Prohexadione calcium on shoot growth of 'Starkrimson' pear trees

Abstract

The objective of this work was to evaluate the fruiting and vegetative growth of 'Starkrimson' pear in response to the application of prohexadione calcium (P-Ca). P-Ca (250 mg L^-1) was sprayed to scaffold limbs and to whole trees in commercial orchards. A randomized complete block design was used to minimize declivity effects. Vegetative growth (length and number of shoots, increment in limb and trunk cross-sectional area, number of nodes, and internode length), production (fruit number, yield, yield efficiency, and fruit size), and return bloom were evaluated from 2010 to 2013. P-Ca efficiently controlled shoot growth in all growing seasons, when applied early in the season, due to the reduction in internode length. Production was not negatively affected by the application of P-Ca in all years and at both sites, and fruit size and return bloom were not reduced. Fruit quality attributes were also little affected by P-Ca, except for total soluble solids content, which was lower than that of the control. This shows that P-Ca is efficient to manage tree vigor in high-density 'Starkrimson' pear orchards.