Effects of Different Fertilizer Types on Pigment Content and Some Stress Molecules in Perennial Ryegrass (Lolium perenne L.)

Background: Perennial ryegrass (Lolium perenne L.) is a grass species known for its dark green color, fine texture and rapid germination in cool seasons. Its resilience to hot, dryand cold weather conditions makes it suitable for both warm and cool climates. Its high resistance to wear stress makes it an ideal plant for sports fields. The use of chemical fertilizers leads to the accumulation of toxic elements in the soil, reducing productivity and polluting water sources. In contrast, organic or biofertilizers improve soil structure, increase water retention capacityand enhance the effective use of plant nutrients. This results in high yields while ensuring environmentally friendly agricultural practices that protect human and animal health. Methods: In this study, perennial ryegrass was treated with six different types of fertilizers (liquid seaweed fertilizer, microbial liquid organic fertilizer, organic liquid vermicompost, chicken manure, bat guanoand fertilizer with 32 micro trace elements) at four different fertilizer doses (2%, 4%, 6% and 8%). A control group with no fertilizer application was also included. The study investigated the effects of fertilizers on the plant’s chlorophyll-a (mg/g), chlorophyll-b (mg/g), total chlorophyll (mg/g), chlorophyll a/b ratio, carotenoid (mg/g), proline (µmol/mL), MDA (Lipid peroxidation activity) (nmol/g), APX (Ascorbate Peroxidase) (EU/ml) and Catalase (EU/ml) levels. Result: The results showed that chlorophyll a content ranged from 3.68 to 0.35, chlorophyll b from 2.07 to 0.22 and total chlorophyll from 5.75 to 0.56, while the chlorophyll a/b ratio was between 2.65 and 1.46. Carotenoid content ranged from 1.01 to 0.14and ascorbate peroxidase activity was measured between 29.02 and 0.67. Catalase activity varied from 175.80 to 11.54, proline content from 48.05 to 1.15 and lipid peroxidation (MDA) levels ranged from 1.50 to 0.36. These results demonstrate that different treatments have significant and wide-ranging effects on the physiological and biochemical parameters of plants.