Damage levels of sunburn in pineapple fruits submitted to natural and artificial protection

Abstract

Pineapple sunburn (SB) occurs mostly in regions with a high incidence of sunlight and temperature, causing damage to the fruits and financial losses for the producer. The objective of this study was to evaluate natural and artificial protection in the reduction of physical and physiological damage in pineapple, submitted to high temperature and sunlight. The experimental design was in randomized blocks with seven treatments: single planting of pineapple (cv. Pérola), with and without the protection of fruits with woven fabrics (TNT) and intercropping with cassava (cv. Amazonas) in different spacing in the row (0.40; 0. 60; 0.80; 1.00; and1.20 m), and three replications. For the study, a scale of damage level (DL) to the pineapple by SB was established, ranging from 0 to 4 (DL0 - 4). Chlorophyll content, mass of fruits and crown, percentage of fruits with SB, and commercial fruits were evaluated. The TNT uses showed maximum protection for the fruits, being all suitable for fresh consumption no damage (DL0). In intercropping, the spacing of 0.80 and 1.20 m is indicated to maximize fruit production and protection. The absence of fruit protection caused damage up to N4, with fruits strictly suitable for industry (70%) and disposal (13%). In an environment with high temperature and irradiation, the adoption of fruit protection is necessary. The planning of floral induction allows the fruiting to not coincide with the critical period of high solar incidence and temperature and can avoid the use of protection strategies. The intercropping of pineapple and cassava protects pineapple fruits against sunburn; moreover, its use does not leave inorganic residues in the environment; therefore, it is strongly recommended as a strategy to reduce sunburn in pineapple fruits.

Do sub-doses of glyphosate and 2,4-D cause hormesis in the pineapple plants? Insights into the response of the pineapple plants to this phenomenon

“…The nutrient solution was applied via the leaves using a manual sprayer at a volume of 10 mL plant -1 , which was applied on the first day of pre-rooting (1st application); 15 mL plant -1 , applied ten days after the start of pre-rooting (2nd application); and 20 mL plant -1 , applied twenty-five days after the start of pre-rooting (3rd application). After transplanting the pineapple plants to the pots, base and topdressing fertiliser was applied based on the chemical analysis of the substrate and following the recommendations of Santos et al (2020) for the pineapple.…”

Teores foliares de macro e micronutrientes em cultivares de abacaxizeiro submetidas à adubação foliar

“…Como a queima solar pode causar perdas elevadas na produção de frutos foi realizada a implementação de medidas de proteção mecânica dos frutos a partir da semana seguinte ao fechamento das últimas flores, com o auxílio de sacos de papel colocados sobre os frutos, a fim de protegê-los contra a ação dos raios solares (Santos et al, 2020).…”

Calidad de fruta de la piña y evaluación del consorcio del piñal, yuca y caupí

“…Sin embargo, uno de los mayores daños causados a los frutos por el clima es la quemadura solar, lo que representa pérdidas económicas para los productores (Lopes et al, 2014;Silva et al, 2019;Santos et al, 2020).…”