DECLINE OF VEGETATIVE GROWTH IN COFFEA-ARABICA L IN RELATION TO LEAF TEMPERATURE, WATER POTENTIAL AND STOMATAL CONDUCTANCE

The decline of vegetative growth of Arabica coffee trees in Vicosa (20 degrees 45' S, 650 m altitude), Brazil, occurring from mid-March thro ugh late May, was observed in both irrigated and non-irrigated plants and did not show a direct relation with leaf water potential. Declinin g growth coincided with lowering temperatures, and particularly with i ncreasing daily periods with low temperatures. Stomatal conductances i n the morning (0800-0900 h) were relatively high until mid-March and d ecreased gradually in parallel with declining growth rates. During the quiescent growth phase in the cool season, starting from late May, st omata were closed for most of the diurnal period. (C) 1997 Elsevier Sc ience B.V.