Current IssueSpecial IssueEditorial BoardOnline First ArticlesArchive
Current IssueSpecial IssueEditorial BoardOnline First ArticlesArchive

Full Research Article

Yield Loss Assessment in Horsegram Due to Yellow Mosaic Disease in Karnataka

S
Sonam R. Pinjar1
G
G.U. Prema2,*
B
B.V. Swapna3
G
Gurupad Balol4
S
Spurthi N. Nayak5
1Department of Plant Pathology, College of Agriculture, Dharwad-580 005, Karnataka, India.
2ICAR-All India Coordinated Research Project on Maize, Main Agricultural Research Station, University of Agricultural Sciences, Dharwad-580 005, Karnataka, India.
3Department of Plant Pathology, College of Agriculture, Vijayapur-586 101, Karnataka, India.
4ICAR-All India Coordinated Research Project on Groundnut, University of Agricultural Sciences, Dharwad-580 005, Karnataka, India.
5Department of Biotechnology, College of Agriculture, University of Agricultural Sciences, Dharwad-580 005, Karnataka, India.

  • Submitted30-10-2025|

  • Accepted12-10-2026|

  • First Online 30-10-2026|

  • doi 10.18805/LR-5595

ABSTRACT

Background: Horsegram [Macrotyloma uniflorum (Lam.) Verdc.] is a drought-tolerant legume widely cultivated in South Asia and is resilient to poor soil conditions. Yellow mosaic disease (YMD) poses a significant challenge to horsegram production in India, potentially resulting in complete yield loss. Since scanty literature is available on loss assessment of YMD in horsegram, an attempt was carried out to assess the losses in horsegram genotypes due to YMD.

Methods: Field experiment was laid out in split plot design using different horsegram genotypes to assess the loss due to YMD.

Result: Loss assessment revealed that, among all the genotypes PHG-9 showed least per cent yield loss (17.35%) with less incidence (21.62%) and VHG-44 showed highest per cent yield loss (31.10 %) with high incidence (58.67%) of YMD. Significant differences in performance of genotypes, between the protected and unprotected blocks, with less yield loss observed under protected conditions.

INTRODUCTION

Horsegram (Macrotyloma uniflorum) is a hardy, drought-tolerant legume grown in South Asia, known for its ability to thrive in arid, nutrient-poor soils. Rich in protein, fiber and essential minerals, it is a valuable food source and fodder. It is also known as kulthi bean, gahat, hurali, ulavalu, muthira or madras gram. It is an under exploited grain legume with great potential in sustainable agriculture (Prema and Rangaswamy, 2017). It is an important crop of south India. It is mainly cultivated in the states of Karnataka, Andhra Pradesh, Orissa, Tamil Nadu, Madhya Pradesh, Chhattisgarh, Bihar, West Bengal, Jharkhand and in foot hills of Uttaranchal and Himachal Pradesh in India. It is a popular pulse crop of Karnataka, grown in districts like Mysuru, Tumakuru, Ballari, Raichur, Bagalkot, Mandya, Hassan, Chamarajanagar, Vijayapura, Chitradurga, Kolar and Koppal districts (Prema and Rangaswamy, 2020).
       
In India, it is cultivated in 0.507 m ha area with total production of 0.262 m t and productivity of 516 kg/ha. Karnataka ranks first in production in India with 0.096 m t and covers an area of 0.147 m ha with the productivity of 655 kg/ha, followed by Tamil Nadu with a production of 0.056 m t and an area of 0.075 m h with the productivity of 745 kg/ha (Sonam et al., 2024; Sonam et al., 2025). Among the viral diseases, the yellow mosaic disease poses a considerable challenge to its cultivation in peninsular India, with its initial detection occurring in the southern districts of Karnataka. The first report of the YMD of horsegram was by Williams et al., (1968).
       
The horsegram YMD caused by yellow mosaic virus, which is transmitted by the whitefly species Bemisia tabaci (Gennadius), has been widely observed in various regions of South India. The incidence of this disease has been reported to range between 50 to 100 per cent in crops cultivated during both the summer and early rainy seasons leading to significant reductions in grain yield. Initially, symptoms appeared as a faint yellow discoloration on young leaves (Swapna and Prema, 2024; Swapna and Prema, 2025; Swapna et al., 2025). As the condition progressed, the leaves showed a mosaic pattern of mottling, characterized by irregular, small, greenish-yellow patches interspersed with normal green areas (Prema, 2013). Gradually, the mottles expanded, brightened to a vivid yellow and eventually turned completely bleached. Severe infection led to stunted plant growth and smaller leaves (Prema et al., 2013; (Prema and Rangaswamy, 2020a).
       
Assessing and managing yellow mosaic disease in horsegram is crucial in Karnataka due to its significant impact on crop yield and farmer livelihoods. Effective loss assessment helps to identify the severity and spread, guiding targeted management practices. Since not much work has been carried out on loss assessment of YMD of horsegram in Karnataka, the current research was carried out with an intention to assess the loss due to YMD in horsegram.

MATERIALS AND METHODS

The present research on yield loss assessment of yellow mosaic disease of horsegram was carried out during summer 2023-24. A field experiment was conducted at Main Agricultural Research Station, Dharwad, which is situated in Northern transition zone (Zone-8) of Karnataka, India.
 
