EFFECTS OF EXTRACTS AND RESIDUES FROM SELECTED MEDICINAL AND AROMATIC PLANTS ON INCIDENCE OF CERTAIN FUNGI OF WILT AND ROOT–ROT AND YIELD OF FABA BEAN

Abstract

The present study comprising of laboratory, greenhouse and field experiments was undertaken at plant pathology laboratory Plant Protection Directorate and Medicinal and Aromatic Plant Research Experimental Area (2005 – 2007), with the objectives of: i) Effects of extract from selected medicinal and aromatic plants on colony growth of the inciting pathogens. ii) Identify the most effective plant residues on disease incidence under field conditions. iii) Determine the effects of the residues on the grain yield of two broad bean cultivars, viz Hudeiba– 72 and Hudeiba– 93. Extracts from, Neem (Azadirachta indica L.) leaves, Argel (Solanostermma argel L.), Fennel (Foeniculum vulgari L.), Basil (Ocimum gratissimum L.), Lemongrass (Cymbopogon citratus L.), Vincarosea (Catharanthus roseus L.) leaves and roots, at 5%, 10% and 7% combined solution, were tested for their antifungal properties against Fusarium. Oxysporum f. sp. fabae, Fusarium. Solani f. sp. fabae, (main c/o of wilt and root rot of braod bean crop), Fusarium moniliforme, Fusarium equesiti and Macrophomina phaseolina L. by poisoned food techniques in vitro at 25 ± 2°C. In general most of the extracts and essential oils used except those of Vincarosea successfully inhibited colony growth. In green house experiment, the incidence and mortality of the host were greatly reduced by the application of the six plants residues to earthen pots (30cm i.d.) filled with two kind of soils (natural and sterilized) for both broad bean cultivars iv (H. 72 & H. 93), with best control in case of the sterilized soil along with V 1 (H. 72) as compare to the control. On the other hand all the residues incorporated into soil generally reduced the disease incidence. The maximum reduction in disease incidence was obtained when Argel, Funnel and Fungicide metalaxyl (Ridomil) were applied separately to the soil in both cultivars (Hudaiba 93 & Hudaiba 72) in the two seasons. The greatest increase in grain yield was obtained in soils supplied with Argel, Fennel, Basil, and Lemongrass residues. Maximum yield of 2.70 kg/plot (3.5 × 4َm) was obtained when Argel residue was used.