Distribuição de raízes de bananeira 'Prata-Anã' no segundo ciclo de produção sob três sistemas de irrigação

Abstract

A informação da distribuição radicular de uma planta permite definir áreas do solo ao redor desta, mais propícia para aplicação de fertilizantes e instalação de sensores de umidade, para melhor monitoramento da irrigação. O presente trabalho teve como objetivo avaliar a distribuição do sistema radicular de bananeira 'Prata-Anã', sob diferentes sistemas de irrigação, durante o segundo ciclo de produção. O delineamento experimental foi em blocos casualizados, com parcelas subdivididas, com três repetições, em que as fontes de variação se constituíram de três sistemas de irrigação (gotejamento, microaspersão e aspersão convencional), seis distâncias da planta (0,15; 0,30; 0,45; 0,60; 0,75 e 1,00 m) e cinco camadas do solo (0,0 - 0,20; 0,20 - 0,40; 0,40- 0,60; 0,60 - 0,80 e 0,80-1,00 m). A bananeira apresentou maior predominância do sistema radicular próxima à superfície do solo, com 80% deste a 0,61 m, 0,51 m e 0,61 m e à distância efetiva de 0,63 m, 0,66 m e 0,79 m do pseudocaule da planta, para os sistemas de irrigação por gotejamento, microaspersão e aspersão convencional, respectivamente. Em geral, predominaram as raízes com diâmetros inferiores a 2 mm, em toda a zona radicular avaliada. As raízes com maior diâmetro tenderam a concentrar-se próximo ao pseudocaule da planta com profundidades inferiores a 0,40 m da superfície do solo.

<b>Roots of ‘BRS Princesa’ banana fertigated with humic substances and saponin-based plant extracts

“…The values of mean effective depth (0.38 m) and mean effective distance (0.78 m) for the HS doses (Table 3) show that, despite the differences in these variables for the doses, there was no fitting that could adequately explain their variation. The mean values of effective depth and effective distance for the HS doses were close to the values reported by Coelho et al (2008) and lower than the mean values obtained by Santana et al (2012), namely 0.74 and 0.63 m, respectively. In this study, the analysis of variance did not show a significant effect of HS dose on the variables total porosity, macroporosity, microporosity, soil density, water retention at 10 kPa and mean weighted diameter of the aggregate (Table 4) at the distances of 0.25 and 0.50 m and in the layer 0-0.20 m, evaluated after 12 months of application.…”

“…The reduction of roots at the depths of 0.10 and 0.20 m with increasing HS dose was not expected, as there was no linear reduction of RL with increasing HS dose applied with plant extract (Table 2) and, in general, there was a quadratic polynomial behaviour of RL with increasing HS doses (Figure 1). It should be noted that, at the depths of 0.10 and 0.20 m, RL is naturally higher than at greater depths in the soil profile for the banana crop, according to Santana et al (2012). The analysis of variance performed to verify whether HS dose influenced the effective depth or the effective distance of the root system did not indicate the effect of the doses on these variables (p > 0.05).…”

“…Sample processing involved the separation of roots and the digitalization and determination of root length, according to Santana, Coelho, Faria, Silva, and Donato (2012). One analysis of variance involved the root length data in a split-split plot design, considering the factors HS dose, presence/absence of plant extract and soil depth.…”

“…The randomized block design was used for two analyses: one considering root length data as a mean of five distances from the plant (0.25, 0.50, 0.75, 1.0, and 1.25 m) and another evaluating the effect of HS doses on root effective depth (EDepth) and effective distance (EDist). EDepth and EDist, where 80% of the roots are found in terms of depth and horizontal distance from the plant, respectively (Coelho, Simões, Carvalho, & Coelho Filho, 2008), were determined according to Santana et al (2012).…”

Fertigation of ‘BRS Princesa’ banana with humic substance and saponin-based plant extracts

“…The samples were collected at distances of 0.25 and 0.50 m from the pseudostems and at depths of 0.10, 0.20, 0.30, and 0.40 m in the subplots under HS and HS + PE application. The processing of the samples involved separation of roots from soil, scanning, and determination of root length and root length density according to Santana et al (2012).…”