Response of strawberry plants to hydrogen cyanamide and potassium nitrate applications

Abstract

Several chemical substances, including hydrogen cyanamide and potassium nitrate, have been used on different plants, such as deciduous fruit trees, to break their dormancy and consequently improve the earliness of the crop. In order to study the effects of hydrogen cyanamide and potassium nitrate on dormancy breaking of strawberry plants, four experiments were carried out over three seasons, using Chandler and Pajaro cultivars, different types of plants (fresh and frigo plants), two concentrations (hydrogen cyanamide: 0.5% and 1%; potassium nitrate: 1.5% and 3%) and two application methods (spraying the whole plant or only the crown). Production, fruit weight and percentage of malformed fruits were measured.

Potassium nitrate improved earliness in two experiments and the yield in one; it increased the fruit weight in one experiment and did not affect the percentage of malformed fruits. Hydrogen cyanamide did not positively affect earliness or yield, it increased the fruit weight in one experiment and the percentage of malformed fruits was reduced in two experiments. Hydrogen cyanamide caused a clear phytotoxicity immediately after applications, only in the first experiment.