Effect of fertilizer nitrogen on drought resistance inCoffea arabicaL.

Summary When coffee trees have a good supply of nitrogen they are less affected by drought. Explanation and evidence are presented. Trees treated with extra nitrogen contained more adenosine triphosphate, aqueous protein and ‘bound water’. Such N-rich trees exhibited lower transpiration rates than trees relatively poor in N when water supply was limiting. They had lower stomatal density and water saturation deficit values. Leaves maintained higher chlorophyll and turgidity. The conclusion is that nitrogen increases the drought-resisting capacity of coffee trees. This aspect was clearly reflected in yield, as nitrogen-rich trees produced more coffee beans.