ABSTRACT
Two field experiments were conducted at the Experimental Farm Station of Hort. Faculty of Agriculture, Benha University, during late summer seasons of 2006 and 2007 on tomato (Lycopersicon esculentum, Mill.) Cv. Super strain B.
Seven weeks old tomato seedling (i.e., at the beginning of May for 2006 and 2007 seasons, respectively) were transplanted to the experimental plots. The plants were sprayed 5 times, 20 days after transplanting and again every 15 days intervals.
Treatments were as follow, Yeast extract at 15 and 30 ml/L, Amino acids at 1.5 and 3ml/L., Citric acid at 2.5 and 5 g/L. and Control (water treated). The obtained results clearly showed that yeast extract at 30 ml/L gave the highest values for each of number of flowers, total fruits per plant and percentages of fruit setting. Most applied treatments were effective and highly increased the fertility of pollen grains, total yields, total fruits per plant, weight of total fruits per plant, fresh and dry fruit weight, length, diameter and shape index per plant in treated plants compared with control.
The quality characteristics of tomato fruits i.e., vitamin C, titratable acidity and total soluble solids as well as minerals content were increased with different treatments. The most effective treatments of tomato plant were yeast extract at 30 ml / L and amino acids at 3 ml / L
Vigorous growth of tomato plant treated with different applied treatments was positively correlated with different anatomical responses of stems and leaves. Since, different applied treatments increased stem anatomical features e.g. stem thickness, increment of stem thickness was accompanied with increases in most of its anatomical features, i.e., thickness of epidermis, thickness of cortex and thickness of parenchymatous pith.
Moreover, increased thickness of midvein, lamina, upper epidermis, lower epidermis, thickness of spongy tissue and palisade tissue as well in tomato leaf. Furthermore, increasing dimenti"ons (length and width) of vascular bundles, thickness of both phloem and xylem tissues and number of xylem vessels.
Different applied treatments were highly increased photosynthetic pigments content, minerals concentrations (N, P, K, Mg mg/g d.w and Fe ppm) also crude protein, total sugars, total carbohydrates, total phenols and total amino acids in tomato leaves, minerals concentrations (N, P, K, Ca mg/g d.w and Fe ppm) in fruit as well as levels of endogenous auxins, gibberellins and cytokinins (in shoot) meanwhile, abscisic acid was decreased as compared with the untreated plants. at 70 days after transplanting during the assigned season.
The application of various treatments induced reduction in enzymatic antioxidants activity (i.e., peroxidase, catalase and superoxide dismutase) as compared with control plant those of activity could be attributed to antioxidantal direct effects of used treatments on scavenging toxic radicals.
Keywords: Antioxidant enzyme; tomato plant; High temperature stress; anatomical study; yeast extract; amino acids and citric acid. |
