Papaya ringspot virus W (PRSV W) is a common aphid transmitted potyvirus, seriously affecting cucurbit production worldwide. This study conducted field surveys to collect PRSV W infecting cucurbit crops in Cu Chi and Hoc Mon districts, two major vegetable-growing areas of Ho Chi Minh City. A total of 48 samples representing sponge gourd, cucumber, bottle gourd, wax gourd, bitter gourd, and pumpkin were collected and tested by indirect ELISA-based serological assay, which detected PRSV in four samples. The indirect ELISA-positive cucurbit samples were then subject to bioassay to identify the type of PRSV, followed by reverse transcription polymerase chain reaction (RT-PCR) confirmation for the PRSV W type. Among all the symptomatic cucurbit samples collected and tested in this study, the highest incidence (27.3%) of PRSV W was recorded on the sponge gourd samples. The infected leaves’extracted total RNA was analyzed by RT-PCR with primer pairs SMK 8701(F)/3’UTR(R), and the PCR product was sequenced. The results revealed that the complete CP genome sequence of isolate PRSV W isolate HocMon (PRSV W-HM) was most closely related (polyprotein nt and aa identities of 93.3 and 95.1%, respectively) to the China isolate of PRSV W (GenBank KX6558741). Briefly, this study provides important insights for the accurate early diagnosis of PRSV W infection and developing effective disease control strategies to limit the spread of this virus isolate.

Sedimentation supplemented by flood is an essential source of soil nutrition in the lower Mekong River basin. This study evaluated the sediment deposited on fields during the 2022 flood season at the Plain of Reeds (PoR), Vietnam. The PoR is a region of soil with heavy acid sulfate. The selected research area was two provinces in PoR, Long An and Tien Giang. The dike system in this region comprises the complete-dyke and semi dyke. This study uses a new sediment trapping design to measure deposited sediment with particle sizes > 50 µm during the whole flooding season of 2022. Three location types were selected for measurement, including internal canal (InC), flat field (FF), and the raising bed (RB). We selected these three location types based on agricultural practices in this region. The deposited sediment in one flood season was at a mean of 1242.3 ± 1102.6 g/m2. There were observed differences between location types, in which the highest was found at the flat field upstream (2941.5 ± 500.8 g/m2), to the flat field downstream (1621.3 ± 141.2 g/m2), to the internal canal (987.5 ± 929.43 g/m2), and lowest at raising bed (119.2 ± 9.43 g/m2). Significant differences were found between the flat field upstream and the other three location types within the study area. Total N and P content of sediment were found at a mean of 9.08 ± 5.05 mg/g dry weight (dw) and 0.62 ± 0.21 mg/g dw, respectively. The data showed a significant amount of sediment, and its nutrient contents can be trapped during the flooding season in this semi-dyke system.

The objective of this study was to examine the abilities of Jussiaea repens L. in removing organic compounds, nitrogen and phosphorus from domestic wastewater under laboratory conditions. The experimental model consisted of four plastic tanks, each measuring 52 x 32 x 27.5 cm, labeled as NT1, NT2, and NT3 corresponding to 150, 300, and 450 g of Jussiaea repens L., respectively. The control tank contained only domestic wastewater without the plants. The input domestic wastewater parameters (mean ± standard deviation, n = 3) were as follows: pH = 6.66 ± 0.32, BOD5 (Biological oxygen demand) = 347.64 ± 39.60 mg/L, NH4+ = 27.53 ± 1.74 mg/L, NO3- = 2.23 ± 0.26 mg/L, and PO43- = 24.69 ± 1.27 mg/L. After twenty days of experimentation, the tank containing 450 g of plants achieved the highest treatment efficiencies for BOD5, NH4+ and NO3-, with respective efficiencies of 29.1, 24.2, and 43.8%. Regarding phosphate removal, the tank (NT2) using 300 g of plants achieved the highest treatment efficiency (by plants), with a reduction of 9.5% after 20 days.

Xao tam phan (XTP) is a valuable medicinal plant native to Southeast Asia, particularly Vietnam. This plant is rich in bioactive compounds, primarily phenolics and saponins, which offers various therapeutic properties. A recent study optimized the extraction of these bioactive compounds from XTP stems using an enzyme-assisted extraction (EAE). Response surface methodology determined optimal enzyme extraction conditions at 0.8% v/w enzyme concentration, 45°C, and 105 min. Combining ultrasound with enzyme treatment (U-EAE) proved most effective, increased total phenolic content (TPC) and total saponin content (TSC) by 1.23 and 3.27 times, respectively, compared to untreated samples. The U-EAE outperformed other methods (E-UAE, UES-AE, UAE, EAE) in extracting bioactive compounds.

Banana is a widely cultivated tropical fruit and one of Vietnam’s key export agricultural products. However, this fruit is difficult to preserve and is susceptible to anthracnose, a disease caused by fungi. The inclusion complexes (ICs) of cinnamon essential oil and lemongrass essential oil with β-cyclodextrin are safe and well-researched method for fruit preservation due to their anti-fungi properties. In this study, the cinnamon essential oil/β-cyclodextrin IC (CEO-β-CD) and lemongrass essential oil/β-cyclodextrin IC (LEO-β-CD) were used to preserve bananas and increase the physicochemical quality of bananas. The results showed that the CEO-β-CD at a dose of 2.5 mg per g of fruit had a better ability to maintain the physicochemical quality of bananas with the lowest weight loss (7.5%) and the highest firmness (3 N). The L* value, a* value, and b* value also demonstrated good quality bananas with few black spots. Moreover, the total soluble solid (TSS) of 6.5oBrix, the highest reducing sugar content of approximately 2.5 mg/g, and the vitamin C content of about 0.37 mg/100 g flesh exhibited that the CEO-β-CD at a reasonable concentration could be a potential preservative for preserving banana.