Growth and Nutritional Disorders of Eggplant Cultivated in Nutrients Solutions with Suppressed Macronutrients

Abstract

2The objective was to evaluate the effects of omitting macronutrients in the nutrients solution on growth characteristics and nutritional status of eggplants. The treatments were complete nutrients solution and solutions with nutrient omission: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S). The experiment was carried out under greenhouse conditions with three replicates in a completely random design. Plant height, number of leaves per plant, leaf area, relative chlorophyll index, photosynthesis rate, stomatal conductance, dry matter, concentration levels of macronutrients in plant aerial part and root system, and nutritional disorders were evaluated. Omitting elements interfered in the concentration of elements in the various plant tissues and this had as consequences limited vegetative growth, reduced dry matter and led to the development of the typical deficiency symptoms of each element. Although potassium was the most demanded of all elements, nitrogen and calcium were the most growth limiting ones.

Growth, nutrient accumulation and nutritional efficiency of sunn hemp in function of nutrient omission

“…Restriction to plant growth under deficiency of this nutrient also caused symptoms such as dark green color of older leaves progressing to necrosis and without the formation of side shoots, with reflection on the formation of a thin stalk and reduced flowering. A similar result was observed by Flores et al (2015).…”

“…Calcium omission caused a reduction in plant development for all growth parameters studied (Table 1), which was also indicated by other authors (Flores et al, 2015;Bianco et al, 2015). The loss in plant development under Ca omission in the nutrient solution is due to the lower Ca accumulation in the dry matter of roots, shoots and the entire plant (Tables 2, 3 and 4) as well as lower nutrient absorption efficiency of the plant (Table 5); however the Ca deficiency resulted in more efficient use of the nutrient compared to the complete nutrient solution (Table 6).…”

“…Deficiency of Mg decreased the stem diameter, leaf area and dry matter production of the plant (Table 1), a fact also observed by Flores et al (2015). Reduced plant development under Mg deficiency in the nutrient solution was due to lower accumulation of this nutrient in dry matter of the root, shoot and entire plant (Table 2, 3 and 4), based on lower efficiency of nutrient absorption and utilization (Tables 5 and 6).…”

“…Restriction of K in the nutrient solution promoted a decrease in stem diameter and leaf area that induces less dry matter production of the root, shoot and entire plant (Table 1), which was also highlighted by Flores et al (2015). This fact can be explained by the lower absorption or accumulation of this nutrient (Tables 2, 3 and 4) and low nutrient absorption efficiency of the plant (Table 5).…”

“…This effect of N omission in reducing plant growth is widely reported in literature Bianco et al, 2015;Flores et al, 2015). An example of this type of study was performed in legumes Valeri et al (2014) verified a decrease in stem diameter and dry matter when compared to plants grown in a complete nutrient solution.…”