Water Stress in the Production and Quality of Bidens pilosa and Raphanus raphanistrum Seeds

Abstract

Plants in soils with low water availability may present a reduction of their leaf area and photosynthetic rate, as well as lower assimilated compound supply for seeds. Knowing the physiological quality and seed production of weeds generated under water deficit conditions can help understanding the survival and competition strategies of species. The objective of this work was to evaluate the effect of water stress on the production and germination of Bidens pilosa and Raphanus raphanistrum seeds. Plants were maintained in soils with different water potentials (-0.03, -0.07 and -1.5 MPa) throughout their cycle, until seed production, when they were harvested. Then, evaluations were performed to find out the number of seeds per plant and number of seeds per pod (Raphanus raphanistrum). The evaluation on the germination of these seeds was performed on moistened paper, with four replications, at 20-35 oC and 8 hours of light per day, weekly, until 28 days after seeding. The experimental design was completely randomized with three treatments (soil water potential: -0.03 MPa, -0.07 MPa and -1.5 MPa). The results were submitted to analysis of variance by F test, and the means of the treatments were compared by Tukey’s test at 5% probability. It was concluded that Bidens pilosa is more adapted to water deficit conditions than Raphanus raphanistrum, due to the higher production of seeds, better germination and seedlings with greater vigor.

The concurrent impacts of drought and leaf harvesting on two traditional African vegetable non-timber forest product species

“…[ 38 , 53 ] and B . pilosa [ 54 , 55 ] have some level of drought tolerance and showed a significant difference in the species behavior in response to drought stress. Also, the resilience of both species differed depending on what plant characteristics were considered, although with some variations (especially for Amaranthus sp .)…”

“…under similar environmental conditions, echoing Pereira et al . [ 54 ] who showed B . pilosa to be better adapted to drought conditions than Raphanus raphanistrum .…”

“…In contrast, B. pilosa is drought tolerant under any level of drought stress. Previous studies elsewhere already emphasized the drought tolerance of B. pilosa under severe drought stress [54,55]. According to previous studies, Bidens species possess a great ability to easily exploit the soil resources (i.e.…”

Multiscale properties of weeds in no-till system

“…The capacity dimension (D 0 ) describes a global view of the system (Leiva et al, 2019;Siqueira et al, 2022), allowing us to verify how the scales are filled by the measurement values. Variations in D 0 values for R. raphanistrum, Commelina ssp., and OW on the sampling dates showed that the scales were filled with measurement values, indicating that the difference in D 0 values for the species under study reflects their ecology (Booth et al, 2003;Brighenti, Oliveira, 2011), mainly with regard to the aggregated distribution (Cheam, Code, 1995;Schaffrath et al, 2007;Chiba et al, 2010;Siqueira et al, 2016;Pereira et al, 2018;Izquierdo et al, 2020;Sousa et al, 2020;Jurado-Expósito et al, 2021). The D 1 dimension is related to the entropy information and quantifies the degree of disorder in the system.…”

“…(L.) in summer crops is a response to characteristics of species ecology. According to Lorenzi (2014) and Pereira et al (2018), the species R. raphanistrum (L.) has a high capacity for the production of viable seeds and is a common spontaneous plant for winter crops. Cheam and Code (1995) report that the occurrence of R. raphanistrum (L.), even if at low populational densities, can compromise the productivity of winter crops.…”