The present work was carried out in order to study: 1. identification of deficiencies symptoms of N, P, K, Ca, Mg and B. 2. The effect of the deficiency of each macronutrient and boron on the chemical composition of the plants. Young Solanum jilo var. Morro Grande Oblongo plants were grown in pots containing pure quartz. Twice a day, the plants were irrigated by percolation with nutrient solutions. The treatments were: complete solution and deficient solutions, in which each of the macronutrients or boron was omited. When the malnutrition symptons appeared the plants were harvested and divided into: superior and inferior leaves and stalk. The dry matter was analysed chemically for N, P, K, Ca, Mg and B. CONCLUSIONS - Symptons of malnutrition were observed for N, P, K, Ca. Mg, B. - High rate of multiplicaiton of Tetranychus urticae was observed on plants deficient in potassium. - Nutrient content expressed in porcentages and in ppm for boron in the ripened leaves of plants cultivated under normal conditions and under deficient conditions were.