Document Type : Research Paper - Olericulture

Authors

1 M.Sc. Graduate of Horticultural Science, Department of Horticultural Science, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran

2 Assistant Professor, Department of Horticultural Science, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran

3 Associate Professor, Department of Horticultural science, Shahid Chamran University of Ahvaz, Iran

4 Associate Professor, Irrigation and Drainage Department, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran

Abstract

Abstract

Introduction

Iran ranks 11th in the world in tomato production, with more than 3 million tons produced. Therefore, providing enough water to produce this amount of product will be one of the challenges of the near future in the agricultural sector due to the drought problem in Iran. Reuse of fish waste in agriculture is one of the important dimensions of water resources planning. Recycling drainage water from aquaculture farms is one of the necessities because it is rich in substances that can be useful in agriculture. World population and food security is one of the most difficult challenges that most of the countries are facing, because the world population is increasing rapidly and will reach 9.6 billion people by 2050. In this situation, the food supply should increase by 70 to 100%. Considering these challenges, it is necessary to conduct applied research to make maximum use of effluents and wastewaters in the production of greenhouse products.

Materials and methods

The treatments of this experiment included 3 types of nutrient solutions (Resh nutrient solution, fish pond water and modified fish pond water) and 3 promising greenhouse tomato lines (AZ4, AZ5 and V4). The experimental design was factorial arranged in complete block design with 3 replications. At the end of the experiment, the plants were removed from the pot and the roots, leaves and stems were separated from each other. Their fresh and dry weight and the number of leaves were recorded separately for each treatment. To check yield indicators, ripe tomato fruits were harvested during the growth period, counted and weighed with a scale with an accuracy of 0.01 g. The firmness of the fruit tissue was measured by a firmness meter, and the pH and EC of the fruit extract were measured by a pH meter and an EC meter, respectively. The measurement of chlorophyll a, b and total chlorophyll was done using a spectrophotometer in mature leaves developed according to the method suggested by Arnon (1967).

Result and Discussion

The results of this experiment showed that V4 and AZ4 cultivars had the highest stem and leaf weight compared to AZ5 cultivar. Also, the results showed that the Resh solution and modified pond water had the highest root dry weight (58 and 56 g, respectively) compared to the fish pond water treatment (47 g). The findings of this study showed that the use of Resh nutrient solution and modified pool water compared to the treatment of fish pool water increased the number of leaves of tomato plants by 23.88% and 18.69%, respectively. It seems that irrigation with modified pool water and Resh solution increases the growth and development of the plant due to the increase in the level of nutrients. The highest amount of total chlorophyll was observed in the Resh solution and modified pool water with concentrations of 2.3 and 2.2 mg/g, respectively. The results of Silva et al (2021) showed that in irrigation with fish waste, greater availability of magnesium in plant tissue increases the content of chlorophyll b in leaves and increases plant chloroplast pigments. The highest total yield was observed in cultivar V4 and in the treatments of Resh nutrient solution and modified pool water. The results showed that modified pool water had the highest EC of tomato extract (1.9 dS/m). Also, the results of the interaction effect of cultivar and nutrient solution showed that the highest fruit firmness was observed in Resh solution and fish pond water in V4 cultivar. Also, the lowest fruit firmness was observed fish pond water in AZ5 cultivar. It seems that, in the present study, the reduction of calcium absorption in fish pond water caused the reduction of firmness of tomato fruit (Kaab omeir et al., 2020).

Conclusion

It seems that according to the above results, it is possible to use pool water with a high density of fish after modification and changes in the amounts of its nutrients in greenhouse tomato cultivation. Among the tested cultivars, the promising line V4 can be recommended for cultivation in the greenhouse for the use of modified fish pond water.

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