Unicellular Algae and Yeast Extracts as Biostimulants

Introduction

In the field of sustainable agriculture, the use of biostimulants has gained relevance for its ability to improve crop productivity and quality. Among the most prominent biostimulants are unicellular algae and yeast extracts. This article focuses on comparing these two options, analyzing their characteristics, benefits, and practical applications in the field.

Unicellular Algae as Biostimulants

Unicellular algae, such as species of Chlorella and Spirulina, are recognized for their high content of nutrients and bioactive compounds. These algae are used in agriculture due to their properties that promote plant growth and improve resistance to environmental stress. Additionally, unicellular algae offer advantages over seaweed in terms of efficiency and application. The use of freshwater unicellular algae to improve fruit set has also been researched to optimize results in specific crops. The use of nitrogen and algae extracts has also proven beneficial in this context.

Benefits of Unicellular Algae

• Growth Stimulation: Unicellular algae provide essential nutrients such as nitrogen, phosphorus, and potassium, promoting root development and vegetative growth. Research has shown that the application of Chlorella vulgaris extracts can increase plant growth by up to 30% compared to untreated crops.
• Improved Stress Tolerance: The bioactive compounds present in these algae help plants withstand adverse conditions, such as droughts or high temperatures. A study conducted by the Agricultural Research Institute of Japan found that plants treated with algae extracts showed a 40% increase in antioxidant production, which contributes to their resistance to water stress.
• Increased Crop Quality: The use of unicellular algae has been shown to improve the quality of agricultural products, increasing nutrient content and enhancing appearance. For example, in trials conducted with tomato crops, a 20% increase in vitamin C content was observed in fruits treated with extracts of Spirulina platensis.

Biochemical Mechanisms of Action

Unicellular algae contain a variety of bioactive compounds, such as polysaccharides, amino acids, and phytohormones, which play a crucial role in their function as biostimulants. Polysaccharides, for instance, can improve water retention in the soil, which is essential for maintaining plant health during drought periods. Additionally, the amino acids present in algae aid in protein synthesis in plants, which is fundamental for their growth and development. A study published in the Journal of Applied Phycology demonstrated that the use of algae extracts increased the activity of the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO), which is crucial for photosynthesis and plant growth.

Practical Applications in the Field

In agricultural practice, unicellular algae can be applied in several ways. For example, in rice crops in Southeast Asia, foliar application of Chlorella extracts has been used to increase yield. Farmers who have implemented this method report an increase in grain production of up to 25% compared to traditional methods. Furthermore, in vegetable crops, fertigation with algae extracts has been shown to improve plant health and overall growth, resulting in higher quality and healthier products. A practical case in a lettuce greenhouse in Spain showed that plants treated with Spirulina extracts had more uniform growth and significantly greater resistance to pests and diseases, reducing the need for pesticides.

Recent Research on Unicellular Algae

Recent studies have expanded the understanding of how unicellular algae can affect plant physiology. For example, a study conducted on onion crops showed that the application of Spirulina extracts not only improved vegetative growth but also increased photosynthetic activity by 18%, resulting in higher bulb yields. Additionally, an increase in the concentration of phenolic compounds, which are important for plant defense against pathogens, was observed.

Specific Crops and Results

The application of unicellular algae has proven to be particularly effective in crops such as corn and sugar beet. In greenhouse trials with corn, a 15% increase in biomass production and a 10% increase in sugar content were reported compared to controls. In the case of sugar beet, the application of algae extracts was shown to increase tuber diameter by 20%, thereby improving the commercial quality of the product.

Yeast Extracts: Benefits and Applications

Yeast extracts, primarily obtained from Saccharomyces cerevisiae, are a valuable resource in agriculture. These extracts are rich in amino acids, vitamins, and plant hormones, making them effective biostimulants.

Benefits of Yeast Extracts

• Metabolic Stimulation: Yeast extracts enhance the metabolic activity of plants, resulting in more vigorous growth and increased biomass production. A study on corn crops showed that the application of yeast extracts increased the photosynthesis rate by 15%, leading to a 20% increase in biomass production. This effect is due to the presence of nucleotides that promote ATP synthesis, essential for cellular energy.
• Stress Response Activation: Similar to algae, yeast extracts help plants cope with stressful situations