Comparative Effects of Organic Substrate and Commercial Germination Growth Media on Germination and Seedling Growth of Various Crops Under Greenhouse Conditions

Abstract The growing needs of sustainable agricultural production have necessitated the research aimed at identifying alternative low-cost growing media compositions like pinecone powder (PCP), a waste product, which is high in lignocellulosic and phenolic compounds. This study examined how the amount of PCP (250 g, 450 g, 650 g, and 1000 g,) mixed with the commercial germination mix (GM) would affect the germination and seedling growth, and vigor of five vegetable crops, which were spinach, okra, beetroot, and two tomatoes (Roma and Heinz cultivars). The results showed that there was a strong crop response related to pinecone powder concentrations. The 100% PCP (1000 g) treatment consistently inhibited the germination and growth of all vegetable crops, and this implies that pinecone powder could be phytotoxic. Results on the moderate levels showed that pinecone powder concentration at 250 g and 450 g increased germination percentage, shoot, and root length of crops, especially tomato cultivars, and beetroot biomass. While the correlation analysis indicated that germination percentage was a good indicator of seedling vigor and biomass accumulation because there were high correlations (r > 0.95) between numerous variables, particularly in spinach, Heinz tomato, and beetroot. The seedling vigor index lacks analytical influence across all vegetable crops, particularly in all tomato cultivars, implying that the role of direct morphological measurements should be included in vigor determination. This study supports sustainable agricultural practices by utilizing and exploring organic substrates that minimize environmental impact and improve seedling vigor, which aligns with SDGs 2 and 12, emphasizing enhanced crop productivity and decreased reliance on synthetic inputs. It was therefore concluded that pinecone powder may be used as an environment-friendly substrate; however, it must be added in carefully dosed concentrations to prevent phytotoxic impact.