Growth and mineral nutrition of Solanum americanum

Abstract

A greenhouse trial was carried out from November 1995 to April 1996 at FCAV/UNESP, Brazil, aiming to study the dry matter production and the accumulation and distribution of macronutrients in Solanum americanum, an important weed for annual and perennial crops in Brazil. The plants were grown in seven liter pots with sand substrate, irrigated daily with Hoagland & Arnon nutrient solution. The experimental design was completely randomized with four replicates. The treatments corresponded to evaluation times at 14 day intervals, beginning 21 days after emergence (DAE). In each evaluation, the plants of four pots were analyzed for dry matter production and macronutrient content. S. americanum had a small dry matter and macronutrient accumulation at the beginning of the experimental stage, increasing after 77 DAE and reaching the maximum theoretical value at 142, 142, 164, 149, 140, 149 and 152 DAE, for dry matter, N, P, K, Ca, Mg, and S, respectively. K and N were the most accumulated macronutrients for S. americanum plants.

Accumulation of dry mass and macronutrients by sourgrass plants

“…Increasing dry mass allocation was provided by greater accumulation by stems rather than leaves, since the percentage of the dry mass accumulation by leaves, main organs producing photoassimilates, rapidly reduced after 35 DAE in comparison with other plant parts. That behavior has been observed for all weeds previously studied and it is attributed to a better plant fixation in the substrate, increasing the contact of nutrients by root interception and causing their rapid accumulation by roots (Bianco et al, 2010;Guzzo et al, 2010;Martins et al, 2010).…”

“…At each time, sourgrass plants accumulated 163.2 mg of N per plant, 27.1 mg of P per plant, 260.5 mg of K per plant, 47.6 mg of Ca per plant, 30.9 mg of Mg per plant, and 13.7 mg of S per plant. After these times, the accumulation of macronutrients reduced due mainly to the plant dry mass accumulation had been diminished in function of the senescence of leaves and due additionally to lower contents of macronutrients had been extracted from plant tissues in function of smaller plant nutrient requirement, as discussed by Bianco et al (2010). Accumulation of dry mass and macronutrients by ...…”

“…Evaluations, processes of collecting and washing plant materials, extraction of macronutrients, and statistical analysis were performed according to procedures used by Bianco et al (2010). At each time of evaluation, plants from four pots were collected and separated into roots, stems, leaves, and reproductive structure (inflorescence, since existing).…”

“…Considering the current importance of sourgrass as a weed, there are needed basic studies on plant biology, regarding aspects such as reproduction, growth, development, nutritional requirements, response to weed control systems, and other issues, aiming to obtain information that allow us to manage this weed efficiently. Those basic studies are essential to understand the behavior of weeds growing under distinct environmental conditions and to provide substantial information for predicting their success as weedy plants when they are being submitted to new agricultural practices or even being introduced into a new environment (Bianco et al, 2010).…”

“…There are many papers on nutritional requirements of weeds emphasizing the importance of this type of research, such as the recent ones published by Bianco et al (2010) on Solanum americanum Mill. (American black nightshade), Guzzo et al (2010) on Ipomoea hederifolia L. (ivyleaf morningglory), Martins et al (2010) on Merremia aegyptia (L.) Urban.…”