Sunlight transmitted by colored shade nets on photosynthesis and yield of cucumber

Abstract

Black shading nets are widely used in the protected cultivation of vegetables as a technique for controlling light and temperature, while the colored shading nets, with special optical properties to improve the use of solar radiation, appeared recently in the agricultural plastics market. Light quality transmitted by gray, aluminized, pearl, blue, red and black (control) nets with 30% shade was evaluated, as well as its effects on photosynthetic properties and fruits production of cucumber plants. Treatments (shade nets) were established under a randomized complete block design with four repetitions. The red net transmitted 23.7 and 40.3% more photosynthetic photon flux density (400 to 700nm) and red light (600 to 700nm) and the blue net transmitted 36% more blue light (400 to 500nm) in comparison with the respective transmissions of black net. All nets increased the photosynthetic responses: transpiration, stomatal conductance and CO2 assimilation, observed in plants grown under black net. Leaf greenness (41.6 SPAD units) and foliar area (90dm2) increased 22.8 and 38.9% with the red net, while the dry weight of leaf (52.5g) increased 21.9% with pearl net. Pearl, red, aluminized and blue nets showed to be viable alternatives because the production of fruit increased in 71, 48, 46 and 46%, respectively, in comparison with the conventional black net (52t ha-1).

Effects of light intensity on the growth, photosynthetic characteristics, and secondary metabolites of Eleutherococcus senticosus Harms

“…The effects of environmental stress on photosynthesis of medicinal plants include regulating the stomatal size and causing damage to the PSII reaction center (Berry and Downton 1982). Previous studies showed that the effects of shading conditions on photosynthesis of different medicinal plants were different (Wang et al 2017, Tafoya et al 2018, Fan et al 2019.…”

Use of colored agrotextiles and length of stay in the cultivation of yellow melons

“…These results have a direct effect related to the color orange, which has a wave range (590-620 nm) very close to the color red (620-750 nm) (Taiz;Zeiger, 2017). Tafoya et al (2018) studied the effects of colored screens on cucumber cultivation and observed that the blue and red nets provided a greater density of the photon flow. According to these authors, light levels favored photosynthesis, which led to an increase in biomass production, which implies a larger leaf area and greater efficiency in the transport of photoassimilates and greater reserve capacity assimilates for later use in the filling of fruits.…”

Photo-Selective Nets and Pest Control: Searching Behavior of the Codling Moth Parasitoid Mastrus ridens (Hymenoptera: Ichneumonidae) under Varying Light Quantity and Quality Conditions

“…Among other benefits, netting provides a reduction in the incidence of direct radiation by maintaining the suited temperature for a particular crop, leading to decreased fruit damage [5]. At present, black standard nets (SN) have been the most used by growers for bell peppers, cucumber, and tomato in countries such as Chile, Israel, and South Africa [6][7][8][9][10], mainly due to their low cost and because they provide a higher shading factor compared to other net colors [11,12]. Black SN reduce the amounts of PAR and UV light throughout the whole light spectra but do not affect the light quality [10].…”

“…The red PSN are specifically designed to absorb three light bands (UV, blue, and green) and to enhance light transmission in the red and far-red ranges (600 nm and up) [10,15]. This light manipulation results in increased biomass (cucumber), vegetative growth (cucumber and foliage crops, e.g., Pittosporum variegatum), and average fruit weight (cucumber and pepper) [9,10].…”