Influence of fall nitrogen and spring nitrogen-potassium applications on yield and fruit quality of 'Chandler' strawberry.

摘要

Annual-hill strawberry production with black plastic mulch and drip irrigation is gaining popularity in North Carolina. Two experiments (E1 and E2) were conducted on a Wagram loamy sand (Arenic Kandiudult) in 1992 and on a Norfolk sandy loam (TypicKandiudult) in 1993 to investigate the effects of autumn-applied N and spring-applied N and K on Chandler strawberry yield and fruit quality. E1 treatments included factorial combinations of banded autumn-applied N (0, 34 or 67 kg/ha) and drip spring-applied N (0, 0.19, 0.37, 0.56 or 0.75 kg ha-1 day-1 and 0, 0.37, 0.75 or 1.12 kg ha-1 day-1 in 1992 and 1993, respectively). E2 treatments included combinations of drip spring-applied N (0.56, 1.12, 1.68 or 2.24 kg ha-1 day-1) and K (0.46, 1.39 or 2.32 kgha-1 day-1 and 0, 0.75, 1.49 or 2.24 kg ha-1 day-1 in 1992 and 1993, respectively). There were no significant interactions among main effects for any of the measured variables. Market yield maximized with total N at～120 kg/ha with one-half banded in theautumn and the remainder drip-applied in the spring. Fruit firmness decreased with increasing N rate. Fruit pH and concentrations of total acids and soluble solids were not affected by N treatments, but soluble solids increased as the harvest season progressed. Plant crown number was not affected by N treatment but crown yield increased with N rate similar to market yield. There was no response to drip-applied K for any variable in either year. Based on soil tests, autumn-applied K (broadcast and soil-incorporated) met the K requirements in both years.