Production of Mimosa caesalpiniifolia benth seedlings using a water-absorbing polymer and different water regimes

Polímero hidroabsorvente na produção de mudas de sabiá sob diferentes turnos de rega

ABSTRACT

Mimosa caesalpiniifolia Benth is an arboreous species native to the Caatinga commonly utilized for restoration of degraded areas. One factor that can affect its development is water shortage. This denotes the importance of searching for alternatives for improving these plant's tolerance to water shortage, such as the use of water-absorbing polymers known as hydrogels. In this context, the objective of this study was to evaluate the production of M. caesalpiniifolia seedlings under different hydrogel rates and water regimes. The experiment was conducted at the Forest Nursery of the Federal University of Campina Grande, Patos, PB, Brazil. Seeds were sown in 2-liter pots made from halved polyethylene terephthalate bottles, containing a substrate consisted of soil and cattle manure (2:1 v v^-1). A completely randomized design with four replications was used, in a 4×2 factorial arrangement consisted of four hydrogel rates in the substrate (0, 1, 2, and 3 g L^-1) and two water regimes (daily irrigation and irrigation every 2 days). The following parameters were evaluated at the end of the experiment (75 days after sowing): number of leaves per plant, stem base diameter, plant height, root length, shoot and root dry weights, water relative content, chlorophyll content, gas exchanges, and Dickson quality index. Most of parameters presented no statistically significant difference; however, the hydrogel rate of 2 g L^-1 resulted in increased production of M. caesalpiniifolia seedlings, whereas the absence of hydrogel resulted in longer roots, regardless of the water regime.

Keywords:
Caatinga; Hydrogel; Substrate