Journal of Agricultural Sciences, Belgrade 2017 Volume 62, Issue 4, Pages: 329-339
https://doi.org/10.2298/JAS1704329M
Full text ( 328 KB)
Effect of a grey hail protection net on the fruit quality of the ‘Bluecrop’ highbush blueberry (Vaccinium corymbosum L.)
Milivojević Jasminka M. (Faculty of Agriculture, Belgrade)
Radivojević Dragan D. (Faculty of Agriculture, Belgrade)
Ruml Mirjana M. (Faculty of Agriculture, Belgrade)
Urošević Suzana S. (Faculty of Agriculture, Belgrade)
Dragišić-Maksimović Jelena J. (Institute for Multidisciplinary Research, Belgrade)
The main focus of our study was to investigate effects of the modified
microclimate under a grey hail protection net (HPN) on biometrical fruit
characteristics (fruit weight, index of fruit shape, and seed number per
fruit) and nutritional value (soluble solid content - SSC, titratable acidity
- TA, total anthocyanins - TACY, total phenolics - TPH and total antioxidant
capacity - TAC) of the ‘Bluecrop’ highbush blueberry (Vaccinium corymbosum
L.). The study was conducted in the ‘Bluecrop’ highbush blueberry plantation
located in Mladenovac (Serbia) during two consecutive years (2013, 2014). The
orchard was established using two-year-old nursery trees in spring 2011, at a
planting density of 3,300 bushes per ha. The grey polyethylene net
(SILVERLUX®, Helios Group, Lurano, Italy) with a Leno wave structure and a
mesh size of 2.8 x 8 mm was used. During the research period, light intensity
was measured weekly at 12.00 hr using a digital lux-meter ‘Peak teck’ PT-5025
(Germany). Air temperature and relative humidity within the canopy were
recorded using climate dataloggers (type DT-171, Shenzhen Flus Technology
Co., Ltd, China) both under HPN and in the open field (OF). Twelve readings
per treatment were taken at 2-hour intervals every day in each season. In
both years of observation, light was reduced by 5-20% under HPN, whereby
daily maximum temperature was 2.4°C lower causing 4% higher daily minimum
relative air humidity than in OF. ‘Bluecrop’ had significantly higher average
fruit weights under HPN ranging from 1.93 g (2013) to 1.86 g (2014) in
comparison to those observed in OF. The SSC did not differ between the
treatments in 2014, whereas a significantly higher mean value was registered
in the fruits harvested under HPN (12.8%) compared to those from OF in 2013.
The mean TA was higher under HPN in 2014 (0.57%), whereas in 2013 a
significantly higher TA content was found in OF (0.87%). HPN showed a
positive effect on the TPH content (7.12 mg GA/g FW), but an almost 2-fold
higher value was registered in 2013. Similar to this, TAC was 2.5-fold higher
in 2013, without a significant effect of HPN in both experimental years.
Keywords: light intensity, air temperature, relative humidity, biometrical and chemical fruit characteristics
Project of the Serbian Ministry of Education, Science and Technological
Development, Grant no. III46008, Grant no. III43007 and Grant no. 173040