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Tuberose (Polianthes tuberosa L.) is an ornamental and medicinal plant, cultivated in tropical and subtropical regions for its fragrant cut flowers and perfume industries, P. tuberosa flowers are the source of the highest-quality tuberose oil that remains today the most expensive raw material in perfumery. Furthermore, bulb size influences the flowering of P. tuberosa L. and creates a problem for tuberose flower production. Aims in this study were climatic condition and bulbs size variation, which were investigated to enhance the bulb size and climatic condition for improving tuberose production in Algeria. A culture of P. tuberosa L. bulbs was conducted in the field and under shelter using different bulb diameters, growing and flowering parameters were recorded for each plant, from planting to maturity. According to the obtained results, a good growth of tuberose was noticed with the big bulbs (diameter≥2 cm), i.e., bulb germination, leaf emergence, and the number of leaves by dominance for the bulbs cultivated under shelter, compared to those grown in the field. Regarding flowering, it was influenced mainly by bulb size, where only big bulbs gave flowers, and flowering characteristics were improved by the under shelter culture neither in the field. In general and according to the present work, for a good growth and for a better production of P. tuberosa flowers, bulbs culture under shelter using bulbs of 2-4 cm in diameter were recommended. [ABSTRACT FROM AUTHOR]

Lilium longiflorum is a wild Lilium, and its flowering transition requires a long period of cold exposure to meet the demand of vernalization. The responses of different sized bulbs to cold exposure and photoperiod are different, and the floral transition pathways of small and large bulbs are different. In this study, small and large bulbs were placed in cold storage for different weeks and then cultured at a constant ambient temperature of 25 °C under long day (LD) and short day (SD) conditions. Then, the flowering characteristics and expression patterns of key genes related to the vernalization and photoperiod pathways in different groups were calculated and analyzed. The results showed that the floral transition of Lilium longiflorum was influenced by both vernalization and photoperiod, that vernalization and LD conditions can significantly improve the flowering rate of Lilium longiflorum, and that the time from planting to visible flowering buds' appearance was decreased. The flowering time and rate of large bulbs were greatly influenced by cold exposure, and the vernalization pathway acted more actively at the floral transition stage. The floral transition of small bulbs was affected more by the photoperiod pathway. Moreover, it was speculated that cold exposure may promote greater sensitivity of the small bulbs to LD conditions. In addition, the expression of LlVRN1, LlFKF1, LlGI, LlCO5, LlCO7, LlCO16, LlFT1, LlFT3 and LlSOC1 was high during the process of floral transition, and LlCO13, LlCO14 and LlCO15 were highly expressed in the vegetative stage. The expression of LlCO13 and LlCO14 was different under different lighting conditions, and the flowering induction function of LlCO9 and LlFT3 was related to vernalization. Moreover, LlFKF1, LlGI, LlCO5, LlCO16, LlSOC1 and LlFT2 were involved in the entire growth process of plants, while LlCO6, LlCO16 and LlFT1 are involved in the differentiation and formation of small bulblets of plants after the inflorescence stage, and this process is also closely related to LD conditions. This study has great significance for understanding the molecular mechanisms of the vernalization and photoperiod flowering pathways of Lilium longiflorum. [ABSTRACT FROM AUTHOR]

The effect of bulb size on storage behavior of onions was investigated in an experiment carried out in Korça region. This study was focused on evaluation of certain bulb characteristics during storage under natural ventilation conditions. The autochthonous cultivar of Miras was involved in the study and three bulb sizes were observed: small, medium and large, with diameters ≤ 3cm, 3-5cm and ≥5cm respectively. The sealed and dries bulbs were placed for storage in the building with natural ventilation. During the storage period, the weight loss, the damaged bulbs and the percentage of sprouted bulbs were estimated. The first two indicators were evaluated for the periods 30, 60, 90 and 120 days of the storage, while the last indicator after 60, 90 and 120 days. The results showed that during storage period, humidity gradually decreases. There were differences of bulb moisture content at different time periods after harvesting depending on their size and storage periods. After 120 days of storage, weight loss of large bulbs was about 23.827%, about 23.604% and 20.263% for small and medium bulbs size respectively. Results indicated that these losses are slightly affected by the size of the bulbs, while the storage period had the greatest impact, whereby the losses increase with the extension of the storage period. The findings raise the need of storage conditions improvement to reduce onions post harvest losses. [ABSTRACT FROM AUTHOR]

