Vol. 24 No. 2 (2026): Tạp chí Khoa học Nông nghiệp Việt Nam

The sweet potato weevil, Cylas formicarius (Fabricius) (Coleoptera: Brentidae), is the most serious pest of sweet potato worldwide. Controlling sweet potato weevil infestations is challenging due to the ineffectiveness of insecticide. Sex pheromone traps are used for monitoring, attracting, and capturing adult weevils in the field. In this study, we evaluated several factors affecting trap effectiveness, i.e. pheromone content, trap height, trap distance, trap types, and place timing. Results showed that lures with 1.0mg or more of pheromone effectively attracted male sweet potato weevils in the field. The number of captured adults were highest when traps were spaced 30-40m apart and positioned 0.5-0.8m above ground. Bucket traps and handmade traps made from two liter plastic bottles captured more adults than 1.5-liter handmade plastic bottles traps and delta traps. The optimal time to place pheromone traps on the field was 21 days after planting. The rate of sweet potato tubers damaged by weevils in fields using pheromone traps decreased by up to 84.7% compared to fields without traps.

This study aimed to evaluate the bio- agronomic characteristics, yield and quality of newly developed japonica rice lines. The japonica lines were evaluated at the Vietnam National University of Agriculture, Gia Lam, Hanoi. The regional trials were conducted in some northern provinces of Vietnam in 2025. The results indicated that the lines exhibited a short growth duration (125-132 days in the spring season and 100-108 days in the summer season), semi-dwarfess, and slight susceptiblity to diseases (blast and bacterial leaf blight) and brown planthopper. The grain yields ranged from 6.78-7.89 tons/ha in the spring season and from 5.92-6.59 tons/ha in the summer season. The japonica lines have short, round-shaped grains with a milled rice recovery of 69.2-70.5% and a head rice recovery of 86.2-90.3% and low amylose content. In regional trials, two lines, VJ2 and VJ6, showed high yield and stability in both spring and summer crops. These findings contribute to the ongoing breeding programme for japonica rice varieties in Vietnam.

The beet armyworm Spodoptera exigua (Hübner) is a major pest of Welsh onion in many regions of Vietnam. In this study, we assessed the effects of insecticides on the biological and developmental parameters of S. exigua using sublethal concentrations (LC₃₀) of formulations containing chlorantraniliprole (Prevathon 5SC) and spinosad (Asaka 25SC). The experiment was conducted using the leaf-dip method on 2nd instar larvae combined with an individual-based age-stage, two-sex life table study of S. exigua. Results indicated that the exposure to LC₃₀ concentrations of chlorantraniliprole and spinosad significantly reduced pre-adult survival, prolonged developmental duration, and decreased adult female longevity and fecundity in comparison with the control. The beet armyworm exposed to LC₃₀ of chlorantraniliprole and spinosad showed markedly reduced population growth parameters, including the net reproductive rate (R₀: 90.87 and 64.55), the intrinsic rate of increase (rₘ: 0.1504 and 0.1332), and finite rate of increase (: 1.162 and 1.142), compared with the control (R₀ = 180.03; rm = 0.181;   = 1.198). In contrast, the mean generation time T (29.99 and 31.29 days, respectively) was prolonged in relation to the control (28.7 days). Compared with chlorantraniliprole, spinosad caused a more pronounced reduction in fecundity and population growth potential; therefore, it can be recommended for managing this pest. These findings provide valuable information for optimizing the use of insecticides within integrated pest management (IPM) programs targeting S. exigua on Welsh onion.

The study was conducted to evaluate the effects of waterlogging durations on germination (experiment 1) and on growth, physiology, and adventitious root formation (experiment 2) of sugarcane cv. ROC10 under a net-house condition. In the first experiment, sugarcane cuttings were subjected to waterlogging for 1 to 8 days, respectively and then transferred to normal condition for growth and germination evaluation. Results showed that different waterlogging durations had varying effects on germination ability of ROC10. Specifically, waterlogging of 1-3 days did not significantly affect germination, but the impact became evident from the 5-day treatment onward under waterlogging. Prolonged flooding reduced the germination rate and shoot height, and in the 8-day waterloging, ROC10 failed to germinate. In experiment 2, sugarcane plants at 100 day after transplanting were placed in plastic containers filled with 30l of water for waterlogging treatments of 5, 10 and 15 days, respectively. Here, different waterlogging treatments affected growth, physiology, and root development in ROC10. Waterlogging conditions reduced growth by decreasing shoot height, SPAD index, and Fv/Fm. Additionally, adventitious root formation was found under waterlogging conditions. Among the waterlogging treatments, the 15-day waterlogging induced the strongest adventitious root formation. The distribution of adventitious roots also varied across different nodes in stem, with most adventitious roots forming in the second and third nodes.

