the effect of different nutrient solutions on yield, nutrient content and physiological characteristics of cucumber (cucumis sativus l.) grown in hydroponics

hydroponics technique accompanied by adjustment of nutrient solution seems to optimize crop production and help in establishing sustainable agriculture. in recent years, the greenhouse production of cucumber has been increased in iran, however there are just a few proper nutrient solutions employed in growing the crop. in line with this, an experiment was conducted to find the effect of various important nutrient solutions including, nsut, nsknop, nsst, nsuk, nsneth, and nsut on the growth, yield and quality of cucumber (cucumis sativus l cvs negeen and katrina) grown in hydroponics. the experiment was arranged in a completely randomized design of three replicates. the seeds of cucumber were sown in the media containing perlite and vermiculite (3:1 v:v) and then were irrigated with different nutrient solutions. the fruits were harvested during the growing period and the final yield calculated over six months. the vegetative and physiological characteristics were studied during the experimental period as well as at the end of the period. the results showed that the yield of the cucumber crop was significantly affected by various nutrient solutions, so that the highest yield was obtained in either of nshog and nsuk while, the lowest yield observed in nsknop. the yield in cv negeen was 30% higher than that in cv katrina. various nutrient solutions changed the leaf area, with the leaf area in the nsuk, nsknop and nshog being higher than those in other nutrient solutions. leaf area in negeen cv was higher than that in cv. katrina. a positive correlation (r2=0.76) was found to exist between leaf area and the yield. spad value decreased in both nsst and nsneth. total soluble solids (tsss) in fruits was significantly affected by either of nutrient solution and cultivars with the maximum tss being observed in nshog while the minimum in either of nsneth and nsut. in petiole, maximum tss was found in nsneth treatment. the concentrations of n and k were significantly affected by the type of nutrient solutions. leaf potassium content was the highest in treatment nsu.k, while there was no difference observed in k concentration between the cultivars. nutrient solution had no effect on p concentration. maximum titratable acidity of the fruits (ta) was observed in nsu.k treatment. it can be concluded that since nsu.k and nshog improved the yield in cucumber crop, they can be recommended for use in the greenhouse cucumber production, however need arises for an....