Effects of anti-hail netting on pollinator activity, fruit quality, and economic yield in kiwifruit

Abstract

Protective anti-hail nets are increasingly used in kiwifruit orchards, yet their integrated effects on pollination and yield are unclear. We compared two prevalent management systems: a netted system (anti-hail net with manual pollination, no on-site hives) versus an open-field system (no net, manual pollination with honey bee hives). Across seven commercial kiwifruit orchards, we assessed pollinator communities, visitation rates, fruit quality (weight and seed number), and economic yield. The management system significantly altered pollinator composition (PERMANOVA: F=4.58, R² = 0.48, p = 0.029). Apis mellifera dominated (>60 % of visits) in openfields but was nearly absent under nets, where syrphid flies prevailed. A complementary analysis on the wild pollinator assemblage (excluding A. mellifera) indicated that netting itself explained 31.5 % of the variation (F = 2.30, R²=0.315, p = 0.086), suggesting a substantial, albeit marginally non-significant, filter effect independent of hive management. Visitation frequency was 47 % lower in the netted system. Fruits from the netted system were 30 % lighter and had 45 % fewer seeds. Gross revenue per hectare was 31.5 % lower under nets (USD 47,385 vs. 69,213). The netted management system explained 46.0–64.6 % of the variance in fruit quality and 58.0 % in economic yield. Our results demonstrate that the netted system creates a substantial pollination deficit not compensated by standard manual pollination, directly reducing fruit quality and profitability. Integrating pollinator-friendly practices is needed to balance crop protection with sustainable production.