Estimation of losses in horsegram due to yellow mosaic disease
 
The field experiment was conducted at MARS, Dharwad which aimed to assess the yield losses caused by YMD in horsegram during summer 2023-24. Seven different horsegram genotypes namely; BGM-1, PHG-9, GPM-6, VHG-44, CRHG-4, CRIDA-1-18R and Local were evaluated under both protected and unprotected conditions using a split plot design. Seed treatment with imidacloprid 600 FS at 5 ml/kg of seeds, followed by spray with thiomethoxam 25% WG at 0.2 g/l was carried out at 30, 45 and 60 DAS for protected plot treatment. Unprotected plot treatment was treated as check.
 
Details of experiment and observations

 
Observations were recorded for yield parameters, including pod number and grain yield, based on five randomly selected plants within each replication during harvesting. The characters studied and the techniques adapted to record the observations are given below:
 
Per cent disease incidence
 
Per cent disease incidence was calculated by the formula given by Wheeler (1969).

            
Per cent disease severity
 
Per cent disease index was calculated by the formula given below and modified scale of AICRP on MULLaRP was used for disease rating (Alice and Nadarajan, 2007).

   
Number of pods per plant
 
The number of pods in an average of five plants were counted and recorded at physiological maturity stage.
 
Pod length
 
The length of five randomly selected pods from each plant were measured from the tip to the bottom, averaged and expressed in centimeters (cm).
 
Number of seeds per pod
 
The number of seeds in five randomly selected pods from each plant and their mean was recorded.
 
Test weight
 
After threshing and winnowing, seeds were collected and were sun dried. The sun dried, one thousand filled seeds taken at random were used to compute weight in an electrical balance. The test weight was recorded in grams.
 
Total seed yield
 
The pods were dried thoroughly, threshed and winnowed to remove the husk. Total seed yield was then assessed by bulking seeds from each plant and weighing them using an electrical balance. The yield was computed in q/ha.
 
Per cent yield loss
 
It was calculated using the formula given below:

 
Modified scale of AICRP on MULLaRP used for disease rating (0-9) (Alice and Nadarajan, 2007).

RESULTS AND DISCUSSION

Estimation of losses in horsegram due to yellow mosaic disease
 
Results revealed that all genotypes performed well under protected condition than unprotected condition with less per cent yield loss under protected condition (Table 1, Table 2 and Fig 1).

Table 1: Yield loss assessment due to YMD incidence in different horsegram genotypes with respect to per cent disease incidence, per cent disease index, no. of pods/plant and pod length.



Table 2: Yield loss assessment due to YMD incidence in different horsegram genotypes with respect to no. of seeds/pod, 1000 seed weight and seed yield.



Fig 1: YMD incidence in different horsegram genotypes under protected and un-protected conditions.


 
Disease incidence (%)
 
Disease incidence was recorded at 15 days interval starting from 45 DAS up to physiological maturity (Table 1 and Fig  1). The incidence increased towards maturity, highest mean per cent disease incidence (52.87%) was recorded in un-protected blocks at harvest when compared with protected blocks (35.51%). Among all the genotypes, GPM-6 recorded significantly highest per cent disease incidence (47.47%) in protected block as well as in unprotected block (69.63%) whereas, PHG-9 recorded lowest per cent disease incidence in both protected (21.62 %) and unprotected block (34.44%). Among the genotypes assessed, highest per cent reduction in disease incidence over unprotected plot was recorded in BGM-1 (29.06%), followed by CRHG-4 (23.98%) and lowest was in VHG-44 (16.12%) and CRIDA-1-18R (17.50%).
 
Disease index (%)
 
Disease index was recorded at 15 days interval starting from 45 DAS up to physiological maturity (Table 1 and Fig 1). The disease index increased towards maturity, highest mean per cent disease index (64.25 %) was recorded in un-protected blocks at harvest when compared with protected blocks (44.59%). Among all the genotypes, GPM-6 recorded significantly highest per cent disease index (61.69%) in protected block as well as in unprotected block (88.24%) whereas, PHG-9 recorded lowest PDI in both protected (20.03%) and unprotected blocks (26.90%). Among the genotypes assessed, highest per cent reduction in disease index over unprotected plot was recorded in local (28.77%), followed by BGM-1 (27.72%) and lowest was in CRIDA-1-18R (13.68 %) and VHG-44 (16.16%).
 
No. of pods per plant
 
Pod number of all genotypes was recorded at harvesting stage, mean pod number was superior in protected block (20.83), whereas it was low in unprotected block (15.83). Among all the genotypes, PHG-9 recorded significantly higher number of pods per plant (23.58%) in protected block as well as in unprotected block (17.76%) whereas, lowest number of pods per plant in both protected and unprotected block was recorded by VHG-44 and GPM-6, respectively which were on par with each other (Table 1). Among the genotypes assessed, highest per cent reduction in number of pods per plant was recorded in BGM-1 (28.21%), followed by CRHG-4 (25.14%) and lowest was in local (19.08 %) and VHG-44 (22.81%).
 
Pod length (cm)
 
Pod length of all genotypes was recorded at harvesting stage, mean pod length was superior in protected block (4.62 cm) when compared to unprotected block (4.17 cm). Among all the genotypes, PHG-9 recorded significantly highest pod length (5.03 cm) in protected block as well as in unprotected block (4.80 cm) whereas, lowest number of pods per plant was recorded by GPM-6 in both protected (4.10 cm) and unprotected block (3.86 cm). Among the genotypes assessed, highest per cent reduction in pod length was recorded in local (17.25%), followed by BGM-1 (16.28%) and lowest was in PHG-9 (4.57%) and GPM-6 (5.85%) (Table 1).
 
