First Report on Post-harvest management of black mold of onion by eugenol

Black mold of onion caused by Aspergillus niger is a serious and prevalent postharvest disease of onion. This problem drastically reduces the quality and marketability of onion bulbs. Conventional fungicides employed to con-trol A. niger contamination posed negative impact on human health and en-vironment and highlighted the need to discover ecofriendly management practices. In the present study we attempted to explore the use of eugenol for the management of black mold of onion. Eugenol may exhibit differ-ences in antifungal activity in liquid state and in volatile phase. Hence, we developed and validated a new method, conical flask- paper cone method to study the antifungal activity of vapour phase disinfectants. This method was found to be precise, reproducible, sensitive and accurate with inter-assay R.S.D < 10%, intra-assay R.S.D <5% and R2>0.99. Conical flask- paper cone method was further utilized to determine the minimum inhibitory concen-tration of eugenol against A. niger. We observed that 0.03355 μl / cm3 eu-genol caused invitro and invivo inhibition of A. niger. Onion bulbs that were stored by eugenol fumigation, prior inoculated by A. niger, did not develop black mold symptoms and maintained high sensory acceptability. Microscop-ic observations revealed that eugenol fumigation resulted in inhibition of spore germination, coagulation of cytoplasm, formation of large vesicles and shrinkage of A. niger mycelium. In conclusion, our study showed for the first time that eugenol fumigation significantly controlled black mold incidence during storage and maintained post harvest quality and sensory acceptance. This study also introduced a new method for evaluating antifungal activity of volatile compounds.

Assessment of Nutritional Properties from Six Varieties of Onion (Allium cepa L., Alliaceae) Produced in Northern Côte d’Ivoire

Aims: Onion is a common vegetable engaging significant nutritional interests and widely consumed over the world. In Côte d'Ivoire, 95% of the onion consumption is filled by imports despite the availability of suitable areas for its local production. The current study aimed to investigate nutritional features of onion varieties for fitting the agronomical trends in order to strengthen the onion cultivation in northern Côte d’Ivoire. Study Design: Six onion varieties produced for bulbs, namely ARES, BATI, CARA, DAMANI, KARIBOU, and SAFARI. Onion bulbs sampled, oven-dried, and then processed to powders for analysis. The main study consisted in analyzing the biochemical properties of the resulted onions powders. Place and Duration of Study: Experimental farming from the plants experimenting location, and onion samples analyzed from Laboratory of Peleforo Gon Coulibaly University, Korhogo, Côte d’Ivoire, between March 2020 and April 2021. Methodology: Batches of 2 kg fresh bulbs collected per onion variety after harvest. Once at Lab, onion bulbs peeled, washed, cut into small dice-shaped pieces and dried into an oven at 80 °C for 24 h using stainless trays. Dried samples ground and kept for analyses regarding physicochemical traits (moisture, acidity, ash) and nutritive parameters (glucides, lipids, proteins, antioxidants). Results: The works showed higher contents in moisture (16.91%), ash (4.46%), and lipids (1.99%) from CARA variety with more significant acidity; while greatest amounts of total soluble carbohydrates (14.5%), tannins (1.02%), and proteins (13.6%) were recorded from BATI and more vitamin C in DAMANI (0.133%). However, SAFARI variety samples were more provided in reducing carbohydrates (1.04%) and total polyphenols (1.46%) as secondary metabolites; and the ARES variety revealed highest flavonoids contents (0.057%). In addition, ARES, CARA, and KARIBOU varieties displayed great dietary fibers amounts compared to BATI, KARIBOU, and SAFARI. Conclusion: The particular nutritional traits of the studied onion varieties could be confronted with their agronomical yield and consumption trends for supporting sustainable production of onion in Côte d’Ivoire.

Effects of Zinc, Manganese, and Sulphur on the Growth and Quality of Onion (Allium cepa L.) cv. Nasik Red

Optimistic and sustainable supply of nutrients to soil affects crop productivity and crop quality. In the present investigation, effects of Zinc (Zn), Sulphur (S), and Manganese (Mn) was observed on growth and quality attributes of onion (Allium cepa L. cv. NasikRed), belongs to family Alliaceae. For this, micronutrients were applied to soil in 8 combinations including 1 control (having no micronutrient). soil application of micronutrients ZnSO 4@ 10 kg/ha + CuSO 4 10 kg/ha + MnSO 4 @ 10 kg/ha in combination with 50 kg N, 40 kg P 2 O 5 and 40 kg K 2 O per hectare before transplanting the onion crop is the most beneficial treatment for obtaining higher vegetative growth and quality of onion bulbs resulted high net income and maximum benefit of per rupee invested. However, for low input technology soil application of ZnSO 4 @ 10kg/ha + recommended dose of NPK can also be followed.

