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Decrease in artificial radiation with netting reduces stress and improves rabbit-eye blueberry ( Vaccinium virgatum  Aiton) ‘Ochlockonee’ productivity
Retamal-Salgado, Jorge; Vásquez, Robert; Fischer, Susana; Hirzel, Juan & Zapata, Nelson
Abstract
Blueberry production under netting has increased in
recent years to mitigate the adverse effects of climate
change. The objective of the present study was to evaluate
the effect of different radiation intensities on rabbit-eye
blueberry (Vaccinium virgatum Aiton) ‘Ochlockonee’
photosynthetic efficiency and productive parameters. Four
treatments were established: T1 (control), T2, T3, and
T4 at 0%, 30%, 60%, and 90% radiation decrease (RD),
respectively, with black shedding netting. The following
were recorded for each treatment: environmental
conditions, photosystem II (PSII) maximum quantum
yield (Fv/Fm), photosystem II effective quantum yield
(ΦPSII), leaf stomatal conductance (gs), quality parameters,
and fruit yield. Results showed an increase of 4.6 ºC in
mean minimum temperatures for the different netting
treatments, which promote development and fruit set, as
well as prevent damage at temperatures near 0 ºC. The
RD treatments increased ΦPSII between 175% and 325%
(P < 0.05) compared to the control. It can be concluded
that netting decreased soil temperature between 1 and 3
ºC and increased minimum temperatures between 1 and
6 ºC, which promoted plant development and decreased
frost damage during flowering and fruit development.
Current direct radiation levels over 1000 μmol m-2 s-1 in V.
virgatum inhibited productivity in T1. Netting decreased
the degree of photoinhibition and increased photosystem
II photochemical efficiency throughout the day, and T4
and T3 exhibited the highest efficiency.
Keywords
Photosystem II; photoinhibition; photosynthetically active radiation; stomatal conductance.
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