This study aimed to determine the optimal water, temperature, and density conditions, alongside antifungal treatments, for pea (Pisum sativum L.) germination in a laboratory setting, with implications for research, breeding, and microgreen production. Germination and early seedling growth were assessed across various temperatures (5 °C to 40 °C), water levels (0–14 mL per Petri dish), seed densities (5, 7, 9, and 11 seeds per Petri dish), and antifungal treatments (Hypo and Bordeaux mixture). The results indicated that optimal germination occurred between 15 °C and 25 °C, with peak performance at 25 °C. Water levels between 7 and 11 mL per 9 cm diameter Petri dish supported robust root and shoot development, while minimal water levels initiated germination but did not sustain growth. Five seeds per Petri dish was optimal for healthy development, whereas higher densities led to increased competition and variable outcomes. Antifungal treatments showed slight improvements in germination and growth, though differences were not statistically significant compared to controls. The study’s novelty lies in its holistic approach to evaluating multiple factors affecting pea germination, offering practical guidelines for enhancing germination rates and seedling vigor. These findings support efficient and resilient crop production systems adaptable to varying environmental conditions, contributing to sustainable agriculture and food security. Future research should explore these factors in field settings and across different pea cultivars to validate and refine the recommendations.

Superabsorbent polymers (SAPs) are increasingly applied in agriculture to enhance soil water retention, reduce nutrient loss, and mitigate drought stress—challenges expected to intensify under global climate change. While their benefits for crop growth are well documented, much less is known about their influence on free-living microorganisms. Here, we examined the effects of three SAP chemistries—potassium polyacrylate (DCM Aquaperla^®), starch-based polyacrylamide (Zeba Plus SP^®), and γ-polyglutamate (Stockosorb^® 660 Medium)—on the growth and pigment composition of Chlorella vulgaris Beijerinck across three initial cell densities (22.8 × 10³, 228 × 10³, and 2.228 × 10⁶ cells/mL). Six spectral indices, derived from weekly absorbance measurements over seven weeks, were used to track biomass and pigment allocation. Nonparametric repeated-measures analysis and principal component analysis revealed strong effects of SAP type, algal density, and time. Zeba consistently maintained biomass comparable to the control while enhancing carotenoid- and xanthophyll-sensitive indices, suggesting pigment reallocation without growth suppression. Stockosorb produced intermediate responses, whereas Aquaperla frequently reduced biomass-related measures, particularly at high density. Pigment allocation was also density-dependent, with low-density cultures investing proportionally more in carotenoids. Overall, these results show that SAP–microbe interactions are strongly influenced by polymer chemistry and starting biomass, with implications for biotechnology, environmental risk assessment, and sustainable crop production systems that aim to support both algal and plant resilience under drought.