Iron‐based magnetic nanoparticles (MNPs) have been studied extensively for the past few decades. They have been applied in various applications, particularly in the biomedical sector. Due to their excellent physical and chemical properties, they have also been used widely in the agricultural sector. MNPs can be synthesized inexpensively and applied in large scale agricultural activities. This paper highlights the applications of iron‐based MNPs in the agricultural sector mainly as antimicrobial agents, plant growth promoters, site‐targeted delivery agents, nanosensors, detection and remediation for pesticide residue. Furthermore, the toxicity and transport of iron‐based MNPs in the soil‐plant system are also elucidated. These aspects have to be well‐understood before MNPs can be fully implemented effectively this pin the agricultural sector. Lastly, a hybrid nanomaterial, which is consisted of iron and magnesium oxide (MgO) nanoparticles (NPs), is proposed. This hybrid nanomaterial is expected to overcome the shortcomings of iron‐based MNPs.

Hybrid nanoparticles (NPs) have received much interest over the past decades because they have the potential to overcome the limits of single-component particles. This study proposes a hybrid magnetic magnesium oxide (m-MgO) NPs to combat the plant pathogenic fungus, Fusarium oxysporum (F. oxysporum). The m-MgO NPs were synthesized via ultrasonic mediated sol-gel method. UV-visible spectrometry confirms the successful formation of m-MgO NPs. In addition, the magnetic activity of m-MgO NPs was illustrated through a preliminary magnetic activity study. A disc diffusion assay was carried out to determine the effectiveness of m-MgO NPs to inhibit the growth of F. oxysporum. The results showed that the zone of inhibition was 7.58 ± 0.30 mm at 10 mg/mL, suggesting that the synthesized m-MgO NPs are an effective fungicide to inhibit the growth of F. oxysporum.