Results of the research of onion in the annual culture in the conditions of the Priobskaya zone of the Altai Territory

Relevance. In the Western Siberia conditions bulb onion is grown mainly from onion sets. With this method of cultivation, large costs are spent on growing and storing the onion sets. In this regard, the cultivation of it through the seeds is of particular importance. This problem has not been studied enough in Priobskaya zone of Altai Territory conditions.Materials and methods. In our research, we studied the influence of cultivation conditions on the formation of economically valuable traits of varieties and a hybrid of bulb onion grown by sowing seeds in the ground in Priobskaya zone of Altai Territory. Three varieties were taken as objects of research: Odnoletniy Sibirskiy, Zolotnichok, Odintsovets, and one Candy F1 hybrid.Results. On average, over the years of research on early maturity, the standard Odnoletniy Sibirskiy variety (87-88 days) showed itself to be the most early maturing. Candy F1 hybrid can be used as a source of early green mass. Leaf regrowth was the earliest of all onion samples studied. The largest leaf apparatus in the conditions of Priobskaya zone of Altai Territory is formed by the varieties Odintsovets (4.1 pieces per plant) and Odnoletniy Sibirskiy (3.8 pieces per plant). The maximum bulb mass was formed by the Candy F1 hybrid (51.5 g). The Candy F1 hybrid also was distinguished by the highest yield in the group of the studied samples. The increase in total yield was 5.1 t/ha, marketable 2.4 t/ha in relation to the standard. The maximum marketability in the experience was in the standard (80.9%).

Postharvest losses of bulb onion (Allium cepa L.) in selected sub-counties of Kenya

Inappropriate postharvest practices such as unsuitable harvesting methods and inadequate curing in bulb onion lead to losses. Postharvest losses in bulb onion contribute to food and nutrition insecurity. Although Kenya has suitable environmental conditions for bulb onion production, its productivity is low, which is attributed to pre-and postharvest factors. Information on bulb onion postharvest losses and their causes in the country is scanty which limits the development of postharvest losses reduction strategies. Therefore, this study was carried out in three major bulb onion growing sub-counties of Kenya namely Mt.Elgon, Buuriand KajiadoEastto determine postharvest practices, causes, and factors influencing postharvest losses of bulb onion. A multi-stage sampling design was used to select the study areas and a total of 166respondents were randomly selected. Face-to-face interviews were conducted using a structured questionnaire to collect information on postharvest handling practices, postharvest loss levels, and their causes at farm level. Data were subjected to descriptive and logistic regression analysis using Statistical Package for Social Scientists(SPSS) software version 2.0. Results indicated that 68% of the respondents were males and with an average age of40 years in the three sites. Forty-eight percent of the respondents used leaves toppling, and 25% used drying of upper leaves as maturity indices. About 42% of the respondents used machete (panga) as a harvesting tool which significantly (P<0.05) influenced postharvest losses. Seventy seven percent of the respondents indicated that up to 30% of postharvest losses occurred at farm level. Forty percent of the respondents indicated that bulb onion rots caused 10 % loss at farm level. The level of education and mode of transport (bicycles and donkeys) significantly (P<0.05) influenced postharvest losses. It was concluded that the postharvest losses at farm levelwas30%andwere mainly caused by rotting. Socio-economic characteristics and postharvest handling practices influenced bulb onion losses at farm level. Development of postharvest losses reduction strategies on bulb onions focusing on alleviating rotting through appropriate postharvest handling practices at farm level was recommended.

A Review of Solar Dehydration of Onion Slices in Developing Countries

The appropriate drying of crops is an essential step towards the minimization of post-harvest losses; further, the improvement of quality of products by drying, and hence an increase in the price, is of tremendous economic significance to the agricultural community. Among the several methods of long-term preservation of bulb onion (Allium cepa L.) dehydration is perhaps the simplest method that does not require sophisticated equipment or highly skilled workers. Traditional dehydration in the sun poses some problems, therefore, it is necessary to consider solar dehydration of onion. Different models of solar dryers had been developed and good quantum of research is progressing in most countries to propagate the solar drying technology for value addition of bulb onion. This review paper discusses reduction of post-harvest losses of bulb onion in developing countries using solar dehydration, special attention was given to Sudan.

