Bioherbicidal action of Phoma dimorpha fermented broth on seeds and plants of Senna obtusifolia 1

Abstract

The weed Senna obtusifolia causes severe damages to pasture areas in Brazil, due to its high production and seed spread. This study aimed to evaluate the bioherbicidal action of Phoma dimorpha fermented broth in the pre-emergence and post-emergence of S. obtusifolia. The experimental design was completely randomized, with two treatments, one with and other without the application of the fermented broth. The bioherbicidal effects were measured in bioassays of pre-emergence (germination percentage), detached leaves (phytotoxicity) and post-emergence (phytotoxicity, plant height and fresh plant mass). The application of the fermented broth provided a pre-emergence bioherbicidal action, inhibiting the seed germination in 100 %. In detached leaves, it caused leaf necrosis and death on the ninth day after the application. In the post-emergence, this application caused moderate symptoms, such as leaf spots and reduction in the weed plant size. It was concluded that the P. dimorpha fermented broth has a potential herbicidal action and, therefore, represents an alternative in the development of bioproducts for a sustainable weed control in pastures.

Alelopatía del extracto de Campomanesia lineatifolia sobre Taraxacum officinale

“…En este caso, las semillas obtuvieron una tasa media de germinación de 9,1 ± 0,18 días (figura 1C). Se ha informado que la germinación de T. officinale más alta en número de semillas se obtuvo de los siete a los diez días después de la siembra, y el tiempo de germinación para este estudio fue de nueve días (Barrera, 2015), lo que se encuentra dentro de los mismos parámetros descritos anteriormente y solo se le determinó al testigo, ya que con los extractos de C. lineatifolia no hubo germinación (figura 1), debido a la inhibición total por el efecto bioherbicida de los compuestos existentes en el extracto (Chaves et al, 2020). En semillas de C. lineatifolia se ha reportado la presencia de β-tricetonas (Bonilla et al, 2005), metabolitos que presentan efecto herbicida (Dayan et al, 2007).…”

Nature-Based Herbicides and Micro-/Nanotechnology Fostering Sustainable Agriculture

“…are well-studied for bioherbicide development. Among fungi, the most studied are Trichoderma ssp, − Aspergillus ssp, Fusarium ssp, − and Phoma ssp. ,, Table lists the different bioherbicides prepared using microbial culture filtrates against various weeds.…”

Assessing the competitive ability of the invader Senna obtusifolia with coexisting natives species under different water stress regimes

“…This species, with a 1.5-2.5 m height size (Holm et al 1997), represent a serious threat to fields and rangelands in many tropical and subtropical regions (Palmer and Pullen 2001;Sosnoskie et al 2021). S. obtusifolia has copious seed production and can germinate and grow under a wide range of environmental conditions (Retzinger 1984;Chaves Neto et al 2020). Under favorable conditions of its development, S. obtusifolia can displace coexisting native species and form dense monospecific stands.…”