Influence of fertilization on growth and generative parameters of two short day strawberry cultivars grown in substrate, and evaluation of analysing tools for leaf nitrate and potassium
We examined the influence of fertigation on vegetative and generative parameters of strawberry plants (Fragaria × ananassa Duch.) and evaluated rapid analysing tools for N and K in leaf tissue. The experiments were undertaken in an open polytunnel on table top with Sonata and Korona grown in 2-L pots filled with a peat-based soil mixture. The experimental design was a randomized plot with three replications. Plants were fertigated with EC levels of 0.5, 1.0, 1.5 and 2.0 mS cm-1, based on two stock solutions of 7.5 kg YaraLiva Calcinit and 7.5 kg Kristalon Indigo, both dissolved in 100 L of water. Percentage N and K in leaves differed between analysing methods, cultivars, EC and date. We found interactions between the cultivar and EC level and between date and cultivar for N and K in leaf. Analysing NO3- by a photometric method (PM) in a lab, and by Laqua twin (LT), showed significant interaction with N% of leaf dry matter (DM) only for LT (r2=0.36). N% increased with higher EC level, more for Korona than for Sonata. LT K+ did not correlate with K% (r2=0.014). The number of crowns and runners increased for both cultivars up to EC 1.5, while the number of leaves was unaffected. Petioles were the shortest at the lowest EC. Flower initiation was earlier at low EC in both cultivars. In the following spring, the time to flowering and first harvest was reduced with the decreasing EC. The number of flowers per plant increased up to EC 1.5, but dropped strongly at EC 2.0 for Korona, while Sonata had a gradual increase of flowers with the increasing EC, but the number was only a third of Korona, except at EC 2.0, where the amount was equal for both cultivars. The conclusion can be drawn that LT correlated better than ChlDualex with N in strawberry leaves. However, r2 was only 0.36 indicating that LT NO3- is a coarse management tool. LT K+ was not a promising tool for rapid K+ test in these experiments. Korona seemed to benefit of higher N levels for both vegetative growth and generative development than Sonata up to EC 1.5, but Sonata reached a higher floral primordia development stage in early October.
Nestby, R., Woznicki, T.L. and Sønsteby, A. (2018). Influence of fertilization on growth and generative parameters of two short day strawberry cultivars grown in substrate, and evaluation of analysing tools for leaf nitrate and potassium. Acta Hortic. 1217, 391-398
branch crowns, electrical conductivity (EC), floral primordia, leaf, runner