Japanese Bulb Onion: Production, Consumption, and Cultivars

Bulb onion is an ancient vegetable crop that has been cultivated for at least 5,000 years. In Japan, this cultivation has only 150 years of history, but nowadays, it ranks fourth in total production, fourth in cropping acreage, and second in consumption among vegetables grown domestically. Until the 1970s, open-pollinated onion cultivars were predominantly cultivated throughout the country; they were selected mainly from old US cultivars. Over the past three decades, these open-pollinated cultivars have been replaced with F1 hybrid cultivars that offer higher yield, better disease resistance, uniformity at maturity, and high bulb quality. In this review, an attempt is made to characterize the commercial production and consumption of Japanese bulb onion as well as agronomic characteristics of representative cultivars.

Morphologic and cytoplasmic assessments of bulb onion (Allium cepa L.) landraces

Today climate change threatens to reduce crop yield and harming the food security. Local landraces have adaptation skills to shifting climatic conditions. Using of this local source in plant breeding programs becoming an alternative strategy. In this study, 97 landraces were collected to initiate the bulb onion breeding program eligible for the current trends. Collected materials were morphologically characterized using 21 descriptors, derived from UPOV (International Union for the Protection of New Varieties of Plants). Clustering which was conducted by the NTSYS (Numerical Taxonomy and Multivariate Analysis System) program using UPGMA (Unweighted Pair Group Method of Arithmetic Averages) method, showed that the genetic similarity rate of the landraces was calculated between 0.06-0.96. Hybrid onion breeding program depends on the cytoplasmic-genic male sterility (CMS) system. Thus, the PCR-markers were applied to identify the cytoplasm types of the landraces. Among landraces N-cytoplasm was found in 78 accessions and S-cytoplasm was found in 19 accessions. At the end of the study, a qualified gene pool has been established consisted of characterized onion genotypes which will might be used in further breeding studies.

Metabolome-Based Discrimination Analysis of Shallot Landraces and Bulb Onion Cultivars Associated with Differences in the Amino Acid and Flavonoid Profiles

Shallot landraces and varieties are considered an important genetic resource for Allium breeding due to their high contents of several functional metabolites. Aiming to provide new genetic materials for the development of a novel bulb onion cultivar derived from intraspecific hybrids with useful agronomic traits from shallots, the metabolic profiles in the bulbs of 8 Indonesian shallot landraces and 7 short-day and 3 long-day bulb onion cultivars were established using LC–Q-TOF-MS/MS. Principal component analysis, partial least squares discriminant analysis, and dendrogram clustering analysis showed two major groups; group I contained all shallot landraces and group II contained all bulb onion cultivars, indicating that shallots exhibited a distinct metabolic profile in comparison with bulb onions. Variable importance in the projection and Spearman’s rank correlation indicated that free and conjugated amino acids, flavonoids (especially metabolites having flavonol aglycone), and anthocyanins, as well as organic acids, were among the top metabolite variables that were highly associated with shallot landraces. The absolute quantification of 21 amino acids using conventional HPLC analysis showed high contents in shallots rather than in bulb onions. The present study indicated that shallots reprogrammed their metabolism toward a high accumulation of amino acids and flavonoids as an adaptive mechanism in extremely hot tropical environments.

Water use efficiency in four irrigation regimes in bulb onion production in the Alto Chicamocha Irrigation District

The bulb onion is one of the most important agricultural products in Colombia. The productive conditions of the Riego del Alto Chicamocha (Boyaca) district are a regional and national benchmark for this market. The objective of this research was to evaluate four irrigation regimes in terms of production and irrigation water efficiency in bulb onion crops. This trial was in the municipality of Nobsa, village of Dicho (Boyaca). A completely randomized design with four treatments was used: irrigation regime with 150% evapotranspiration (Evt); moisture-based irrigation regime, detected with soil moisture sensors; irrigation regime with 100% Evt; irrigation regime with 60% Evt, along with four repetitions. Starting three weeks after transplant and for 11 weeks (77 days), the polar diameter (cm), equatorial diameter (cm), root length (cm), leaf length (cm), SPAD units, stomatal conductance and irrigation water use efficiency were determined. The irrigation regime with 100% Evt had the best performance in terms of the polar and equatorial diameters and the root and leaf lengths, which were reflected in the fresh weight at harvest. The irrigation regime with soil moisture values obtained from remote sensors, with lower amounts of applied water, had better values for the transformation of water to fresh mass, with 13.64 kg mm-1.