Seed germination of Bidens subalternans DC. exposed to different environmental factors

Abstract

Bidens subalternans DC. is a weed found in several tropical countries such as Brazil. Large number of produced seeds and easy dispersion favor the colonization of agricultural fields by this species. To know the factors that affect the germination of B. subalternans can help to understand its ecology, permitting to develop control strategies. Laboratory experiments were carried out to evaluate how the temperature, photoperiod, burial depth, water deficit, and salt stress affect the seed germination of B. subalternans. The means of the treatments of each experiment were shown in scatter plots with the bars indicating the least significant difference (LSD, p�0.05). The results showed a germination percentage above 77% for a wide alternating temperature (15/20 C to 30/35 C night/day). The highest germination and uniformity occurred at 25/30˚C night/day. Only 11% of the seeds germinated at a temperature of 35/40˚C night/day. The deeper burial of seeds reduced their germination. Only 17% of the seeds germinated in darkness conditions. However, in constant light and 12 hours of light/dark conditions the germination percentage was over 96%, confirming the light dependence of the B. subalternans during germination. In constant light and 12 hours of light/dark, the germination was over 96%. B. subalternans seeds showed sensitivity to water and salt stress, and their germination was inhibited under a water potential of-0.4 MPa and 100.09 mM, respectively. The sensitivity of B. subalternans seeds to high temperatures, water stress, and salt stress explains the high frequency of this weed in south-central Brazil. The light and sowing depth showed that burial of seeds by mechanical control is a strategy to reduce the high infestation of B. subalternans.

Seed germination ecology of Conyza stricta Willd. and implications for management

“…Slight differences among seed germination of the tested populations are due to the morphological/genetic variations. Several studies have reported that populations of the same species differ in their temperature requirement due to morphological variations [17,[53][54][55][56][57]. However, no strong evidence is available for genetic effect on seed germination of different populations of the same species.…”

Weed Interference in Carrot Yield in Two Localized Irrigation Systems

“…The number of plants that emerged was high owing to the high availability of resources, mainly water, light, and nutrients. However, as plants grow, there is an increase in intra and interspecific competition, reducing the availability of resources, leaving only the species with the highest initial growth rate, and those with seeds of greater vigor or absence of dormancy (PAMPLONA et al, 2020). In the initial periods of coexistence of an infesting community with agricultural crops, there is a high density of infestation, whereas in the final periods there is a reduction in density, as was observed in this study.…”

WATER DEFICIT ON GROWTH AND PHYSIOLOGICAL INDICATORS OF Bidens pilosa L. AND Bidens subalternans DC.

“…Two species of the genus Bidens, Bidens pilosa and Bidens subalternans, are easily confused in the field due to their very similar morphological characteristics. Easy dispersion and high seed production capacity allow both B. pilosa and B. subalternans to colonize cultivated and noncultivated areas (PAMPLONA et al, 2020). In addition, these species have a great capacity to extract water and nutrients from the soil, making these species good competitors for growth resources, during various crop cycles (SANTOS et al, 2015;FREITAS et al, 2019;SOARES et al, 2019).…”