The effects of pressure trunk injections of potassium on the mineral content,growth, yield and fruit quality of sweet cherry (Prunus avlum L.) and mineral content of prune (Prunus domestica L.)

Abstract

Fall trunk injections of 200 g K in K₂SO₄ solution or up to 300 g K in K₂HPO₄ solution had no effect on sweet cherry mid‐shoot leaf K in August. Phosphorus content was significantly increased in buds in March and midshoot leaves in August one year by fall injection of K₂HPO₄ (79.2 g P).

Spring trunk injections of 12.5 g K (K₂S04 or K₂HPO₄) in prune increased leaf K within four days and K levels remained higher than controls for at least 22 days with K₂SO₄ Leaf P was increased within four days by K₂HPO₄ and was higher than controls in August.

Fruit set in sweet cherry was significantly lower on trees injected with 200 g K (K₂S0₄) and 300 g K (K₂HPO₄). Yield was significantly lower for all injection treatments and was probably caused at least in part by reduced fruit set. Fruit quality was not affected by K injections.