Effect of water temperature on basil growth in hydroponics and evaluation of hydrogen peroxide products on algae and plant growth

Abstract

Root zone temperature is an important factor in growing plants, whether in the field or hydroponically. In this research, three temperatures (23°C, 27.5°C, and 31°C) were evaluated to measure their effect on plant growth on 17 cultivars of basil in an Nutrient Film Technique hydroponic system. Algae is a common problem in agricultural water usage, especially in hydroponic systems. Hydrogen peroxide (H2O2) has been commonly used in other agricultural systems to prevent or lessen the buildup of algae. In this research, three hydrogen peroxide products (Zerotol, PERpose Plus, and 3% hydrogen peroxide) were evaluated based on their ability to limit algae growth while not causing phytotoxic effects on the lettuce and basil crops in the hydroponic system. Results of this research found that warmer nutrient solutions, such as 27.5°C and 31°C, produced a greater shoot fresh weight and leaf number in most varieties of basil. For all cultivars of basil except purple basil and ‘Large Leaf Italian’, growing with a 27.5°C or 31°C nutrient temperature will result in a greater yield. For control of algae, there were no significant differences between hydrogen peroxide products and the control, though concentrations of 60 mL of hydrogen peroxide products such as Zerotol and PERpose Plus can visually lessen the appearance of algae. Lower concentrations of hydrogen peroxide treatments had less phytotoxic effects on lettuce, while basil was not influenced by the presence of greater concentrations of hydrogen peroxide, except in terms of shoot dry weight.