Growth response surface for optimizing fertilization in Andean blackberry (Rubus glaucus Benth.) nurseries

Abstract

Fertilization in soils cultivated with the Andean blackberry has been carried out empirically because there is no complete knowledge on its nutrient requirements. Therefore, the aim of this study was to estimate the effect of variable doses of N, P, K and Ca on the growth of thornless Andean blackberry in nurseries. This research was carried out in the nursery of AGROSAVIA C. I. Tibaitata (Mosquera, Colombia) using vitroplantlets sown in peat moss, sand and rice husks (2:1:1). A completely randomized block design with 25 treatments and 15 plants per experiment unit was used. The nutritive solution application frequency was established as every four d for three months with a volume of 44 mL/plant; the concentration was increased each month. Destructive sampling was carried out 30, 60 and 90 d after transplanting, registering plant height, leaf area, root length and volume, number of leaflets, and leaf, stem and root dry matter. Regression models were used establishing significance (P<0.05 and <0.01) between N, P, K and Ca using SAS 9.3. Doses of 36 N, 43 P2O5, 18 K2O, and 9 CaO g/plant improved the root development in terms of dry matter and length and increased the number of leaflets, aerial length and leaf dry matter.

Keywords

• vitroplantlets
• dry matter
• optimum dose
• application rate.