Guava is an important revenue generating crop for small, medium, and commercial guava cultivators all over the world. Nematode infestation is one of the factors that cause declines in fruit production. Researches have proven that the application of plant growth regulators induces the synthesis of defense-related proteins in Guava. IBA is one such plant growth regulator, and its effects on guava plants has not yet been elucidated. Thus, this research is focused on the optimization of IBA concentrations, which results in the induction and production of maximum defense-related proteins to defend against root knot nematode. The present study includes the application of IBA on M. enterolobii-infested experimental guava plants at different concentrations ranging from 100 ppm to 2000 ppm. The synthesis of defense-related proteins is identified with 1000 ppm of IBA. At this concentration, IBA influences the morphological, physiological, and biochemical characteristics and enhances the induction of defense-related proteins in M. enterolobii-infested experimental guava plants. Thus, 1000 ppm of IBA prevents nematode infestation in Lucknow-49 guava plants.

Background: Groundnut, Arachis hypogaea is a leguminous crop grown in tropical and subtropical regions of the world. Meloidogyne spp., is considered to be nematode pest of economic importance for the groundnut throughout the world. Plant metabolites with nematicidal property have been in use for a long time for nematode control that offer many environmental advantages. Methods: The nematicidal activity of methanolic leaf extract of Simarouba glauca on eggs and juveniles (Js) of root-knot nematode, Meloidogyne incognita infesting vegetables was evaluated at three concentrations in vitro (100%, 50%, 25%) with control at three exposure times. Result: Results revealed that at 100% concentration, the methanolic leaf extract of S. glauca showed the least number of eggs hatched (7.85, 12.63, 16.30/egg mass) and the highest mortality (60.58, 70.23, 92.58/100 juveniles) at the exposure times of 24 hrs, 48 hrs, 72 hrs, respectively. The phytochemical compounds viz., Hexadecanoic acid-methyl ester, Isopropyl palmitate, Octadecanoic acid and Methyl stearate detected through GC-MS profiling of methanolic extract of S. glauca were found to inhibit the nematode activity. Pot and field studies proved that soil application of Simarouba leaf powder @ 10 g/plant and 5 kg/ha reduced the nematode infestation. This study implies that use of Simarouba leaf powder produces nematicidal effect against plant parasitic nematodes and reduced the nematode infestation in groundnut and is more suitable candidate in the context of biological control.