Leaf extracts of 11 plant species were used for controlling infection of F. oxysporum in ridge gourd seeds. All the plant extracts enhanced seed germination and inhibited growth of pathogen on seed and seed-ling surface and proved superior for controlling incidence of the pathogen.

Review of literature has given in heading result and discussion .

Fresh leaves of 11 plants viz. Azadirachta indica, Calotropis procera, Cassia tora, Catharanthus roseus, Dalbergia sissoo, Datura innoxia, Eucalyptus rudis, Lantana camera, Lawsonia inermis, Parthinium officinalis, Riccinus communis were tried for treatment. 5 gm fresh leaves of each plant were crushed separately in 20 ml distilled water using pastle and mortor. The extracts were filtered through double layer of cheese cloth. Five replicates of 10 seed (surface sterilized with 2% sodium hypochlorite were taken randomly and treated with each of 11 aqueous extracts for four h. Ten seeds per plates were sown on sterilized moistened blotter for 8 days in Petriplate. The plates were incubated under 12 h alternating cycles of light and dark for 8 days (Anonymous,1985). Observations were made under Nikon Stereo binocular microscope. The data on seed germination, incidence of pathogen and infected seedlings were recorded after every 24 h intervals up to 8 days. The seed-ling without any symptom showing normal seed-ling growth and vigour were considered as uninfected. Seeds soaked in distilled water served as control. The percentage of seed germination, seed-ling infection and control of pathogen or percent inhibition of pathogen incidence was calculated.

The germination was effectively enhanced by all the plant extracts used. Dalbergia sissoo showed maximum effect 94% against F. oxysporum followed by Lawsonia 86%Cassia 84% Catharanthus,Datura and Parthinium 80%, Azadirachta, Calotropis and Lantana76%.

Best infection control of F. oxysporum was achieved by Dalbergia sissoo (90.90%) followed by Azadirachta indica, Calotropis procera, Lawsonia inermis (86.36%), Eucalyptus and Lantana camera (81.81%). In other plant extract it ranged from (72.72-77.77%). Incidence of pathogen was significantly controlled by all the 11 leaf extract and was maximum (91.66%) in Dalbergia sissoo and Cassia tora (Fig.A&B). Similarly Gupta et al. (1996) evaluated efficacy of leaf extracts of Azadirachta indica, Calotropis procera, Eucalyptus rudis, Parthinium  hysterophorus and Pongemia pinnetta  against Fusarium oxysporum sp. from diseased malberry plant .

Mantha spicata has also been found to have antifungal properties against F. oxyporum by Singh et al. (1994). Sharma & Triwedi (2002) have also recommended many leaf extracts to control nematodal disease of crop plants caused by Meloidogyne incognita and also fungi F.oxysporum in cumin plant.

Ogachi et al. (2006) has also studied antifungal effect of some plant extracts against F. oxysporum to control tomato wilt and found neem extract was the most effective (100%) to inhibit the mycelial growth of F. oxysporum. Tinospora cordifolia, Cymbopogon citratus and Moringa olifera showed promising antifungal potentiality against F. oxysporum sp. Ciceri with maximum inhibition in chick pea. (Dwivedi and Sangeeta,2015).

Plant extracts are natural, herbal antifungal materials. Because of their easy availability, low cost and easy biodegradability these can be easily used to control seed-borne pathogen. In the present study all leaf extracts gave good results to control seed-borne pathogen.

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