COFFEE SHADE WITH GREVILEA-ROBUSTA IN THE NORTH OF PARANA STATE, BRAZIL

Two field experiments have been carried out in the North of Parana Sta te, Brazil (latitude 23 degrees 45' S, longitude 52 degrees 30' W), to evaluate coffee shade with Grevilea robusta for protection against ra diation frost. A quadratic response of coffee production as a function of distance from the shade trees was found for one year of high yield , with yield reduction observed up to 12 m away from the trees. Coffee leaf damage by frost had a sigmoid response, with minimum damage clos e to the shade trees and no protection beyond 14 m. Coffee shade with 50 to 70 trees per hectare increased mean coffee yield up to 9% relati ve to fully exposed plots, on the total of 8 harvests. These results s how the potential of this practice for coffee production in regions wh ere frosts are likely to occur.