Detection of seed-borne pathogens in sesame and their management through seed biopriming

Sesame is a significant oilseed crop cultivated extensively in the tropical and subtropical areas of India. Seed-borne pathogens are the most important biological constraints in seed production worldwide. Seed health testing to detect seed-borne pathogens is an important step in the management of crop diseases. In addition, it is also essential to adopt environmentally friendly strategy for preventing and managing seed-borne diseases. The main objectives of the present investigation including testing the seed health status of different sesame seed samples, evaluation the seed health testing methods, and assessing the efficacy of different biological agents against seed-borne pathogens and seed quality in sesame through seed biopriming and dry seed treatment. To find the mycoflora that was positively correlated with seeds, samples of sesame seeds were collected from farmers, research stations, and seed production plots. According to the findings, the most common types of fungi that are associated with sesame seeds are Macrophomina phseolina, Alternaria sesami, Aspergillus flavus, Aspergillus niger, Rhizopus sp., Curvularia sp., and Fusarium sp. Among the seed-borne fungi, the infection of M. phaseolina was observed highest in most of the sesame seed samples followed by A. sesami, A. flavus and A. niger. Various techniques used to detect seed mycoflora, the blotter technique was the most efficient method, with a maximum recovery of 45.1 %, followed by the potato dextrose agar (PDA) plate method (35.2 %), while the minimum recovery was observed in deep freezing blotter method (16.4 %). However, the detection of seed- borne pathogens of significance like A. sesami and Macrophomina M. phseolina  was best in PDA plate method (9.82 and 14.2 %) followed by standard blotter method (7.9 and 11.8 %). Among the different bioprimed seeds individually and in combination, Bacillus subtilis (1%) alone primed seeds recorded lesser seed infection (0.66 %) and higher germination per cent (92 %) and seedling vigour (1186). When compared to dry seed treatment, sesame seeds primed with biocontrol agents generally showed lower seed infection (%) and higher seed quality parameters. The findings revealed the presence of several mycoflora in all sesame seed samples, and these seed mycoflora can be detected effectively by the standard blotter paper method and the PDA plate method. Furthermore, the biopriming technique has the potential to mitigate the detrimental impact of these microbes, thereby improving seed quality characteristics.