today, hormones and nutrients are used in order to improve vegetative and reproductive growth of many agricultural products in the world. the purpose of this study, was to increase fruit set, fruit weight, and finally, increase of yield along with improvement of vegetative growth with putrescine treatments (0, 0.01, 0.001m) and potassium nitrate (0, 2 and 4%) of quince (cydonia oblonga cv. esfa...