Streptomyces scabies is a Gram-positive bacterial pathogen that causes common scab disease to several crops, particularly in the potato. It is a soil borne pathogen, a very devastating scab pathogen and difficult to manage in the field. Streptomyces has several species that cause common scab such as S. scabiei, S. acidiscabies, S. europaeiscabiei, S. luridiscabiei, S. niveiscabiei, S. puniciscabiei, S. reticuliscabiei, S. stelliscabiei, S. turgidiscabies, S. ipomoeae. Common scab disease harmfully affects potato economic and market value due to the presence of black spots on the tuber. Owing to its genetic diversity and pathogenicity, the determination of pathogen presence in potato fields is still challenging. In this study, S. scabies genetic diversity was measured by surveying five potato-growing areas of Pakistan during the growing season 2019. A total of 50 Streptomyces isolates, including S. scabies, S. acidiscabies, S. griseoflavus were isolated and identified based on morphologic, biochemical and molecular analysis. Virulent confirmation assays confirmed ten virulent strains of Streptomyces spp. On the potato cultivars Cardinal and Santee. Among the Streptomyces species, S. scabies showed the highest scab index, followed by S. acidiscabies and S. griseoflavus by exhibiting the scab-like lesions on potato tubers. Ten potato cultivars were screened against these virulent isolates of Streptomyces. The Faisalabad white variety showed the highest scab index followed By Cardinal, Tourag, Kuroda, Santee, Lady Rosetta, Asterix, Diamant, Faisalabad red and Sadaf. Moreover, genetic diversity and pathogenicity of Streptomyces spp. on potato tubers were also likely diverse in different geographical regions and also potato cultivars. This study represents a contribution to understanding the local interaction between potatoes and Streptomyces spp. in Pakistan. It will aid in supporting a solution for the management of this pathogen around the world.

Chilli pepper (Capsicum annuum L.) has significant importance as a cash crop, like other vegetables, and occupies 20% of the total vegetable production area in Pakistan. Pythium spp. are notorious fungal-like agents that may result in 90% plant death either as pre and/or post-emergence damping off. During surveys of nine major chilli growing areas of Punjab, Pakistan in September-November 2015-16, disease incidences ranging from 13.8 to 45.4% was recorded. The symptoms consisted of damping off, and on older seedlings (15 to 30 days post-transplanting) reduced growth, wilting, water-soaking, brown discoloration and root rot. Infected roots were cut into small pieces, surface sterilized using 1% sodium hypochlorite for 3 to 5 min, followed by a rinse with sterile distilled water. Root saps were serially diluted to appropriate dilutions, streaked onto corn meal agar (CMA) medium supplemented with ampicillin (250 mg/l), rifampicin (10 mg/l) and pimaricin (10 mg/l) (Jeffers and Martin 1986) and incubated at 28...

Root-knot nematodes (Meloidogyne spp.) are major pests of vegetable crops, causing significant yield losses in numerous species worldwide. Their widespread distribution and polyphagous nature make them particularly challenging to manage effectively. The use of biological agents and botanical extracts has emerged as a sustainable alternative to chemical nematicides. The present study evaluated the effectiveness of aqueous extracts from Moringa oleifera and a novel strain of plant growth-promoting rhizobacteria, Bacillus australimaris strain LWD73, native to Florida, in reducing Meloidogyne incognita infection and enhancing plant growth. The combined application of M. oleifera extracts and B. australimaris LWD73 significantly reduced the number of galls, eggs per root system, second-stage juveniles (J2) per 60 cc of soil, and the nematode reproduction factor. Moreover, it improved key growth parameters in tomato cultivar HM1824. Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography-Mass Spectrometry (GC-MS) analyses of M. oleifera extracts identified antimicrobial and nematicidal phytochemicals. Similarly, solid-phase microextraction GC-MS (SPME-GC/MS) analysis of B. australimaris LWD73 revealed the presence of volatile organic compounds (VOCs), including 2-nonanone and 2-undecanone, which are known for their potent nematicidal properties. The synergistic application of M. oleifera and B. australimaris LWD73 demonstrated enhanced nematode suppression and improved plant growth, offering a promising, eco-friendly approach to managing root-knot nematodes in vegetable crops.