Desenvolvimento inicial de mudas de melancia cv. Crimson Sweet em função de doses de boro aplicadas na semente

Abstract

R E S U M OA melancia apresenta pouca tolerância à deficiência de boro e seu fornecimento via tratamento de sementes pode atender a necessidade da planta e melhorar seu desenvolvimento especialmente na fase de mudas. Objetivou-se com esse trabalho avaliar o desenvolvimento inicial de mudas de melancia em função da aplicação de boro nas sementes. O experimento foi realizado em abrigo telado (50% de luminosidade), em Bom Jesus-PI no período de abril a maio de 2011. Adotou-se o delineamento em blocos casualizados, com os tratamentos: 0,0; 4,24; 8,50; 17,00; 34,00 g de B kg -1 de sementes, com cinco repetições e cinco plântulas por parcela experimental. Foram utilizados como recipientes tubetes com capacidade para 50 cm 3 , preenchidos com substrato constituído de solo (Latossolo Vermelho), areia lavada e esterco bovino na proporção (1:1:2), respectivamente. No final do experimento, avaliou-se: i) a altura da planta; ii) diâmetro do caule; iii) matéria seca de raiz e da parte aérea (g planta -1 ); iv) clorofila; v) comprimento da raiz e vi) volume radicular. A aplicação de boro nas sementes influenciou positivamente as variáveis altura da planta, clorofila, matéria seca da parte aérea, comprimento radicular e volume radicular. A dose de 25,5 g de B kg -1 de sementes é recomendada para maior produção de matéria seca das mudas. Palavras-chave: ácido bórico, adubação via semente, olerícola. A B S T R A C TWatermelon has little tolerance to boron deficiency and supply via seed treatment can meet the need of the plant and improve its development especially in the seedling stage. The objective of this study was to evaluate the initial development of watermelon seedlings due to boron application in seeds. The experiment was conducted under greenhouse conditions (50% brightness) in Bom Jesus-PI from April to May 2011. A randomized complete block design was adopted with treatments: 0.0; 4.24; 8.50; 17.00; 34.00 g of B kg -1 of seeds, with five replications and five seedlings per experimental plot. There were used containers with a capacity of 50 cm 3 , filled with a substrate composed of soil (Oxisol), washed sand and manure in the ratio (1:1:2), respectively. At the end of the experiment, it was evaluated: i) the height of the plant; ii) stem diameter; iii) dry matter of root and shoot (g plant -1 ); iv) chlorophyll; v) root length and vi) root volume. The application of boron in the seeds positively influenced the variables plant height, chlorophyll, dry matter of shoot, root length and root volume. The dose of 25.5 g of B kg -1 of seeds is recommended for higher dry matter production of seedlings.

Physical-physiological quality and early performance of sorghum plants under different boron doses via seed

“…SL had a quadratic behavior and maximum efficiency at 2.58 g kg -1 B (40.5 cm) but decreased at higher doses (Figure 3A). These results corroborate those found by Silva-Matos et al (2017), who observed growth of watermelon seedlings up to a dose of 11.66 g kg -1 B, followed by a decrease with increasing doses.…”

“…However, the dose of 2.5 g kg -1 promoted an increase in RL, with the highest value in the control without B addition (Figure 4B). These results corroborate Silva-Matos et al (2017), who found a significant effect of B doses, applied via seed, on RL of watermelon seedlings, increasing up to a dose of 15.75 g kg -1 , and then decreasing. Seeds treated with B doses above 2.5 g kg -1 showed a decrease in SDM and RDM (Figure 4C and 4D).…”

Rooting of azalea cuttings of Otto and Terra Nova cultivars treated with auxin and boron

“…When there was no IBA addition, those cuttings treated with boron in the concentrations of 2.5; 5.0; and 7.5 mg L -1 showed higher root number when compared with 0 mg L -1 boron ( Figure 1A). When boron-treated Otto cuttings are observed, root number increases under 2,000 mg L -1 IBA ( Figure 1A), demonstrating the action of the exogenous auxin stimulating root formation and number (Figueiredo et al, 2009, Taiz et al, 2017. However, from this concentration, there is a tendency to reduce root number, indicating phytotoxicity when the concentration increases ( Figure 1A).…”

“…The correlation among the studied variables evidences such rooting process (Tables 3 and 4). It is known that auxin and boron are closely linked in rhizogenesis, auxin by root induction and boron by the action of cell elongation, nucleic acid synthesis and membrane function (Taiz et al, 2017). Table 3.…”

Nutritional status of watermelon irrigated with brackish water in different planting systems

“…Planting using seedlings has gained ground as it promotes better nutritional and phytosanitary control, makes it possible to select more vigorous and uniform plants, minimizes losses during the establishment of the crop in the field, reduces early infection of seedlings by viruses, and ensures the homogeneity of the crop (Silva-Matos et al, 2017).…”