Physiological state of plants and quality of plum fruits grafted on the rootstocks of various strength of growth depending on the plant nutrition mode

The influence of the nutrition mode on the physiological state, productivity, and quality of the plum harvest of the Stanley variety on the rootstocks of various strengths of growth was investigated. The fertilizer system included the intra-soil application of the complex organic-mineral fertilizer based on peat and non-root dressings combined with the “Novosil” phytoregulator. The nutrition mode of plum plants was studied by the method of gross content diagnostics of elements in leaves and fruits. The significant increase of nitrogen and phosphorus content, number of functional pigments, free amino acids, and protein synthesis, especially in plants on the rootstock Best, was established during the period of the intensive shoot and ovary growth. In the early summer, the increase of calcium content and decrease of secondary metabolite one was found against the background of a decline of growth activity in plum leaves on the dwarf and medium rootstocks. The statistically reliable positive correlation between nitrogen, potassium, calcium and their content in plum fruits on the rootstock VVA 1 (r = 0.68, r = 0.74, r = 0.52) and rootstock Best (r = 0.75, r = 0.84, r = 0.61) was identified against the background of the application of fertilizers during the period of stress influence of abiotic factors in July. The green pigment content was also increased. The decline of protein content in leaves in the trees on the rootstock Best and rootstock PK SK 1 was minimal. At that time maximum losses of shared water were in plants on the rootstock cherry plum seedlings and minimum ones were on the rootstock PK SK 1. In early August the gross content of nitrogen, potassium, and calcium in the leaves of shoots increased with the application of fertilizers. In early September the excess of the sum of amino acids in plum leaves was 26,6-30,8% while the one in plum fruits was 12.5 and 23.5%; 24.2 and 11.5%; 17.3 and 19.6% on the rootstock VVA 1, rootstock Best, rootstock PK SK 1 respectively. The nutrition mode optimization promoted increasing of plant productivity on the rootstock Best and fruit weight on the rootstock VVA 1, rootstock Best, and rootstock PK SK 1.