Vol. 22 No. 5 (2024)

This study aimed to evaluate drought-related traits of black bean accessions suffering drought at the flowering stage. The experiment was conducted on 5 black bean accessions grown in pots placed in a greenhouse in Summer season and was arranged in a randomized complete block design with 3 repetitions. The drought was imposed intermittently in 6 cycles, each cycle consisted of 2 days withoutg irrigation and 1 day watering. The results showed that drought in the summer crop caused leaf and stem wilting and reduced root length ane fresh and dry weight of roots and stems of the accessions. The number of pods/plant and the number of seeds/pod decreased seriously in the accessions G2 and G4, respectively. The accession G5 had the lowest yield loss and maintained highest plant greeness score. These results may contribute to promoting drought-tolerant breeding programs in black beans.

The experiment was conducted to determine suitable composting method to convert agricultural by-product into organic fertilizer and evaluate effect on the growth and yield of cucumber in 2023 spring season. The experiments were carried out at the field of the Faculty of Agronomy, Vietnam National University of Agriculture. The traditional aerobic composting and mix aerobic composting were tested to compost agricultural by-products consisting of rice straw, chicken manure and elephant grass. Research results showed that the mix aerobic composting method produced higher mass and quality of compost in comparison with traditional method. Combination treatment of mix aerobic compost with chemical nitrogen fertilizers had a positive effect on growth, development and yields of cucumber than other treatments.

This study aimed to investigate the biological and ecological characteristics of the mealybug destroyer, Cryptolaemus montrouzieri, an important predator of the papaya mealybug, Paracoccus marginatus. The mealybug destroyers were reared at two different temperatures: 30Cand 33C,with 80% humidity, 14L:10D, feeding on papaya mealybugs, P. marginatus. The results showed that the life cycle of C. montrouzieriwhen reared at 30°C (28.00 days) was significantly longer than at 33C(23.91 days). The total pre-adult period of male C. montrouzieriat 30Cwas 22.00 days, longer than when reared at 33C(17.95 days). The total number of eggs laid by C. montrouzieriwhen reared at 30C(253.72 eggs) was significantly higher than when reared at 33C(206.65 eggs). However, the daily oviposition did not differ significantly between the two temperatures, with an average of 5.50 eggs/day. The intrinsic rate of increase (rm) of C. montrouzieriat 33C(0.134) was significantly higher than at 30C(0.121). The total consumption of the larval stages of C. montrouzierifeeding on P. marginatusat 30Cwas higher than at 33C, and the consumption increases with each successive larval stage, peaking at the fourth instar with consumption rates of 19.26 and 18.19 individuals/day at 30Cand 33C, respectively.

Chrysanthemum is an important floriculture crop in the international flower market because it has an attractive beauty and a high economic value. They are popularly grown as cut flowers and potted flowers world-wide due to their varied in flower color, size, and petal shape. The study aimed to evaluate the growth and development characteristics of five Chrysanthemum cultivars in Gia Lam, Hanoi. The single- factor experiment on five Chrysanthemum cultivars was arranged in a randomized completeblock design with three replications. The results showed that all five Chrysanthemum cultivars grew and developed well in Gia Lam,Hanoi. The plant height of five studied cultivars ranged from 32.50-58.12cm, with 0.53-0.55cm of stem diameter. The number of leaves varied from 17.6-33.0 leaves with 4.82-6.62cm in width and 8.50-12.36cm in length. The number of days to 30% inflorescence bud initiation varied from 40-58 days after transplanting. All cultivars had double head inflorescence form with 3-7 head inflorescences/plant. Head inflorescences bloomed after 23-32 days from the initiation of inflorescence buds. The diameter of head inflorescences ranged between 4.33 to 11.70cm. The head inflorescence longevity varied from 34 to 40 days.

The present study was conducted to evaluate the effects of dietary co-supplementation of peptidoglycan and probiotics on growth performance, survival, feed utilization, and hematological parameters in Nile tilapia. Commercial feed specialized for tilapia were supplemented with peptidoglycan and probiotics at various concentration (g/kg of diet): 0; 3+3; 5+3; 5+5; 3+5 corresponding to experimental treatments: NT1, NT2, NT3, NT4, NT5. Nile tilapia juveniles were fed on the experimental feed for 4 weeks at a ration of 5% body weight; the feed amount was daily recorded. During the feeding period, fish were weekly weighed to monitor the fish growth. After a 4-week trial, blood samples were collected for hematological analysis; the fish number and weight were used to determine the survival rate and fish growth. Results show that the co-supplementation of probiotics and peptidoglycan induced positive effects on the fish survival, growth, and feed conversion ratio, in which fish fed 3g peptidoglycan + 3g probiotics displayed the best results.

