Effect of crop residues applied isolated or in combination on the germination and seedling growth of horse purslane (Trianthema portulacastrum)

Abstract

-Soil incorporation of crop residues can lead to weed suppression by posing allelopathic and physical effects. Allelopathic potential of the crops sorghum, sunflower, brassica applied as sole or in combination for horse purslane (Trianthema portulacastrum) suppression was evaluated in a pot investigation. Chopped crop residues alone and in combination were incorporated at 6 g kg -1 soil (12 t ha -1), and a weedy check was maintained. Germination traits time to start germination; time to 50% emergence, mean emergence time, emergence index and final germination percentage were negatively influenced by residue incorporation. Crop residues also exerted a pronounced negative influence on the shoot and root length of horse purslane. Significant suppression in leaf and root score and leaf area per plant was also observed. A combination of sorghum and sunflower residues accounted for maximum (71%) seedling mortality. Soil incorporation of allelopathic crop residues can be employed for horse purslane management.Keywords: residues, allelopathic, sorghum, sunflower, brassica, Trianthema portulacastrum, germination/seedling growth, suppression.RESUMO -A incorporação de resíduos vegetais pode levar à supressão de plantas daninhas devido a efeitos físicos, químicos e alelopáticos. O efeito alelopático potencial de resíduos de sorgo, girassol e canola, aplicados isolados ou em combinação, foi avaliado em relação à germinação e crescimento inicial de beldroegas-cavalo (Trianthema portulacastrum) em experimento em vasos. Os resíduos vegetais foram picados e incorporados no solo na quantidade de 6 g kg -1 de solo, que é equivalente a 12 t ha -1 ; manteve-se também um tratamento sem resíduos. O tempo para iniciar a germinação, tempo de emergência de 50% (E50), tempo médio de emergência, índice de emergência e porcentagem final de germinação foram influenciados negativamente pela incorporação dos resíduos. A palhada também exerceu forte influência negativa sobre o crescimento da parte aérea e comprimento radicular de beldroegas-cavalo. Também foi observada supressão significativa na contagem de folhas e raízes e área foliar. A combinação de resíduos de sorgo e girassol causou a máxima mortalidade de plântulas, que foi de 71%. A incorporação de resíduos vegetais de culturas pode ser utilizada para o manejo de beldroegas-cavalo.

Long‐term decomposed straw return positively affects the soil microbial community

“…This might be because more available nutrients may be consumed by soil microbial organisms, but may be less utilized by crops in FS‐100%. Although greater amounts of nutrients might be released from 100% of straws than 50% (Salas et al ; Bhupinderpal‐Singh et al ), 100% of fresh straw return might hamper the root penetration and suppress the germination and seedling growth of the subsequent crop (Khaliq et al ; Su et al ), and thus decrease crop yields (Table ). These interesting results suggest that decomposed straw return could release more available nutrients to soils and might provide suitable conditions for the growth of both microbes and crops, compared with fresh straw return, irrespective of the low or high return rate.…”

“…; Yang et al ; Chen et al ), which might play key roles in straw decomposition (Bastian et al ), soil nutrient cycling (Cusack et al ) and soil health maintenance (Janvier et al ). However, high C/N ratio of straws and the presence of polymers, such as cellulose and lignin in straws may act as natural barriers for the biological degradation of the straw, and, as a consequence, hamper root penetration (Su et al ) and suppress the germination and seedling growth of the subsequent crop (Khaliq et al ), especially at relatively higher straw return rates. Moreover, straws may provide suitable circumstances for the pathogen growth, propagation and accumulation, and then contribute to crop disease (Jia et al .…”

Assessing the Response of Sesame to Inorganic and Organic Nutrient Sources

“…In contrast, shorter sesame plants produced in plots treated with 6 t/ha of sorghum husks could be attributable to increased levels of sorgoleone supplied by sorghum husks that inhibited sesame growth. Khaliq et al (2011) similarly observed negative shoot growth of horse purslane crop treated with sorghum straw. They equally attributed it to the presence of sorgoleone in sorghum straw.…”

Allelopathic Effects of Giant Sensitive Plant (Mimosa pigra) Leaf Powder on Germination and Growth of Popping Pod and Purslane

“…However, RosadoVallado et al (2000) and Rakotomalala et al (2013) reported the presence of flavonoid, quinone, saponin, sterol, tannin and phenolic compounds in M. pigra. Khaliq et al (2011) recommended that allelochemicals are usually more effective at influencing the target in a mixture than as individual compounds and Jabran et al (2015) also suggested that allelopathic activity and allelopathic effects are often due to the synergistic activity of allelochemicals rather than to a single compound because of the diversity of allelochemicals in plants. However, further isolation of the individual allelopathic substances in M. pigra responsible for the allelopathic effect of weed is a challenging and meaningful task.…”