Growth, flowering and physiological responses of olive trees to growth retardants under rain-fed conditions of Himachal Pradesh

Abstract

A field experiment was carried out during two subsequent years to ascertain the influence of paclobutrazol and cycocel on growth, cropping and water relations in olive. Eight treatments, viz., PP333 at 2.0 and 4.0 g a.i. tree-1 applied once in November or December as soil drench and cycocel @ 1000, 2000 and 3000 ppm as foliar spray two weeks after flowering to the trees of olive cv. Leccino. Soil application of PP333 at 4.0 g a.i. tree-1 in November decreased growth (15.69 cm), length of internode (1.84 cm), leaf area (4.60 cm2), stomatal size (13.61 μm), water potential (-15.69 bar), transpiration rate (0.160 m mol m-2 s-1), endogenous GA3 (9.61hg/g fresh weight), stomatal conductance (1.51 mol m-2s-1) and increased leaf thickness (0.62 cm), leaf chlorophyll content (3.05 mg/g fresh weight), photosynthesis (24.62 μ mol m-2 s-1), proline (2717 μg/g) and ABA (60.74 (hg/g fresh weight), flowering intensity (0.65 %) and fruit set (7.57%), and thus might be helpful in mitigating water stress under rainfed conditions.