The study aimedto determine the ocurrence of Gyrovirus in chickens raised inseveral districts in Thai Nguyen province. A total of 42 pooled samples were collected from chickens with symptoms such as stunting, drooping, and diarrheaat svarious farms in Phu Binh, Phu Luong, and Vo Nhai districts of Thai Nguyen province from March to August 2023. Resultsof Polymerase chain reaction(PCR)showed that the positiveratefor chicken Gyrovirus virus was 17.65%, 28.57%, and 27.27% collected from Phu Binh, Phu Luong, and Vo Nhai districts, respectively. The partial sequencing of the gene encoding the VP2 protein revealed that the field virus strainsin chickens showing drooping and stunted behavior belonged to the Gyrovirus galga 1 and weregeneticallyclose to the ChineseGyrovirusstrain (2014) and BrazilianGyrovirus strain(2019). The results of this studysupplementthe presence of Gyrovirus galga1 in chickens as a basis for future in-depth research on Gyrovirus.

This study was conducted to determine the antimicrobial resistance profileand some virulence-associated genesof Escherichia coli isolated frompork and chicken meatsamples collected at local markets in Cau Giay district, Ha Noi city.E. colistrains were isolated by culture method using selective media. Theantimicrobial susceptibility of E. coliisolates was conducted using the broth microdilution method. Virulence-associated genes were detected by PCR. The results showed that 72% of chickenand 74% of pork samples werepositive for E. coli. Theisolatesexhibited thehighestresistancerateto florfenicol (95.89%)and the lowest resistancerateto ceftazidime (1.37%). Among 73 E. coli isolates, 3 (4.11%) harbored stx2and none carried stx1 gene. Furthermore, 4(5.48%) outof 73 isolateswere found tosimultaneously possessbotheae and ehxAgenes.

The aim of this study was to advance grow-out cultivation techniques of slender red seaweed (Gracilaria tenuistipitata)in experimental conditions, serving as basis for experimental farming on a commercial scale, contributing to improving productivity and ensuring the quality of raw material seaweed. Four experiments were conducted: (1) culture density, (2) fertiliser doses, (3) depth for cultivation and (4) biomass of seaweed seedlings left after harvesting. Each experiment was repeated three times from May to December 2022 in Thai Thuy District, Thai Binh Province. Research results show that the optiml initial density of seaweed seedling was 600 ± 50 g/m2; basal fertilizer with a dosage of 0.2 kg/m2and inorganic fertilizer as nutrient supplement with a dosage of 0.02 kg/m2were most appropriate in commercial slender red seaweed farming; the depth for cultivation of Gracilaria tenuistipitataof 60 ± 5cm was best for control of the algae fouling; and the appropriate biomass of algae seedlings left after harvesting was 550 ± 50 g/m2.

The study was carried out to determine reproductive performance and egg quality of Van Linh chicken from 17 to 40 weeks raised at the Faculty of Animal Science, Vietnam National University of Agriculture. A total of 40 hens and 6 roosters were randomly divided into 2 groups to monitor reproductive performance, feed consumption per ten eggs, egg quality and egg hatching rate. The results showed that Van Linh chickens attained sexual maturity at 120 days of age and the highest of laying egg rate at 193 days of age. In theperiod from 17-40 weeks of age, the egg yield was 66.93 eggs/hen, laying rate was 39.81%, feedconsumption/10 eggs was 3.24kg. The eggs of Van Linh chickens had an average weight of 43.81 g/egg, morphological index of 1.33; Haugh unit was 80.12. The rate of fertile eggs, hatched/fertile eggsand the rate of type I chicks/hatched eggswere 83.17; 86.98 and 90.48% respectively.

This study was conducted to identify the species of pinworms in experimental mice. Eggs of pinworms were examined from four white mice that were purchased from an animal facility before the conduct of experimental infection. The eggs were detected by the perianal tape test method, adult worms were collected by necropsy method, and then eggs and adult worms were identified based on their morphology. Besides, PCR and sequencing techniques were also applied to confirm the species identification. The results show that eggs were pointed oval (with one side flatted) in shape and approximately 129.2 x 39.17m in size. Adult worms were 3-5mm in length, having two subtle cervical alea, a bulb at the end of the esophagus, and a long and pointed tail. PCR and sequencing techniques revealed the species of pinworm to be Synphacia obvelata. Even though the scope of the study was still limited, the results of the study provided information on the presence of S. obvelatain experimental mice and gave a warning signal about monitoring and eradication of pinworms for experimental animal facilities.