A study was conducted to evaluate and select promising accessions of Polyscias fruticosa from five collected accessions with high medicinal yield and quality. The experiment was arranged in a randomized complete block design with three replications in Hanoi from 2019 to 2021. The results indicated that all varieties were shrubby growth habit, stems with irregularly distributed lenticels, and bipinnate to tripinnate compound leaves. VT-ĐL5.1 possessed broadly oval leaves with a blunt apex; VT-ĐL4.1 was the darkest green foliage; and VT-ĐL3.1 had the smallest leaf size. VT-ĐL5.1 (large-leaf genotype from Nam Định) exhibited the most vigorous growth in plant height and the highest dry matter accumulation, resulting in the greatest fresh root yield (6.54 ton/ha), followed by VT-ĐL4.1 (6.23 ton/ha) and VT-ĐL2.1 (6.14 ton/ ha). In terms of phytochemical composition, VT-ĐL4.1 recorded the highest oleanolic acid content (0.104%), whereas VT-ĐL2.1 showed a relatively high oleanolic acid content (0.094%) and extractive content (3.15%). Overall, the variety of VT-ĐL4.1 and VT-ĐL2.1 demonstrated superior agronomic performance and phytochemical quality, and are therefore recommended as potential varieties for large-scale cultivation and medicinal raw material production.

This study aimed to identify the cryptic species of the whitefly (Bemisia tabaci) infesting cassava in Vietnam and to characterize its transmission of Sri Lankan cassava mosaic virus (SLCMV) (Begomovirus stanleyi). The study employed mitochondrial cytochrome c oxidase subunit I (mtCOI) gene sequence analysis of 47 whitefly samples collected from cassava plants in 10 provinces, together with experiments assessing the virus transmission ability of whiteflies. The results showed that all whitefly samples belonged to the cryptic species AsiaII-1. The AsiaII-1 population on cassava in Vietnam and across Asia, mainly in Southeast Asia, exhibited a small effective population size, low genetic diversity, and dominance of haplotype H2. The minimum acquisition access period and inoculation access period for SLCMV were 1 hour and 15 minutes, respectively. Female whiteflies transmitted the virus more efficiently than males; the virus was transmittable through mating between adult whiteflies, whereas whitefly age had no clear effect on transmission efficiency. In conclusion, this study provides a scientific basis for the development of effective management strategies for cassava mosaic disease in Vietnam.

The study evaluated the in vitro regeneration of different mungbean varieties under different culture conditions and explant types. The study used 10 varieties and different explant types, concentrations of plant growth regulators, and kanamycin. The results showed that callus induction increased with higher BAP concentrations and was strongly enhanced when combined with NAA. Media containing 3-4 mg/l BAP +1.0 mg/l NAA produced the highest callus induction rates (73.2-75.3%), especially in shoot and hypocotyl explants (~ 50%), whereas leaf explants exhibited the lowest rate (28.7%) and were more susceptible to contamination (26.5%). In shoot regeneration from cotyledon, MS + 0.5-2.0 mg/l BAP + 0.1 mg/l IAA yielded the best results, with shoot induction rates of 80.0-82.2% and 0.8-1.7 shoots/explant. HMB0024 showed the best regeneration capacity (1.7 shoots/explant). Root formation on MS was  50.0-61.7% depending on the variety; HMB0036 produced the highest number of roots and root length  (10.1 roots/explant; 9.0cm). Thus, the optimal medium for callus induction from shoots and hypocotyls was MS + 3-4 mg/l BAP + 1.0 mg/l NAA, while shoot regeneration from cotyledonary leaves was most effective on MS + 0.5-2.0 mg/l BAP + 0.1 mg/l IAA. Kanamycin concentrations of 75-100 mg/l were identified as suitable for screening cells, tissues or plants in genetice manipulation. The findings provide foudation for genetic transformation or genome editing in mungbean.

