Effect of Cultar on the Photosynthetic Apparatus and Growth of Cherry Trees

V. LICHEV, M. BEROVA and Z. ZLATEV
Agricultural University, BG-4000 Plovdiv, Bulgaria

Abstract

LICHEV, V., M. BEROVA and Z. ZLATEV, 2001. Effect of cultar on the photosynthetic apparatus and growth of cherry trees. Bulg. J. Agric. Sci., 7: 29-33

An experiment was conducted in 1998-1999 with trees of the bigareau-type cherry cultivar Burlat, grafted on Prunus mahaleb rootstocks and planted in 1989 at a distance of 5.5 × 3.5 m. In early March 1992, 1994, 1996 and 1998 Cultar (containing 25% paclobutrazol) was applied to the soil at rates of 1, 2 and 4 g active ingredient per tree.
It was established that the Cultar rates tested inhibited significantly the annual shoot growth. When applied at 4 g a.i., the preparation improved the photosynthetic activity of trees, both in the year of treatment and in the year of its aftereffect. It could be assumed that the increased photosynthetic activity would provide for the efficient use of assimilates in yield formation.

Key words: paclobutrazol, leaf gas exchange, photosynthetic pigments, growth, cherry trees
Abbreviations: A – net photosynthetic rate; E – transpiration rate; gs – stomatal conductance; A/E – photosynthetic water use efficiency