An energy-saving glasshouse film reduces seasonal, and cultivar dependent Capsicum yield due to light limited photosynthesis

Abstract

Glasshouse films can be used to reduce energy costs by limiting non-productive heat-generating radiation, but the impact on yield of greenhouse horticultural crops remains unknown. The effects of energy-saving film ULR-80 (referred to as Smart Glass; SG) designed to block long wavelength light that generates heat also reduced photosynthetically active radiation (PAR) consequently affecting crop morphology, photosynthesis, leaf pigments, and yield of two hydroponically grown capsicum (Capsicum annuum L.) cultivars (Red and Orange). The crops were grown in four high-tech glasshouse bays over two seasons of similar daily light integrals (DLI) during ascending (Autumn) and descending (Summer) photoperiods. The Red cultivar exhibited higher photosynthetic rates (light saturated - Asat and maximal - Amax) and yield than the Orange cultivar in control but displayed stronger reductions in modelled photosynthetic rates at growth light and yield in SG without changes in photosynthetic capacity. Foliar pigment ratios of chlorophyll a/b and carotenoid:chlorophyll remained unaffected by the SG during both seasons indicating that chloroplast homeostasis was similar between SG and control. The seasonal differences in photosynthetic pigments and xanthophyll de-epoxidation state (DPS) revealed that cultivars were able to sense the SG-altered light environment during the ascending, but not descending photoperiod. The descending photoperiod correlated with a lower daily light level and a substantial yield reduction of 29 % and 13 % in Red and Orange cultivars, respectively. Thus, SG-induced higher reductions in yield during the descending photoperiod indicate that SG may be more beneficial for capsicum crops planted during Autumn with an ascending photoperiod.

Enhancing drought tolerance in chilli pepper through AdDjSKI‐mediated modulation of ABA sensitivity, photosynthetic preservation, and ROS scavenging

“…The cultivation of chilli pepper is experiencing a notable rise, fueled by shifting dietary preferences and the growing popularity of its pungent flavor, coupled with substantial economic benefits (Widuri et al, 2020). Nonetheless, drought has been reported to exert negative consequences on morphology, growth, and photosynthesis in various crops, including chilli peppers (Widuri et al, 2020, Chavan et al, 2023, highlighting the urgent need for innovative strategies.…”

“…The cultivation of chilli pepper is experiencing a notable rise, fueled by shifting dietary preferences and the growing popularity of its pungent flavor, coupled with substantial economic benefits (Widuri et al, 2020). Nonetheless, drought has been reported to exert negative consequences on morphology, growth, and photosynthesis in various crops, including chilli peppers (Widuri et al, 2020, Chavan et al, 2023), highlighting the urgent need for innovative strategies. Our current study provides compelling evidence that overexpression of the AdDjSKI gene in chilli peppers substantially improves drought tolerance while concurrently maintaining better phenotype, growth indices, photosynthetic features, and antioxidant defense system.…”

Light blocking film in a glasshouse impacts Capsicum annuum L. yield differentially across planting season

“…Two weeks after transplantation, two stems from each plant were selected and trellised onto plastic strings supported by a high-wire system. Plants were grown according to commercial practices of hydroponic production of vegetables in greenhouses under non-limiting water and nutrient (EC: 2.5 dS m −1 -3.0 dS m −1 , pH: 5.0-5.5) conditions at [CO 2 ] (489.6 ml l −1 and 476.6 ml l −1 daytime average), temperature (25.3/19.3 and 25.2/19.3°C day/night average), RH (74.2/72.9% and 74.2/77.5%, day/night average) and natural light for AE and SE, respectively (He et al, 2022). The environmental variables, including temperature, relative humidity, and CO 2 concentration at canopy level, were monitored in all glasshouse compartments at 5-minute intervals.…”

“…Hence, it is vitally important to measure the light quantity and quality regimes in PC under Australian solar and climatic conditions. LBF reduces the heat load when applied to glasshouse roofs and sidewalls, but it alters the spectral quantity and quality of light, and has been shown to affect crop development and yield of S. melongena and C. annuum ( Chavan et al., 2022 ; T. Lin et al., 2022 ). However, the impact of LBF on spectral quality has not been fully assessed across a crop’s lifetime nor has it been compared across different planting seasons.…”