Application of dry powders of six plant species, as soil amendments, for controlling Fusarium solani and Meloidogyne incognita on pea in pots

Background Application of organic amendments could improve soil properties as well as controlling of soil-borne pathogens. Soil amendments with dry powders of six plant species materials, i.e. caraway seeds, fennel seeds, garlic gloves, onion bulbs, pomegranate peel and spearmint leaves were separately applied for controlling Fusarium solani and Meloidogyne incognita on pea plants in pots. The control is untreated check pots for Fusarium solani and Meloidogyne incognita. Results The dry powder of pomegranate peel (as the rate of 10 g/1 kg soil)highly reduced the Fusarium- disease assessments (pre-emergence and post-emergence damping-off and root-rot diseases incidence), followed by spearmint leaves, caraway seeds, fennel seeds, garlic gloves and onion bulbs, respectively. The tested dry powder of plant species showed the nematicidal activity on M. incognita criteria, i.e. second juvenile (J2) in soil and roots as well as galls and egg-masses in roots of pea. The spearmint leaves, onion bulbs and fennel seeds highly reduced the J2 in soil and roots as well as galls and egg-masses. The pea plant growth parameters i.e. length of shoot, fresh & dry weights of shoot and fresh weight of roots, yield parameters, i.e. fresh and dry weight of pea pod and pod parameters as well as Rhizobium nodules number were increased in pea plants with reducing infestation with F. solani and M. incognita. Conclusions Soil amendments with dry powders of six plant species materials were used in this study reduced F. solani and M. incognita and improved pea plants

The Effect of Gaseous Ozone Generated by Surface Dielectric Barrier Discharge on the Decay and Quality of Stored Onion Bulbs

An effective and eco-friendly technology is needed to prevent postharvest loss of onion bulbs during cold storage. This study investigated the effect of gaseous ozone on the decay and quality of onion bulbs during storage at 2 °C and 70% relative humidity for two months. Gaseous ozone was adjusted to a concentration of 1.27 ± 0.024 ppm in the storage room by generating a high voltage discharge in air. After two months of storage, gaseous ozone significantly reduced the counts of aerobic bacteria (e.g., Rahnella aquatilis) and fungi (e.g., yeast and mold) in the onion bulbs by 4 log (CFU g−1) and 0.92 log (CFU g−1) compared with those of an untreated control, respectively. The microbial reduction by gaseous ozone resulted in a lower rotten rate of the onion bulbs, which was less than 20.0% compared with that of the untreated control. Moreover, the ozone exposure extended the storage life of the onion bulbs by delaying its color change and softening during storage. Our results suggest that gaseous ozone can control the decay of onion bulbs safely during storage.

UJI INVIVO EKSTRAK UMBI BAWANG HUTAN (Eleutherine americana Merr.) TERHADAP GAMBARAN MAKROSKOPIS ORGAN JANTUNG TIKUS PUTIH JANTAN GALUR WISTAR (Rattus norvegicus)

ABSTRACTForest onion bulbs (Eleutherine americana Merr.), Including the Iridaceae family, have been used for generations by the Dayak people as medicinal plants for various types of diseases such as breast and colon cancer, hypertension, diabetes mellitus, hypercholesterolemia and stroke. This study was conducted to evaluate the effect and side effects of extracts of forest onion bulbs to the macroscopic description of cardiac organ in rats. Thirty male white rats Wistar strain was used as research object, which is divided into three groups of dose that applied with the ethanol extract of Forest onion bulbs orally (5mg/ml, 10mg/ml, 15mg/ml) and one group as controls for comparison. The tests were carried out for 15 days, with observations made against the body weight of rats, macroscopic observation of cardiac organ and observation of cardiac organ weights. The results showed that the provision of forest onion bulbs extract did not cause significant changes based on the graph of observations made on the macroscopic image of the heart organ and the weight of the rats. Keywords : Forest onion bulbs (Eleutherine Americana Merr.), cardiac macroscopic, white rat (Rattus norvegicus) ABSTRAKUmbi bawang hutan (Eleutherine americana Merr.) termasuk familia Iridaceae, secara turun temurun telah dipergunakan oleh masyarakat dayak sebagai tumbuhan obat untuk berbagai jenis penyakit seperti kanker payudara dan kolon, hipertensi, diabetes mellitus, hiperkolesterol dan strok. Penelitian ini bertujuan untuk melihat pengaruh yang ditimbulkan dari konsumsi ekstrak Umbi bawang hutan terhadap gambaran makroskopis organ jantung pada tikus putih. Penelitian dilakukan menggunakan hewan percobaan tikus putih jantan galur wistar berjumlah 30 ekor, yang dibagi dalam empat kelompok dosis yang diberi ekstrak etanol umbi bawang hutan secara oral yaitu (5mg/ml, 10mg/ml, 15mg/ml) dan satu kelompok kontrol sebagai pembanding. Masa pengujian dilakukan selama 15 hari, dengan pengamatan yang dilakukan berupa pengamatan berat badan tikus, pengamatan makroskopis organ jantung dan pengamatan berat organ. Hasil penelitian menunjukkan bahwa pemberian ektrak umbi bawang hutan tidak menimbulkan perubahan yang signifikan berdasarkan grafik pengamatan yang dilakukan pada gambaran makroskopis organ jantung serta penimbangan berat badan tikus. Kata kunci : Umbi bawang hutan (Eleutherine americana Merr.), makroskopis jantung, tikus putih (Rattus norvegicus)