The purpose of this study was to investigate the mixing ratio to create aherbal product from six types of extracts: Syzygium aromaticum, Glycyrrhiza uralensis, Andrographis paniculata, Zingiber officinale, Phyllanthus urinaria, andPsidium guajavato support weight gain and prevent diarrhea in pigs and chickens. The antibacterial activity was evaluated using the MIC method, screened by the Plackett-Burman matrix, and the efficacy of the herbal product on pigs and chickens was assessed.The mixing ratio of herbs was screened by Plackett-Burman matrix. The results showed that the mixture of three extracts Syzygium aromaticum, Glycyrrhiza uralensisand Andrographis paniculatamixed in a 1:1:1 ratio exhibited good antibacterial using MIC. The MIC was obtained at 2.083 mg/ml on E. colivàS. typhimurium. This herbal product formulation yielded better weight gain and disease prevention efficiency in both pigs and chickens. Results on disease preventive efficiency showd that the survival rate in pigs and chickens after 6 weeks was 100% and 98.44%, respectively. This indicates that the herbal product had significant effect on supporting the resistance of pigs and chickens and on improving weight gain for pigs and chickens due to the biologically active ingredients of herbs combined in the product.

This paper presented route planning method for agricultural spraying UAV that ensures the requirements of full coverage, low overlap, no leaving-out, and no spraying outside the working area. The routes were determined based onlatitudes/longitudes in the geographical grid, which can be applied to any location on earth. The algorithm was validated by simulation on Matlab/Simulink combined with QGroundControl software. Simulation results show that the main lines were routed parallelly with a distance 2.73% smaller than the spraying width of the UAV. A margin reduction of the working area before route planning helped limit pesticides being sprayed outside the operational area, avoiding pesticide waste and environmental pollution.

The purpose of this study was to find out an optimal sample and plant growth regulartors for developing an in vitrorapid propagation procedure of triploid daylily. The experiments were conducted on the different explants (flower base, petals, anthers and filaments), also plant growth regulators BA (N6-benzyladenine), 2,4-D (2,4-Dichlorophenoxyacetic acid)và α-NAA (α-naphthaleneacetic acid). The research results showed that petals were the optimal and most effective explant source for culture. The callus induction rate of 83.3% was achieved on MS medium (Murashige and Skoog) supplemented with 2 mg/l 2,4-D and 10 mg/l BA. MS medium supplemented with 2 mg/l BA and 0.25 mg/l α-NAA gave the highest shoot multiplication (12.9 shoots). MS medium supplemented with 0.3 g/l activated carbon was the best for rooting induction (5.8 roots/bud). The results also showed that the ploidy level of the regenerated plants was similar to the donor plant (3x = 33). The plant bloomed after 11 months of planting. Flower number, color of flower, as well as length and width of flower petals were similar to those of donor plant.

This research aimed to apply IoT technologies in monitoring and controlling the water and air environment parameters of a small-scale aquaponics system in households. In this study, parameters of water environment (pH, DO, temperature, water level) and air environment (temperature, humidity, light) of an aquaponics system (NFT - Nutrient Film Techniquec) are monitored remotely (24/24h) through the application of Blynk on a smartphone or a computer. Test results show that the parameters displayed on the remote monitoring interface have quite small errors compared to the values measured on the sample measuring tool, fluctuating in the range of 1% ÷ 2%. When the measured parameters are outside the range of expected threshold values, the system will send a warning message to the phone. In addition, the system is also able to store the measured data in a 6 months period for researching and evaluating the operation of the aquaponics system.

Rice yield in Vietnam is heavily influenced by climate change, particularly weather patterns. This study aimed to examine the relationship between weather and provincial rice yield in Vietnam from 1987 to 2016. The weather data considered in this analysis included the maximum daily temperature for each province or cityand the total annual rainfall. The Red River Delta and Mekong Delta regions exhibited the highest levels of rice yield. To represent the temperature patterns across a given year, a compositional vector consisting of 28 dimensions was utilized. Using a compositional regression model, the highest daily temperatures with the greatest impact on rice yield fall within the range of 28°C-30°C. More specifically, the frequency of days within the year that temperatures fall within 28°C-29°C and 29°C-30°Chad the most significant effect on increasing rice yield in Vietnam. Under the climate change scenario RCP2.6, the projected rice yields for all ecological regions in the year 2099 are estimated lower than those in 2016. The climate scenarios RCP4.5, RCP6.0, and RCP8.5 showedheterogeneous impacts on the difference in rice yield in 2099 and 2016.