Integrating host resistance and botanical agents: Screening pigeonpea [Cajanus cajan (L.) Huth] genotypes for Fusarium wilt (Fusarium udum Butler) management

Fusarium wilt, caused by Fusarium udum Butler, is a major biotic constraint limiting pigeonpea (Cajanus cajan L. Huth) productivity in tropical and subtropical regions. Wilt incidence varied widely among 143 pigeonpea genotypes, ranging from 0.40 to 15.60 % at 30 days after sowing and escalating to 2.00 to 78.00  % at 75 DAS. Area under disease progress curve (AUDPC) values ranged from 57.9 to 2258.1, indicating diverse disease progression. Based on the percent disease index (PDI), relative AUDPC (rAUDPC) and r-values, genotypes were categorised as resistant (38.5 %), moderately resistant (37.8 %), susceptible (11.9 %) and highly susceptible (11.9 %). Notable resistant genotypes included Pusa Arhar 21-60, ICP 8863 and NAM 88. In vitro evaluation of seven plant extracts at 10, 15 and 20 ppm using the poisoned food technique revealed significant variation in antifungal activity. Thuja occidentalis L., Cannabis sativa L. and Mentha spicata L. consistently exhibited the highest inhibition in a dose-dependent manner, whereas Chenopodium album L. was least effective. Integration of resistant genotypes with potent botanical extracts offers an eco-friendly strategy for sustainable management of Fusarium wilt in pigeonpea.