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Yams are important items of diet throughout the Caribbean Region and, among them, the cultivars of the species, Dioscorea alata L. and D. esculenta (Lour.) Burkill are particularly important in the Eastern and Southern Caribbean, although the latter is so to a lesser extent. With a growing period of approximately nine months and a corresponding dormancy period, these cultivars are produced on an annual basis like clockwork, providing food yams for approximately three months of the year, the period of availability coinciding with the period of dormancy as the latter marks the natural period of storage of the tuber. Consequently, the breakage of dormancy marks the beginning of the end of natural storage as the emerging sprouts signal the onset of the next growing period. This coincides with the start of the rainy season and the yam is adapted to existing climatic conditions that provide the ideal environment for both plant establishment and tuber growth. Cultivars of the two species bear no reproductive seed and therefore, are completely dependent on vegetative means for perpetuation. Any adverse development during storage or early growth that prevents sprouting or tuber initiation and growth, results in the permanent loss of the affected material and potentially threatens loss of the specific cultivar. Hence, climate change events such as shifts in the onset of the rainy season, extension of the dry period and incidences of severe weather associated with excessive flooding that can result in death of roots and developing tubers, pose real risks to the persistence of the cultivars of D. alata and D. esculenta that are produced in the Caribbean Region. In order to counteract these effects, what is needed is the manipulation of the growth cycle to allow for year-round production so that the changes that have been observed with respect to climatic and weather patterns will not result in a loss of planting material and, by extension, loss of germplasm. It is well-established that the growth cycle is under hormonal control and that the key to year-round production is the breaking of the physiological lock on the growth cycle that is responsible for the seasonal production by which these species are characterized. There have been many attempts by researchers in the past to achieve this, but without success until relatively recently. Most attempts have explored the use of natural and synthetic plant growth regulators. Further, past attempts have focussed on the breakage of natural dormancy and induction of early sprouting, but instead, the success reported here, was achieved by delaying sprouting to beyond the period of natural dormancy in a novel approach that eliminates the use of growth regulators and other chemicals. This paper reports how reduced temperature storage has been used successfully to break the physiologically controlled growth cycle in cultivars of D. alata and D. esculenta, producing yams all year long by delaying the breakage of dormancy, ensuring not only an extension of the availability of yam tubers for food but also availability of viable planting material throughout the year. It was found that tubers can be stored successfully for an entire cycle, so that tubers from the previous year can meet tubers of the current year's harvest providing a buffer against crop loss from any adverse biotic or climatic event. The effects on sprouting patterns are described. The use of reduced temperature storage for this purpose has not been reported and this account serves to fill an important gap in documented yam dormancy research. [ABSTRACT FROM AUTHOR]

Artemisia princeps (Ganghwa wormwood) is a medicinal plant that produces two major flavonoids, eupatilin and jaceosidin, which are used in the treatment of gastritis and peptic ulcers. A. princeps is primarily field cultivated, which has some drawbacks, including only one cultivation period per year and variations in flavonoid production due to environmental changes. The objective of this study was to analyze the effects of seasonal light variation and artificial light treatments on the growth and flavonoid production of A. princeps grown in greenhouses for year-round production. The plants were cultivated and harvested nine times in one year under natural seasonal light conditions in greenhouses. During the winter growth period (when natural light is substantially lower), four artificial light treatments were applied during two cultivation periods, from September 2016 to January 2017: supplemental light, night interruption, low light, and low light with night interruption. The plants grown under the natural light condition in greenhouses were used as a control. After harvest, the growth of the plants was measured, and the contents of eupatilin and jaceosidin were determined. The plants had the highest biomass when the accumulated radiation and duration were highest. The growth and flavonoid production were significantly associated with accumulated radiation and light duration. The supplemental light and night interruption treatments resulted in significantly higher biomass and flavonoid production, with the night interruption treatment requiring less energy input than the supplemental light treatment. Therefore, for consistent biomass and flavonoid production of A. princeps, a night interruption treatment is suggested in greenhouse cultivation during low irradiation and short days (less than 13 h). [ABSTRACT FROM AUTHOR]

