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ABSTRACT. The objective of the present study was to evaluate pitaya seed germination under different hydrogen potentials, with or without fungicide treatment. A completely randomized design was employed under a 3 x 13 x 2 factorial scheme, corresponding to three pitaya species (white pitaya, pitaya hybrid I, pitaya hybrid II), thirteen hydrogen potentials (3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, and 9.0) and two fungicide conditions (presence and absence), with four replications. The percentage of germination, germination speed index and mean germination time were evaluated. The data were subjected to ANOVA, and the means were compared using the Scott-Knott test (p < 0.05). The pH influenced the germination speed index in white pitaya. The mean germination time was affected by the pH levels for white pitaya and pitaya hybrid II. The fungicide did not increase the germination percentage in the evaluated species. Keywords: Hylocereus undatus, H. costaricensis, carboxim+thiran, vigor, viability, physiological quality.Potencial hidrogeniônico e fungicida na germinação de sementes de pitaya RESUMO. O trabalho teve como objetivo avaliar a germinação de sementes de pitaya submetidas a diferentes potenciais hidrogeniônicos, com ou sem fungicida. Utilizou-se o delineamento experimental inteiramente casualizado, em esquema fatorial 3 x 13 x 2, correspondente a três espécies de pitaya (pitaya branca, pitaya híbrida I e pitaya híbrida II), treze potenciais hidrogeniônicos (3,0; 3,5; 4,0; 4,5; 5,0; 5,5; 6,0; 6,5; 7,0; 7,5; 8,0; 8,5 e 9,0) e dois níveis de fungicida (presença e ausência), com quatro repetições. Foram avaliados a porcentagem de germinação, o índice de velocidade e o tempo médio de germinação. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Scott-Knott (p < 0,05). O pH influenciou o índice de velocidade de germinação da pitaya branca. O tempo médio de germinação foi alterado pelos níveis de pH para a pitaya branca e híbrida II. O fungicida não favoreceu a porcentagem de germinação das espécies avaliadas.

The lack of water and soil acidity are current problems occurring in many regions around the globe. Therefore, it is essential to investigate the effects of seed germination and seedling development, in order to determine the species adaptability to the ever-changing environment. The aim of this study was to evaluate the effects of water deficit and pH on seed germination and seedling development in Cereus jamacaru. A completely randomized experiment was performed. A factorial scheme of 6 × 7, corresponding to six osmotic potential values (0.0, -0.2, -0.4, -0.6, -0.8, and -1.0 MPa) induced by PEG 6000, and seven pH levels (3, 4, 5, 6, 7, 8, and 9) with four replications was used. The variables analyzed were germination (G), germination speed index (GSI), mean germination time (MGT), normal seedling (NS), root length (RL), shoot length (ShL), seedling length (SL), and seedling dry mass (SDM). The statistical analysis included ANOVA and binomial models (G and NS), regression models with quadratic terms (GSI and MGT), and response surface method (ShL and SL) for the variables with at least one significant factor (p < 0.05). C. jamacaru showed susceptibility to water deficit at seed germination and seedling development stages, indicated by the decreases in G, GSI, NS, ShL, and SL at osmotic potential below to 0.0 MPa. The pH interaction with osmotic potential affected C. jamacaru seedling development. The increase in pH was favorable for seedling development, but not for seed germination.

The fruit of pitaya has occupied a growing niche in the fruit market, since its organoleptic characteristics and rusticity have attracted the attention of consumers and producers, respectively. The organoleptic and nutritional quality of fruits are due to maturity stage. Therefore, determining the period in which the fruits reach the physiological maturity is important, since it aids the planning of the harvest and the quality control of fruits. In this sense, the aim of this review is establish the ideal period for harvesting their fruits of pitaya (Hylocereus undatus), by determining of the physiological maturity point. For this species, the number of days from anthesis to the full development of the fruit has shown to be the most reliable variable to determine the moment of harvest. From this designation, it is possible to indicate the stage (physiological maturity) in which the fruits present characteristics favorable to the species, for example, color, soluble solids content, ratio, and others. It is known that the place of production and the edaphoclimatic conditions are able to interfere and cause variation in the period in which the fruits reach the physiological maturity. Some studies in Mexico confirmed that the physiological maturation of pitaya fruits occurred between 25 and 31 days after anthesis (DAA). Other researches, including in Brazil, confirmed that this point occurred from 28 to 32 DAA. Thus, from the scientific studies carried out and published in the literature, to avoid losing their commercial value of fruits, it is recommended to harvest this fruits of pitaya between 25 and 32 DAA.

A produção de mudas de lichieira (Litchi chinensis Soon.) por meio da estaquia, é uma alternativa promissora visando à redução do período de juvenilidade e à manutenção das características desejáveis da planta matriz. O objetivo deste trabalho foi avaliar o enraizamento de estacas semilenhosas de lichieira cv. Bengal, tratadas com ácido indolbutírico (AIB) em diferentes substratos. O delineamento experimental foi o inteiramente casualizado, em arranjo fatorial 3 x 2, correspondendo aos substratos: casca de arroz carbonizada, vermiculita e fibra de coco e duas concentrações de AIB, a 0 e 1.000 mg L-1 , com cinco repetições de 10 estacas por parcela. Não se constatou influência dos substratos e da concentração de AIB sobre a sobrevivência das estacas. As estacas enraizadas em fibra de coco apresentaram maior retenção foliar. A aplicação de AIB nas estacas na casca de arroz carbonizado e vermiculita resultou nas maiores médias de enraizamento. Obtiveram-se, para a massa seca de raízes, melhores resultados com a vermiculita e o AIB. A utilização de casca de arroz carbonizada e vermiculita-e a aplicação de 1.000 mg L-1 de AIB são as mais indicadas para o enraizamento de estacas de lichieira 'Bengal'.