No. of seeds per pod
 
No. of seeds per pod of all genotypes was recorded at harvesting stage, mean number of seeds per pod was superior in protected block (4.94) when compared to unprotected block (4.44). Among all the genotypes, PHG-9 recorded significantly highest number of seeds per pod (5.27) in protected block as well as in unprotected block (4.86) whereas, lowest number of pods per plant was recorded by GPM-6 in both protected (4.40) and unprotected block (4.02). Among the genotypes assessed, highest per cent reduction in number of seeds per pod was recorded in local (16.76%), followed by CRIDA-1-18R (11.61%) and lowest was in VHG-44 (7.22%) and PHG-9 (7.78%) (Table 2).
 
1000 seed weight (g)
 
Thousand seed weight was recorded in all genotypes after harvest, mean test weight was superior in protected block (38.65 g) when compared to unprotected block (35.96 g). Among all the genotypes, PHG-9 recorded significantly highest 1000 seed weight (42.07 g) in protected block as well as in unprotected block (38.92 g) whereas, lowest 1000 seed weight was recorded by GPM-6 in protected block (36.27 g) and VHG-44 in unprotected block (34.21 g). Among the genotypes assessed, highest per cent reduction in 1000 seed weight was recorded in VHG-44 (8.70%), followed by local (7.79%) and lowest was in GPM-6 (4.14%) and BGM-1 (6.45%) (Table 2).
 
Seed yield (q/ha)
 
Yield of all sub-blocks was recorded after harvest and converted into q/ha, mean seed yield was superior in protected block (4.26 q/ha), when compared with unprotected block (3.28 q/ha). Among all the genotypes, PHG-9 recorded significantly highest seed yield (5.07 q/ha) in protected block as well as in unprotected block (4.19 q/ha) whereas, lowest seed yield was recorded by VHG-44 in both protected (3.44 q/ha) and unprotected block (2.37 q/ha) (Table 2).
 
Yield loss (%)
 
The yield loss analysis revealed that VHG-44 (31.10%) suffered the highest yield loss among the genotypes, followed by GPM-6 (28.21 %). In contrast, PHG-9 (17.35%) had the lowest yield loss, followed by CRIDA-1-18R (18.50%), local genotype (20.22%), CRHG-4 (22.19%) and BGM-1 (25.45%) (Table 2).
       
The use of protective measures significantly reduced the disease incidence, disease index and subsequent yield losses. Among the genotypes evaluated, PHG-9 showed better performance in terms of pod number, pod length, seeds per pod, disease incidence, disease index, test weight and seed yield, indicating its potential for YMD resistance. PHG-9 and CRIDA-1-18R showed less yield loss which implies that, they could be used as resistant genotypes in breeding programme and could be farmer’s choice for sowing in the field. Whereas VHG-44 and GPM-6 showed severe yield loss which indicates their susceptibility to YMD and if chosen by farmers, many preventive protective measures should be taken up. These findings underscore the importance of implementing protective measures and selecting resistant genotypes for sustainable horsegram production in YMD-prone areas. Further research and development efforts should focus on the identification and characterization of resistant genotypes, as well as the optimization of protective strategies to minimize yield losses and ensure food security.
       
Similar results were reported by Kumar et al., (2022) who conducted an experiment to estimate the influence of yellow mosaic disease (YMD) on yield attributing traits in twelve soybean varieties under high disease pressure conditions. Plants suffering from yellow mosaic disease showed reductions in number of pods (10.22 to 48.22%), yield (15.02 to 62.53%) and 100 seed weight (7.42 to 23.14%) in a severity range of 28.40 to 71.28 per cent. A highly significant positive link was shown using Pearson correlation between the severity of yellow mosaic disease and reduction in number of pods, weight of 100 seeds and soybean yield. The greatest yield reduction was observed in JS 20-34 (62.53%) followed by MACS 1520 (60.63%) and RSC 10-46 (58.94%) with 68.40, 71.28 and 62.63 per cent disease index of YMD, respectively.
       
Zeshan et al., (2022) conducted an experiment which highlighted the prominent influence of Mungbean yellow mosaic virus (MYMV) on greengram yield, potentially causing up to 100 per cent loss under severe attack. Significant reductions in key yield parameters like plant height, pods per plant, pod length, seeds per pod, 1000 seed weight and branches per plant were observed. Advanced line M-97001 exhibited the highest reduction in 1000 seed weight (52.59%). Yellow Mosaic Disease (YMD) leads to substantial crop damage and yield reduction in leguminous crops across India (Mishra et al., 2022; Swathi et al., 2023). The vector relationship with whiteflies (Bemisia tabaci) plays a vital role in viral transmission, resulting in yield losses that can reach severe levels depending on crop stage and genotype susceptibility (Swathi et al., 2023; Vadivel et al., 2023). Identification and screening of resistant crop varieties along with the insect vector management present the most reliable avenue to mitigate the field yield losses (Appu and Prema, 2024; Madhumitha et al., 2022; Mishra et al., 2022).

CONCLUSION

Loss assessment results revealed that YMD caused losses in grain yield in horsegram genotypes ranging from 17.35 to 31.10 per cent with an average yield loss of 23.29 per cent. Among all the genotypes, PHG-9 showed least per cent yield loss (17.35%) with less disease incidence (21.62%) and VHG-44 showed highest per cent yield loss (31.10%) with high disease incidence (58.67%) due to YMD occurrence. The genotypes with lower yield losses may be recommended to disease endemic areas to avoid economic yield losses.

CONFLICT OF INTEREST

The authors declare no conflict of interest.

