Field Evaluation of Fungicides for the Management of Banded Leaf and Sheath Blight of Maize and Their Effect on Yield Parameters

Maize (Zea mays L.) is the world’s most important cereal crop. It has a high yielding capacity and ranks third after wheat and rice in grain production. Maize is a rich source of nutrients; it contains about 72 per cent starch, 10 per cent protein and 4 per cent fat (Nuss and Tanumihardjo, 2010). Among all grain crops, maize has the highest genetic potential and is therefore considered the ‘Queen of cereals’. Maize is widely used in many fields such as feed, alcoholic beverages, food additives, cosmetics, food, chemical products and ethanol production. About 50-60 per cent of all corn production is consumed as food and nutrition and the rest is consumed in the oil industry, starch industry and dry milling industries such as corn-bread, sattu, corn chips and Dalia (Sharma et al., 2015). Maize ranks fifth in the area and third in production in India. Maize has wider adaptability, palatability, quick growing habit and it provides quality fodder also for livestock. Good quality of fodder is required for livestock production and to meet the demand especially in rural areas (Rajkumara et al., 2020). In India, about 28 per cent of total maize production is consumed as food, 48 per cent for livestock and only 12 per cent is consumed in milling industries (Singh and Misal, 2021). Handrid et al., (2020) also reported that, with the increase of maize based industries there will be high demand of production, which can only be attained by controlling various diseases adversely affecting maize production worldwide. It has an area of about 9.70 million hectares having the production of about 30 million metric tons in 2020-2021 (USDA, 2021).

Various pathogens such as fungi, bacteria, viruses and nematodes are collectively about sixty factors that cause diseases in maize and have adverse effects on the produce (Payak and Sharma, 1980). Outbreaks appear to be exacerbated during various stages of development. Among the various diseases of maize, banded leaf and sheath blight (BLSB) caused by Rhizoctonia solani f. sp. sasakii Exner (Thanatephorus sasakii) is considered most destructive. The pathogen belongs to the kingdom Fungi, phylum Basidiomycota, class Agaricomycetes, order Cantharellales, family Ceratobasidiaceae and genus Rhizoctonia. De Candolle (1815) described this genus. R. solani f. sp. sasakii is highly pathogenic and has a very wide host range (Binder et al., 2005). Symptoms of the disease begin to appear on the leaves and sheath in 40-50 days older plants and later stages when the infection increases, the ear can also be infected. The pre-flowering stage is most affected by the disease. The rings formed by lesions can be noticed on the lower leaves and sheath also. In the early stages of infection, the plant produces globular to elongated bands (1-3 mm thick in diameter) that appear as water-soaked lesions. Under favorable weather conditions, the symptoms may extend to silk, glumes and grains. Keeping in view the economic importance, occurrence and spread of disease worldwide, the main purpose of this experiment was to evaluate the effect of various chemicals to manage banded leaf and sheath blight of maize, so that losses can be minimized.

Disease incidence (%)

It was found that, fungicides used in different treatments effectively reduced the disease incidence (Table 1). A minimum per cent disease incidence was found in plants treated with foliar applications of azoxystrobin @ 0.1% twice at 30 and 45 DAS. It was found most effective in reducing the disease with 23.10% disease incidence. Results with foliar spray with propiconazole @ 0.1% at same DAS was found effective next to azoxystrobin @ 0.1%, as it recorded 36.08 % disease incidence over the untreated check. Validamycin @ 0.1% followed by carbendazim @ 0.1% were also found effective and recorded disease incidence i.e., 45.68% and 47.63%, respectively. Contrarily, foliar sprays of mancozeb @ 0.2% at 30 and 45 DAS were found least effective and disease incidence (54.05%) was maximum. Bhuvaneswari and Krishnam (2012) reported disease incidence of 27.06 per cent and evaluated that azoxystrobin 23 SC alone was effective in controlling disease caused by the R. solani pathogen. Malik et al., (2018) reported that validamycin @ 0.1% recorded minimum per cent index and gave 49.15 per cent disease control over untreated check and favors this study.



Disease severity (%)

It was found that, disease severity percentage was different in treatments with different chemicals used (Table 1) and their differences were statistically significant. The results of the experiment (Table 1, Fig 1) clearly showed that all the five fungicides tested significantly controlled BLSB disease and increased the grain yield. Azoxystrobin @ 0.1% foliar sprays twice at 30 and 45 DAS was found most effective in reducing the disease upto 73.54 per cent as compared to control (Plate 1). Results with foliar spray with propiconazole @ 0.1% at same DAS was found effective next to the above treatment, as it reduced the disease upto 49.52 per cent over the untreated check. Validamycin @ 0.1% followed by carbendazim @ 0.1% was also found effective in controlling disease. Two foliar sprays with mancozeb @ 0.2% at 30 and 45 DAS was found least effective in controlling disease (20.84%) as compared to control. In the findings of earlier studies, it was reported that carbendazim and validamycin are efficient in controlling R. solani pathogen (Ahuja and Payak, 1986; Sharma and Rai, 1999). Saxena (2002) also favored that propiconazole is an effective fungicide against the BLSB disease of maize. Whereas findings of Akhtar et al., (2010) revealed that carbendazin and validamycin were effective in controlling BLSB disease in maize and supports our observation. Malik et al., (2018) reported that application of validamycin @ 0.1% was found best in controlling BLSB disease, which favoured the results of this experiment.





Yield parameters

Significant differences in cob weight (fresh and dry) and grain yield were observed in different treatments (Table 2). Maximum fresh and dry cob weight (q/ha) were 106.94 and 77.13 and grain yield (q/ha) was 64.06, recorded from the treatment with azoxystrobin @ 0.1% and it increased grain yield by 77.30 per cent as compared to untreated control. Results with foliar spray with propiconazole @ 0.1% at same DAS was found effective next to the above treatment, as it recorded grain yield 56.12 q/ha and increased grain yield upto 55.32 per cent over untreated check. Validamycin @ 0.1% followed by carbendazim @ 0.1% was also effective in increasing the grain yield. Contrarily, foliar sprays of mancozeb @ 0.2% at 30 and 45 DAS resulted in minimum grain yield among all chemical treatments and increased grain yield by 26.82% as compared to control. Batsa et al., (2004) from his study also confirmed that highest yield was recorded in the treatment sprayed with validamycin. Akhtar et al., (2010) revealed that, the treatments with carbendazin application attained highest yield among all treatments that favours our study. Malik et al., (2018) reported that validamycin @ 0.1% was most effective in controlling disease and produced the highest yield.

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