Effect of Gibberellic Acid and Potassium Foliar Sprays on Productivity and Physiological and Biochemical Parameters of Parthenocarpic Cucumber cv. ‘Seven Star F₁’

A study was carried out to evaluate the potential of exogenously applied potassium nitrate [1.0 g·dm⁻³ (K₁), 2.5 g·dm⁻³ (K₂) and 5 g·dm⁻³ (K₃)] plus gibberellic acid (GA₃) [0.005 g·dm⁻³ (G₁), 0.01 g·dm⁻³ (G₂) and 0.015 g·dm⁻³ (G₃)] on the growth and development of the cucumber (Cucumis sativus L.) ‘Seven Star F₁’ during various growth stages (40, 55 and 70 days after sowing). Treatment of plants with K plus GA₃ stimulated growth shortened the fruit maturation period and increased quality compared with non-sprayed control. The combination G₂K₂ resulted in maximum total yield, plant height, and total chlorophyll, phosphorus and nitrogen content in the leaves compared with other treatments. Fruit matured significantly earlier in plants sprayed with G₂K₂. Total yield and fruit quality dry matter, total suspended solids and antioxidant activity percentages were significantly higher in sprayed plants compared with controls. Potassium content in leaves and fruits reached the maximum level with G₃K₃ treatment. The results clearly showed that the foliar application of G₂K₂ proved to be the best choice for growing cucumber in terms of quantity and quality of yield.