Progression of bacterial blight disease (Xanthomonas axonopodis pv. cyamopsidis) of clusterbean relation to weather parameters

Vikash Kumar^{* *}Correspondence: Vikash Kumar, Department of Agriculture, RNB Global University, Bikaner, Rajasthan, India, Email:

Author info »

Introduction

Clusterbean (Cyamopsis tetragonaloba) commonly known as "guar" is an arid and semi-arid legume crop belonging to the family Leguminaceae. Its resilience to drought, attributed to its extensive taproot system and ability to withstand water stress effectively. The name "guar" originates from the Sanskrit word "GAUAAHAR," which translates to "food of cow" or "fodder for livestock". Additionally, referred to by various other names such as khutti, dararretic and guari, this crop is particularly suited for cultivation in rainfed conditions during the Kharif season in India. Notably, it contributes to soil fertility enhancement through atmospheric nitrogen fixation. While predominantly grown during the rainy season, it can also thrive in irrigated settings during the summer period. The seeds are highly valued for industrial gum. It is cultivated mainly in the rainy season as a rainfed crop in arid zones of India and various other parts of the world [1]. The clusterbean seed consists of three parts seed coats (14-17%), the endosperm (35-42%) and the kernel (43-47%). Guar gum (19-43% of the whole seed) is derivative from the endosperm, which is the major beneficial product of the plant. Clusterbean is grown for different purposes, namely vegetables, green fodder, green manure and seed production. Beside all this, used as a concentrate for animals and for the extraction of gum mainly present in the endosperm of the seed, provide a useful raw material for a wide range of industrial products. It is additionally grown for the seeds and drawing out of guar gum manufacturing in India. The clusterbean gum is likewise regarded to contain medicinal significance inside the remedy for diabetes and excessive cholesterol [2]. Clusterbean is commercially grown in India, Pakistan and USA and to a limited extent in Australia, Brazil and South Africa. It has grown in the share of 1:10 as a mixed crop. Overall, India produces approximately 80% of worldwide clusterbean production. It is cultivated on more than 4 m ha in India, Rajasthan only accounts for approximately 80% of the region and production. Left behind to its need in the international market, it has been introduced in the non-conventional growing areas including Andhra Pradesh, Tamil Nadu, Karnataka, Maharashtra and Chhattisgarh [3]. In India, the total area under the clusterbean crop is 39.36 lakh hectare, production 16.24 lakh tones and with yield 428 kg/ha. In Rajasthan, total area under the clusterbean crop is 28.41 lakh hectare, production 12.84 lakh tones and with yield 452 kg/ha. Rajasthan is the leading state in clusterbean production and share more than 70% production in India.

The decline in clusterbean crop productivity is often attributed to several bacterial, fungal and viral diseases, including bacterial blight (Xanthomonas axonopodis pv. cyamopsidis), vascular wilt (Fusarium moniliformae and Fusarium sp.), charcoal rot (Macrophomina phaseolina), powdery mildew (Leveillula taurica), anthracnose (Colletotrichum capsici) and alternaria blight (Alternaria cyamopsidis). Similarly, the limited and inconsistent national yield of grain and fodder can largely be ascribed to diseases caused by various plant pathogens. Among them, bacterial blight disease caused by Xanthomonas axonopodis pv. cyamopsidis is a major disease in Rajasthan and India. Bacterial blight has become a serious problem in many cluster bean production areas, during monsoon season i.e., July-October [4,5].

Materials and Methods

Effect of environmental factors on disease development

The field experiments were conducted under artificial field conditions during kharif season. Observations on the severity of bacterial blight disease of clusterbean were recorded 7 days after inoculation from each plots at weekly interval (July-November). To find out the effect of environmental factors on the progression of bacterial blight disease of clusterbean. Weather variables viz., temperature, relative humidity, rainfall, rainy day and sunshine etc., were recorded and correlation among environmental factors and bacterial blight disease progression was worked out. Means of maximum temperature, minimum temperature, relative humidity (morning), relative humidity (evening), rainfall, number of rainy days, sunshine hours, were symbolized as X₁, X₂, X₃, X₄, X₅, X₆ and X₇, respectively. The per cent disease intensity was calculated and symbolized as Y.

Establishment of linear relationship between per cent disease index and key abiotic factors

The per cent disease index was correlated to the prevailing mean a biotic environmental factor (maximum temperature, minimum temperature, maximum relative humidity, minimum relative humidity, rainfall, number of rainy days and sunshine). The correlation coefficient values (r) between the per cent disease index and the abiotic factors were computed using the standard methodology as given by Karl Pearson. To study the relationship between seven independent variables (maximum temperature, minimum temperature, maximum relative humidity, minimum relative humidity, rainfall, number of rainy days and sunshine) and dependent variables i.e., per cent disease index, multiple linear regression analysis were done by fitting this equation. The analysis (s) is as under:

Y = a+b₁X₁+b₂X₂+b₃X₃+b₄X₄+b₅X₅+b₆X₆+b₇X₇(R²)

Where,

R²=Multiple correlation coefficients

Y=Per cent disease incidence (depended variable)

a=Constant (intercept)

b₁ to b₇=Partial regression coefficients

X₁=Maximum temperature (°C)

X₂=Minimum temperature (°C)

X₃=Maximum relative humidity (%)

X₄=Minimum relative humidity (%)

X₅=Rainfall (mm)

X₆=Number of rainy days

X₇=Duration of sunshine (h/day)

Results and Discussion

The effect of weather parameters viz., temperature maximum (X₁), temperature minimum (X₂), relative humidity morning (X₃), relative humidity evening (X₄), rainfall (X₅), number of rainy days (X₆) and sunshine hours (X₇) on the progression of bacterial blight of clusterbean studied in Kharif 2023 (Table 1 and Figure 1).

