INFLUENCIA DO HIDROGEL NO CRESCIMENTO E NO TEOR DE NUTRIENTES DAS MUDAS DE Eucalyptus dunnii

Abstract

ResumoObjetivou-se avaliar doses do hidro-retentor adicionado ao substrato sobre crescimento, teor nutricional e qualidade de mudas de Eucalyptus dunnii Maiden. O experimento foi realizado em delineamento inteiramente casualizado, com seis tratamentos, constituídos de concentrações crescentes do hidrogel (0; 1,5; 3,0; 4,5 e 6,0 g.L -1). Foram utilizadas seis repetições, cada uma composta por 24 plantas. Aos 90 dias após a semeadura, foi realizada a avaliação de parâmetros morfológicos das mudas e análise nutricional da parte aérea. A dose em torno de 4,5 g.L -1 ocasiona a melhor resposta quanto às variáveis avaliadas, proporcionando maior altura, diâmetro de coleto, massa seca da parte aérea e radicular e índice de qualidade de Dickson. O uso de doses abaixo de 3 g.L -1 ou acima de 4,5 g.L -1 diminuíram a qualidade das mudas. Todos os macronutrientes apresentaram maior teor na parte aérea (caule + folhas) na presença do hidrogel. O teor dos macronutrientes na parte aérea das mudas aumenta com a adição do hidrogel, porém diminui o teor dos micronutrientes. Em geral, o uso do polímero hidro-retentor aumentou a qualidade das mudas de E. dunnii. Palavras-chave: Produção de mudas; polímero hidroretentor; retenção de água e nutrientes; análise nutricional. Abstract Doses of hydrogel influencing growth and nutritional content in seedlings Eucalyptus dunnii.The objective was to evaluate different dosages of hidroretentor added to the substrate on the growth, nutrient content and quality of Eucalyptus dunnii Maiden. The experiment was conducted in a completely randomized design with six treatments, and increasing concentrations of the hydrogel (0, 1.5, 3.0, 4.5 and 6.0 g.L -1 ). Were six replicates, each consisting of 24 plants. At 90 days after sowing was evaluated morphological parameters of seedlings and nutritional analysis of the seedlings. The dose around 4.5 g.L -1 brings the best answer for the variables evaluated, providing greater height, diameter collect, shoot dry mass, root parts and Dickson quality index. The use of doses below 3 g.L -1 or above 4.5 g.L -1 decreased the quality of seedlings. All macronutrients showed higher content in shoots (leaves + stem) in the presence of the hydrogel. The macronutrient content of the shoots of seedlings increases with the addition of the hydrogel, but decreases the content of micronutrients. In general, the use of polymer hidroretentor increased the quality of the seedlings of E. dunnii.

Effect of Hydrogel Doses in the Quality of Corymbia citriodora Hill & Johnson Seedlings

“…These authors also found that the use of this product allows a reduction of at least 20% of routine fertilization, used by the merchantable nursery. Besides, Navroski et al (2015a) observed increased content of macronutrients in the shoots of eucalyptus (Eucalyptus dunnii) seedlings (stem + leaves) after the addition of hydrogel. In turn, Navroski et al (2015b) observed a reduction in irrigation with the incorporation of hydrogel to the substrate (3 g L -1 ) in the production of Eucalyptus dunnii seedlings.…”

“…However, Navroski et al (2015b) warn that the use of higher irrigation water can dispense with the use of hydrogel, as in this case its presence may adversely influence the quality of the seedlings due to the excessive amount of water in the substrate. Furthermore, it is important to note that the use of excessive doses of hydrogel may also affect the nutritional status of the seedlings, since it alters the pH of the substrate and thus affects the absorption of some micronutrients, reducing their development (BERNARDI et al 2012;NAVROSKI et al, 2015a). Although Sousa et al (2013) have not found differences in relation to the parameters related to the shoot of 'angico vermelho' (Anadenanthera peregrina) seedlings produced with different doses of hydrogel (0 to 8 g L -1 ), they have found that doses greater than 4 g L -1 have negatively influenced the root dry mass and total dry mass, affecting the formation of the root system and hence the quality of the seedlings.…”

“…It is a synthetic polyacrylamide product with large retention and water storage capacity (AZEVEDO et al, 2002;NAVROSKI et al, 2015a), and when incorporated into the soil, it increases the availability of water and nutrients to the plants, acting as soil conditioners (CAMARA et al, 2011;BERNARDI et al, 2012).…”

Cowpea bean production under water stress using hydrogels

“…Therefore, even when submitted to 20-day water stress in the most critical period of the crop (flowering), the formation of beans in the pod was higher than for the control, highlighting the potential of the product to supply the plants nutritional and water needs during this period of adversity, which is common in the region studied. Navroski et al (2015) concluded that the use of hydrogel increases the water retention capacity in the soil and the content of macronutrients in shoots of Eucalyptus dunnii seedlings.…”

Does the quality of Luehea divaricata seedlings in the nursery correspond to their behavior in the field?

“…The quality of the seedlings is of fundamental importance and is linked to the success of reforestation (Lima et al, 2014;Navroski et al, 2015). Therefore, it is important to establish a quality standard for seedlings of different species or groups, for adequate growth and survival in One of the important factors that influences the development of seedlings in nurseries is the composition of the substrate and proportion of components (Filho et al, 2015), which is directly related to seedling vigor at the time of sowing and consequently in post-planting.…”