Field Efficacy of Fungicides for the Management of Rice Neck Blast (Caused by Pyricularia oryzae) in the North-Western Region of Haryana, India

Neck blast is one of the most damaging fungal disease of rice, causing severe yield losses in the North-Western region of Haryana, India. Due to the lack of resistant cultivars commonly grown in Haryana, the management of the disease has relied predominantly on the foliar application of fungicides. Therefore, this study evaluated the field efficacy of various fungicides against rice neck blast in the North-Western region of Haryana, India, over the kharif seasons of 2020, 2021 and 2022. Fungicides were applied twice per season, at panicle emergence and 10 days later. Among the seven fungicides tested, isoprothiolane 40% EC, propineb 70% WP and difenoconazole 25% EC significantly reduced neck blast severity by 63.2%, 55.2% and 47.3% in 2020; 60.6%, 51.4% and 47.4% in 2021; and 70.0%, 64.9% and 62.5% in 2022, respectively with corresponding reductions in area under disease progress curve values compared with the untreated control. The highest grain yield was recorded for isoprothiolane 40% EC, followed by propineb 70% WP and difenoconazole 25% EC. The greatest increase in grain yield was observed in kharif 2020, whereas the lowest yield in kharif 2022 was associated with moderate total rainfall (284 mm) and high average relative humidity (94.4%) following the appearance of neck blast. These results suggest that these fungicides are effective in reducing rice neck blast and enhancing grain yield in the North-Western region of Haryana, India.