This study was conducted to investigate the effects of Se application on the growth and physiology of TR4 robusta coffee variety under drought stress. The experiment was a randomized complete block design with six Se concentrations (0; 0.01; 0.02; 0.04; 0.06; 0.08 g/l) under the normal watering and drought stress conditions. The results showed that under drought conditions, growth and physiological parameters such as leaf area, SPAD value, Fv/Fm value, relative water content in leaves were lower, while the relative ion leakage in leaves of coffee plant was higher compared to that under watering conditions. Application of Se increased growth and physiological parameters under both normal watering and drought stress conditions. Comparing among Se concentrations, higher growth and physiological parameters and lower percentage reduction of leaf area (10.63%) were observed in the Se concentration of 0.04 mg/l.

The study evaluated the growth characteristics, yield, and grain quality of ten rice varieties cultivated in Bac Dong Hung commune, Hung Yen province in 2024 Spring season. The experiment was arranged in a randomized complete block design (RCBD) with three replications. The results showed that the varieties had a short growth duration (117-119 days) and medium plant height (102.1-123.1cm). The SPAD and LAI values of TBR85, ĐC17, and TBR36 were significantly higher than those of the control variety HT1 at most observed stages. The head rice rate ranged from 75.2% to 81.1%, with ĐC12, ĐC17, and LDA12 showing the highest values. TBR88 and ĐC12 were evaluated as having the best sensory quality. Principal component analysis (PCA) indicated that grain yield was mainly influenced by SPAD, LAI, panicle number per square meter, grain number per panicle, and filled grain percentage. The TBR85 recorded the highest actual yield (6.55 t ha⁻¹) and exhibited strong resistance to bacterial leaf blight, while TBR87 yielded 6.28 t ha⁻¹ and also showed good resistance. These two varieties were considered promising for large-scale cultivation in the Red River Delta region.

Neoseiulus longispinosus is an important predatory mite that plays a key role in the biological control of phytophagous mites. This study aimed to evaluate the sublethal effects of bifenthrin (Talstar 25EC) and pyridaben (Alfamite 200WP) at LC30 on the biological traits and population growth of N. longispinosus. Adult females were exposed to each pesticide at LC30, and developmental, reproductive, and life-table parameters of the F1 generation were subsequently assessed under laboratory conditions. The results showed that neither pesticide significantly affected the developmental duration of immature stages. However, the pre-oviposition period and female life span were prolonged, whereas oviposition period, total fecundity, and longevity were significantly reduced with stronger effects observed for Alfamite 200WP. Life-table analyses revealed a marked reduction in population growth potential, as indicated by a decrease in the intrinsic rate of increase (rₘ) from 0.304 in the control to 0.279 and 0.246 in the Talstar 25EC and Alfamite 200WP treatments, respectively. These findings demonstrate that sublethal exposure to bifenthrin and pyridaben can substantially impair the biological control efficiency of N. longispinosus and should be carefully considered when integrating these pesticides into integrated pest management programs.  

Carallia brachiata, a member of the Rhizophoraceae family, contains various bioactive compounds with antioxidant, anti-inflammatory, and antibacterial properties.The present study applied microanatomical methods to the roots, stems, and leaves of Carallia brachiata to provide botanical data for classification, conservation, and genetic resource development. Primary roots were characterized by five to six xylem bundles and well-developed cortical and pith parenchyma. Secondary roots exhibited a thick periderm and prominent secondary vascular tissues, enhancing mechanical support and conduction capacity. In the primary stem, open vascular bundles were arranged in a ring and surrounded by a continuous sclerenchyma layer. In the secondary stem, secondary xylem occupied most of the cross-section, reflecting increased mechanical reinforcement. The leaf blade consists of well-differentiated mesophyll tissues, with palisade parenchyma more developed than spongy parenchyma. Anomocytic-type stomata were confined to the abaxial surface, reducing water loss. The midrib and petiole feature collenchyma concentrated at the protruding angles and a crescent-shaped vascular bundle enclosed by sclerenchyma. Overall, the microanatomical structure of C. brachiata demonstrates mechanical and conductive development and strong adaptation to dry,  high-light environments.

