+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Photosynthetic Response to Low and High Light of Cacao Growing Without SHADE IN AN AREA OF LOW EVAPORATIVE DEMAND

Photosynthetic Response to Low and High Light of Cacao Growing Without SHADE IN AN AREA OF LOW EVAPORATIVE DEMAND

Acta Biologica Colombiana 23(1): 95-103

Cacao (Theobroma cacao L.) breeding programmes in Ecuador have focused on obtaining high-yield clones with improved disease resistance. Cacao clones should also have photosynthetic characteristics which support increased productivity. Regarding the weather conditions at the coast of Ecuador, where most of the year there are overcasts and low air evaporative demand, there is the possibility to grow cacao without overhead shade. This study focused on the photosynthetic response at two different photosynthetic photon flux densities (PPFD) of Ecuadorian cacao clones. Seven-year old cacao clones were evaluated: eight clones of Nacional type and two commercial clones (CCN 51 and EET 103), used as controls. All clones showed an increase of 35 % on average in net photosynthetic rate (A) with increasing PPFD from the light saturation point for cacao (i.e. 400 mu mol m(-2) s(-1)) to high values (1000 mu mol m(-2) s(-1)). Such light responsiveness in A has not been reported before. Higher A was associated with higher apparent electron transport rate, while high stomatal conductance was maintained under both PPFD conditions. Under high PPFD, low non-photochemical quenching values were found, suggesting low energy dissipation. All clones showed high maximum quantum yields of PSII (F-v/F-m), suggesting the absence of damage of the photochemical system.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 066356051

Download citation: RISBibTeXText

DOI: 10.15446/abc.v23n1.64962

Related references

Photosynthetic responses of sun- and shade-grown barley leaves to high light: is the lower PSII connectivity in shade leaves associated with protection against excess of light?. Photosynthesis Research 119(3): 339-354, 2014

The ratio of leaf to total photosynthetic area influences shade survival and plastic response to light of green-stemmed leguminous shrub seedlings. Annals of Botany 91(5): 577-584, 2003

Variation in light-intercepting area and photosynthetic rate of sun and shade shoots of two Picea species in relation to the angle of incoming light. Tree Physiology 32(10): 1227-1236, 2012

Effects of elevated CO(2) and light availability on the photosynthetic light response of trees of contrasting shade tolerance. Tree Physiology 16(3): 351-358, 1996

Photosynthetic activity, chloroplast ultrastructure, and leaf characteristics of high-light and low-light plants and of sun and shade leaves. Photosynthesis Research 2(2): 115-141, 1981

Evaporative flux from irrigated cotton as related to leaf area index soil water and evaporative demand. Agronomy Journal 70(6): 912-917, 1978

Photosynthetic Light Response and Epidermal Characteristics of Sun and Shade Pecan Leaves. Journal of the American Society for Horticultural Science 134(3): 372-378, 2009

Photosynthetic light response of the C4 grasses Brachiaria brizantha and B. humidicola under shade. Scientia Agricola 59(1): 65-68, 2002

Shade root structure of conifers and the photosynthetic response to light at two CO-2 partial pressures. Functional Ecology 9(3): 413-421, 1995

Shade Shoot Structure of Conifers and the Photosynthetic Response to Light at Two Co2Partial Pressure. Functional Ecology 9(3): 413-421, 1995

Regulation of photosynthetic metabolite pool sizes in sun and shade plants in response to light flecks. Plant Physiology (Rockville) 80(4 Suppl.): 51, 1986

The response of photosynthetic characteristics and enzymatic antioxidant system in leaves of two tropical seedlings growing in shade conditions as temperature fall. Scientia Silvae Sinicae 40(1): 47-51, 2004

Novel photosynthetic responses to growth in high light in Aechmea magdalenae, a shade tolerant CAM plant. Bulletin of the Ecological Society of America 77(3 Suppl. Part 2): 411, 1996

Stomatal response to high evaporative demand in irrigated grain sorghum in narrow and wide row spacing. Agronomy Journal 87(5): 1010-1017, 1995

Transpiration from banana leaves in the subtropics in response to diurnal and seasonal factors and high evaporative demand. Scientia Horticulturae 37(1-2): 129-144, 1988