SOIL MULCHING AFFECTS FRUIT QUALITY IN STRAWBERRY - Ecological Consequences of Increasing Crop Productivity - page 171

with black polyethylene—0.89-1.06 percent which corresponds to the data of Casi-
erra-Posada F. et al. [9]. The strawberries grown without mulching had a lower indica-
tor—0.14-0.31 percent. Our earlier tests prove [16] that in the process of the straw-
berry ripening the organic acid content decreases gradually. Thus, the organic acid
content did not decrease to an optimal level in the strawberries grown on a mulched
soil and when they developed red coloring. 'Ducat' strawberries were the tartest ones
(0.99-1.06%).
The strawberries grown without mulching had high vitamin value—57.1-99.8
mg/100 g, whereas the use of agro cloth resulted in its decrease by 2-27.1 percent.
The highest content of ascorbic acid was recorded in the strawberries of 'Festyvalna
romashka' cultivar (74.8-99.8 mg/100 g). It should be noted that the use of mulching
facilitated faster ripening of the berries, but it had a negative effect on the accumula-
tion of the main components of the chemical composition.
During the storage because of berry respiration and selective gas permeability of
polyethylene, a modifi ed gas atmosphere with higher carbon dioxide content and lower
oxygen content is formed [17]. When strawberries were stored in this atmosphere, we
observed natural mass loss—from 0.9 to 2.2 percent. The highest mass loss was typi-
cal for the berries grown on row mulching with black polyethylene—2.0-2.2 percent,
depending on the cultivar; the lowest one, from 0.9 to 1.6, for control. Strawberries
of 'Festyvalna romashka' cultivar were characterized with higher mass loss compared
with others—from 1.6 to 2.1 percent.
The loss of organic substances occurs together with mass loss in the process of
storage. Within 11 days, the content of dry soluble substances in the berries decreased
by 4.5-11.3 percent as compared with their content before the storage. The lowest
losses of dry soluble substances were recorded for the strawberries grown without
mulching—0.2-1.6 percent, the losses were higher by 1-3 percent in the berries grown
with the use of mulching.
The highest losses of dry soluble substances, depending on mulching type, were
observed in the berries of 'Honey' cultivar was 5.9-11.3 percent; the same indicator
for 'Festyvalna romashka' cultivar was 7.3-9.4 percent. The lowest losses—4.5-8.2
percent—were recorded for 'Ducat' strawberry.
The use of mulching in the strawberry rows made it possible to reduce the losses of
dry soluble substances from 9.4 to 7.3-8.8 percent ('Festyvalna romashka' cultivar).
The strawberries of 'Ducat' and 'Honey' cultivars, grown without mulching, showed
the highest content of dry soluble substances after the storage—9.4-9.5 percent.
Within 11 days of the storage sugar content in the berries decreased by 2.3-35.5
percent. Among the cultivars studied, strawberries of 'Honey' cultivar showed the high-
est losses of sugars by 2.3-35.5 percent, those of 'Festyvalna romashka' cultivar were
2.5-25.3 percent. The lowest losses were recorded for 'Ducat' strawberries—5.2-18.1
percent. The use of mulching enhanced the stabilization of sugar content in the berries
during the storage. Their losses were smaller by 4.0-32.2 percent depending on the
mulching type. The strawberries of 'Ducat' cultivar were characterized by high sugar
content after the storage.
In the process of the storage, the decrease of organic acid content in the strawber-
ries by 1.3-35.8 percent was observed. 'Ducat' strawberries showed the highest losses