Amino Acid Water Soluble Fertilizer for pepper planting

      Amino acids are natural growth stimulators for crops and are widely used as a foliar spray to promote crop yield and quality. In this study, we investigated the effects of soil amendment with different concentrations (1.8, 2.7, and 3.6 kg) of amino acid water soluble fertilizer on plant physiological characteristics and pepper fruit morphology and chemical composition. Pepper plants treated with 1.8 kg amino acid water soluble fertilizer had the highest soluble sugar content, which is associated with improved photosynthesis. This increase in soluble sugar content is also related to increased synthesis of protein. Protein is a fundamental component of living cells, which plays a critical role in many biological functions, including cell growth and development. It is also important for nutrient storage and transport in the plant.

     A significant increase in chlorophyll (chl) a and b content was observed for the 1.8 kg amino acid water soluble fertilizer treatment. Chl is an essential pigment for the photosynthetic reaction center in the chloroplast. Chl fluorescence is a measurement of the state of PSII photochemistry, and it indicates the maximum quantum yield at which a plant can exploit energy acquired by absorbing light. The results of this study indicate that 1.8 kg amino acid water soluble fertilizer significantly enhanced the maximum quantum yield of PSII photochemistry, indicating that it improves the opening degree of the PSII reaction center.

     Moreover, chl fluorescence data indicated that the 1.8 kg amino acid water soluble treatment increased the kinetics of PSII photochemistry by decreasing the quenching rate of light. This result is similar to the findings of Popko et al., who showed that foliar application of high concentrations of amino acid combinations as a phosphate substitute increased most pepper cultivars’ vegetative characteristics and physiology.

     The 1.8 kg amino acid water soluble fertilizer also increased the amount of capsaicin and dihydrocapsaicin in pepper fruits. This increase could be attributed to the high contents of valine and phenylalanine, which are involved in the biosynthesis of secondary metabolites. The 2.7 kg and control treatments decreased the capsaicin and dihydrocapsaicin content in pepper fruits.

     Amino acid water soluble fertilizer has the advantage of being easily absorbed by plant leaves. This is due to the fact that amino acids are zwitterions and they have strong attractions with polar water molecules. In addition, amino acid water soluble fertilizers are readily soluble in non-polar organic solvents such as hydrocarbons and have a low molecular weight. In contrast, mineral sources such as potassium humate and seaweed fertilizers have a long time to absorb in the leaf. Moreover, these mineral sources require the plants to synthesize them in the course of photosynthesis, which consumes a great deal of energy. Therefore, it is no surprise that the amino acid water soluble fertilizer has the fastest absorption rate among quick-acting organic nitrogen sources. Amino acid water soluble fertilizers are also easy to use, as they can be mixed with a small quantity of water.