Timing and rates of two hydrogen peroxide products to control algae and evaluation of water temperature on lettuce quality for hydroponic production

Abstract

Hydroponic systems are an ideal environment for algal growth. Algae poses several threats to hydroponic crops and needs to be controlled. Use of hydrogen peroxide (H2O2) as an algaecide has been on the rise in recent years. Hydrogen peroxide also serves as a signaling molecule for processes involved in plant growth and development. Thus, the objective of our study was to find the optimum rate and application timing of two H2O2 products 'Zerotol' and 'PERpose Plus' to control algae in an Ebb and Flow hydroponic system without inhibiting growth of pepper and tomato plants. Among various factors which affect hydroponic production, temperature of the nutrient solution is considered one of the most important determining factors of crop yield and quality. Optimum water temperature in a hydroponics system positively influences the production of vegetables. Hence, the effect of three different water temperature (18.3 degrees C, 21.1 degrees C, and ambient) on growth and quality of seventeen cultivars of lettuce was studied in an NFT hydroponic system. Results indicated that weekly application of 70 mL of either Zerotol or PERpose Plus produced the best results in terms of controlling algae and improving the growth of pepper and tomato plants. For lettuce, hydroponics growers can maintain the water temperature at 21.1 degrees C for greater growth and yield, while 18.3 degrees C water temperature can be maintained to produce lettuce with greater oBrix. Our results also indicated that all the cultivars in Romaine type performed better in terms of growth and quality compared to all other lettuce types.