Effects of light intensity modification by reflective aluminized screenhouse on sweet pepper growth and yield

Abstract

Sweet pepper is one of the ten most consumed vegetables in world. Although it develops better under protected environment, the cultivation in tropical countries is practiced in open field due greenhouse structure higher costs. Unfortunately, such practice has compromised the crop to reach either best yield or fruit quality. Since production and cost are the most important criteria for agricultural production, we aimed to evaluate reflective aluminized polypropylene shading net influence on sweet pepper (Capsicum annuum L.) growth and production as intermediary alternative for low/middle income producers from Brazilian tropical regions. Sweet pepper Magali R hybrid was cultivated in two environments: FC -field conditions (control) and RS -reflective shading net with 40% shading rate. RS caused reductions in incident solar radiation (SR) and photosynthetically active radiation (PAR) on the amount of 46.3% and 48.3%, respectively. There were no significant changes in temperature and relative humidity recorded for the two environments. In addition, RS allowed best use efficiency of photosynthetically active radiation since it promoted higher values of plant height, leaf number and area index than those reached on FC on the amount of 29%, 22% and 80 %, respectively. Similarly, plants grown under RS showed higher yield and marketable fruits and promoted less loses by sunscald. KEYWORDS:Capsicum annuum L., shading, photosynthetically active radiation, solar radiation use efficiency. EFEITOS DE MODIFICAÇÕES NA INTENSIDADE LUMINOSA POR TELAS REFLEXIVAS NO CRESCIMENTO E PRODUÇÃO DE PIMENTÕESRESUMO: O pimentão figura entre as dez olerícolas mais consumidas em todo o mundo. Embora, ele se desenvolva melhor sob ambiente protegido, seu cultivo, no Brasil, ainda é realizado principalmente sob condições de campo aberto, devido aos altos custos das estruturas fechadas. Infelizmente, tal prática tem comprometido o alcance de melhores rendimento e qualidade dos frutos. Uma vez que a produção e os custos são os critérios mais importantes na produção agrícola, o presente estudo teve como objetivo avaliar a influência de telado de polipropileno aluminizado reflexivo no crescimento e na produção de pimentão (Capsicum annuum L.) como alternativa intermediária para produtores de baixa / média renda das regiões tropicais brasileiras. Pimentão híbrido Magali R foi cultivado em dois ambientes: FC -condições de campo (testemunha) e RStelado reflexivo com 40% de taxa de sombreamento. A tela reflexiva causou reduções na radiação solar incidente (SR) e na radiação fotossinteticamente ativa (PAR) na ordem de 46,3% e 48,3%, respectivamente. Não houve mudanças significativas na temperatura e na umidade relativa do ar registradas para os dois ambientes. O RS permitiu melhor eficiência na utilização da radiação fotossinteticamente ativa, uma vez que promoveu maiores valores de massa por planta, número de folhas e índice de área foliar que em FC na ordem de 29%, 22% e 80%, respectivamente. Da mesma forma, as plantas crescidas sob RS alcanç...

Effect of shading by coloured nets on yield and fruit quality of sweet pepper

“…PAR is highest in the tunnel with a red net of the shade index 40% PAR, 832.3 μmol m -2 s -1 . In July, around 1 pm, the sun radiation in the tunnel without nets during cloudy day is 692 W m (Ferreira et al, 2014). In addition to light intensity and quality (Shahak, 2008;, shade-nets may modify environmental variables such as temperatures, wind speed, or relative humidity inside the canopy (Arthurs et al, 2013).…”

Mineral Nutrients, Physiological Disorders, Postharvest Water Loss, and PR Gene Expression in Bell Pepper (Capsicum annuum L.) Fruit under Shade Nets

“…Shade net reduced the incidences of bell pepper fruit disorders, particularly sunscald. Losses in bell pepper yield due to sunscald have been reported (Espinoza 1991;Olle & Bender 2009;Díaz-Pérez 2014;Ferreira et al 2014;Kabir et al 2020). Sunscald occurs due to fruit exposure to high irradiation, resulting in increased fruit surface temperature and photooxidative damage to fruit tissues (Maughan et al 2017).…”

“…Sunscald-related losses in bell pepper account for a reduction of marketable yield by at least 20% (Kabir et al 2020), 32% (Rylski & Spigelman 1986), and up to 52% (Day 2014). Shade nets reduce fruit physiological disorders and improve bell pepper's chemical composition and postharvest-keeping quality (Rylski 1985;Espinoza 1991;Olle & Bender 2009;Díaz-Pérez 2014;Ferreira et al 2014;Shahak 2014).…”