International Journal of Plant & Soil Science

Aims: The objective of this study was to describe and photograph the initial symptoms and the development of nutritional deficiencies in cucumbers, and determine the concentration of the omitted macronutrient in leaves, on which symptoms of deficiency were observed.

Study Design: A completely randomized design with six treatments and three replications were made.

Place and Duration of Study: Sector of Horticulture Crops and Aromatic Medicinal Plants belonging to the Department of Plant Production of the Faculty of Agriculture and Veterinary Sciences, UNESP Jaboticabal, São Paulo, Brazil, from March 6 to May 9, 2014.

Methodology: Treatments corresponded to a complete nutrient solution and to individual omissions of N, P, K, Ca and Mg, when plants were in early fruiting. The symptoms of macronutrient deficiencies were described and recorded by photographs, and the omitted macronutrient contents were determined at the onset of symptoms.

Results: Physiological deficiencies of N, P, K, Ca and Mg in cucumber were first observed at 3, 20, 2, 3 and 5 days after nutrient omission, respectively. N and P deficiencies were initially characterized by uniform chlorosis and browning, respectively, while the lack of K lead to chlorosis initially on the margins of the leaf blade progressing to necrosis. The Mg deficiency was characterized by internerval chlorosis, which evolved to tissue necrosis. Ca deficiency symptoms were observed in leaves next to meristems, with leaf shriveling and marginal tissue necrosis of the leaf blade. At the observation of deficiency symptoms, the levels of N, P, K, Ca and Mg in leaves with a deficiency were 18.9, 1.5, 9.5, 1.5 and 1.2 g kg^-1, respectively.

Conclusion: With the omission of nutrients in early fruiting plants, the symptoms of the deficiencies of N, P, K and Mg are observed initially in intermediary leaves and Ca deficiency in young leaves.