Enhancing Vegetative Growth by Adding Phosphorus, Silicon, and Citric Acid to Pepper Plants Cultivated in Plastic Greenhouses

Abstract

The research was conducted in a plastic greenhouse at the College of Agricultural Engineering Sciences, University of Baghdad - Jadiriyah Campus, during the 2021-2022 season, to study the effect of phosphorus, silicon, and citric acid on pepper plants using a factorial experiment design with three replicates. The first factor had three levels of phosphorus (0, 160, and 320 kg P2O5 per hectare), the second factor had three levels of potassium silicate (0, 75, and 100 kg per hectare), and the third factor had four levels of citric acid (0, 2, 4, and 6 kg per hectare). The statistical analysis showed that treatment P2S2C1 resulted in an increase in the main stem diameter (25.10 mm), treatment P3S3C1 led to an increase in the main branch diameter (16.10 mm), and treatment P3S3C2 showed an increase in the diameter of secondary and tertiary branches (13.50 mm and 8.90 mm, respectively). Treatment P2S3C1 resulted in an increased number of leaves and the dry weight of the total vegetative mass (1286.7 leaves and 415.0 g plant-1 respectively). Treatment P3S2C4 led to an increase in the dry weight of roots (25.47 g plant-1), treatment P2S3C4 showed an increased number of fruits (48.34 fruits plant-1), and treatment P3S3C4 resulted in an increased total yield (4.87 tons greenhouse-1).