The study aimed to evaluate the morphological characteristics of Carallia brachiata (Lour.) Merr. to serve the conservation and development of medicinal plant genetic resources. The experiment was conducted in 2024-2025 on two age groups of trees (> 10 years and < 6 months) at Tinh Lu Pagoda-Bac Ninh and the Vietnam National University of Agriculture. The morphological characteristics were described and the results showed that Carallia brachiata is a straight trunk and dense canopy tree. The young trunk is brownish green, turning grayish brown when getting old; the taproot develops strongly and has the ability to generate shoots. The simple leaves grow opposite, the leaf blade is smooth, the edges are intact with two forms: round-oval and long-oval.In young trees, the leaves are long elliptic and have serrated edges. Flower buds appear in November; flowers bloom in February and the fruits ripen in April. The umbel-shaped inflorescences grow in the leaf axils; The flowers are small, ivory-white with 7 or 8 petals and 1 inferior ovary with 3-5 locules. The calyx does not fall off but closes when the ovary develops fruit. The small berries are spherical or slightly oval, turning from green to orange-yellow to red when ripe; the seeds are oval, nearly round or kidney-shaped, 5-6mm long, and have a horseshoe-shaped embryo. The C. brachiata has potential for development as an ornamental plant and a medicinal plant for herbal tea production.

This paper provides an overview of the applications of Unmanned Aerial Vehicles (UAVs) in crop production to meet the demands of precision agriculture development and climate change adaptation. The objective of the study was to systematize the technologies, applications, and challenges associated with UAV use in crop management. The synthesis results indicate that UAVs have been effectively applied in monitoring crop growth, predicting crop yield, detecting pests and diseases, automated spraying and fertilization, and managing soil, water and nutrients. By integrating multispectral, hyperspectral, thermal, and LiDAR sensors with artificial intelligence and machine learning techniques, UAVs enable precise data acquisition and decision-making and reducing water, fertilizer and pesticide use by 20-50% while lowering emissions. Despite limitations in investment cost, payload capacity, and regulatory frameworks, UAVs are emerging as a core technology driving smart, efficient, and sustainable agricultural development in Vietnam.

The study aimed to improve the in vitro propagation of Curculigo orchioides Gaertn. Four experiments were conducted: (1) The effect of BAP and IBA on the ability to shoot cluster formation; (2) The effect of IBA and Kinetin on the ability to rapidly shoot multiplication coefficient; (3) The effect of α-NAA on the ability to root formation; (4) The effect of substrate moisture on the survival rate of in vitro plantlets. The results determined that the optimal medium used for shoot regeneration was MS medium + 20 g/l sucrose + 6.5 g/l agar + 0,3 g/l activated charcoal + 2 mg/l BAP + 0.1 mg/l IBA (shoot formation rate of 78.33%). The optimal shoot multiplication medium was MS + 20 g/l sucrose + 6.5 g/l agar + 0,3 g/l activated charcoal + 1.0 mg/l IBA + 1.0 mg/l Kinetin (shoot multiplication of  17.75 shoots/sample). The most suitable rooting medium was MS (with halved NH4NO3) + 20 g/l sucrose + 6.5 g/l agar + 0.7 g/l activated charcoal (7.2 roots/plant, root length of 11.9cm, rooting of 100%). A mixture of alluvial soil + burnt rice husk + manure (1:1:1) at 80-90% moisture content was the most suitable substrate for the growth of in vitro derived plantlets with a survival rate of 100%.

The study was conducted to determine the effects of rootstock type, grafting season, and foliar fertilizer on the survival rate and growth performance of Huong Tich apricot (Prunus mume) scions during the nursery stage. The experiment was carried out at the Vietnam National University of Agriculture from June 2023 to March 2025 using a two-factor experimental design. The study involved three types of rootstocks (plum, apricot, and peach), four grafting times (September, October, November, and December), and two foliar fertilizers (Antonick and Dau Trau NPK). The results showed that grafting in September was the most suitable, enabling better growth of grafted plants and achieving the highest bud-break rate. In particular, grafting onto plum rootstock produceda higher bud-break rate of 63.1% comapred to, apricot (56.7%) and peach (54.4%) rootstocks. During this grafting time, growth parameters such as scion length and diameter, number of leaves, and leaf length and width were all higher than those in the other grafting times across all three rootstock types. In addition, the use of Antonick foliar fertilizer was more effective than Dau Trau NPK in most growth-related parameters.