Environmental Control in Biology 

About: Environmental Control in Biology is an academic journal. The journal publishes majorly in the area(s): Plant factory & Transpiration. It has an ISSN identifier of 1883-0986. Over the lifetime, 393 publications have been published receiving 2763 citations.

Effect of Light Quality on Growth and Vegetable Quality in Leaf Lettuce, Spinach and Komatsuna

Abstract: The effects of light quality on biomass and internal quality of leaf lettuce, spinach and komatsuna were examined. The plants were grown hydroponically in an environmentally controlled room with a 12-h light period and under a light/dark temperature of 20±1°C/18±1°C and a photosynthetic photon flux density (PPFD) of 300 μmol m-2 s-1 under four light quality treatments, i.e., red light from red fluorescent lamps (R) or blue light from blue fluorescent lamps (B) or a mixture of R and B (RB) or white light from white fluorescent lamps (W). The irradiation of R compared with W increased shoot dry weight in komatsuna and decreased the nitrate content in spinach. Irradiation of B or RB compared with W increased the L-ascorbic acid content in leaf lettuce and komatsuna and decreased the nitrate content in leaf lettuce. Irradiation of B was not suitable for the spinach cultivation due to an extremely decreased shoot dry weight although the carotenoid content was slightly increased. Our data show that controlling light quality is useful to achieve higher productivity or higher nutritional quality of the commercial crops even under limited light intensity in controlled-environment agricultural facilities although the effective light quality treatment differs depending on the plant species.

Bruise Detection using NIR Hyperspectral Imaging for Strawberry (Fragaria * ananassa Duch.)

Abstract: Bruising in fruits and its detection is a great concern for food safety to the consumers, and for incurrence of economic losses to industry. This research was aimed at developing techniques for detection of compression bruises in ‘Akihime’ variety strawberries (Fragaria × ananassa Duch.) using near infrared (NIR) hyperspectral imaging. Using 120 fruit samples at 70-80% ripe and full-ripe levels of maturity that had received six levels of bruising force (0 N, 0.5 N, 1.0 N, 1.5 N, 2.0 N and 3.0 N), spectral images were taken from 650 to 1, 000 nm at 5 nm wavelength intervals and from 0 to 4 days after bruising. Using stepwise linear discriminant analysis, optimal wavelengths of 825 nm and 980 nm were identified. The three judgment methods (linear discriminant analysis, normalized difference and artificial neural network) had performed equally well, while the normalized difference method was found to be more useful. Additionally, the extent of bruising damage detected in strawberries by the judgment method had markedly decreased with time, which elucidated temporal changes in bruising pattern while in storage.

Supplementary Ultraviolet Radiation B Together with Blue Light at Night Increased Quercetin Content and Flavonol Synthase Gene Expression in Leaf Lettuce (Lactuca sativa L.)

Abstract: Establishment of an effective supplementary lighting procedure is necessary to increase the value of leaf lettuce grown using a hydroponic method involving a low production cost. In leaf lettuce extracts, quercetin, one of the flavonoids, was isolated and identified. It was investigated that quercetin has important functions that can be used as a dietary supplement. Flavonol synthase (FLS) is a key enzyme involved in quercetin biosynthesis, catalyzes the conversion of dihydroquercetin to quercetin. Therefore, we determined the sequence of the flavonol synthase gene (FLS) in red leaf lettuce. We harvested leaf lettuce grown using supplementary light sources, such as ultraviolet radiation B (UV-B), ultraviolet radiation A, blue, and red lamps during the night. It is noteworthy that FLS expression and the quercetin content were particularly increased to a greater extent in young leaves than in mature leaves when UV-B and blue light were used simultaneously at night. We suggest that UV-B with blue light is used simultaneously at night for producing leaf lettuce with high quercetin content.

Effect of Supplemental Lighting from Different Light Sources on Growth and Yield of Strawberry

Abstract: Commercial strawberry production in Japan is seriously plagued by many problems, including lack of farm operation successors, sluggish commodity prices, and rising crude oil expenses. As a consequence, production areas and levels are continuously declining. For a solution of these problems, the spread of large-scale industrial facilities and the development of consistently high-yield strawberry production technique for large-scale greenhouse are required, and further this developed technique is also expected to be applicable to the small-scale family-managed greenhouse. For high yield production, the control of environmental factors (e.g., light, air temperature, CO2 concentration, humidity, and wind velocity) is essential to allow plants to realize their full photosynthetic potential. Light is one of the most important environmental factors affecting plant growth, and directly influences leaf photosynthesis and fruit yield in strawberry (Hidaka et al., 2012). Because of variable light environments dependent on factors such as cropping season and cultivation location, inadequate light levels frequently lead to declining productivity during greenhouse vegetable production in Japan. Consequently, the development of a supplementary lighting technique, not dependent on cropping season or cultivation location, is needed for consistently high strawberry production. Although supplemental lighting has been used to achieve high yields of some greenhouse vegetables, such as tomatoes and cucumbers (Demers et al., 1998; Hovi et al., 2004; Gunnlaugsson and Adalsteinsson, 2006; Trouwborst et al., 2010), there are currently few examples of supplemental lighting applied to strawberry production (Ceulemans et al., 1986). On the other hand, there have been many recent advances in LED light source technology, and the agricultural use of commercial LED lighting is expected to become more widespread (Goto, 2009; 2011). To aid in the development of supplemental lighting techniques in forced strawberry cultivation, we examined the effects of supplemental lighting on plant growth and yield using two different types of commercially-available light sources: LEDs and fluorescent lamps.