Applying aqueous crude leaf extracts and organic soil amendments manages Meloidogyne incognita on hot pepper

Abstract

The root-knot nematode, Meloidogyne incognita, can severely damage hot pepper plants (Capsicum annum and C. frutescens). Therefore, it is crucial to develop effective management strategies. The impact of aqueous crude leaf extracts from Vernonia amygdalina and Lantana camara and organic soil amendments with vermicompost and poultry manure was investigated in an open-field pot experiment on three pepper genotypes (Oda Haro, Acc.03, and Melka Awaze). The growth performance, yield, and nematode population were assessed. Twenty-seven treatments, including the untreated checks, were arranged in a factorial RCBD in three replications. Plots treated with leaf extracts and/or organic soil amendments resulted in significantly lower number of root galls, egg masses, and nematode populations than the untreated checks in all the pepper genotypes. The combined treatments were more effective than individual treatments in all the genotypes. The lowest nematode population was on the genotype Melka Awaze Lantana camara with vermicompost on genotype Melka Awaze, L. camara with poultry manure on genotype Oda Haro, and V. amygdalina with vermicompost on genotype Acc.03 sustained fewer root galls, egg masses and nematode populations. On the genotype ‘Oda Haro’, the untreated control gave significantly lower values for the number of pods, marketable pods, number of branches and plant height than the remaining treatments except V. amygdalina applied without soil amendments for number of branches. Similarly, on the genotype‘Acc.03’, except L. camara without soil amendments for number of branches and V. amygdalina and poultry manure for plant height, values were significantly lower in the untreated control than the other treatments. Vermicompost enhanced the growth and yield of pepper and reduced the number of root galls, egg masses and nematode populations. Therefore, applying leaf extracts and organic soil amendments appeared promising to control M. incognita.