Assessing post-emergence herbicides in chickpea (Cicer arietinum L.) for economic benefits, yield response, and weed control under different mega-environments in India

Context

Weed infestation is a major constraint in crop production across the globe but few herbicide options are available. In India, the world’s major chickpea producer, broadleaf weeds are most damaging to chickpea due to lack of post-emergence herbicides.

Objective

The study aimed to systematically evaluate the selectivity and efficacy of topramezone, a novel post-emergence (POST) herbicide, for broad-spectrum weed control in chickpea.

Methods

We tested different pre-emergence (PRE) and POST herbicides alone and in combination with topramezone during 2021–22 and 2022–23 in thirteen locations under major mega-environments of India, comprising different agro-climatic conditions.

Results

The average yield loss due to weed infestation was 52.3 % (24.1 – 73.6, CI 95 %) across locations. Across all locations, the sequential herbicide application comprising oxyfluorfen 150 g a.i. ha⁻¹ PRE - topramezone 20.6 g a.i. ha⁻¹ POST at 14 days after sowing, DAS (OXYF150-TOPR20.6) exhibited the highest weed control efficiency of 70 % (68.2 – 81.1, CI 95 %) and recorded yields up to 98 % of the weed-free check, reducing yield losses by up to 60 % over weedy check. In contrast, narrow-spectrum herbicides such as propaquizafop at 150 g a.i. ha⁻¹ and quizalofop-p-ethyl 150 g a.i. ha⁻¹ at 25 DAS had the lowest efficiency (∼55–58 %) and yielded only 60–80 % of weed-free check, proving the need of herbicides for managing broadleaf weeds in chickpea. The OXYF150-TOPR20.6 significantly enhanced the grain yield (1537–1858 kg ha⁻¹) and delivered the highest net return (∼₹52,000) and benefit-cost ratio (BCR: ∼3.0), proving its superiority in both productivity and profitability across agro-climatic zones.

Conclusion and significance

It is the first comprehensive evaluation of topramezone and its sequential use with PRE herbicides under major mega-environments of India. This study highlights topramezone's potential as a globally viable POST herbicide, offering effective weed control, improved chickpea yield, and sustainable weed management.