REFERENCES


  1. Alice, D. and Nadarajan, N. (2007). Pulses: Screening techniques and assessment for disease resistance. All India Coordinated Research Project on MULLaRP-Tamil Nadu Agricultural University. Kasturi Graphics and Printers, Coimbatore-24.

  2. Appu, H.K. and Prema, G.U. (2024). Molecular detection and partial characterization of coat protein gene of moth bean yellow mosaic virus (MBYMV) from Northern Karnataka. Legume Research. 47(2): 305-311. doi: 10.18805/LR-5171.

  3. Kumar, S., Amrate, P.K., Upadhyay, A., Paroda, M. and Mohare, S. (2022). Influence of yellow mosaic disease on biochemical and yield attributing traits in soybean. Plant Disease Research. 37(2): 192-197.

  4. Madhumitha, B., Aiyanathan, K.E.A., Raveendran, M. and Sudha, M. (2022). Identification and confirmation of resistance in mungbean [Vigna radiata (L.) Wilczek] derivatives to mungbean yellow mosaic virus (MYMV). Legume Research. 45(1): 122-127. doi: 10.18805/LR-4437.

  5. Mishra, N., Tripathi, M.K., Tiwari, S., Tripathi, N. and Trivedi, H.K. (2022). Morphological and molecular screening of soybean genotypes against yellow mosaic virus disease. Legume Research. 45(10): 1309-1316. doi: 10.18805/LR-4240.

  6. Prema, G.U. (2013). Molecular characterization of horsegram yellow mosaic virus and its management. Ph. D. Thesis, University of Agricultural Sciences, Bangalore (India).

  7. Prema, G.U., Rudraswamy, P. and Rangaswamy, K.T. (2013). Field screening of horsegram (Macrotyloma uniflorum) genotypes against horsegram yellow mosaic virus (HGYMV) disease.  Bioinfolet. 10(2b): 599-601.

  8. Prema, G.U. and Rangaswamy, K.T. (2017). Field evaluation of horsegram germplasm/ genotypes against horsegram yellow mosaic virus (HgYMV) disease and biological transmission of horse gram yellow mosaic virus to different leguminous hosts through white flies. International Journal of Current Microbiology and Applied Sciences. 9(54): 4934-4939.

  9. Prema, G.U. and Rangaswamy, K.T. (2020). Molecular characterization of coat protein gene of horsegram yellow mosaic virus (HgYMV) from southern India. International Journal of Current Microbiology and Applied Sciences. 9(1): 1381- 1391.

  10. Prema, G.U. and Rangaswamy, K.T. (2020a). Molecular characterization of DNA-A component of horsegram yellow mosaic virus (HgYMV) from southern India. International Journal of Current Microbiology and Applied Sciences. 9(1): 1360- 1380.

  11. Sonam, R.P., Prema, G.U., Gurupad, B. and Spurthi, N.N. (2024). Prevalence and population dynamics of whitefly transmitting horsegram yellow mosaic disease in northern Karnataka. Journal of Farm Sciences. 37(4): 367-370. 

  12. Sonam, R.P., Prema, G.U., Gurupad, B., Spurthi, N.N., Revanappa, B., Subhash, K. and Bangaramma, W. (2025). Screening of horsegram genotypes for resistance against yellow mosaic disease. Journal of Advances in Biology and Biotechnology. 28(1): 354-63.

  13. Swapna, B.V. and Prema, G.U. (2024). Coat-protein gene based identification and characterization of yellow mosaic virus infecting blackgram in Northern Karnataka, India. Journal of Advances in Biology and Biotechnology. 27(12): 271- 281. 

  14. Swapna, B.V., Prema, G.U., Basamma, K. and Sadhana, R.B. (2025). Identification of resistant sources and population dynamics of whitefly transmitting yellow mosaic disease in blackgram. Journal of Farm Sciences. 38(1): 57-64.

  15. Swapna, B.V. and Prema, G.U. (2025). Efficacy of insecticides in the management of whiteflies, vector of blackgram yellow mosaic disease. Legume Research. 48(10): 1789-1794. doi: 10.18805/LR-5523. 

  16. Swathi, M., Gaur, N. and Singh, K. (2023). Virus vector relationship of yellow mosaic virus and whitefly, Bemisia tabaci (Gennadius) in soybean. Legume Research. 46(7): 946- 950. doi: 10.18805/LR-4479.

  17. Vadivel, K., Manivannan, N., Mahalingam, A., Satya, V.K. and Ragul, S. (2023). Inheritance pattern of mungbean yellow mosaic virus (MYMV) disease resistance in blackgram [Vigna mungo (L.) Hepper]. Legume Research. 46(5): 660-663. doi: 10.18805/LR-4439.

  18. Wheeler, B.E.J. (1969). An Introduction to Plant Diseases. John Wiley and Sons, London, 301 p.

  19. Williams, F.J., Grewal, J.S. and Amin, K.S. (1968). Serious and new diseases of pulse crops in India in 1966. Plant Disease Reporter. 52(4): 300-304.

