Effects of defoliation on the cultivated strawberry (Fragaria X ananassa Duch.)

Abstract

Using 'Redchief' (Junebearer) and 'Tribute' (dayneutral) cultivars, greenhouse and field studies were conducted to determine the effects of defoliation on photosynthesis, growth and yield of the strawberry. From preliminary photosynthesis experiments it was found that both 'Redchief' and 'Tribute' strawberry leaves reached maximum net photosynthesis (Pn) concurrently with full leaf expansion at approximately 8 to l0 days and 4 to 5 days, respectively, after unfolding. By exposing the plants to increasing irradiance it was determined that these cultivars were light saturated at 600 to 700)Ï molâ ¢m⁻²s⁻¹. Neither cultivar showed a consistent diurnal pattern when Pn was monitored hourly over two consecutive days.