Categorization of Lycium barbarum nutrient disorders and substrate pH values

P. Cockson, I. McCall, B. Whipker
To produce goji berries (Lycium barbarum), growers must be equipped with cultural information to recognize and remedy nutrient disorders and pH imbalances. Nutrient diagnostic criteria and optimal pH values for goji are limited or absent from current literature. Therefore, goji plants were grown in two studies to determine nutrient disorders and optimal substrate pHs. In experiment 1, plants were grown in silica sand culture to induce nutrient disorder conditions. Nutrient-deficient treatments were induced with a complete nutrient formula minus a single nutrient. Boron (B) toxicity was induced by increasing the element 10-fold. Daily documentation and photographs were taken of symptoms as they developed. Out of 13 treatments, nine exhibited symptomologies. Symptoms of nitrogen (N), manganese (Mn), phosphorus (P), potassium (K), iron (Fe), and sulfur (S) deficiencies, manifested early, therefore these nutrients should be monitored more closely by growers. Unique symptoms were observed on N, P, and Mg deficient plants. In experiment 2, three goji cultivars were grown to determine an optimal substrate pH for early plant establishment in the greenhouse. The goji plants were grown for five weeks using an 80:20 peat perlite mix calibrated to four target pHs (5.0, 6.0, 7.0 and 8.0). Upon termination, data was taken on plant dry weight, height and diameters, SPAD values, and plant leaf tissue nutrient values. Results indicate that the optimal pH for goji is greater than 5.0 and less than 7.0. In both lower and higher pH substrates, plants exhibited stunting (lower pH) or interveinal chlorosis and yellowing (higher pH). Plants grown in the desired pH range were larger and exhibited higher SPAD values.
Cockson, P., McCall, I. and Whipker, B. (2019). Categorization of Lycium barbarum nutrient disorders and substrate pH values. Acta Hortic. 1265, 107-112
DOI: 10.17660/ActaHortic.2019.1265.15
goji berry, soilless media, deficiency, toxicity, nutrition, optimal ranges

Acta Horticulturae