EFFECT OF BIO-STIMULANTS ON THE YIELD PERFORMANCE OF ORGANICALLY-GROWN EGGPLANT CULTIVARS IN THE U.S. VIRGIN ISLANDS

Crop bio-stimulants derived from commercial marine algae extracts have been known to improve yields in fruits and vegetable crops in conventional production system. Therefore, studies of biostimulants in organic management system are needed to determine their potential impact on yield. In organic management system ten cultivars of eggplant (Nubia, Fairy Tale, Dancer, Beatrice, Calliope, Orient Charm, Barbarella, RosaBianca, Machiaw and Shooting Stars) were selected to evaluate bio-stimulant effect. Ten cultivars of eggplant (Solanum melongena L.) were treated weekly with Stimplex® (5 mL/L) (liquid seaweed extract of Ascophyllum nodosum) and Biozest® (20 mL/L) crop bio-stimulants as foliar spray. Half of the plants in a row (5 plants) were sprayed weekly and the other half of the plants (5 plants) were untreated as a control. The organically managed, experimental design was a randomized complete block with 3 replications consisting of rows spaced 3' apart with plants spaced 2' between each plant within a row. Results showed that Stimplex® treated plants performed better than biozest treated plants. Marketable yields were higher in Stimplex® treated plants of Nubia (10.7%), Fairy Tale (42.5%), Dancer (31.9%), Beatrice (27.8%), Barbarella (13.9%), Machiaw (84.2%) and Shooting Stars (9.9%) than their respective untreated controls. Higher marketable yields were obtained in Biozest® treated plants of Nubia (35.8%), Beatrice (10.3%), Orient Charm (1%), Rosa Bianca (68.8), and Shooting Stars (55%) relative to their respective untreated controls. The remaining cultivars produced lower or non-significant yields. These results suggest that bio-stimulants may increase yields in eggplant. Additional research trials are needed to fully explain the effects of bio-stimulants in organically managed commercial production of eggplant