  20. Zeshan, M., Binyamin, R., Ahmed, N., Ashraf, W., Li, Y., Ghani, U. M., Safdar Ali, Ata Ul Khan, M., Ahmed, R., Mohamed, A.A., Aljowaie, . R., Alkahtani, M.A. and Vachova, P. (2022). Prediction of mungbean yellow mosaic virus disease using multiple regression models. Journal of King Saud University-Science. 34(5): 1018-3647.
Published In
Legume Research
Article Metrics
Metrics Icon
19
Views
0
Citations
Reviewed By
Share Article
Download Article
In this Article
    Contact us
    Follow us

    Full Research Article

    Yield Loss Assessment in Horsegram Due to Yellow Mosaic Disease in Karnataka

    S
    Sonam R. Pinjar1
    G
    G.U. Prema2,*
    B
    B.V. Swapna3
    G
    Gurupad Balol4
    S
    Spurthi N. Nayak5
    1Department of Plant Pathology, College of Agriculture, Dharwad-580 005, Karnataka, India.
    2ICAR-All India Coordinated Research Project on Maize, Main Agricultural Research Station, University of Agricultural Sciences, Dharwad-580 005, Karnataka, India.
    3Department of Plant Pathology, College of Agriculture, Vijayapur-586 101, Karnataka, India.
    4ICAR-All India Coordinated Research Project on Groundnut, University of Agricultural Sciences, Dharwad-580 005, Karnataka, India.
    5Department of Biotechnology, College of Agriculture, University of Agricultural Sciences, Dharwad-580 005, Karnataka, India.

    • Submitted30-10-2025|

    • Accepted12-10-2026|

    • First Online 30-10-2026|

    • doi 10.18805/LR-5595

    ABSTRACT

    Background: Horsegram [Macrotyloma uniflorum (Lam.) Verdc.] is a drought-tolerant legume widely cultivated in South Asia and is resilient to poor soil conditions. Yellow mosaic disease (YMD) poses a significant challenge to horsegram production in India, potentially resulting in complete yield loss. Since scanty literature is available on loss assessment of YMD in horsegram, an attempt was carried out to assess the losses in horsegram genotypes due to YMD.

    Methods: Field experiment was laid out in split plot design using different horsegram genotypes to assess the loss due to YMD.

    Result: Loss assessment revealed that, among all the genotypes PHG-9 showed least per cent yield loss (17.35%) with less incidence (21.62%) and VHG-44 showed highest per cent yield loss (31.10 %) with high incidence (58.67%) of YMD. Significant differences in performance of genotypes, between the protected and unprotected blocks, with less yield loss observed under protected conditions.

    INTRODUCTION

    Horsegram (Macrotyloma uniflorum) is a hardy, drought-tolerant legume grown in South Asia, known for its ability to thrive in arid, nutrient-poor soils. Rich in protein, fiber and essential minerals, it is a valuable food source and fodder. It is also known as kulthi bean, gahat, hurali, ulavalu, muthira or madras gram. It is an under exploited grain legume with great potential in sustainable agriculture (Prema and Rangaswamy, 2017). It is an important crop of south India. It is mainly cultivated in the states of Karnataka, Andhra Pradesh, Orissa, Tamil Nadu, Madhya Pradesh, Chhattisgarh, Bihar, West Bengal, Jharkhand and in foot hills of Uttaranchal and Himachal Pradesh in India. It is a popular pulse crop of Karnataka, grown in districts like Mysuru, Tumakuru, Ballari, Raichur, Bagalkot, Mandya, Hassan, Chamarajanagar, Vijayapura, Chitradurga, Kolar and Koppal districts (Prema and Rangaswamy, 2020).
           
    In India, it is cultivated in 0.507 m ha area with total production of 0.262 m t and productivity of 516 kg/ha. Karnataka ranks first in production in India with 0.096 m t and covers an area of 0.147 m ha with the productivity of 655 kg/ha, followed by Tamil Nadu with a production of 0.056 m t and an area of 0.075 m h with the productivity of 745 kg/ha (Sonam et al., 2024; Sonam et al., 2025). Among the viral diseases, the yellow mosaic disease poses a considerable challenge to its cultivation in peninsular India, with its initial detection occurring in the southern districts of Karnataka. The first report of the YMD of horsegram was by Williams et al., (1968).
           
    The horsegram YMD caused by yellow mosaic virus, which is transmitted by the whitefly species Bemisia tabaci (Gennadius), has been widely observed in various regions of South India. The incidence of this disease has been reported to range between 50 to 100 per cent in crops cultivated during both the summer and early rainy seasons leading to significant reductions in grain yield. Initially, symptoms appeared as a faint yellow discoloration on young leaves (Swapna and Prema, 2024; Swapna and Prema, 2025; Swapna et al., 2025). As the condition progressed, the leaves showed a mosaic pattern of mottling, characterized by irregular, small, greenish-yellow patches interspersed with normal green areas (Prema, 2013). Gradually, the mottles expanded, brightened to a vivid yellow and eventually turned completely bleached. Severe infection led to stunted plant growth and smaller leaves (Prema et al., 2013; (Prema and Rangaswamy, 2020a).
           
    Assessing and managing yellow mosaic disease in horsegram is crucial in Karnataka due to its significant impact on crop yield and farmer livelihoods. Effective loss assessment helps to identify the severity and spread, guiding targeted management practices. Since not much work has been carried out on loss assessment of YMD of horsegram in Karnataka, the current research was carried out with an intention to assess the loss due to YMD in horsegram.

    MATERIALS AND METHODS

    The present research on yield loss assessment of yellow mosaic disease of horsegram was carried out during summer 2023-24. A field experiment was conducted at Main Agricultural Research Station, Dharwad, which is situated in Northern transition zone (Zone-8) of Karnataka, India.
     
    Estimation of losses in horsegram due to yellow mosaic disease
     
    The field experiment was conducted at MARS, Dharwad which aimed to assess the yield losses caused by YMD in horsegram during summer 2023-24. Seven different horsegram genotypes namely; BGM-1, PHG-9, GPM-6, VHG-44, CRHG-4, CRIDA-1-18R and Local were evaluated under both protected and unprotected conditions using a split plot design. Seed treatment with imidacloprid 600 FS at 5 ml/kg of seeds, followed by spray with thiomethoxam 25% WG at 0.2 g/l was carried out at 30, 45 and 60 DAS for protected plot treatment. Unprotected plot treatment was treated as check.
     
