QUANTUM YIELD, PHOTOSYNTHETIC PIGMENTS AND BIOMASS OF MINIWATERMELON UNDER IRRIGATION STRATEGIES AND POTASSIUM1

ABSTRACT This study was conducted with the objective of evaluating quantum yield, photosynthetic pigments and biomass accumulation mini watermelon cv. Sugar Baby, under strategies irrigation saline water potassium fertilization. The experiment in a randomized block design, 8 × 3 factorial scheme, three replicates, corresponding to eight applied at different phenological stages crop (control - low-salinity throughout cycle, salt stress vegetative, vegetative/flowering, flowering, flowering/fruiting, fruiting, fruiting/ fruit maturation stage) doses (50, 100 150% recommendation). dose 100% corresponded 150 mg K2O kg-1 soil. Two levels electrical conductivity were used: 0.8 4.0 dS m-1. Irrigation m-1 continuously vegetative flowering increased initial fluorescence decreased efficiency photosystem II fertilized K recommendation. Fertilization 50% recommendation did not interfere parameters watermelon, regardless management strategy. Chlorophyll synthesis is inhibited by fruiting/maturation stages, as well for total chlorophyll, except stage. Application promoted greater watermelon.