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4 Egyptian mosquito species were tested for their ability to transmit the Egyptian ZH-501 strain of Rift Valley fever virus (RVFV) to golden Syrian hamsters. Culex (Cx.) antennatus was the most efficient vector, showing a 37.5% transmission rate following a hamster blood meal containing 10 suckling mouse intracerebral 50% lethal doses (SMILD50) per ml. Fully engorged mosquitoes of this species showed an infection rate of 85% with the mean viral titres of transmitting mosquitoes 100-fold higher than non-transmitters. Autogenous and anautogenous populations of Aedes (Ae.) caspius were tested separately, and the transmission rates were 23.1% and 9.7% respectively, following feeding on hamsters with similar levels of viraemia. Two anopheline species, Anopheles (An.) multicolor and An. pharoensis, showed 12.5% and 3.5% transmission rates under similar conditions. In these 3 species infection rates exceeded 75% and mosquitoes transmitting had a higher average titre than those not transmitting.

Cropping under conservation agriculture (CA) has become increasingly attractive among farmers in recent years. However, weed control may be more difficult during the transition to CA from conventional establishment methods due to the reduction in tillage intensity. Conversely, CA changes to weed dynamics can alter the weed seed bank in the longer run. In Bangladesh’s intensively cropped rice-based rotations, the nature of weed seed bank shifts over time after adopting CA are poorly known. Two 2-year studies were sampled from on-farm CA experiments under wheat-mungbean-winter rice and monsoon rice-mustard-winter rice rotations. We investigated the effects of reduced soil disruption in the form of strip-tillage (ST) combined with increased deposition of standing reside from previous crops (0 vs. 50%). The weed seed bank in 0–5, 5–10, and 10–15 cm depths of soil were quantified in a shade-house experiment by measuring weed emergence over 12 months in seedling trays. After 2 years of field study, the year-round count of emerged weeds from the seed bank showed that ST plus 50% mulch had a lower weed abundance and biomass and fewer weed species than that of conventional tillage (CT) without residue. The perennial weeds Ageratum conyzoides L., Alternanthera philoxeroides L., Cynodon dactylon L., Cyperus rotundus L., Jussia decurrence Walt., Leersia hexandra L., Scirpus mucronatus (L.) Palla., and Solanum torvum Sw. were enriched in the smaller-sized ST seed banks in terms of both density and biomass. The CT, on the other hand, was dominated by annual weeds: Cyperus difformis L., Cyanotis axillaris Roem., Echinochloa crus-galli (L.) Beauv., Eleusine indica L., Fimbristylis miliacea (L.) Vahl., and Rotala ramosior L. Overall, ST plus 50% residue had a more diverse seed bank than CT without mulch. The majority of weed seeds were amassed in the 0–5 cm soil depth of the ST, while most of them were accumulated in the 10–15 cm layer of the CT. The wheat-mungbean-winter rice rotation had a more diverse floristic composition with many more weed species than the monsoon rice-mustard-winter rice rotation.

The study aims to investigate the potential effect of nanocurcumin as feed additive in the diet of Oreochromis niloticus to improve its growth performance, health status and resistance against Aspergillus flavus. The control group was fed on a basal diet without nanocurcumin, and four diets T1, T2, T3 and T4 were supplemented with 10, 25, 40 and 55 mg/kg of nanocurcumin, respectively, in triplicate (20 fish/replicate). The duration of the feeding trial was 60 days. The final body weight, weight gain, specific growth rate and survival rate showed significantly (p < 0.05) increased values in the nanocurcumin groups than the control. Fish fed with nanocurcumin supplementation showed improvement in RBCs, haemoglobin, total protein, albumin and globulin while there was a decrease in the liver enzymes (AST and ALT), glucose and alkaline phosphatase. The creatinine was also decreased in fish fed nanocurcumin. The digestive enzymes amylase and lipase increased in the nanocurcumin‐treated groups, and the triglycerides values showed non‐significant increase, whereas the cholesterol values showed non‐significant decrease in T1 and T4. Meanwhile, the cortisol was nearly the same in all groups. At the end of the trial, the fish were challenged with Aspergillus flavus for 15 days. Aspergillus flavus resulted in the mortality of 100% of the control group and the groups with lower doses of nanocurcumin (T1 and T2) within the first week and second week post challenge respectively. In the treatments with high doses (T3 and T4), higher survival rates were recorded in a dose‐dependent manner. The pathogenicity of Aspergillus flavus was confirmed histopathologically. It was concluded that the dietary supplementation of nanocurcumin enhanced the health status of O. niloticus by improving the haemato‐immunological response and body composition parameters of the fish, and protected it from the Aspergillus flavus infection with optimum inclusion levels of 25–40 mg/kg diet.

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