    Details of experiment and observations

     
    Observations were recorded for yield parameters, including pod number and grain yield, based on five randomly selected plants within each replication during harvesting. The characters studied and the techniques adapted to record the observations are given below:
     
    Per cent disease incidence
     
    Per cent disease incidence was calculated by the formula given by Wheeler (1969).

                
    Per cent disease severity
     
    Per cent disease index was calculated by the formula given below and modified scale of AICRP on MULLaRP was used for disease rating (Alice and Nadarajan, 2007).

       
    Number of pods per plant
     
    The number of pods in an average of five plants were counted and recorded at physiological maturity stage.
     
    Pod length
     
    The length of five randomly selected pods from each plant were measured from the tip to the bottom, averaged and expressed in centimeters (cm).
     
    Number of seeds per pod
     
    The number of seeds in five randomly selected pods from each plant and their mean was recorded.
     
    Test weight
     
    After threshing and winnowing, seeds were collected and were sun dried. The sun dried, one thousand filled seeds taken at random were used to compute weight in an electrical balance. The test weight was recorded in grams.
     
    Total seed yield
     
    The pods were dried thoroughly, threshed and winnowed to remove the husk. Total seed yield was then assessed by bulking seeds from each plant and weighing them using an electrical balance. The yield was computed in q/ha.
     
    Per cent yield loss
     
    It was calculated using the formula given below:

     
    Modified scale of AICRP on MULLaRP used for disease rating (0-9) (Alice and Nadarajan, 2007).

    RESULTS AND DISCUSSION

    Estimation of losses in horsegram due to yellow mosaic disease
     
    Results revealed that all genotypes performed well under protected condition than unprotected condition with less per cent yield loss under protected condition (Table 1, Table 2 and Fig 1).

    Table 1: Yield loss assessment due to YMD incidence in different horsegram genotypes with respect to per cent disease incidence, per cent disease index, no. of pods/plant and pod length.



    Table 2: Yield loss assessment due to YMD incidence in different horsegram genotypes with respect to no. of seeds/pod, 1000 seed weight and seed yield.



    Fig 1: YMD incidence in different horsegram genotypes under protected and un-protected conditions.


     
    Disease incidence (%)
     
    Disease incidence was recorded at 15 days interval starting from 45 DAS up to physiological maturity (Table 1 and Fig  1). The incidence increased towards maturity, highest mean per cent disease incidence (52.87%) was recorded in un-protected blocks at harvest when compared with protected blocks (35.51%). Among all the genotypes, GPM-6 recorded significantly highest per cent disease incidence (47.47%) in protected block as well as in unprotected block (69.63%) whereas, PHG-9 recorded lowest per cent disease incidence in both protected (21.62 %) and unprotected block (34.44%). Among the genotypes assessed, highest per cent reduction in disease incidence over unprotected plot was recorded in BGM-1 (29.06%), followed by CRHG-4 (23.98%) and lowest was in VHG-44 (16.12%) and CRIDA-1-18R (17.50%).
     
    Disease index (%)
     
    Disease index was recorded at 15 days interval starting from 45 DAS up to physiological maturity (Table 1 and Fig 1). The disease index increased towards maturity, highest mean per cent disease index (64.25 %) was recorded in un-protected blocks at harvest when compared with protected blocks (44.59%). Among all the genotypes, GPM-6 recorded significantly highest per cent disease index (61.69%) in protected block as well as in unprotected block (88.24%) whereas, PHG-9 recorded lowest PDI in both protected (20.03%) and unprotected blocks (26.90%). Among the genotypes assessed, highest per cent reduction in disease index over unprotected plot was recorded in local (28.77%), followed by BGM-1 (27.72%) and lowest was in CRIDA-1-18R (13.68 %) and VHG-44 (16.16%).
     
    No. of pods per plant
     
    Pod number of all genotypes was recorded at harvesting stage, mean pod number was superior in protected block (20.83), whereas it was low in unprotected block (15.83). Among all the genotypes, PHG-9 recorded significantly higher number of pods per plant (23.58%) in protected block as well as in unprotected block (17.76%) whereas, lowest number of pods per plant in both protected and unprotected block was recorded by VHG-44 and GPM-6, respectively which were on par with each other (Table 1). Among the genotypes assessed, highest per cent reduction in number of pods per plant was recorded in BGM-1 (28.21%), followed by CRHG-4 (25.14%) and lowest was in local (19.08 %) and VHG-44 (22.81%).
     
    Pod length (cm)
     
    Pod length of all genotypes was recorded at harvesting stage, mean pod length was superior in protected block (4.62 cm) when compared to unprotected block (4.17 cm). Among all the genotypes, PHG-9 recorded significantly highest pod length (5.03 cm) in protected block as well as in unprotected block (4.80 cm) whereas, lowest number of pods per plant was recorded by GPM-6 in both protected (4.10 cm) and unprotected block (3.86 cm). Among the genotypes assessed, highest per cent reduction in pod length was recorded in local (17.25%), followed by BGM-1 (16.28%) and lowest was in PHG-9 (4.57%) and GPM-6 (5.85%) (Table 1).
     
