.58 b 60.13 a

Skin colour (scale 1-5) 4.69 a 4.97 b 4.43 b 3.05 a 3.11 a 3.10 a
Skin russeting (scale 1-9) 1.04 a 1.51 b 2.08 a 2.14 a 2.02 b 1.31 a
Number of normal seeds (N°of
seedsfruit-1)
3.8 a 5.0 b 6.6 a 8.2 b 3.9 a 6.2 b
Number of degenerated seeds
(N°of seedsfruit-1)
2.65 b 0.31 a 0.01 a 0,04 a 0.27 a 0.28 a
Total number of seeds (N°of
seedsfruit-1)
6.4 b 5.3 a 6.6 a 8.2 b 4.2 a 6.4 b
Flesh firmness (kGcm-2) 10.42 b 9.21 a 6.04 a 7.17 b 7.95 b 6.83 a
Soluble solids content (%) 12.49 a 12.96 b 12.23 a 14.22 b 11.60 a 12.99 b
Dry matter content (%) 15.35 a 15.61 a 14.39 a 16.82 b 13.79 a 15.07 b
*Mean in the row in within the cultivar, followed by the same letter, do not differ =0.05.

Table 7. Mean monthly air temperatures and precipitation in the years 2013-2014 against the
multi-year mean values (1951-2012) in Felin near Lublin
Month Temperature (°C) Multi-
year
(1951-
2012)
mean
(°C)
Precipitation totals (mm) Multi-
year
(1951-
2012)
mean
(mm)
2013 2014 2015 2013 2014 2015
April 7.9 9.7 7.8 7.4 55.1 50.3 29.2 39.0
May 14.8 13.4 12.5 13.0 109.2 242.8 115.1 60.7
June 17.8 15.6 16.7 16.3 114.5 62.7 18.8 65.9
July 18.6 20.2 19.3 18.0 88.1 87.4 47.5 82.0
August 18.6 17.8 21.9 17.2 16.0 93.2 7.4 70.7
September 11.5 14.1 14.7 12.6 42.2 30.7 88.4 53.7
October 9.8 9.1 6.7 7.6 6.9 23.6 60.2 40.1
Mean/Sum
for
vegetation
season
14.1 14.3 14.2 14.2 432 590.7 366.6 412.1
Fig.1. The size distribution (%) in individual classes of fruit
diameter for ‘Braeburn Mariri Red’ in 2013
Fig. 2.The size distribution (%) in individual classes of
fruit diameter for ‘Braeburn Mariri Red’ in 2014
Fig.3. The size distribution (%) in individual classes of fruit
diameter for ‘Šampion’ in 2014
Fig.4. The size distribution (%) in individual classes of
fruit diameter for ‘Šampion’ in 2015

Fig.5. The size distribution (%) in individual classes of fruit
diameter for ‘Gala Must’ in 2014
Fig.6. The size distribution (%) in individual classes of
fruit diameter for ‘Gala Must’ in 2015