Intercropping short duration leafy vegetables with pumpkin in subtropical alluvial soils of Bangladesh

Intercropping may allow increasing both the productivity and diversity of crop through efficient utilization of land in densely populated countries like Bangladesh where fertility of agricultural land is declining gradually. A field experiment was conducted at a recently developed alluvial soil in Bangladesh during 2015–16 and 2016–17 winter seasons to select suitable leafy vegetables intercropping with pumpkin for higher productivity, better land and time utilization and maximum economic return. Six leafy vegetables viz., coriander green, red amaranth, radish green, mustard green, jute green, and spinach were intercropped with pumpkin and compared with sole pumpkin using a randomised complete block design. Intercropping leafy vegetables with pumpkin did not reduce pumpkin yield but increased system productivity by 39–120% over sole cropped pumpkin. All the intercropping combinations performed better than sole pumpkin. However, the highest system yield (72.7 & 75.6 t ha–1), land equivalent ratio (1.74 & 1.75), area time equivalent ratio (1.20 & 1.16), net return (8001 & 8350 USD ha–1) and benefit cost ratio (10.3 & 10.7) were obtained in 2015–16 & 2016–17, respectively from pumpkin + spinach system indicating that this system might be suitable for higher crop productivity, better land and time utilization as well as economic return for the selected area.

Evaluation of nutrient uptake of selected cover crops and biochar on the yield advantage of two taro (Colocasia esculenta) cultivars in Samoa

A study was conducted in three agro ecological zones of Samoa to compare the dry matter yields and nutrient uptake of selected tropical cover crops and biochar application on different Samoan inceptisols. Subsequent improvements in corm yield of the two taro cultivars, (Samoa 1 and Samoa 2), under these fallow systems were also determined. The split-plot arrangement with main plots as cover crops and subplots as the cultivars was used, with four replications. The evaluated cover crops included: a reference – grass fallow treatment (farmers practice), Mucuna pruriens, Erythrina subumbrans, Mucuna pruriens + 200 kg of NPK fertiliser (12-5-20), farmer’s reference practice + 400 kg of NPK fertiliser (12-5-20), and biochar produced from coconut shells. The biomass samples were collected after the six month of fallow duration. Plant tissue analyses revealed that the nitrogen and the phosphorus contents of erythrina was higher than corresponding mucuna cover across all three sites. However, as a result of higher biomass production, Mucuna pruriens showed the highest nutrient accrual over the six month fallow duration. The general yield trend under different fallow practices across all the sites indicates that mucuna with modest supplementation of complete fertilisers can help maintain optimum taro yields. However, it appears that the yield responses of the taro crop to fallow treatments are site-specific.

Sodium and potassium intake through juices and low alcohol beverages in Fiji

Sixty four different fruit juices, juice concentrates, soft drinks and beers, available in Fiji supermarkets were analysed for Na+ and K+ contents with a view to assess their potential for nutritional supplementation or exposure risk in daily life. Drinks fall in five broad categories of (a) fruit based drinks, (b) flavoured artificial drinks, (c) carbonated fizzy drinks, (d) sports drinks and (e) low alcohol drinks. The Na+, K+ contents in 100 mL of the drinks were found to be in fruit based drinks (Na+ 2–34 mg, K+ 84–246 mg), flavoured artificial drinks (Na+ + 0–59 mg), carbonated fizzy drinks (Na+ + 0–4 mg), sport drinks (Na+ 30–81 mg, K+ 0–40 mg) and beers (Na+ 1–14 mg, K+ 23–61 mg). All fruit based drinks contained significantly higher amount of potassiumas well as lower Na+/K+ ratio. Although Na+ overload is less likely to arise, except through sports drinks, fruit based drinks and beers could offer appreciable advantage in K+ supplementation. A shift towards popularization of fruit based drinks through policy decisions and taxation might have beneficial effect in controlling the growing epidemic of hypertension and CHD/CVD events in the long run in the country.

Comparative investigation of body mass index of tertiary students of the South Pacific origin

The body mass index (BMI) trends in the South Pacific Island Countries (PICs) have been analysed. Five South Pacific countries, namely; Fiji, Tonga, Nauru, Kiribati and Solomon Islands have been analysed based on the population that have stayed in Fiji at some point (mean age 25.20±5.27). Standard BMI threshold defined as underweight (2), normal weight (18.5–24.9 kg/m2) overweight (25–30 kg/m2) and obese (≥30 kg/m2) was used to study the BMI trends. The data collection was carried out by randomly selecting the subject of study and manually recording their heights (in meters) and weight (in kg). These measurements were done during the period of 2014–2015. The data showed that only Fiji had an average BMI with normal weight of 23.74±4.63 kg/m2 while other countries’ population were either overweight (Solomon Islands) or obese (Nauru) in the range of 25.29±4.37 kg/m2 to 37.24±12 kg/m2. Cohen’s d and eta square test were performed to see differences in height and weight where large differences were found primarily in the male population compared to female. The average BMI for gender within a country did not show variation (p>0.001) but variation was seen among the PICs (p