Table 1: Progression of bacterial blight on clusterbean in relation to weather parameters epiphytotic conditions during Kharif 2023.

Figure 1: Per cent disease intensity of bacterial blight of clusterbean in relation to weather parameters. disease intensity.

The disease first appeared on July 25^th and became more conspicuous from the last week of August to the first week of November and declined after mid- November. The correlation between individual weather variables and disease intensity was determined for Kharif 2023 (Table 2). The results indicated that progression of bacterial blight intensity was strongly significantly negative correlated with maximum temperature (X₁). Minimum temperature (X₂) were significantly negative correlated with disease intensity. Relative humidity morning (X₃) and relative humidity evening (X₄) was strongly significantly positive correlated with disease intensity. Rainfall (X₅), rainy days (X₆) and sunshine (X₇) were none significantly positive correlated with disease intensity. The coefficient of multiple determinations (R²) was 94.95 per cent in Kharif 2023. Which means that 94.95 per cent disease intensity was depend on the weather parameters (Table 3).

Table 2: Correlation matrix for bacterial blight disease progression on clusterbean in relation to weather parameters under epiphytotic conditions during Kharif 2023.

Table 3: Regression equation for bacterial blight of clusterbean in relation to weather parameters.

Y = 4.436 − 0.812X₁ −1.116X₂ +1.253X₃ − 0.499X₄ + 0.059X₅ − 5.933X₆ − 0.367X₇

The analysis of all the seven independent variables individually and in combinations revealed that every weather parameter played a major role in disease development in clusterbean. Similar finding is supported with results obtained by earlier workers by Shah et al., [6] they observed that the temperature ranges of 20-30°C and relative humidity between 70% and 80% favored the rapid progress of the bacterial blight of clusterbean. Also Similarly, reported by Yadav et al., [7] and Amin et al., [8].

Conclusion

Clusterbean is the legume annual herb has a deep-rooted system, is resilient and drought resistant pulse crop grown on sandy soil of arid and semi-arid region. A number of pathogens causes diseases in this crop. Among them, bacterial blight disease caused by Xanthomonas axonopodis pv cyamopsidis is a major disease in Rajasthan and India. The leaf blight pathogen Xanthomonas pv. cyamopsidis causes harsh reduction in plant stand and yield as high as 58% in cultivar. The seed borne pathogen can survive in seeds for up to one year. The favorable conditions causing spread of this disease. Weather parameter plays a major role in bacterial blight disease development in clusterbean. The analysis of all the seven independent variables individually and in combinations revealed that every weather parameter played a major role in disease development in clusterbean. The correlation between individual weather variable and disease intensity was determined. The results indicated that progression of bacterial blight disease intensity was strongly significantly negative correlated with maximum temperature (X₁) and minimum temperature (X₂). Relative humidity morning (X₃) and Relative humidity evening (X₄) was strongly significantly positive correlated with disease intensity. Rainfall (X₅), rainy days (X₆) and sunshine (X₇) were none significantly positive correlated with disease intensity. The coefficient of multiple determinations (R²) was 94.95 per cent in Kharif 2023. Which means that 94.95 per cent disease intensity was depend on the weather parameters.

References

1. Pathak R, Singh M, Henry A. Genetic divergence in clusterbean (Cyamopsis tetragonoloba) for seed yield and gum content under rainfed conditions. Indian Agric Sci. 2009;79:559-561.

   [Google Scholar]

2. Bhan S, Prasad R. Guar has many uses. India Pharm. 1967;17(6):17-19.

   [Google Scholar]

3. Bhatt RK, Jukanti AK, Roy MM. Cluster bean Cyamopsis tetragonoloba (L.) Taub. An important industrial arid legume: A review. Leg Res. 2016;40(2):207-214.

   [Google Scholar]

4. Patel MK, Dhande GW, Kulkarni YS. Bacterial leaf-spot of Cyamopsis tetragonoloba (L.) Taub. Curr Sci. 1953;22:183.

   [Google Scholar]

5. Srivastava DN, Rao YP. Bacterial blight of Guar. Indian Phytopathol. 1963;16:69-73.

   [Google Scholar]

6. Shah R, Dashora PK, Bhatnagar MK. Forcasting model for bacterial blight of clusterbean. Int Conf Pl Path Bact. 1996:525-527.
7. Yadav S, Nath R. Effect of weather parameters and different sowing times on the occurrence of clusterbean bacterial blight. J Mycol Pathol Res. 2006;44:267-269.

   [Google Scholar]

8. Amin AM, Patel NR, Jaiman RK, et al. Management of bacterial blight in clusterbean. India Envi Eco. 2017;35(2):1223-1227.

   [Google Scholar]