Nitrogen accumulation and monitoring by strawberry stock plants for runner tips production

Resumo

The aim of this work was to determine runner tips production and nitrogen (N) accumulation by strawberry stock plants grown under five N concentrations in the nutrient solution and its relationships with chlorophyll meter readings. From September 2010 to March 2011, strawberry stock plants of cultivar Oso Grande and Camino Real were grown on sand polyethylene bags. Nitrogen was supplied by nutrient solutions at concentrations of 5.12 (C1), 7.6 (C2), 10.12 (C3), 12.62 (C4) and 15.12 (C5) mmol L^‑1. Runner tips bearing at least on expanded leaf were collected weekly and counted. The chlorophyll index (ICF) was measured fortnightly on the last second full expanded leaf of stock plant. A polynomial relationship was adjusted between the chlorophyll index and the N concentration in leaflets, which can be used for monitoring the N status of this crop. Runner tips production was not affected by N concentration.  The highest N and nitrate concentration were recorded on leaflets and petioles of stock plants supplied by the N concentration of 7.62 mmol L^{-1 in the nutrient solution, which can be used for the commercial production of runner tips.}