Impacts of leaf age and heat stress duration on photosynthetic gas exchange and foliar nonstructural carbohydrates in Coffea arabica

• DOI: 10.1002/ece3.2681
• Publication Date: 2017-01-30T03:37:25Z
• Authors: Danielle E. Marias; Frederick C. Meinzer; Christopher Still
• Keywords: Stomatal Conductance

Abstract Given future climate predictions of increased temperature, and frequency intensity heat waves in the tropics, suitable habitat to grow ecologically, economically, socially valuable Coffea arabica is severely threatened. We investigated how leaf age stress duration impact recovery from C. . Treated plants were heated a growth chamber at 49°C for 45 or 90 min. Physiological was monitored situ using gas exchange, chlorophyll fluorescence (the ratio variable maximum fluorescence, F V / M ), nonstructural carbohydrate ( NSC ) on mature expanding leaves before 2, 15, 25, 50 days after treatment. Regardless age, 90‐min treatment resulted greater reduction 2 slower than 45‐min In both treatments, photosynthesis recovered more slowly leaves. Stomatal conductance g s decreased but did not change These responses led reduced intrinsic water‐use efficiency with increasing classes. Based energy balance model, aftereffects would be exacerbated by increases temperature low under full sunlight where often grown, also partial sunlight. Starch total content group significantly then accumulated 15 25 coinciding contrast, sucrose day suggesting that phloem transport inhibited. Both contrasted control plant starch, which declined time associated subsequent flower fruit production. No treated produced flowers fruits, short can lead crop failure.