Increase of Onion Productivity by Regulation of Growing Technology Elements

This article describes the impact of growth regulators used as foliar dressing on the high-quality commercial production of Mars and Candy F1 hybrid onion bulbs grown in the Rostov Region. The highest yield of finished product per 1 thousand m2 of leaf area and 1 thousand units of photosynthetic potential (PSP) was observed when the Candy and Mars hybrids were treated with Novosil (3.9-4.1 t and 45.0-47.0 kg, respectively), which also produced the highest rates of net photosynthesis productivity: 8.5-8.7 g / m2 per day. The effect of the agent on growth processes was slightly more effective in the Candy hybrid. It was established that the use of Novosil and Immunocytophytes foliar dressing in growing technology makes it possible to obtain the Mars and Candy hybrids at the level of 49.0-50.1 t / ha, reduce the consumption of additional irrigation water per unit of production and improve the quality of commercial onion bulbs and their storage for a long winter period. The increase in storage resulting from the use of Novosil occurred due to the decrease in the natural loss and mass of the sprouted bulbs. Keywords: onion, hybrid, yield, stimulant fertilizer, storage, quality

Studies on engineering properties of multiplier onion

The knowledge of physical and mechanical properties of onion bulb is important for successful design of any planter. Multiplier onion is propagated through bulbs and bulbs are planted manually. Manual planting of onion bulb is highly labour intensive (80-100 man-days ha-1) due to the close plant geometry (plant to plant and row to row spacing is 10 × 15 cm) among the vegetable crops. Engineering properties of multiplier onion were determined in order to design and develop a tractor operated raised bed onion bulb planter. In multiplier onion each onion comprises of 4-5 bulbs. These bulbs were cleaned, separated into single bulbs and divided in to 9 categories manually based on their individual weight viz., <2g, 2-3 g, 3-4 g, 4-5 g, 5-6 g, 6-7 g, 7-8 g, 8-9 g, >9 g. The onion bulb had a moisture content of 80.62±0.87 %. It was observed that the properties varied for different sizes of onion grades and the grades had highly significant effect on most of the properties. The linear dimensions of onion bulbs viz., length, width, thickness for nine grades ranged from 21.21±2.60 to 32.31±3.30 mm, 13.54±1.77 to 30.95±2.91 mm and 10.91±1.40 to 22.63±2.15 mm. The geometric mean diameter, sphericity, shape index and projected area all ranged from 28.22±2.04 to 14.54±0.96 mm, 0.87±0.06 to 0.69±0.08, 1.78±0.32 to 1.22±0.14 and 5.50±0.51 to 1.55±0.30 cm2, respectively. The one hundred onion bulb weight, bulk density, true density were in the range of 1185±19.59 to 121.6±6.30 g, 793.20± 9.45 to 480.19±13.13 kg.m-3, 1086± 205.22 to 1013.6±348.85 kg.m-3, respectively. The angle of repose decreased with increase in size of onion bulbs. The interaction between sphericity, shape index and angle of repose indicated that as the size of the onion size increase angle of repose decreased.

Nutritional Values of Onion Bulbs with Some Essential Structural Parameters for Packaging Process

Onions belong to the Allium genus that has been frequently used for human diet and the traditional medication due to the bioactive compounds. The main nutritional values, vitamins, and amino acid compositions of onion bulbs (Yellow, Red, Green, Leek, and Baby onions) with some essential structural parameters for the packaging process were investigated. Physical and structural parameters with frictions were applied for the packaging process. The results reported that moisture content was the main component of onion bulbs (88.65%). Besides, they were rich in proteins (9.22–13.21 g/100 g infresh weight) (FW). Results reported that Red and Yellow varieties established the largest vitamin C and carotenoids contents (45.07 mg/100 g−1 FW) and (1.44 µg/mL FW), respectively. The major amino acid was arginine which was highly found in Green variety (17.02 mg/g FW) and a relatively high amount of glutamic and aspartic acids as (9.88–14.89 mg/g FW) and (4.93–10.55 mg/g FW), respectively. Yellow variety established the largest width, thickness, surface area, aspect ratio, and sphericity. The highest static and kinetic frictions were established on steel (0.14–0.52) and (0.75–0.96), respectively. This study presents the nutritional evidence of onion varieties for the human diet besides the horticultural processing for packaging quality improvement.