Potassium improves fruit deep green color, firm flesh, shape, and overall yields.

   Magnesium is required in cucumbers to help obtain a deep-green fruit color. Magnesium deficiencies will be intensified in fields which have received high N or K fertilizer rates. For soils low in magnesium, apply magnesium sulfate (epsom salt, 9.8% Mg.) or its equivalent at 150 - 500 lbs/Acre. Soil magnesium deficiencies can also be corrected with periodic light dolomitic limestone applications.

   Cucumber's nutrition program should be tuned to achieve maximum yields and optimum market quality. For example insufficient potassium will result in misshapen fruit or "bottlenecks", and low nitrogen restricts growth, modifies the length-to-diameter ratio of fruit, reduces fruit set and color development. The symptoms listed in Table 2 should be helpful to help diagnose specific deficiencies. However, be aware that abnormalities such as those caused by root rot and nematode infections may produce similar symptoms in plants.

      Table 2. Common Nutrient Deficiency Symptoms in Cucumber

      Nutrient Deficiency Symptoms

   

Nitrogen Mature leaves yellowish green to yellow; stems slender, hard and fibrous; fruits light in color, pointed at blossom end; Stunted roots turn a brownish color and then die. Phosphorus Mature leaves change from a dark to dull green; Stems slender; Fruits dull green to bronze.

       Potassium Mature leaves bluish green near veins,

  

   Bronzing and necrosis of leaf margins; Young leaves are puckered or crinkled; Fruits constricted at stem end; Plant growth slow.

       Magnesium Plants are small and appear weak;

center-veinal chlorosis on mature leaves, veins remain green; Mature leaf edges brittleand ragged; Yields are low and quality of fruit is poor.

   Calcium Misshapen fruit; Water soaked and necrotic

  lesions on blossom end; "Pillowy" fruit disorder. Reduced shoot, root and fruit growth.