    No. of seeds per pod
     
    No. of seeds per pod of all genotypes was recorded at harvesting stage, mean number of seeds per pod was superior in protected block (4.94) when compared to unprotected block (4.44). Among all the genotypes, PHG-9 recorded significantly highest number of seeds per pod (5.27) in protected block as well as in unprotected block (4.86) whereas, lowest number of pods per plant was recorded by GPM-6 in both protected (4.40) and unprotected block (4.02). Among the genotypes assessed, highest per cent reduction in number of seeds per pod was recorded in local (16.76%), followed by CRIDA-1-18R (11.61%) and lowest was in VHG-44 (7.22%) and PHG-9 (7.78%) (Table 2).
     
    1000 seed weight (g)
     
    Thousand seed weight was recorded in all genotypes after harvest, mean test weight was superior in protected block (38.65 g) when compared to unprotected block (35.96 g). Among all the genotypes, PHG-9 recorded significantly highest 1000 seed weight (42.07 g) in protected block as well as in unprotected block (38.92 g) whereas, lowest 1000 seed weight was recorded by GPM-6 in protected block (36.27 g) and VHG-44 in unprotected block (34.21 g). Among the genotypes assessed, highest per cent reduction in 1000 seed weight was recorded in VHG-44 (8.70%), followed by local (7.79%) and lowest was in GPM-6 (4.14%) and BGM-1 (6.45%) (Table 2).
     
    Seed yield (q/ha)
     
    Yield of all sub-blocks was recorded after harvest and converted into q/ha, mean seed yield was superior in protected block (4.26 q/ha), when compared with unprotected block (3.28 q/ha). Among all the genotypes, PHG-9 recorded significantly highest seed yield (5.07 q/ha) in protected block as well as in unprotected block (4.19 q/ha) whereas, lowest seed yield was recorded by VHG-44 in both protected (3.44 q/ha) and unprotected block (2.37 q/ha) (Table 2).
     
    Yield loss (%)
     
    The yield loss analysis revealed that VHG-44 (31.10%) suffered the highest yield loss among the genotypes, followed by GPM-6 (28.21 %). In contrast, PHG-9 (17.35%) had the lowest yield loss, followed by CRIDA-1-18R (18.50%), local genotype (20.22%), CRHG-4 (22.19%) and BGM-1 (25.45%) (Table 2).
           
    The use of protective measures significantly reduced the disease incidence, disease index and subsequent yield losses. Among the genotypes evaluated, PHG-9 showed better performance in terms of pod number, pod length, seeds per pod, disease incidence, disease index, test weight and seed yield, indicating its potential for YMD resistance. PHG-9 and CRIDA-1-18R showed less yield loss which implies that, they could be used as resistant genotypes in breeding programme and could be farmer’s choice for sowing in the field. Whereas VHG-44 and GPM-6 showed severe yield loss which indicates their susceptibility to YMD and if chosen by farmers, many preventive protective measures should be taken up. These findings underscore the importance of implementing protective measures and selecting resistant genotypes for sustainable horsegram production in YMD-prone areas. Further research and development efforts should focus on the identification and characterization of resistant genotypes, as well as the optimization of protective strategies to minimize yield losses and ensure food security.
           
    Similar results were reported by Kumar et al., (2022) who conducted an experiment to estimate the influence of yellow mosaic disease (YMD) on yield attributing traits in twelve soybean varieties under high disease pressure conditions. Plants suffering from yellow mosaic disease showed reductions in number of pods (10.22 to 48.22%), yield (15.02 to 62.53%) and 100 seed weight (7.42 to 23.14%) in a severity range of 28.40 to 71.28 per cent. A highly significant positive link was shown using Pearson correlation between the severity of yellow mosaic disease and reduction in number of pods, weight of 100 seeds and soybean yield. The greatest yield reduction was observed in JS 20-34 (62.53%) followed by MACS 1520 (60.63%) and RSC 10-46 (58.94%) with 68.40, 71.28 and 62.63 per cent disease index of YMD, respectively.
           
    Zeshan et al., (2022) conducted an experiment which highlighted the prominent influence of Mungbean yellow mosaic virus (MYMV) on greengram yield, potentially causing up to 100 per cent loss under severe attack. Significant reductions in key yield parameters like plant height, pods per plant, pod length, seeds per pod, 1000 seed weight and branches per plant were observed. Advanced line M-97001 exhibited the highest reduction in 1000 seed weight (52.59%). Yellow Mosaic Disease (YMD) leads to substantial crop damage and yield reduction in leguminous crops across India (Mishra et al., 2022; Swathi et al., 2023). The vector relationship with whiteflies (Bemisia tabaci) plays a vital role in viral transmission, resulting in yield losses that can reach severe levels depending on crop stage and genotype susceptibility (Swathi et al., 2023; Vadivel et al., 2023). Identification and screening of resistant crop varieties along with the insect vector management present the most reliable avenue to mitigate the field yield losses (Appu and Prema, 2024; Madhumitha et al., 2022; Mishra et al., 2022).

    CONCLUSION

    Loss assessment results revealed that YMD caused losses in grain yield in horsegram genotypes ranging from 17.35 to 31.10 per cent with an average yield loss of 23.29 per cent. Among all the genotypes, PHG-9 showed least per cent yield loss (17.35%) with less disease incidence (21.62%) and VHG-44 showed highest per cent yield loss (31.10%) with high disease incidence (58.67%) due to YMD occurrence. The genotypes with lower yield losses may be recommended to disease endemic areas to avoid economic yield losses.

    CONFLICT OF INTEREST

    The authors declare no conflict of interest.

