Use of bio agents for the management of Heterodera cajani Koshy and Fusarium udum Butler on Pigeonpea

Abstract

Pigeonpea is determined as one of the primary pulse crops which is grown in India. Fusarium wilt which is a well-known soil-borne pathogen caused by Fusarium udum, affecting up to 67 per cent yield losses during maturity period. Yield losses by cyst nematode infestation are reported from India to about 30%. Analysis for the determination of pigeonpea wilt disease was conducted during 2015-16 in different pigeonpea growing areas of Prayagraj District. In this analysis, maximum Fusarium wilt disease incidence was found in Dadri (58%) and least in Jhusi (10%) and Naini (11%). Cyst nematode (H. cajani) was observed with incidence of cyst/ soil sample was highest in Jari (51%) and least incidence was found in Meza (14%) and Soraon (18%). In order to reduce the use of chemical fungicides against Fusarium wilting in pigeonpea, bio-agents have been used for this disease management. Ten isolates of Pseudomonas spp. and Trichoderma spp. were isolated from rhizosphere of pigeonpea field and evaluated against Fusarium udum in vitro and in Heterodera cajani and Fusarium udum in pot condition. Out of ten isolates four isolates of Pseudomonas spp. Pf 7 (58.24%), Pf1 (52.75%), Pf10 (44.46%) and Pf8 (39.43%) showed highest % inhibition of radial growth of Fusarium udum in dual culture. While, five isolates of Trichoderma spp. Th7 (35.33%), Th6 (32.17%), Th2 (26.75%), Th3 (26.57%) and Th10 (25.08%) showed highest % inhibition of radial growth of Fusarium udum in dual culture. In pot experiment, Pseudomonas spp. isolates significantly reduced the per cent of wilt incidence in T7-PC (79.5-89.9%) at 90 DAS, T7-PC (76.5-84.4 %) at 120 DAS respectively during (2016-18). The highest shoot length (64.6-165.2 cm) at 90 DAS, (76.3-174.2 cm) at 120 respectively were recorded. Similarly the maximum fresh shoot weight (118.7-120.1 g) at 120 DAS and dry shoot weight (55.1-62.4 g) were observed inT7-PC. Whereas, the maximum fresh root weight (13.7-18.2 g) and dry root weight (7.7-7.8 g) were recorded at 120DAS in isolate T7-PC. Similarly, the m