Guava (Psidium guajava L.) is a valuable tropical fruit crop known for its nutritional benefits and economic significance, especially in India. Nevertheless, guava farming encounters difficulties, including early flower and fruit drop, which are frequently linked to inadequate nutrient management and excessive reliance on chemical inputs. This research sought to evaluate the effects of organic fertilizers, seaweed extract, and Pink Pigmented Facultative Methylotrophs (PPFM) on the growth stages, physiological characteristics, and yield factors of the guava variety Taiwan Pink. A field experiment was carried out in Rajampalayam village, Tamil Nadu, from February 2024 to May 2025 utilizing a Randomized Block Design (RBD) with 12 unique treatment combinations, each replicated three times. The treatments included various combinations of goat manure, poultry manure, seaweed extract (2–3%), and PPFM (1–2%). Observations were made on phenological parameters (such as bud emergence and fruit set), vegetative parameters (including shoot and leaf count, and leaf area), and physiological parameters (chlorophyll index). The data were analyzed using standard ANOVA methods at a 5% significance level. Treatment T3 (Goat manure 2.5 kg combined with 3% seaweed extract) achieved the earliest bud emergence at 12.42 days. Meanwhile, T10 (Poultry manure 2.5 kg with 2% PPFM) resulted in the quickest fruit set at 27.96 days, alongside the highest number of flower buds (144.69) and the most fruit set (139.67). T5 (Goat manure with 2% PPFM) exhibited the greatest leaf area at 61.16 cm². Additionally, T10 recorded the highest chlorophyll index during the flowering stage at 43.96, while T2 (Goat manure with 2.5% seaweed extract) excelled during fruit set with an index of 38.46. Combining organic fertilizers with bio-inputs such as seaweed extract and PPFM greatly improved vegetative growth, chlorophyll levels, and fruiting characteristics in guava cv. Taiwan Pink. This environmentally friendly method not only boosts yield and fruit quality but also promotes sustainable agriculture by decreasing reliance on chemical fertilizers

Guava, Seaweed extract, PPFM, Organic manure, Poultry manure, Goat manure

The study highlights the significance of sustainable practices in guava cultivation, especially for the Taiwan Pink variety, which provides important nutritional and economic benefits. Utilizing organic fertilizers like goat and poultry manure, along with Pink Pigmented Facultative Methylotrophs (PPFMs) and seaweed extract, can enhance soil fertility and support plant growth. This approach reduces reliance on chemical fertilizers and addresses issues such as premature flower and fruit drop, ultimately improving yield and fruit quality. The findings from the study suggest that these integrated strategies can boost productivity and sustainability in guava farming, essential for India's leading role in global guava production. Further research could lead to even better practices in cultivation

Manojkumar K., Akino A., Gopu B. and R. Angelin Silviya (2025). Optimization of Phenological Stages and Growth of Guava cv. Taiwan Pink through Organic Amendments and Bioinoculants. Biological Forum, 17(7): 142-147