Articles
Extending blueberry production season with different covering materials
Article number
1357_11
Pages
69 – 78
Language
English
Abstract
Blueberry production in the southwest of Portugal shows strong interest, due to the possibility of production from April to October.
To extend the blueberry production season, several types of tunnel covers were tested in Grândola (Alentejo), standard polyethylene to anticipate production and two different nets to delay production.
Standard polyethylene was used from bud break to harvest, a white reflective net from fruit set to harvest, and a silver reflective net throughout the year.
The control group had no tunnel cover.
These different covers were applied to five cultivars, Alix Blue, Gupton, Star, Legacy and Sky Blue. In 5 plants of each cultivar and cover, phenological stages using an adapted BBCH scale, total number of fruits and total fruit weight plant1 , average fruit weight, °Brix, average fruit dry matter and new shoot growth were evaluated and radiation under the covers (PAR, PFD and the fraction of PAR in total light) was measured using a ceptometer and a spectroradiometer.
Results obtained evidenced that average fruit weight and new shoot growth were not significantly affected by the tunnel cover and that all parameters were negatively affected by the permanent silver net, while the white net provided best results for total number (152 fruits) and total weight of fruit (363 g). The polyethylene cover increased mostly fruit dry matter (18.2%). Total PAR, PFD, and fraction of PAR in light was mostly reduced by the white net (51, 54% and less 1.3% points, respectively), but all the covers showed negative outcomes when compared to the control.
Polyethylene was responsible for earlier flowering when compared to a white net (4 days), earlier fruit set (7 days), and an earlier start of fruit ripening (10 days). An adequate combination of cultivars and covers (white net applied to Sky Blue’) may prolong harvest season up to two weeks.
To extend the blueberry production season, several types of tunnel covers were tested in Grândola (Alentejo), standard polyethylene to anticipate production and two different nets to delay production.
Standard polyethylene was used from bud break to harvest, a white reflective net from fruit set to harvest, and a silver reflective net throughout the year.
The control group had no tunnel cover.
These different covers were applied to five cultivars, Alix Blue, Gupton, Star, Legacy and Sky Blue. In 5 plants of each cultivar and cover, phenological stages using an adapted BBCH scale, total number of fruits and total fruit weight plant
Results obtained evidenced that average fruit weight and new shoot growth were not significantly affected by the tunnel cover and that all parameters were negatively affected by the permanent silver net, while the white net provided best results for total number (152 fruits) and total weight of fruit (363 g). The polyethylene cover increased mostly fruit dry matter (18.2%). Total PAR, PFD, and fraction of PAR in light was mostly reduced by the white net (51, 54% and less 1.3% points, respectively), but all the covers showed negative outcomes when compared to the control.
Polyethylene was responsible for earlier flowering when compared to a white net (4 days), earlier fruit set (7 days), and an earlier start of fruit ripening (10 days). An adequate combination of cultivars and covers (white net applied to Sky Blue’) may prolong harvest season up to two weeks.
Publication
Authors
M. Pereira, M. Mota, P.B. Oliveira
Keywords
photosynthetically active radiation, polyethylene, white net, silver net, Vaccinium
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