Distribution of long-horn beetles (Cerambycidae: Coleoptera) within the Fijian archipelago

Long-horn beetles (Family: Cerambycidae) in Fiji consist of 124 described species within 45 genera, of which 110 (88.7%) species are considered endemic. Despite their conservation value, ecological significance and cultural importance, little scientific research has been conducted on the taxonomy or ecology of Cerambycidae in Fiji. This biogeographical study surveyed Cerambycidae by Malaise trapping on ten Fijian Islands. A total of 438 individuals and 44 species of Cerambycidae were recorded. Thirty three of the species collected are endemic to Fiji; three other species are native and eight species are new records for Fiji and/or new species. Twenty seven species were recorded from only one island and 20 species were recorded only as singletons. There was an expected significant relationship between the number of species collected on an island and the number of sampling events. The highest number of species, 23, was recorded on the largest island, Viti Levu, followed by Gau with 13 species and Vanua Levu and Kadavu with 12 species each. There was a positive relationship between species richness and island size but this was lost if the effect of sample number was taken into account. The results indicate that the species-area relationship may hold for Fijian Cerambycidae, but additional collecting events, over more of the annual cycle, and involving multiple collecting methods may be required to fully catalogue the current Fijian fauna.

Organic amendments increased sweetpotato (Ipomoea batatas L.) yield in a calcareous sandy soil of Samoa

A five-month field experiment was conducted to investigate the effects of organic amendments on yields of two sweetpotato cultivars in a calcareous sandy soil of Samoa. The treatments consisted of three organic amendments; gliricidia, gliricidia + biochar, poultry litter, and a control, and two improved sweetpotato cultivars (IB/PH/03 and IB/PR/13). All amendments were applied at equivalent rate of 100 kg N ha–1 while biochar at 5 t ha–1. Plots were arranged in a RCB design with four replicates. Results showed that all organic amendments significantly increased total storage root and marketable storage root yields, compared to yields of the control. Total marketable root yield was increased by 134, 118, and 294% over control in response to gliricidia, poultry litter, and gliricidia + biochar treatments. The highest yield, yield attributing parameters and nutrient uptake by storage root were recorded in gliricidia + biochar treatment, which appears to synergistically influence crop yield relative to organic amendments applied singly; a potential amendment for improving sweetpotato productivity in sandy calcareous soil. Cultivar IB/PH/03 performed better than IB/PR/13 on all measured crop parameters except for fresh weight of non-marketable root and percent dry matter content showing better potentiality for promotion under similar agro-environmental conditions.

Antibacterial and antifungal activities of essential oils from medicinal plants found in the South Pacific

Natural products such as essential oils have been studied since ancient times to understand their biological properties. Essential oils are noted for their antimicrobial activity. Thus, the focus of this study was to evaluate the antimicrobial effect of five essential oils (EOs) from selected medicinal plants found in the South Pacific, on selected human pathogenic bacteria and fungi affecting agricultural industries. The disc diffusion method was carried out and the diameter of inhibition zones (mm) (DZI) using 0.25, 0.5, 5, 25, 50 and 100% (v/v) of essential oil concentrations were reported. The activity of Cananga odorata essential oils against Thermus thermophiles and Pseudomonas aeruginosa were among the selected bacteria that only showed the susceptibility at the lowest concentration (0.25% v/v). The diameter inhibition zones were 1.60 mm and 4.20 mm, respectively. The inhibitory effect of Ocimum tenuiflorum L essential oils at the highest concentration (100%) showed DZI ranging above 14 mm for all the selected bacteria and above 25 mm for the all selected fungi. The inhibitory effect of selected bacteria and fungi increased with stronger concentrations of essential oils. Hence, the essential oils from medicinal plants found in the South Pacific hold great potential for the antibacterial and antifungal properties.

Digital energy monitor: design, simulations and prototype

This paper demonstrates the design and implementation of a GSM based digital energy monitoring device. Firstly fuzzy based model is developed to replicate the characteristic of current and voltage sensors. The entire system is also studied and simulated in terms of utility side supply, load, microcontroller digitization and GSM communication. A virtual data sharing technic is also studied for the proposed system using state flow logic. A prototype system is verified real-time with its test and verification phase results. In this work, remote monitoring of electricity has been made easier for the utility. Demand side management is also presented as customers can instantly get their electricity consumptions when requested. Further, an effective overcurrent monitoring system has been embedded along with a backup battery source. Results obtained from the experiments prove that with this emerging technology it is possible to move towards a smarter grid at a rapid and cost effective way.