In Vitro and In Vivo Management of Alternaria Leaf Spot of Brassica campestris L.

Abstract

Alternaria black leaf spot caused by Alternaria brassicae is one of the most destructive disease of brassicaceae crops and causes 30 to 45% overall yield loss in the world. Plant susceptibility toward this saprophytic and necrotrophic pathogen is greatly influenced by extreme weather conditions e.g. temperature and humidity. Six plant extracts, six Biological agents and six fungicides were evaluated both in vitro and in vivo experiment for their effectiveness to manage Alternaria leaf spot of Brassica campestris. In cause of in vitro pathogenic fungus was applied in the field at 2 g colonized mustard seeds kg-1 soil. plant extract, Biological agents and six fungicides were evaluated for their efficacy at various concentrations 5%, 10%, 15% and were sprayed in the field at 0.2% a.i. l-1. Out of all treatments, Allium sativum, Parthenium hysterophorus, Trichoderma harzianum, Trichoderma viride, Wisdom (50% WP) and Proctor (60% WP) were screen out in laboratory at 15% concentration. The maximum growth inhibition (in laboratory 57.83%, in field 6.07% and in greenhouse 26.32%) was recorded by Allium sativum followed by Parthenium hysterophorus (in laboratory 53.01%, in field 17.05%, in green and house 29.08%). Out all biological agents, the maximum growth inhibition (in laboratory 61.44%, in field 27.34% and in greenhouse 38.45%) by Trichoderma harzianum followed by Trichoderma viride (in laboratory 55.42%, in field 29.63%, in green and house 29.08%). Out of all fungicides, the maximum growth inhibition (in laboratory 98.79%, in field 56.08% and in greenhouse 63%) by Wisdom (50% WP) and followed by Proctor (60% WP) (in laboratory 100%, in field 51.76% and in greenhouse 55.16%). It was worth noting that the fungicides, Wisdom (50% WP) and Proctor (60% WP) have highest net value as compare to other treatments but the biological agents also show off their importance.