EFFECT OF PRUNING AND PLANT GROWTH REGULATORS ON GROWTH, FLOWERING, FRUITING AND YIELD OF CUCUMBER

Abstract

field experiment was conducted in the Horticulture Farm of Sher-e Bangla Agricultural University, Dhaka, Bangladesh during the period from April to August 2006 to study the effect of pruning and different plant growth regulators on growth, flowering, sex ratio and fruit setting and yield of cucumber (Baromashi). The experiment was laid out in the two factors Randomized Complete Block Design (RCBD) with three replications. A statistically significant variation was recorded in terms of all the characters related to growth and yield of cucumber. Three different type of growth regulators viz. H 1 (Maleic hydrazide 200 ppm), H2 Ripen-l S ( ethephon 300 ppm), HJ Crops care (NAA 18 ppm) with control (No growth regulator, Ho) and two different shoot pruning practices; Pl (Pruning to 3 primary branches), P2 (pruning to 5 primary branches) with control (No pruning, Po) were applied in the experiment. Maximum stem length (193.17 cm) at 50 DAS was found in Ho treatment and minimum (167.5 cm) was found in H2 treatment. Maleic hydrazide and NAA showed higher stem length than ethephon 300 ppm. However, the highest number of primary branches ( 12.37), secondary branches (24.31 ), female flower (22.94), fruit per plant (17.07), fruit setting percentage (74.81%), fruit weight (239.78 gm) and yield (45.82 t/ha) were recorded from H2 treatment. The minimum values of the same parameters were observed in Ho treatment or control. Maleic hydrazide and NAA were given lower yield than Ethephon but higher values than the control. Pruning to 5 primary branches showed better results in flowering fruit setting and yield of cucumber than pruning to 3 primary branches. The lowest yield (13.36 kg/plot) was found in Po and highest yield (19.92 kg/plot) was found in P2 treatment. Six days early female flower initiation and four day early fruit maturity was recorded from H2 treatment over control. The lowest male to female flower ratio (2. 75) was found in Ethephon treated plant and highest ratio was found in control. Pruning did not give any significant value in terms of male to female flower ratio. In the interaction of pruning and growth regulators the maximum yield (53.73 t/ha) was found in P2H2 treatment and lowest (17.69 t/ha) was recorded in PoHo treatment. The second highest (48.30 t/ha) yield was obtained from P1H2 treatment which was closely followed by P2H3 treatment (40.58 t/ha). The highest benefit cost ratio (3.54) was attained from the treatment combination of pruming to 3 primary branches and ethephon 300 ppm treated plants.