The impact of the ongoing COVID-19 pandemic has caused disastrous food shortages and increased food prices due to the disruption of agricultural systems and activities. Less consumption of nutrient-rich foods made the people more susceptible to COVID-19 infection during the pandemic. The situation resulted in a pivot to develop technology for economic and year-round production of nutrient-rich vegetables to alleviate malnutrition and to improve the immunity of the human body. Hydroponic farming (growing plants without soil) is a resilient food production system which provides perfect conditions for better and faster growth. This study involved the estimation of the total cost of establishing a polyhouse; setting up nutrient film technique (NFT) hydroponic system, the production costs of selected five vegetables, namely, tomato, broccoli, capsicum, lettuce and cabbage; the determination of their annual production and gross income based on prevailing market prices; and the net profits from hydroponic farming techniques. An amount of BDT 18.75 million (USD 0.22 million) could be earned by growing the selected five vegetables in a polyhouse of 100 m × 75 m size following the NFT technique of hydroponic farming. By investing BDT 31.56 million with a concurrent annual addition of BDT 0.59 million from the 2nd year, an amount of BDT 1.17 million net profit per year can be achieved. If the farmer pays a loan of BDT 0.60 million per year, a profit of BDT 0.56 million can still be earned every year and all the debts can be paid within eight years.

There is increasing demand for essential fatty acids (EFAs) from non-fish sources such as microalgae, which are considered a renewable and sustainable biomass. The open raceway system (ORS) is an affordable system for microalgae biomass cultivation for industrial applications. However, seasonal variations in weather can affect biomass productivity and the quality of microalgal biomass. The aim of this study was to determine the feasibility of year-round Tetraselmis sp. cultivation in a semi-ORS in Korea for biomass and bioactive lipid production. To maximize biomass productivity of Tetraselmis sp., f medium was selected because it resulted in a significantly higher biomass productivity (1.64 ± 0.03 g/L) and lower omega-6/omega-3 ratio (0.52/1) under laboratory conditions than f/2 medium (0.70/1). Then, we used climatic data-based building information modeling technology to construct a pilot plant of six semi-ORSs for controlling culture conditions, each with a culture volume of 40,000 L. Over 1 year, there were no significant variations in monthly biomass productivity, fatty acid composition, or the omega-6/omega-3 ratio; however, the lipid content correlated significantly with photosynthetic photon flux density. During year-round cultivation from November 2014 to October 2017, areal productivity was gradually increased by increasing medium salinity and injecting CO2 gas into the culture medium. Productivity peaked at 44.01 g/m2/d in October 2017. Throughout the trials, there were no significant differences in average lipid content, which was 14.88 ± 1.26%, 14.73 ± 2.44%, 12.81 ± 2.82%, and 13.63 ± 3.42% in 2014, 2015, 2016, and 2017, respectively. Our results demonstrated that high biomass productivity and constant lipid content can be sustainably maintained under Korean climate conditions.

