Eco-Friendly Practices Support Higher Wild Plant Diversity Than Conventional Practices in Tropical Fruit Farms

Rising concern over unsustainable agricultural practices has spurred many farmers to adopt organic and eco-friendly practices. While numerous studies have compared conventional and eco-friendly farms in temperate regions, we still lack data from tropical regions, where the agricultural environment is very different (e.g., smaller farms with greater crop diversity). Thus, the objective of this study was to assess plant diversity in tropical smallholdings, comparing 13 eco-friendly and 13 conventional guava farms in central Thailand. We conducted plant surveys across all seasons and quantified plant diversity and floral resources for all wild (weedy) and cultivated plant species observed on study farms. We recorded 154 plant taxa from 51 families (73 wild taxa, 81 cultivated taxa). Wild plant diversity was significantly higher on eco-friendly than conventional farms (11.77 vs. 7.25 taxa, on average). In contrast, cultivated plant diversity did not differ between the two farm types (9.15 vs. 7.77 taxa). Plant diversity was highest during the rainy season, while floral richness and abundance did not differ across seasons. These findings reflect the agricultural practices of tropical smallholders, where crop diversification with both cash and subsistence crops is common, even in conventional farms. Importantly, the lack of herbicide use on eco-friendly farms promotes greater wild plant diversity, providing beneficial habitat and resources for pollinators, natural enemies of crop pests, and other local biodiversity.