18th International Symposium on Iron Nutrition and Interaction in Plants
Madrid – May 30-June 3 2016
EFFECTS OF SUSTAINABLE MANAGEMENT TECHNIQUES TO PREVENT IRON DEFICIENCY ON CARBON
FIXATION, WATER AND CHLOROPHYLL USE EFFICIENCY IN EMERALD BLUEBERRIES CULTIVATED IN A
CALCAREOUS SOIL
Lucía Michel, José I. Covarrubias*
Facultad de ciencias Agronómicas, Universidad de Chile. Av. Santa Rosa 11.315, Santiago, Chile.
*[email protected]
Blueberries are recognized worldwide as one of the foremost health foods, becoming one of the crops with the
highest productive and commercial projections (Lobos and Hancock, 2015). Over the last 100 years, the
geographical area where highbush blueberries are grown has extended dramatically into hotter and drier
environments, often associated with calcareous and sub-alkaline soils (Lobos and Hancock, 2015). In such
context, iron chlorosis is a common problem in such environments, being particularly harmful to calcifuges
species such as highbush blueberry. The strong reduction in plant longevity and productivity, root and shoot
growth, and berry yield and quality caused by iron deficiency has been well established. However, the effects
of iron chlorosis in carbon fixation and associated parameters in leaves, have not been fully studied in a
calcifuge and shade-adapted crop species as blueberry. Moreover, in the current climate change scenario,
field investigations about quantification of the water and chlorophyll use efficiency in iron deficient plants, and
the impact of sustainable management techniques to correct iron chlorosis in such parameters, are needed to
optimize irrigation and light management in blueberry orchards located in drought areas. The aim of the present
investigation is to determine the effects of sustainable management techniques to prevent iron deficiency on
carbon fixation, water and chlorophyll use efficiency in Emerald blueberries cultivated in a calcareous soil. Two
sustainable management techniques were evaluated: (1) application of a bovine blood meal compound and
(2) intercropping with graminaceous species, being selected Festuca rubra rubra and Poa pratensis. These
treatments were compared with plants treated with Fe-EDDHA and with untreated plants (control). The
experimental design employed was a latin square with 5 repetitions of each treatment. During the season, leaf
chlorophyll concentration, net photosynthesis (mol CO2 m-2 s-1), stomatal conductance (mmol CO2 m-2 s-1),
transpiration (H2O mol m-2 s-1), leaf temperature and incident radiation were evaluated (PPFD) (mol m -2 s-1).
Furthermore, chlorophyll and water use efficiency were estimated. In addition, these parameters were
evaluated in leaves with different degrees of iron chlorosis (severe, moderate and no chlorosis). Data obtained
indicate that iron chlorosis decreased leaf net photosynthesis, stomatal conductance and transpiration,
whereas the opposite behavior has been recorded in the leaf temperature, supporting the role of leaf
transpiration on the temperature regulation in plants. In addition, a lineal and positive correlation (p=0.0033)
was observed between the leaf total chlorophyll concentration and the water use efficiency (WUE). On the
other hand, a negative correlation (p=0.0023) was observed between the leaf chlorophyll concentration and
the chlorophyll use efficiency (CUE), and the opposite behavior was recorded between the leaf chlorophyll
concentration and the chlorophyll a/b rate (p=0.005). These results, indicate that a chlorotic leaf is able to fix
a higher amount of CO2 units (µmol) per chlorophyll unit (µg), and has a higher proportion of chlorophyll a as
compared with chlorophyll b. At harvest (66 DAB), a higher leaf chlorophyll concentration, net photosynthesis,
stomatal conductance and transpiration were recorded in plants associated with both graminaceous and in
those treated with Fe-EDDHA, in comparison with control blueberries. In contrast, the application of bovine
blood meal did not increase leaf chlorophyll concentration, and therefore, did not improve foliar gas exchange.
In conclusion, intercropping with graminaceous species increased leaf chlorophyll concentration, foliar gas
exchange and WUE, so it represents an effective and efficient sustainable strategy to control iron chlorosis
Emerald blueberries.
Keywords: intercropping, iron chlorosis, photosynthesis, chlorophyll, bovine blood meal.
REFERENCES. Lobos and Hancock 2015 Frontiers in Plant Science DOI: 10.3389/fpls.2015.00782
ACKNOWLEDGEMENT. This investigation was supported by FONDECYT 11130328 project.
Preferred Presentation format: POSTER.
Selected Sessions: Agronomic practices to correct Fe deficiency: fertilizer development
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