Evaluation of some commercial bacterial biofertilizers and isolates against root knot nematode, Meloidogyne incognita infesting green bean, Phaseolus vulgaris

Abstract

Under field conditions, Four commercial biofertilizers namely, phosphorine (containing phosphate dissolving bacterium namely Bacillus megatherium or megaterium), Rhizobacterin (containing plant growth promotimg bacteria e.g. Bacillus spp. and Pseudomonas fluorescens), potassiumag ( containing potassium dissolving bacterium namely, Bacillus circulans), al-aukadin (containing Rhizobium phaseoli) as well as bacteria, Pseudomonas fluorescens and Serratia spp. as liquid cultures either alone or in combination were tested for biocontrolling root knot nematode, Meloidogyne incognita infesting green bean cv. Hama plants. The results showed that all treatments had the potentiality to significantly (p≤0.05) reduce the root-knot nematode infectivity and reproduction, to great extend, along the growing season of green bean plants as indicated by the number of galls, egg masses and hatched juveniles on roots and number of juveniles in soil. Three months after application, the percentages reduction of the number of galls ranged from 46.4 for phosphorine only (T1) to 72.5% for phosphorine + S. fluorescens (T7) and phosphorine + Serratia spp. (T11). The same trend was noticed for the percentages reduction of egg masses. Single treatments were superior to the combined ones in increasing the studied pod yield parameters (Number and weight of green pods). Phosphorine (T1) and al-aukadin (T4) were as equal as each other in increasing the percentage increase of weight of green pods (92.1%) followed by that recorded by using rhizobacterin (T2). Co-toxicity factors for the two combined treatments of commercial products of phosphorine + S. fluorescens(T7) and phosphorine + Serratia spp.(T11) with M incognita after three months showed additive interaction effects, as they caused higher percentage gall reduction than that caused by either of them alone. At the same trend, the soluble carbohydrate, soluble protein, nitrogen and potassium contents increased in leaves and pods of green bean by some of the tested compounds compared with those of untreated check

Biocidal and Antinemic Properties of Aqueous Extracts of Ageratum and Coccinia Against Root-Knot Nematode, Meloidogyne Incognita In Vitro

“…In recent years, studies have shown the importance of natural nematicidal compounds in the plants themselves that have potential to suppress nematode populations (Pavaraj et al, 2010;Moosavi, 2012;Nelaballe and Mukkara, 2013;Muniasamy et al, 2010). Many botanical extracts have been found to contain phytochemicals such as alkaloids, tannins, saponins, flavonoids, diterpenes, glucosinolates, acetylenes and thinlys (Chitwood, 2002) which are effective against plant parasitic nematodes ( Goswani and Vijayalakshmi, 1986;Adegbite, 2003).…”