Integrated disease management of Curvularia leaf spot of maize (Zea mays L.)

Introduction

Maize (Zea mays family Poaceae) is a cereal crop plant that produces grain that is used for cooking, roasting, grounding, frying and crushing to prepare different food items and is high yielding, easy to process, readily digested and cheaper than other cereals. Maize is an imperative crop and all parts of plant have monetary value; the grain, leaves, stalks, tassel and cob can be used to prepare large variety of food and non-food products, animal feed, industrial products such as biofuels, snacks foods and alcohol production (Shiferaw et al., 2011) [6] . In India, maize is the third most vital food crop after rice and wheat. It is cultivated throughout the year in different parts of the country for diverse purposes as well as grain, fodder, green cobs, baby corn, sweet corn, popcorn and industrial purposes etc. The main maize producing states are Karnataka, Madhya Pradesh, Bihar, Tamilnadu, Telangana, Maharashtra, Andhra Pradesh, Uttar Pradesh, Rajasthan (Anonymous, 2017) [2] . Maize is susceptible to several bacterial, viruses, nematode and fungal diseases, out of which leaf spot of maize caused by Curvularia lunata is one of the most destructive disease and causes up to 60% losses (Huang et al., 2004; Akinbode, 2010) [5,1] . The range of yield losses is 10.10% to 48.62. Studies on survival and spread of the pathogen need to be worked out to understand the disease cycle and to break the infection chain at appropriate time in order to manage the disease effectively. Host plant resistance is considered as most practical, feasible and economical method of plant disease management. Hence, it is most important to carry out screening of genotype/variety to identify sources of resistance and also resistant composites and hybrids under different maturity groups. Effective management of this disease by a single method may not be possible. Hence, it is necessary to develop an integrated disease management strategy by combining fungicides, bioagents, botanicals practices as efficient components. In the present study attempt was made to develop and study the in vivo antifungal activity of plant extracts, bioagents and chemical based formulation against Curvularia lunata the causal organism of leaf spot of maize for management of this disease.

Materials & Methods

The proposed study was conducted in the Experiment Field of the Department of Plant Pathology at Central Research Farm, SHUATS, Prayagraj, (UP.) during Kharif 2022 and 2023

Results & Discussion

In-vivo management of Curvularia leaf spot of maize using bioagents, plant extracts and fungicides (Rabi 2022) Before spray the minimum percent disease incidence of Curvlaria leaf spots of maize were recorded in T 2 -Metiram + Pyraclostrobin (FS) (30.74%) followed by T 3 -Trichoderma virens (ST) (32.66%), T 4 -Bacillus subtilis (FS) + Ampelomyces quisqualis (ST) (33.87%) also at par with each other's which significantly reduce the incidence as compared to rest of the treatments. Percent disease incidence of Curvlaria leaf spots of maize were recorded in T 9 -Ampelomyces quisqualis (FS) + Cestrum nocturnum (FS) (36.01%) followed by T 6 -Trichoderma harzianum (ST) + Azotobacter chroococum (ST) (39.37%),T 11 -Azospirillum lipoferum (ST) + Moringa oleifera (FS) (39.92%), T 5 -Trichoderma viride (ST) + Terminalia arjuna (FS) (42.99%), T 12 -Paecilomyces lilacinus (FS) + Cycloheximide (FS) (43.85%), T 8 -Lawsonia inermis (FS) (49.07%), T 10 -Rauvolfia serpentine (FS) (49.43%), T 7 -Bacillus subtilis (FS) + Pseudomonas fluorescens (ST) (52.40%) respectively, which significantly reduce the percent disease incidence as compared to control (57.87%). Kotramma, (2015) evaluated various fungicides against C. lunata the causal agent of Curvlaria leaf spots in maize. Among the eight systemic fungicides, myclobutanil 10% WP, hexaconazole 5% EC, tebuconazole 25.9% EC and propiconazole 25% EC recorded 100 percent inhibition of mycelial growth, at all the concentration. After first spray the minimum percent disease incidence of Curvlaria leaf spots of maize were recorded in T 2 -Metiram + Pyraclostrobin (FS) (31.41%) followed by T 3 -Trichoderma virens (ST) (34.59%), T 4 -Bacillus subtilis (FS) + Ampelomyces quisqualis (ST) (35.28%) also at par with each other's which significantly reduce the incidence as compared to rest of the treatments. Percent disease incidence of Curvlaria leaf spots of maize were recorded in T 9 -Ampelomyces quisqualis (FS) + Cestrum nocturnum (FS) (36.96%) followed by T 6 -Trichoderma harzianum (ST) + Azotobacter chroococum (ST) (41.00%), T 5 -Trichoderma viride (ST) + Terminalia arjuna (FS) (43.88%), T 12 -Paecilomyces lilacinus (FS) + Cycloheximide (FS) (47.52%), T 8 -Lawsonia inermis (FS) (50.81%), T 10 -Rauvolfia serpentine (FS) (52.08%), T 7 -Bacillus subtilis (FS) + Pseudomonas fluorescens (ST) (54.11%) respectively, which were significantly reduce the percent disease incidence as compared to control (68.14%). The effectiveness of the systemic fungicide hexaconazole 5 EC against the fungs C. clavata were assessed in vitro by Sneha and Satya Prasad (2014) at various concentrations, namely 50, 100, 150, and 200 ppm. The mycelial growth of the fungi decreased as the fungicide concentration increased. There were noticeable growth inhibition at a dosage of 200 ppm.

After second spray the minimum percent disease incidence of Curvlaria leaf spots of maize were recorded in T 2 -Metiram + Pyraclostrobin (FS) (31.49%) followed by T 3 -Trichoderma virens (ST) (36.02%), T 4 -Bacillus subtilis (FS) + Ampelomyces quisqualis (ST) (36.90%) also at par with each other's which significantly reduce the incidence as compared to rest of the treatments. Percent disease incidence of Curvlaria leaf spots of maize were recorded in T 9 -Ampelomyces quisqualis (FS) + Cestrum nocturnum (FS) (37.86%) followed by T 6 -Trichoderma harzianum (ST) + Azotobacter chroococum (ST) (41.59%),T 11 -Azospirillum lipoferum (ST) + Moringa oleifera (FS) (42.54%), T 12 -Paecilomyces lilacinus (FS) + Cycloheximide (FS) (50.09%), T 8 -Lawsonia inermis (FS) (51.95%), T 10 -Rauvolfia serpentine (FS) (52.80%), T 7 -Bacillus subtilis (FS) + Pseudomonas fluorescens (ST) (54.70%) respectively, which significantly reduce the percent disease incidence as compared to control (71.83%). Aparna et al. (2017) assessed how well different fungicides worked against C. lunata. Among all the systemic, non-systemic and combi products evaluated, complete inhibition were achieved in tridemorph, propiconazole, dithaneM45, carbendazim + mancozeb, tricyclozole + mancozeb and zineb + hexaconazole and minimum inhibition (10.17%) were recorded in carbendazimaT 0 .1 percent while 65.33 mm radial mycelial growth were recorded in control.

References

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