Vol. 2 No. 2 (2019): Vietnam Journal of Agricultural Sciences

To study the effects of organic fertilizer and HB101 organic plant vitalizer on the growth and yield components of the BH9 rice variety, a field experiment with 4 x 3 factorial design was conducted at Hong Thai commune, Kien Xuong district, Thai Binh province in 2017 summer season using a randomized complete block design with 3 replications. Organic fertilizer derived from chicken manure and peat was applied at 3 levels (0 ton ha-1, 4 tons ha-1, and 6 tons ha-1) while the HB101 plant vitalizer was sprayed in 4 levels (0%, 0.015%, 0.025%, and 0.035%; the amount of water to dilute HB101 was 1000 litre ha-1). The application of the organic fertilizer alone and the combination of organic fertilizer and HB101 positively increased the total tiller number, effective tiller number, leaf area index (LAI), SPAD value, dry matter accumulation, yield components, and grain yield of rice. There were also differences in the SPAD values (at flowering stage), dry matter weight (at active tillering stage), and 1000 grain weight under the influence of the HB101 solution. The combination of 6 tons ha-1 organic fertilizer and  HB101 significantly increased the grain yield as compared to the other treatments, and the highest grain yield (3.03 tons ha-1) was obtained when  organic fertilizer (6 tons ha-1) was applied in combination with HB101 plant vitalizer (0.025%).

Starch metabolism is known to be an important pathway in the growth and development of plants. This study was conducted to investigate the genome-wide identification and structural analysis of genes encoding uridine diphosphate glucose pyrophosphorylase (UGPase), a key enzyme in starch synthesis in cassava, and to analyze the expression profiles of these genes based on publicly available RNA-seq data. A total of 11 members were found in the UGPase gene family (MeUGP) in cassava. Ten of the MeUGP genes were successfully mapped onto the chromosomes of the current cassava genome assembly. Based on their nucleotide sequences, the lengths of the genomic DNA sequences of the MeUGP genes ranged from 3,200 to 11,601bp, while the size of the coding sequence (CDS) varied from 831 to 3,654bp. According to the recent RNA-seq data, we found that a majority of the MeUGP genes were expressed in at least 1 tissue under normal conditions. Interestingly, MeUGP4 was greatly expressed in the shoot apical meristem, while MeUGP10 was more specific in the root apical meristem. The expression profiles of these MeUGP genes should be carried out in various conditions in further studies.

High levels of polyunsaturated fatty acids in chicken spermatozoa make them susceptible to lipoperoxidation and reduce their fertility. This study was conducted to assess the effect of sesame seed  suplementation in the diet on the semen quality of Ho cocks. Eighteen 13-14 month-old cocks were randomly divided into three groups and were assigned to one of the following treatments: 0% SS (control), 5% SS, or 7% sesame seeds per kg of diet for ten consecutive weeks after a two-week adaptation period. Semen characteristics were evaluated once a week. In the 7% sesame seed treatment group, seminal traits including semen ejaculate volume (1.02mL), sperm concentration (3.68 x 109 sperm), and abnormal spermatozoa (10.51% were improved (P <0.05) compared to the control group (0.82mL, 2.81 x 109 sperm, and 11.04% for semen ejaculate volume, sperm concentration, and abnormal spermatozoa, respectively). Supplementation with sesame seeds did not significantly affect sperm motility, mass movement, or semen pH. Our results demonstrate that sesame seed supplementation at 7% successfully improved the ejaculate volume, sperm concentration, and normal spermatozoa percentage of Ho cocks.

The present study was conducted to evaluate the effects of different dietary calcium levels on the growth and survival rate of black apple snails (Pila polita) in the grow-out period. There were 3 replicates for each treatment and the snails were fed with five calcium levels (% dry matter) in diet as follows: 1% (Ca1), 3% (Ca3), 5% (Ca5), 7% (Ca7), and 9% (Ca9). Two-month-old juveniles with an average initial body weight of 2.13g, shell height of 21.71mm, and shell width of 16.35mm were reared in tarpaulin tanks (1 × 1 × 1m; 40cm water depth) at the density of 100 individuals per tank. After 4 months of the rearing period, the average body weight, shell height, and shell width of the snails reached the highest values in the Ca5 treatment (28.43 g, 54.97 mm, and 40.09mm, respectively) and these values were significantly different compared to the remaining calcium contents (Ca1, Ca3, Ca7, and Ca9). The survival rate of the snails in Ca3 (75.7%) was higher than in Ca1 and Ca7 (74.7%), Ca5 (73.7%), and Ca9 (71.7%). However, the survival rate was not significantly different among the treatments. Snails in Ca5 obtained the highest productivity (2.88 kg m-2) and this value was significantly different from Ca1 (2.55 kg m-2) and Ca9 (2.35 kg m-2). The results of this study showed that the growth rate and productivity of black apple snails were highest when they consumed a diet containing 5% calcium. The optimum requirement of calcium for the black apple snails in the grow-out period was 4.51%.

Minimally processed fruits and vegetables are economically important commodities due to convenience, and healthiness, etc. These commodities are susceptible and shelf life limited as cut surfaces of vegetable result in microbiological and physiological spoilage. To extend the shelf life of Asian spinach vegetables, different washing treatments (i.e. tap water, chlorine dioxide, and peracetic acid) and packaging materials (i.e. Polypropylene-PP, High Density Polyethylene-HDPE and Low Density Polyethylene-LDPE) were evaluated in the study. The results obtained show that washing treatment of the Asian spinach with peracetic acid solution of 100 ppm for five minutes was effective due to reduced significantly E. coli and Coliforms counts. The Asian spinach was packed in HDPE material might optimally prolong the shelf life up to 7 days at 10±1oC.