Vol. 12, Issue 11 (2023)

Safflower (Carthamus tinctorius L.), a vital Rabi oilseed crop, is significantly affected by soil- and seed-borne fungal pathogens, particularly Fusarium oxysporum f. sp. carthami (wilt) and Macrophomina phaseolina (root rot), which can cause severe yield losses under dryland conditions. A three-year field study (2017-2020) was conducted in a randomized block design to evaluate the efficacy of biopriming and seed treatments using Trichoderma harzianum Th4d WP and Pseudomonas fluorescens Pf2 WP, alongside a recommended chemical fungicide (cymoxanil + mancozeb), in managing these diseases and enhancing seed yield.

The results revealed that seed biopriming with T. harzianum Th4d WP (T1) significantly reduced disease incidence (14.2% for Fusarium wilt and 3.3% for root rot) and achieved the highest seed yield (878 kg/ha), with a benefit-cost ratio of 1.79. Seed treatment with T. harzianum (T3) also demonstrated high efficacy, with a Fusarium wilt incidence of 17.0%, root rot incidence of 5.8%, and a seed yield of 819 kg/ha. In contrast, untreated controls (T7) showed the highest disease incidence (44.9% for Fusarium wilt and 15.9% for root rot) and the lowest seed yield (350 kg/ha).

Economic analysis confirmed the superiority of T. harzianum-based treatments in terms of net returns and profitability. These findings highlight the potential of biopriming with T. harzianum as a sustainable, eco-friendly strategy for managing soil-borne diseases and improving safflower productivity in dryland farming systems.