The Effect of Chemical Fertilizers and Poultry Manure Combination on Yield, Nitrate Accumulation, Color and Firmness of Two Cucumber Cultivars

In order to investigate the role of nutrients on yield and quality of two commercial cucumber cultivars, Royal and Hike, the effect of poultry manure at levels of 0, 6, and 12 tons per hectare and chemical fertilizers in four different combinations including the one-time application of 50 kg of urea without micronutrient fertilizer; one-time application of 109 kg ammonium sulfate without micronutrient fertilizer; application of urea, phosphorus, and potassium fertilizers as well as complete micronutrient fertilizer according to soil test; and ammonium sulfate, phosphorus, and potassium fertilizers as well as complete micronutrient fertilizer according to soil test, were studied at three harvesting time. Total yield increased in both cultivars by using fertilizers consisting of poultry manure in the amount of 6 tons per hectare in combination with urea, phosphorus, potassium, and complete micronutrient fertilizers based on soil tests. With increasing poultry manure, the quantity of nitrate accumulation increased, but it was below the allowed threshold in all treatments. In most treatments, tissue firmness in the first and second harvests was higher than in the third harvest and its amount decreased with more nitrogen application. In the Hike cultivar, at all levels of chemical fertilizers, the amount of chlorophyll accumulation in the first and third harvests was higher than in the second harvest. The green color index in the Royal cultivar increased with the application of ammonium sulfate and poultry manure fertilizers. In total, the consumption of six tons of poultry manure with chemical fertilizers based on soil tests and also foliar application of the micronutrient fertilizers improved the yield and quality of cucumber fruit..