SEASONAL DIFFERENCES IN SOLUBLE AND INSOLUBLE NONSTRUCTURAL CARBOHYDRATES IN ROWCOVERED AND NON-ROWCOVERED STRAWBERRY.
Leaves of rowcovered and non-rowcovered strawberry plants were analyzed for soluble and insoluble nonstructural carbohydrates from September 1986 through May 1987 to determine the effect of growing season extension with rowcovers on partitioning of carbohydrates. A rowcover treatment of extruded polypropylene-polyamide mesh was applied on 11 September 1986 and was removed at bloom on 12 May 1987. A protective winter mulch of straw was applied to both treatments on 22 December 1986 and was removed from the rowcover treatment on 27 March 1987 and from the control treatment 24 April 1987. In autumn maximum levels of total nonstructural carbohydrates (TNSC) were attained three weeks later and were higher for the season in rowcovered treatment compared to non-rowcovered control. There was an increase in soluble sugars in the rowcovered treatment and there were treatment by sample date interactions for fructose, glucose and maltose. For all sample dates in spring TNSC levels were higher in leaves in the rowcovered treatment. Sucrose levels were higher in the second sample and fructose levels were higher in the second and third samples while glucose levels were higher for all but the first sample in the rowcover treatment. There were significant treatment by sampling time interactions for fructose, glucose and sucrose. In the rowcover treatment total soluble sugar concentrations increased while in controls they decreased or remained constant. Rowcovers in autumn and rowcovers plus early mulch removal in spring sustain carbohydrate metabolism longer in autumn and initiate it earlier in spring compared to non-rowcovered control.
Gast, K. L.B. and Pollard, James E. (1989). SEASONAL DIFFERENCES IN SOLUBLE AND INSOLUBLE NONSTRUCTURAL CARBOHYDRATES IN ROWCOVERED AND NON-ROWCOVERED STRAWBERRY.. Acta Hortic. 265, 369-376