The First Report on Nutrient Distribution and Resorption in Mature Alternate Bearer Seedless Barberry Trees: Storage Pools of Nitrogen, Phosphorus, Potassium and Carbohydrates

Abstract

The main physiological problem of seedless barberry is alternate bearing (non-regular fruiting). Thus, we considered bearing (ON) and non-bearing (OFF) mature trees to check the nutrient content, carbohydrates, their distribution, and resorption. Overall, the highest content of N, P, K and carbohydrates was indicated in OFF-trees. Regarding tissues, the highest content of N, P and carbohydrates was observed in canopy branches. Crop loading significantly influenced N distribution within organs and reduced both above-ground and root parts N, P, K and carbohydrate reserves on fruit removal stage. Bearing trees resorbed only 66, 33, 98 and 16% as much N, P and K, respectively, compared to OFF-year status. Although higher N and total carbohydrate remobilization were observed in non-bearing trees, K movement was low in those trees during September (fruit color change). All resorbed and remobilized nutrients are accumulated in perennial storages observed in OFF-year status compared with ON-bearer, with a higher resorption rate. It is concluded that carbohydrates might be important in supporting new vegetative growth and development and supplying berry weight. However, more studies are recommended to find all aspects influencing growth and development of whole tree parts specifically in ON-year status