    REFERENCES


    1. Alice, D. and Nadarajan, N. (2007). Pulses: Screening techniques and assessment for disease resistance. All India Coordinated Research Project on MULLaRP-Tamil Nadu Agricultural University. Kasturi Graphics and Printers, Coimbatore-24.

    2. Appu, H.K. and Prema, G.U. (2024). Molecular detection and partial characterization of coat protein gene of moth bean yellow mosaic virus (MBYMV) from Northern Karnataka. Legume Research. 47(2): 305-311. doi: 10.18805/LR-5171.

    3. Kumar, S., Amrate, P.K., Upadhyay, A., Paroda, M. and Mohare, S. (2022). Influence of yellow mosaic disease on biochemical and yield attributing traits in soybean. Plant Disease Research. 37(2): 192-197.

    4. Madhumitha, B., Aiyanathan, K.E.A., Raveendran, M. and Sudha, M. (2022). Identification and confirmation of resistance in mungbean [Vigna radiata (L.) Wilczek] derivatives to mungbean yellow mosaic virus (MYMV). Legume Research. 45(1): 122-127. doi: 10.18805/LR-4437.

    5. Mishra, N., Tripathi, M.K., Tiwari, S., Tripathi, N. and Trivedi, H.K. (2022). Morphological and molecular screening of soybean genotypes against yellow mosaic virus disease. Legume Research. 45(10): 1309-1316. doi: 10.18805/LR-4240.

    6. Prema, G.U. (2013). Molecular characterization of horsegram yellow mosaic virus and its management. Ph. D. Thesis, University of Agricultural Sciences, Bangalore (India).

    7. Prema, G.U., Rudraswamy, P. and Rangaswamy, K.T. (2013). Field screening of horsegram (Macrotyloma uniflorum) genotypes against horsegram yellow mosaic virus (HGYMV) disease.  Bioinfolet. 10(2b): 599-601.

    8. Prema, G.U. and Rangaswamy, K.T. (2017). Field evaluation of horsegram germplasm/ genotypes against horsegram yellow mosaic virus (HgYMV) disease and biological transmission of horse gram yellow mosaic virus to different leguminous hosts through white flies. International Journal of Current Microbiology and Applied Sciences. 9(54): 4934-4939.

    9. Prema, G.U. and Rangaswamy, K.T. (2020). Molecular characterization of coat protein gene of horsegram yellow mosaic virus (HgYMV) from southern India. International Journal of Current Microbiology and Applied Sciences. 9(1): 1381- 1391.

    10. Prema, G.U. and Rangaswamy, K.T. (2020a). Molecular characterization of DNA-A component of horsegram yellow mosaic virus (HgYMV) from southern India. International Journal of Current Microbiology and Applied Sciences. 9(1): 1360- 1380.

    11. Sonam, R.P., Prema, G.U., Gurupad, B. and Spurthi, N.N. (2024). Prevalence and population dynamics of whitefly transmitting horsegram yellow mosaic disease in northern Karnataka. Journal of Farm Sciences. 37(4): 367-370. 

    12. Sonam, R.P., Prema, G.U., Gurupad, B., Spurthi, N.N., Revanappa, B., Subhash, K. and Bangaramma, W. (2025). Screening of horsegram genotypes for resistance against yellow mosaic disease. Journal of Advances in Biology and Biotechnology. 28(1): 354-63.

    13. Swapna, B.V. and Prema, G.U. (2024). Coat-protein gene based identification and characterization of yellow mosaic virus infecting blackgram in Northern Karnataka, India. Journal of Advances in Biology and Biotechnology. 27(12): 271- 281. 

    14. Swapna, B.V., Prema, G.U., Basamma, K. and Sadhana, R.B. (2025). Identification of resistant sources and population dynamics of whitefly transmitting yellow mosaic disease in blackgram. Journal of Farm Sciences. 38(1): 57-64.

    15. Swapna, B.V. and Prema, G.U. (2025). Efficacy of insecticides in the management of whiteflies, vector of blackgram yellow mosaic disease. Legume Research. 48(10): 1789-1794. doi: 10.18805/LR-5523. 

    16. Swathi, M., Gaur, N. and Singh, K. (2023). Virus vector relationship of yellow mosaic virus and whitefly, Bemisia tabaci (Gennadius) in soybean. Legume Research. 46(7): 946- 950. doi: 10.18805/LR-4479.

    17. Vadivel, K., Manivannan, N., Mahalingam, A., Satya, V.K. and Ragul, S. (2023). Inheritance pattern of mungbean yellow mosaic virus (MYMV) disease resistance in blackgram [Vigna mungo (L.) Hepper]. Legume Research. 46(5): 660-663. doi: 10.18805/LR-4439.

    18. Wheeler, B.E.J. (1969). An Introduction to Plant Diseases. John Wiley and Sons, London, 301 p.

    19. Williams, F.J., Grewal, J.S. and Amin, K.S. (1968). Serious and new diseases of pulse crops in India in 1966. Plant Disease Reporter. 52(4): 300-304.

    20. Zeshan, M., Binyamin, R., Ahmed, N., Ashraf, W., Li, Y., Ghani, U. M., Safdar Ali, Ata Ul Khan, M., Ahmed, R., Mohamed, A.A., Aljowaie, . R., Alkahtani, M.A. and Vachova, P. (2022). Prediction of mungbean yellow mosaic virus disease using multiple regression models. Journal of King Saud University-Science. 34(5): 1018-3647.
    In this Article
      Contact us
      Follow us
      Published In
      Legume Research

      Editorial Board

      View all (0) Â