Yams are important items of diet throughout the Caribbean Region and, among them, the cultivars of the species, Dioscorea alata L. and D. esculenta are particularly important in the Eastern and Southern Caribbean, although the latter is so to a lesser extent. With a growing period of approximately nine months and a corresponding dormancy period, these cultivars are produced on an annual basis like clockwork, providing food yams for approximately three months of the year, the period of availability coinciding with the period of dormancy as the latter marks the natural period of storage of the tuber. Consequently, the breakage of dormancy marks the beginning of the end of natural storage as the emerging sprouts signal the onset of the next growing period. This coincides with the start of the rainy season and the yam is adapted to existing climatic conditions that provide the ideal environment for both plant establishment and tuber growth. Cultivars of the two species bear no reproductive seed and therefore, are completely dependent on vegetative means for perpetuation. Any adverse development during storage or early growth that prevents sprouting or tuber initiation and growth, results in the permanent loss of the affected material and potentially threatens loss of the specific cultivar. Hence, climate change events such as shifts in the onset of the rainy season, extension of the dry period and incidences of severe weather associated with excessive flooding that can result in death of roots and developing tubers, pose real risks to the persistence of the cultivars of D. alata and D. esculenta that are produced in the Caribbean Region. In order to counteract these effects, what is needed is the manipulation of the growth cycle to allow for year-round production so that the changes that have been observed with respect to climatic and weather patterns will not result in a loss of planting material and, by extension, loss of germplasm. It is well-established that the growth cycle is under hormonal control and that the key to year-round production is the breaking of the physiological lock on the growth cycle that is responsible for the seasonal production by which these species are characterized. There have been many attempts by researchers in the past to achieve this, but without success until relatively recently. Most attempts have explored the use of natural and synthetic plant growth regulators. Further, past attempts have focussed on the breakage of natural dormancy and induction of early sprouting, but instead, the success reported here, was achieved by delaying sprouting to beyond the period of natural dormancy in a novel approach that eliminates the use of growth regulators and other chemicals. This paper reports how reduced temperature storage has been used successfully to break the physiologically controlled growth cycle in cultivars of D. alata and D. esculenta, producing yams all year long by delaying the breakage of dormancy, ensuring not only an extension of the availability of yam tubers for food but also availability of viable planting material throughout the year. It was found that tubers can be stored successfully for an entire cycle, so that tubers from the previous year can meet tubers of the current year's harvest providing a buffer against crop loss from any adverse biotic or climatic event. The effects on sprouting patterns are described. The use of reduced temperature storage for this purpose has not been reported and this account serves to fill an important gap in documented yam dormancy research. [ABSTRACT FROM AUTHOR]

Supplemental light (SL) is a technique used to increase horticulture yield, especially in northern countries, where the Daily Light Integral (DLI) is a limiting factor during fall and winter, and which could also be used to obtain higher tomato yield at the Mediterranean latitude. In this study, three tomato hybrid (F1) cultivars were grown for year-round production in a commercial semi-closed glasshouse in Southern Italy: two of the cherry fruit-type (‘Juanita’ and ‘Sorentyno’) and one mini plum fruit-type (‘Solarino’). From 120 to 243 days after transplant, light-emitting diode (LED) toplights were used as SL, with a photoperiod of 18 h. The main climatic parameters inside and outside the glasshouse were recorded, and tomato plants’ development and yield were examined. Plants grown with LEDs had longer stems as compared to control treatment (9.53 vs. 8.79 m), a higher stem thickness and yielded more trusses. On average, the yield was 21.7% higher with LEDs. ‘Sorentyno’ was the cultivar with the highest cumulated productivity when it was grown under SL. However, the cultivar with best light use efficiency under LEDs was ‘Solarino’. Therefore, supplemental LED from mid-December until March enhanced tomato growth and yield, opening a favorable scenario for large-scale application of this technology also in the Mediterranean area.

Algae were recently considered as a promising third-generation biofuel feedstock due to their superior productivity, high oil content, and environmentally friendly nature. However, the sustainable production became the major constraint facing commercial development of algal biofuels. For this study, firstly, a factorial experimental design was used to analyze the effects of the process parameters including temperatures of 8-25 °C, light intensity of 150-900 µmol·m-2s-1, and light duration of 6-24 h on the biomass yields of local alga Chlamydomonas debaryana in swine wastewater. The results were fitted with a quadratic equation (R² = 0.9706). The factors of temperature, light duration, the interaction of light intensity-light duration, and the quadratic effect of temperature were statistically significant. When evaluating different scenarios for the sustainable production of algal biomass and biofuels in North Carolina, US, it showed that: (a) Growing C. debaryana in a 10-acre pond on swine wastewater under local weather conditions would yield algal biomass of 113 tonnes/year; (b) If all swine wastewater generated in North Carolina was treated with algae, it will require 137-485 acres of ponds, yielding biomass of 5048-10,468 tonnes/year and algal oil of 1010-2094 tonnes/year. Annually, hundreds of tonnes of nitrogen and phosphorus could be removed from swine wastewater. The required area is mainly dependent on the growth rate of algal species. [ABSTRACT FROM AUTHOR]

