Does Root-Zone Heating Mitigate the Cold Injury in Coffee Tree (Coffea arabica)?

Area of Science:

• Horticulture
• Plant Physiology
• Agricultural Engineering

Background:

• Tropical trees face cold injury in temperate climates, requiring costly greenhouse heating.
• Conventional heating is energy-intensive and expensive for protecting sensitive crops.

Purpose of the Study:

• To evaluate root-zone heating as an alternative to whole-greenhouse heating for cold protection.
• To assess the impact of root-zone heating on coffee tree physiology and survival during cold stress.

Main Methods:

• Coffee trees were subjected to cold treatment with and without root-zone heating.
• Leaf relative water content, defoliation, and photosynthetic parameters (CO2 assimilation, Fv/Fm, electron transport rates) were measured.

Main Results:

• Root-zone heating maintained leaf relative water content above 90%, preventing wilting.
• Defoliation was reduced by approximately 20% in heated treatments compared to controls.
• Photosynthetic function recovered significantly in heated plants post-cold treatment.

Conclusions:

• Root-zone heating is a viable strategy to mitigate cold injury in tropical trees.
• This method preserves leaf water content, reduces defoliation, and supports photosynthetic recovery.
• Root-zone heating offers a cost-effective and efficient alternative for cultivating tropical species in non-native climates.