Status and Integrated Disease Management of Fusarium Wilt of China Aster [Callistephus chinensis (L.) Nees]
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Date
2023
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SKUAST Kashmir
Abstract
China aster [Callistephus chinensis (L.) Nees] belongs to the family Asteraceae and is native to China. It is one of the important annual flower crops grown in most parts of the world. It is a hardy annual commercial flower crop grown for loose as well as cut flower purpose. Fusarium wilt is the most important economical disease of China aster. The present investigation entitled “Status and Integrated Disease Management of Fusarium Wilt of China Aster [Callistephus chinensis (L.) Nees]” was carried out at Division of Plant Pathology, FoA, Wadura, during 2021. An extensive survey conducted in three districts of Kashmir valley viz., Srinagar, Baramulla and Anantnag revealed that disease was prevalent in all the three districts with overall mean disease incidence of 33.74 per cent. Symptomatological studies revealed that yellowing of lower leaves started after 21 days of inoculation and wilting and drying up of the whole plant on the 36th day. Cultural characters of isolated pathogen on PDA showed greyish to pinkish colony colour, fluffy texture on upper side and dark violet to pinkish colour on underside of colony. The morphological characters recorded revealed that, mycelium was septate, chlamydospores were globose to subglobose, macroconidia were long sickle shaped with three to eight septa while microconidia were short cylindrical with zero to one septa. Based on symptomatology and morpho-cultural characters, the isolated pathogen was identified as Fusarium oxysporum. Pathogenicity test was proved by Koch’s postulates. Non-systemic fungicides, systemic fungicides and bio-agents were evaluated in vitro. Amongst non-systemic fungicides, mancozeb 75 WP was found to be the most effective against Fusarium oxysporum with mean mycelial growth inhibition of 92.46 per cent followed by captan 50 WP (86.01%) and chlorothalonil 75 WP (60.71%), whereas minimum inhibition was observed in copper oxychloride 50 WP (52.88%). Among systemic fungicides, maximum mean mycelial growth inhibition of 93.49 per cent was observed in carbendazim 50 WP followed by thiophenate methyl 75 WP (91.86 %) and difenoconazole 25 EC (86.02%), whereas least inhibition was observed in kresoxim-methyl 44.3 per cent SC (72.99%). Among bio-agents, maximum mean mycelial inhibition of 78.45 per cent was observed in Trichoderma viride followed by Trichoderma harzianum (73.17%) and Pseudomonas fluorescence (23.17%), whereas least mycelial inhibition was observed in Bacillus subtilis (21.34%). Integrated disease management study revealed that vermicompost @ 100g/pot + Trichoderma viride @ 25 ml cell suspension (2.1 107 cfu/ml)/pot as soil amendment and carbendazim 50 WP as seed treatment and seedling dip was observed to show significantly the least disease incidence of 4.45 per cent, maximum average number of flowers per plant, maximum average flower diameter and maximum average leaf area of 11.47, 7.36 cm and15.56 cm2, respectively followed by VAM @ 50g/pot as soil amendment + carbendazim 50 WP as seed and seedling dip, with the disease incidence of 8.89 per cent, average number of flowers per plant, average flower diameter and average leaf area of 10.93, 6.76 cm and 14.43 cm2, respectively in contrast to control which showed significantly maximum disease incidence of 88.89 per cent, minimum average number of flowers per plant (1.33), minimum average flower diameter (3.66 cm) and minimum average leaf area (9.24 cm2). The study showed fungicides and bio-agents along with soil amendments can effectively be used for managing the Fusarium wilt of China aster.
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Keywords
Bio-agents, China aster, Fungicides, Fusarium oxysporum, IDM Disease status, Plant Pathology.