The damage of thrips (Thripidae: Thysanoptera) on mangosteen production were studied in local orchards in Nakhon Si Thammarat from September 2008 to July 2010. It was found that the damage was related directly to thrip population and the cycles of mangosteen growth such as the young leaves, flowering and young fruit stages. For the first and second year-rounds, off-season production, thrip abundance in October was averaged at 0.57 and 0.26 thrips/shoot in September. For the in-season production in April; the amount of thrips was averaged at 0.12 with 0.15 thrips/shoot, respectively. The lowest amount of thrips was noticed in the harvesting season of the two-year-round production. The damage at the flowering and young fruits stages due to rough scarring on the fruit surfaces and calyxes at the harvesting period were caused by thrips. The average rough scars on the fruit surface in the first- and second year- round, off-season production were 22.03 and 28.87 %; in-season production were 23.12 and 21.60 %, respectively. However, the rough scars on fruit calyxes at the harvesting period were found to be 100 %. The fruit gamboges in the first- and second year- round, off-season production were averaged at 45.40 and 23.92 %; and in-season production at 46.44 and 13.19 %, respectively. Over 20 % of rough scars appearing on fruit surfaces of the total mangosteen production lowered the quality for export. Good management in the local orchards is essential for increasing the marketing quality of mangosteen production.

The damage of thrips (Thripidae: Thysanoptera) on mangosteen production were studied in local orchards in Nakhon Si Thammarat from September 2008 to July 2010. It was found that the damage was related directly to thrip population and the cycles of mangosteen growth such as the young leaves, flowering and young fruit stages. For the first and second year-rounds, off-season production, thrip abundance in October was averaged at 0.57 and 0.26 thrips/shoot in September. For the in-season production in April; the amount of thrips was averaged at 0.12 with 0.15 thrips/shoot, respectively. The lowest amount of thrips was noticed in the harvesting season of the two-year-round production. The damage at the flowering and young fruits stages due to rough scarring on the fruit surfaces and calyxes at the harvesting period were caused by thrips. The average rough scars on the fruit surface in the first- and second year- round, off-season production were 22.03 and 28.87 %; in-season production were 23.12 and 21.60 %, respectively. However, the rough scars on fruit calyxes at the harvesting period were found to be 100 %. The fruit gamboges in the first- and second year- round, off-season production were averaged at 45.40 and 23.92 %; and in-season production at 46.44 and 13.19 %, respectively. Over 20 % of rough scars appearing on fruit surfaces of the total mangosteen production lowered the quality for export. Good management in the local orchards is essential for increasing the marketing quality of mangosteen production. [ABSTRACT FROM AUTHOR]

This review describes the effects of the current and emerging lighting technologies on plants, and the plant-mediated effects on herbivorous and beneficial arthropods in high-technology year-round greenhouse production, where light quality, quantity and photoperiod differ from the natural environment. The spectrum provided by the current lighting technology, high-pressure sodium lamp (HPSL), differs considerably from that of solar radiation. The major plant-mediated effects on arthropods were predicted to result from (a) extended photoperiods and lower light integrals, (b) the attenuation of ultraviolet (UV) wavelengths, particularly UV-B, (c) the high red: far-red (R : FR) ratio and lower blue : red (B : R) in comparison with solar radiation and (d) the high proportion of yellow wavelengths during winter months. Of these light factors (a-d) ( ceteris paribus), (a) and (b) were hypothesised to result in increased performance of herbivores in winter months, whereas the high R : FR ratio decreased herbivore performance or not affected it, at least when interlights are used. The predictions obtained on the basis of this review are also discussed in relation to the modifying factors prevailing in these production environments: enriched CO2 levels, high nutrient amounts, optimised irrigation and temperatures optimal for plants' needs. Based on the carbon/nitrogen and growth/differentiation balance theories, these modifying factors tend to produce plants that allocate most resources to growth at the expense of defensive secondary metabolism and physicochemical defensive structures. At the end, this review discusses knowledge gaps and future research prospects, in which light-emitting diodes, the emerging lighting technology, play an important role by enabling the targeted manipulation of plant responses to different wavelengths. [ABSTRACT FROM AUTHOR]

