Field evaluation of fungicides against black point of wheat

Introduction

Wheat often called the "King of Cereals" is a crucial staple food for about 36% of the world's population (Kumar et al., 2019) [7] . Belonging to the family Poaceae (Braun et al., 2010) [1] . Wheat (Triticum aestivum L.) is a self-pollinated crop. In India, three major types of wheat were cultivated T. dicoccum Schrank. (Emmer wheat) and T. durum Desf. (Macaroni or Durum wheat) T. aestivum L. (Bread wheat) (Peng et al., 2011) [12] . Wheatbased products are widely consumed in India, Pakistan and Iran (Kumar et al., 2011) [6] . Rich in protein, dietary fibre, B vitamins and minerals. Wheat is valued as a nutritious health food. However, the crop suffers from several fungal diseases that cause annual yield losses of 15 to 20 per cent. Key diseases include rusts, black point, blotches and head blight. Black point is complex disease; it is cause by many of the fungus. Among these, B. sorokiniana is the most common, followed by A. alternata and C. lunata. The disease is usually linked to high humidity and wetter patches in fields. The critical period for black point occurrence begins 30 days after heading and continues for 14 to 20 days (Moschini et al., 2006) [11] . During this time, warm temperatures above 17°C combined with daily relative humidity between 60 to 85 per cent promote higher incidence of black point. The black point disease has been reported from Punjab, Haryana, Jammu Kashmir, Uttar Pradesh, Uttarakhand, Himachal Pradesh, Bihar, Delhi, West Bengal, Orissa, Gujarat, Rajasthan, Maharashtra, Madhya Pradesh, Assam, Karnataka and Andhra Pradesh (Singh et al., 2018) [15] . The black point disease is identified by a dark discoloration of the embryo sides of the wheat grains (Mak et al., 2006) [9] . Diseased kernels are black and discolored at the ends of the seed. Embryos become often shriveled and brown to black in color.

Materials and Methods

A field trial was carried out at the Research Farm of the Wheat Research Station, Junagadh Agricultural University, Junagadh during 2025-2026 in Rabi season and evaluated the efficacy of fungicides for the management of black point of wheat. The fungicides found effective under in vitro condition against the test pathogen were used for field experiment as per Table 1. Wheat plants were inoculated with spore suspension of A. alternata, B. sorokiniana and C. lunata (3x10 5 conidia ml -1 ) prepared in sterilized distilled water at the milking stage with the help of a hand sprayer during evening hours. The fungicides found effective from in vitro trial were sprayed at 15 days after inoculation by dissolving at their effective concentration at the rate of 500-liter solution per hectare. The required quantity of respective fungicides was added to measured quantity of water so as to get desired concentration. Control was maintained without spraying of any fungicide. Observations on per cent disease incidence were recorded from randomly selected five tagged plants from each treatment at harvesting time. The selected plant was evaluated into diseased seed out of total seeds then converted into per cent disease incidence (PDI) by using the formula given by Sesiz (2023) [13] .

The per cent disease reduction over control was calculated with the help of following formula (Mathur et al., 1971) [10] .

Disease control (%) = PDI in control plot -PDI in treated plot PDI in control plot × 100

Result

Discussion

The present results get similarity with finding of Iqbal et al.

(2014) [5] . They reported minimum disease infection of black point in wheat with propiconazole 25 EC with 23.03 per cent disease incidence. Shrestha et al. (2017) [14] also reported among different doses of treatments propiconazole at the rate of 2ml/L water showed significant result for the efficient management. Kumar et al. (2021) [8] also found propiconazole 0.1% at boot leaf stage followed by second spray at 20 days interval proved to be best in reducing disease. Tiwari et al. (2022) [16] found similar result that propiconazole has low per cent disease incidence (25.80%) compare to other fungicidal treatment. Nil et al. shown propiconazole has highest efficacy against black point of wheat, which are in line with the present findings.

Field view of experimental site

Conclusions

Total eight treatments along with control were applied under field condition. Among them, tebuconazole 50 + trifloxystrobin 25 WG at 0.075% showed minimum disease incidence (23.61%) with maximum disease reduction over control (57.99%) and found significantly superior over the rest of the treatments, but it was remained statistically at par with propiconazole 25 EC at 0.025 per cent concentration, hexaconazole 4 + zineb 68 WP at 0.075 per cent concentration and azoxystrobin 18.2 + difenoconazole 11.4 SC at 0.075 per cent concentration with 24.95, 26.29 and 26.90 per cent disease incidence and 55.62, 53.25 and 52.07 per cent disease reduction over control, respectively.

Acknowledgement

AcknowledgmentsThe first author gratefully acknowledges the Department of Plant Pathology and Wheat Research Station, Junagadh Agricultural University, Junagadh to support this work.

References

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