Effect of sorghum root exudates on pathogens of pulse crops

A grave impact of non-polar groups of allelocompounds of sorghum root exudates was observed against a variety of fungal pathogens of pulse crops. The isolated non-polar fraction was not only found tremendously active against Sclerotinia sclerotiorum (LD₅₀ 17μg ml⁻¹) and Sclerotium rolfsii (LD₅₀ 20μg ml⁻¹) but also observed quite toxic to Fusarium udum (LD₅₀ 250μg ml⁻¹), Fusarium oxysporum sp. ciceri (LD₅₀ 270μg ml⁻¹), Rhizoctonia bataticola (LD₅₀ 182μg ml⁻¹), Alternaria alternata (LD₅₀ 146μg ml⁻¹) and Choenephora cucurbitarum (LD₅₀ 87.5μg ml⁻¹). Detrimental effect of isolated compounds was also observed on the production of conidia and their viability of all the three conidia producing fungi. Similar were the trends for sclerotia production and their viability in the treatments of three sclerotia forming pathogens. All kinds of inhibitory effects in all test pathogens were found concentration dependent i.e., increase in concentration caused more retardation. Such broadspectrum effect of non-polar allelocompounds of sorghum root exudate against a wide range of pathogens is being reported for the first time in pulses.