Young rose plants cv. Mercedes were grown either year-round or by interrupting the growing period in winter with a rest period of 2 or 6 weeks at 2°C. In fast start of forcing the temperature was immediately raised to 20°C for 2 weeks, whereas in slow start of forcing the temperature was kept at 8°C during the first week, at 13°C during the second and thereafter at 20°C. The growing temperature was 17°C and the photosynthetic photon flux (PPF) was either 100 or 65 μmol m[sup -2] s[sup -1] 20 h day[sup -1]. The lower PPF was tested only in fast forcing. Production with a rest period did not reduce the yield compared with year-round production. An interaction between rest period length and forcing rate on yield and quality was observed. Fast forcing at 100 μmol m[sup -2] s[sup -1] PPF resulted in a higher yield than did slow forcing at 100 μmol m[sup -2] s[sup -1] and fast forcing at 65 μmol m[sup -2] s[sup -1] PPF after a 6-week rest period. Plants with 2 weeks' rest, however, gave a higher yield with slow than with fast forcing at both PPF. Irradiance of 65 μmol m[sup -2] s[sup -1] PPF combined with a 6-week rest and slow forcing impaired flower quality. Vase life, when expressed as mean values, did not differ between treatments, but the proportion of cut flowers with a short vase life was higher after 6 than after 2 weeks' storage. [ABSTRACT FROM AUTHOR]

There is increasing demand for essential fatty acids (EFAs) from non-fish sources such as microalgae, which are considered a renewable and sustainable biomass. The open raceway system (ORS) is an affordable system for microalgae biomass cultivation for industrial applications. However, seasonal variations in weather can affect biomass productivity and the quality of microalgal biomass. The aim of this study was to determine the feasibility of year-round Tetraselmis sp. cultivation in a semi-ORS in Korea for biomass and bioactive lipid production. To maximize biomass productivity of Tetraselmis sp., f medium was selected because it resulted in a significantly higher biomass productivity (1.64 ± 0.03 g/L) and lower omega-6/omega-3 ratio (0.52/1) under laboratory conditions than f/2 medium (0.70/1). Then, we used climatic data-based building information modeling technology to construct a pilot plant of six semi-ORSs for controlling culture conditions, each with a culture volume of 40,000 L. Over 1 year, there were no significant variations in monthly biomass productivity, fatty acid composition, or the omega-6/omega-3 ratio; however, the lipid content correlated significantly with photosynthetic photon flux density. During year-round cultivation from November 2014 to October 2017, areal productivity was gradually increased by increasing medium salinity and injecting CO2 gas into the culture medium. Productivity peaked at 44.01 g/m2/d in October 2017. Throughout the trials, there were no significant differences in average lipid content, which was 14.88 ± 1.26%, 14.73 ± 2.44%, 12.81 ± 2.82%, and 13.63 ± 3.42% in 2014, 2015, 2016, and 2017, respectively. Our results demonstrated that high biomass productivity and constant lipid content can be sustainably maintained under Korean climate conditions. [ABSTRACT FROM AUTHOR]

Supplemental light (SL) is a technique used to increase horticulture yield, especially in northern countries, where the Daily Light Integral (DLI) is a limiting factor during fall and winter, and which could also be used to obtain higher tomato yield at the Mediterranean latitude. In this study, three tomato hybrid (F1) cultivars were grown for year-round production in a commercial semi-closed glasshouse in Southern Italy: two of the cherry fruit-type ('Juanita' and 'Sorentyno') and one mini plum fruit-type ('Solarino'). From 120 to 243 days after transplant, light-emitting diode (LED) toplights were used as SL, with a photoperiod of 18 h. The main climatic parameters inside and outside the glasshouse were recorded, and tomato plants' development and yield were examined. Plants grown with LEDs had longer stems as compared to control treatment (9.53 vs. 8.79 m), a higher stem thickness and yielded more trusses. On average, the yield was 21.7% higher with LEDs. 'Sorentyno' was the cultivar with the highest cumulated productivity when it was grown under SL. However, the cultivar with best light use efficiency under LEDs was 'Solarino'. Therefore, supplemental LED from mid-December until March enhanced tomato growth and yield, opening a favorable scenario for large-scale application of this technology also in the Mediterranean area. [ABSTRACT FROM AUTHOR]