Sustainable use of nanotechnology in crop protection requires an understanding of the plant’s life cycle, potential toxicological impacts of nanomaterials and their mechanism of action against the target pathogens. Herein, we show some properties of a candidate antifungal nanocomposite made from copper oxide (CuO; otherwise an essential soil nutrient) nanoparticles (NPs), with definite size and shape, decorating the surface of reduced graphene oxide (rGO) nanosheets. The successful preparation of the rGO-CuO NPs was confirmed by spectroscopic and microscopic analyses, and its antifungal activity against wild strains of Fusarium oxysporum affecting tomato and pepper plants was successfully confirmed. A comparative analysis in vitro indicated that this nanocomposite had higher antifungal activity at only 1 mg/L than the conventional fungicide Kocide 2000 at 2.5 g/L. Further investigation suggested that rGO-CuO NPs creates pits and pores on the fungal cell membranes inducing cell death. In planta results indicated that only 1 mg/L from the nanocomposite is required to reduce Fusarium wilt and root rot diseases severity below 5% for tomato and pepper plants without any phytotoxicity for about 70 days. Comparatively, 2.5 g/L of Kocide 2000 are required to achieve about 30% disease reduction in both plants. The present study contributes to the concept of agro-nanotechnology, showing the properties of a novel ecofriendly and economic nanopesticide for sustainable plant protection.
Mesoporous silica nanoparticles (MSNs) can promote the solubility and absorption of pesticides by plants and are widely used as a delivery system to improve the efficacy of pesticide applications. In this study, MSNs with 20 nm particle size were produced. Additionally, a water-soluble chitosan (CS) derivative, here called N-(2-Hydroxyl) propyl-3- tri-methyl-ammonium CS chloride (HTCC) was produced and used to cap the outer surface of the MSNs preloaded with the pesticide fludioxonil (Flu). The HTCC coating layers resulted in a pesticide loading efficiency of 84% on the MSNs in comparison to a loading efficiency of 20% of uncoated particles. A comparative in vitro analysis indicated that Flu@MSNs20nm-HTCC loaded with a 0.05 mg/L dose of fungicide had significant higher fungicidal activity than the same fungicide at 1 mg/L dose against F. oxysporum f. sp. radicis-lycopersici (FORL). Moreover, after an initial burst, MSNs20nm-HTCC kept releasing Flu for 21 d, compared to an activity of 7 d associated with the direct release of Flu. Greenhouse data showed that 0.1 mg/L Flu applied through MSNs20nm-HTCC is sufficient to reduce Fusarium crown and root rot disease severity to a value of less than 6% in tomato plants, without any noticeable phytotoxicity after 70 d. In comparison, 1.56 mL/L of the fungicide are required to reach a 27% disease severity level. Thus, we suggest that HTCC-decorated MSNs20nm has a great potential as a nanodelivery systems for agrochemical applications. We also suggest that this work contributes to the notion that agro-nanotechnology is a powerful, environmentally-safe and cost-effective approach for a sustainable and long term protection of plants from disease.
he inhibitory effect of potassium, calcium and sodium silicate was assessed, in in vitro at different concentrations (0.1, 0.5 , 1, 2, 4 and 8ml /l) against Sclerotium cepivorum the causal of onion white rot . The results indicated that potassium and calcium silicate at 0.5 ,1,2,4 and 8ml/l inhibited the mycelial growth and sclerotia formation of S. cepivorum, but at 0.1ml/l concentration, the mycelial growth decreased to (2.4cm and 5.0 cm) respectively compared with control treatment . On the contrary sodium silicate resulted in low effect on the mycelial growth and sclerotial formation. Our results also showed that, potassium and calcium silicate increased the pH of the PDA medium from 8.8 to 11.4 by increasing K 2 SiO 3 and from 8.7 -11.5 by increasing CaSio 3 concentration from 0.1to 8 ml/l. Under greenhouse conditions, the incidence of white rot disease was significantly decreased when onion plants were treated with potassium silicate(2,4 and 8ml/l) only or with VAM fungi, as soil drench in potted soil infested with S. cepivorum compared with the control. Adding 4ml/l potassium silicate as soil drench showed high reduction to the disease incidence by 71.43%. On the other hand, onion plants treated with different concentrations of potassium silicate as soil drench and VAM fungi or Folicur 25%, increased apparently healthy survived plants at harvest under field conditions of Kalubiya Governorate during 2015/2016 and 2016/ 2017 seasons, since they decreased disease infection percentages. The highest reductions of onion white rot were observed when onion plants were treated with Folicur 25% followed by potassium silicate at (2 ml/l +VAM fungi). Regarding the yield of onion bulbs, our results indicated that all treatments showed significant increase to bulb yield in contrast to the non-treated plants. Spores count and percentage of root colonization with VAM fungi were increased by increasing potassium silicate concentration, in contrast to the percentage of hypha which was increased by decreasing potassium silicate concentration. In addition, VAM fungi and VAM+ 2ml/l potassium silicate treatments were considered the T 126 EFFECT OF INTEGRATION BETWEEN VASCULAR ARBUSCULAR ……..
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.