Agronomical and physiological studies on zinc deficiency in crop plants, 2: Effect of zinc concentration in the nutrient solution culture and shade level on the growth, nitrogen content and nitrate reductase activity in tomato plants (Lycopersicon esculentum Mill)

• Published in: Japanese Journal of Tropical Agriculture Vol. 37; no. 1; pp. 22 - 27
• Main Authors: Takahashi, H. (Tokyo Univ. of Agriculture (Japan)), Shennan, C, Huffaker, R.C
• Format: Journal Article
• Language: Japanese; English
• Published: Japanese Society for Tropical Agriculture 01.03.1993
• Subjects: CINC; CONTENIDO DE NITROGENO; DEFICIENCY DISEASES; ENFERMEDADES CARENCIALES; FISIOLOGIA VEGETAL; LYCOPERSICON ESCULENTUM; MALADIE DE CARENCE; METABOLISME DE L'AZOTE; METABOLISMO DEL NITROGENO; NITRATE REDUCTASE; NITRATO REDUCTASA; NITROGEN CONTENT; NITROGEN METABOLISM; NUTRIENT SOLUTIONS; OMBRAGE; PHYSIOLOGIE VEGETALE; PLANT PHYSIOLOGY; Shade; SHADING; SOLUCIONES NUTRITIVAS; SOLUTION NUTRITIVE; TENEUR EN AZOTE; Tomato; UMBRIA; ZINC; Zinc deficiency
• ISSN: 0021-5260; 2185-0259
• DOI: 10.11248/jsta1957.37.22

A study was carried out on the effect of the zinc concentrations in the nutrient solution and shade level on the growth, nitrogen content and nitrate reductase activity in tomato plants. The three zinc concentrations used were 0, 0.005 and 0.05 ppm. The four levels of shade used were 0%, 25%, 50% and 70%. The height of the 0.05 ppm plants was the greatest compared to that of the other plants on Dec. 21 but only slightly greater than that of the 0.05 ppm plants on Dec. 7. Total nitrogen content of the leaves showed no apparent differences in the 0, 0.005 and 0.05 ppm plants. On Dec. 21, the highest total nitrogen content was recorded in the 0.05 ppm plants. Total nitrogen content of the stems and roots showed the same tendency as that of the leaves. The ratios of soluble nitrogen to total nitrogen in the Oppm plants was higher than in the 0.05 ppm plants. Nitrate reductase activity of the leaves in the 0.05 ppm plants was the highest on both dates. Nitrate reductase activity of the stems was the highest in the 0.05 ppm plants on both dates. Nitrate reductase activity of the roots was lower than that of the leaves and stems on both dates. In the shade experiment, the values for the fresh and dry weight of the plants not subjected to the shade treatment were the largest as compared to those of the other plants throughout the growth period. Nitrate reductase activity of the leaves in the shade experiment was the highest in the plants not subjected to the shade treatment and lowest in the 70% shade plants on all the three dates. The nitrate reductase activity of the roots was the highest in the plants not subjected to the shade treatment on Apr. 12 and 19. But it was lower than that of the leaves and stems.