Response of Chlorophyll Content and Chemical Composition (Ca+2, K+, and NO3-) in Tomatoes and Peppers Saplings to Foliar Nutrition in Growing Chambers

Abstract

The chlorophyll content and mineral compositions of plants are highly dependent on the species' physiological responses and environmental stress tolerance. The chlorophyll content is important for determining abiotic stress tolerance in tomatoes and peppers. Several studies found that foliar applications of specific components increased tomato and pepper output by increasing nutrient uptake. After transferring the seedlings to the incubator, three tomatoes (Mobil, Korall, and Tyking F1) and three pepper varieties (Carma, Fokusz, and Bobita F1) were sprayed. The following solutions were applied at a rate of 4 mL to each different plant: sodium bicarbonate (0.52%), 50 mg L-1 salicylic acid, and distilled water. A chlorophyll sensor (SPAD-502) was used to collect 5 measurements from each plant after 2 days and 8 days of spraying. Five plant sap samples were collected from ten plants after 38 days of transplantation. The calcium ion (Ca+2), potassium ion (K+), and nitrate (NO3-) contents (mg L-1) in plant sap were measured using three calibrated electronic sensors of the type (HORIBA instruments LAQUA-TWIN). The factorial analysis of two factors was used in data collection and statistical analysis. The first variable was the variety and the second was the spray treatment, and each record had five observations. The Tukey-Kramer test in Minitab 20 was used to assess differences in means between groups. Minitab 20's regression response optimizer was used to determine the maximum and minimum responses to calcium, potassium, nitrate, and chlorophyll content factors in each plant. Salicylic acid 50 mg L-1 produces the strongest multiple responses, particularly in tomato cultivars (Tyking F1 and Korall). The multiple minimum responses were for the variety (Mobil). Spraying (Mobil) with salicylic acid (50 mg L-1) and sodium bicarbonate (0.52%) produced unsatisfactory results. Salicylic acid 50 mg L-1 elicits also the most powerful multiple responses, particularly in the (Carma) pepper cultivar. The results revealed multiple minimum responses for the variety (Bobita F1). Finally, it is recommended that growers grow tomatoes (Mobil) without any supportive spraying treatment because the vigor of tomato (Mobil) seedlings was significantly higher in suboptimal environmental conditions. Gardeners should consider growing (Carma) pepper with a supportive spraying application of salicylic acid 50 mg L-1.