Effect of saline water and shading on dragon fruit (‘pitaya’) seedling growth

Abstract

‘Pitaya’ (Hylocereus undatus) is a fruit-bearing, climbing cactus with great food potential for the semiarid region. This study aimed to evaluate the production of ‘pitaya’ seedlings irrigated with low and high salinity water and grown in different light intensities. The experiment was conducted in a completely randomized design, in a 2 × 2 factorial arrangement, with two electrical conductivities of irrigation water: S1 - 0.3 dS m-1 (low salinity) and S2 - 5.0 dS m-1 (moderate salinity) in two environments: A1 - black net with 50% shading, and A2 - full sun, with ten replicates. The variables evaluated were plant height, main cladode diameter, above-ground biomass, root biomass, total plant biomass, number of secondary cladodes, root length, and length of secondary cladodes. The 50% shading (black net) promoted higher plant height, number of secondary shoots, and root length of the ‘pitaya’ plants. The irrigation with moderate saline water (5.0 dS m-1) reduced the number of secondary cladodes, length of root, and length of secondary cladodes. The ‘pitaya’ seedlings grown under 50% shading (black net) showed greater root dry biomass when irrigated with low-salinity water. Greater values of diameter of the primary cladode, above-ground dry biomass, and total dry biomass were observed under full sunlight and elevated saline stress.

Research on the Current Status of Light Supplementation Technology for Dragon Fruit

“…The experimental results provide useful suggestions for dragon fruit cultivation in arid areas. Sousa et al [7] investigate the effect of low and high salinity irrigation on dragon fruit seedling yield under different lighting conditions. The research finds that 50% shading can increase the plant height, secondary shoot number, and root length of dragon fruit plants.…”

Pitaya as a New Alternative Crop for Iberian Peninsula: Biology and Edaphoclimatic Requirements

“…The ideal soil pH for pitaya is between 5.5 and 6.5 [ 44 ], but it seems there is no restriction to development in alkaline soils, which are frequent in Mediterranean countries. Pitaya is sensitive to salinity, especially when associated with high levels of sodium [ 45 , 46 ].…”

Salinização secundária no semiárido e seus impactos no solo, na agricultura e cultivo das plantas – uma revisão

“…A pitaia é uma planta frutífera rústica que se desenvolve nos mais diferentes habitats, podendo ser encontrada sobre troncos de árvores, maciços rochosos, campos e solos arenosos, podendo ser cultivada em regiões de baixa pluviosidade e solos pobres (Junqueira et al, 2002;Gomes, 2014), com grande potencial de alimento para a região semiárida (SOUSA et al, 2021a). Orozco et al (2017) pesquisaram os efeitos da salinidade na germinação de sementes e crescimento de mudas de pitaia em meio de cultura acrescido de NaCl nas concentrações de 0, 2, 4, 6, 8 e 10 (X 103) ppm.…”

“…Os autores destacaram ainda na pesquisa que a aplicação das diferentes doses de H2O2 não reduziram significativamente os efeitos negativos na cultura quando irrigada com água de diferentes concentrações de sais. Sousa et al (2021a) avaliaram os efeitos na produção de mudas de pitaia cultivadas em diferentes tipos de ambientes, irrigadas com água de baixa (0,3 dS m -1 ) e salinidade moderada (5,0 dS m -1 ). Os resultados indicaram que o sombreamento de 50% favoreceu o maior crescimento da planta, promovendo ainda um aumento da biomassa seca da raiz quando irrigadas com água de baixa salinidade.…”