The aim of this study, conducted in the years 2010-2012, was to evaluate bolting and seed production of shallot depending on storage temperature of steckling bulbs with different diameters. The present study included 4 cultivars ('Toto', 'Ambition F1', 'Bonilla F1', and 'Matador F1') and one local population ('U'). Bulbs with the following diameters: 20-30 mm, 31-40 mm, 41-50 mm, and 51-60 mm, were stored from the first 10-day period of November (2010 and 2011) until the end of March (2011 and 2012) at a temperature of 0-1 °C, 4-6 °C, and 8-10 °C. After they were planted in the field (the second 10-day period of April), observations of bolting were carried out, while the weight of seed umbels and seed yield were determined only for the cultivar 'Toto' and the population 'U'. The storage temperature of steckling bulbs in the range of 4-6 °C and 8-10 °C was most conducive to bolting, in particular in plants grown from large bulbs with a diameter above 40 mm. In the cultivar 'Toto', plants from bulbs with a diameter above 40 mm and stored at a temperature of 4-6 °C were characterized by the highest weight of seed umbels. This had an effect on obtaining the highest seed yield (on average 1604.16-2300.7 g per 100 m² of area). Shallot plants from the population 'U' grown from bulbs with a diameter of 20-30 mm were characterized by a distinctly lower percentage of bolting plants compared to the cultivars studied. For this reason, this population does not promise positive effects in shallot production for seed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two onion hybrids have differed significantly in their agronomic and spectroradiometric response. [•] The more productive hybrid Cometa presented no significant correlations between yield and VIs. [•] In the late growth stage, onion biomass and yield were highly correlated to nine VIs in Red Mech. [ABSTRACT FROM AUTHOR]

Agricultural communities in the semiarid regions of the world are constantly being affected by water scarcity, increased regulations restricting water use, strong competition for irrigation water with the urban sector, and severe drought periods. Conversely, the consumer demand for high-quality and nutritious foods is increasing rapidly. A 2-year field study evaluated growth, yield, and bulb quality in response to precision planting density and deficit irrigation of onion (Allium cepa L.) in southwest Texas. Seeds of short-day sweet onion cv. Texas Grano 1015Y were planted in the field on II Nov. 2007 and 30 Oct. 2008 at two planting densities (PDs), 397,000 (standard) and 484,000 (high) seeds/ha. Three irrigation rates using growth stage-specific crop coefficients and subsurface drip were imposed after plants were fully established, 100%, 75%, and 50% crop evapotranspiration rates (ETc). Total rainfall plus irrigation received for each irrigation rate were 594, 501, and 413 mm in 2008 and 662, 574, and 486 mm in 2009. In both seasons, there were consistent trends in growth, yield, and quality parameters. Leaf fresh weight was unaffected by PD but was reduced by deficit irrigation at 50% ETc. Although increasing planting density reduced the average bulb size by 12%, it increased the number of marketable bulbs by 21% to 33% and marketable yield by 7% to 14%. In contrast, deficit irrigation showed a trend to reduce both the number of bulbs and bulb size with yield reductions of 8% to 13% at 75% ETc and 19% to 27% at 50% ETc. Neither planting density nor deficit irrigation rate had a significant effect on soluble solids content, pungency, or quercetin contents. These results suggest that growers of short-day onions in semiarid regions could adjust PDs to target high-value bulb sizes. Implementing water-conserving practices (deficit irrigation at 75% ETc rate) would result in a decrease of high-value bulb grades and modest losses in yield but not flavor or nutritional components. [ABSTRACT FROM AUTHOR]

The experiment was conducted at horticulture farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh to study the influence of bulb size and different levels of GA3 on bulb and bulblets production of tuberose during the period of April 2006 to January 2007. The two factors experiment was laid out with Randomized Complete Block Design (RCBD) with 3 replications. Factor A: Three sizes of bulb, i.e. small (1-1.5 cm), medium (>1.5-2.0 cm) and large (>2.0-2.5 cm) and Factor B: Six levels of GA3 (0, 100,150, 200, 250 and 300 ppm). In case of bulb size, maximum weight of individual bulb (45.48 g), maximum number of bulblets plant-1 (14), and maximum yield of bulb (9.10 t ha-1) and bulblets (11.44 t ha-1) was recorded in large size bulb as compared to other sizes of bulb. The highest yield of bulb (8.76 t ha-1) and bulblets (12.14 t ha-1) was found in 300 ppm concentration GA3. [ABSTRACT FROM AUTHOR]

Different doses of paclobutrazol (PBZ) and different bulb sizes of onion were evaluated to determine their effect on growth and seed production of onion. Onion variety 'Taherpuri' with three-bulb sizes - small, medium and large - was used. Four doses of PBZ were 0 (control), 20, 40, and 80 mg l-1. The two-factor experiment was laid out in a randomized complete block design with three replications. Application of PBZ significantly reduced the plant height, tillers per bulb, leaves per plant and length of scape. However, in other parameters such as the number of flowers, umbels per bulb, umbel diameter, 1000-seed weight and seed yield, there were no significant influences of PBZ concentrations used (p < 0.05). On the contrary, plant height, number of leaves per plant, length of scape, effective fruits per umbel, percentage of fruit set, and seed yield were positively influenced by different bulb sizes of onion. Higher values were obtained for the above-mentioned parameters from the larger-sized bulbs and values were decreased as the bulb sizes decreased. The maximum seed yield was recorded in plants grown from the large-sized mother bulb. The interaction between the PBZ doses and bulb sizes were also significant for some variables while it was not significant for others. [ABSTRACT FROM AUTHOR]