Among the plant pathogens, around 85% of diseases in plants are caused by fungi. Rapid and accurate detection of fungal phytopathogens up to the species level is crucial for the implementation of proper disease control strategies, which were previously relied on conventional approaches. The conventional identification methods have been replaced by many rapid and accurate methods like high throughput sequencing, real-time polymerase chain reaction (PCR), serological and spectroscopic technique. Among these rapid pathogen detection techniques, spectroscopy is a rapid, cost-effective, non-destructive method and does not require sample preparation. Nowadays, visible, infrared and near-infrared rays are commonly employed for pathogen detection. Fluorescence Spectroscopy, Nuclear Magnetic Resonance (NMR) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, Attenuated Total Reflection (ATR)-FTIR spectroscopy, Raman Spectroscopy, Matrix-assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS). Biocontrol fungus-like Trichoderma spp. can be detected with the help of MALDI-TOF MS. Fluorescence spectroscopy used fluorescence emanating from the sample and successfully used in the detection of powdery mildew (Blumeria graminis). Hyperspectral imaging is an advanced approach which uses artificial intelligence in plant disease detection. This literature discusses briefly about the features of above-mentioned spectroscopy techniques which may impel the general understanding and propel the research activities.

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Papaya plant is severely affected by different viruses among them papaya ring spot virus is causing considerable yield loss leading to the complete failure of fruiting. Therefore, present investigation commenced with molecular diagnosis, current status and temporal incidence of disease. Various symptomatic plants gave positive amplification in one step RT-PCR with both Potyvirus and PRSV CP gene specific primers indicating an amplicon of ~330bp and 850bp bands, respectively. In leaf samples, 46 to 89 per cent RNA was found positive for PRSV infection. Whereas least infection of 13 per cent was found in seeds collected from infected fruits. The disease was observed at three different experimental plots which ranges from 49 to 75.3 per cent incidence. A rapid increase in the aphid population was noticed from middle of December to February. Further, maximum aphid population was noticed at experimental plot-1 (plant pathology) followed by plot-3 (IFS) with 5.48 and 5.14/plant. Periodic observation of the disease was assessed. The appearance of ringspot was noticed in first week of October with diverse symptom. It slowly increased upto middle of January and exponentially increased upto middle of May month with 65.3 per cent incidence. The peak aphid population was noticed in middle of February (20.5/plant) which was gradually declined upto 3.9/plant in May. The present information will helpful in understanding the epidemiology of ring spot disease and suitable management possibilities.

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