Residues of sweet sorghum promotes suppression of weeds in sugarcane rotation

Sorghum is an important crop to plant in rotation with sugarcane. This is mainly because both are inputs for the ethanol industry. Crop residues of sweet sorghum promote suppression of weed re-infestation, avoiding weed interference to the sugarcane crop due to the strong allelopathic potential of sorghum. In order to determine the suppressive effects of sorghum crop residues on weeds, a field experiment was carried out. Seven vegetation covers were used as options for crop rotation with sugarcane. The treatments were sweet sorghum, velvet bean, sunflower, soybean, sugar cane, fallow, and an area without cover. The experiment was randomized blocks with four replications of 27 m2 plots. The weed community of each plot was evaluated by phytosociological indexes at 60 and 120 days after the formation of vegetation cover. The composition of soil seed bank was also evaluated. The weeds with the highest indexes of relative importance during the evaluations were Cyperus rotundus, Raphanus raphanistrum and Parthenium hysterophorus. The diversity of the weed community, estimated by relative importance indexes, was lower in the area with velvet bean as soil cover. Sorghum, velvet bean and sunn hemp covers reduced the soil seed bank compared to the fallow treatment and the treatment without vegetation cover. Crop residues of sweet sorghum and velvet bean provide a decrease in weed infestation in field, and the weed suppression period can last up to 120 days during the dry season.

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Variation of seed dormancy and longevity in Raphanus raphanistrum L.

Seed Science Research ◽

10.1017/s0960258517000319 ◽

2017 ◽

Vol 28 (1) ◽

pp. 34-40 ◽

Cited By ~ 5

Author(s):

Yann Tricault ◽

Annick Matejicek ◽

Henri Darmency

Keyword(s):

Seed Bank ◽

Management Practices ◽

Soil Seed Bank ◽

Seasonal Pattern ◽

Fruit Size ◽

The Other ◽

Integrated Weed Management ◽

Raphanus Raphanistrum ◽

Rapid Reduction ◽

Fruit Wall

AbstractRaphanus raphanistrum (wild radish) is a highly competitive weed in winter crops. Integrated weed management practices and decision-making tools benefit from the ability to predict seed longevity and dormancy status in the soil seed bank, as well as time and density of emergence in the field. We wondered if unique values taken from databases could serve for modelling purposes, whatever the origins of the weed populations. We investigated dormancy and longevity of fruits buried in the soil over a four-year seed burial experiment of two highly contrasted populations that differ by their biogeographical origin (oceanic versus continental climate), their habitat (arable field versus undisturbed) and their fruit size (thick versus thin fruit wall). High viability persisted over two years, followed by a rapid reduction, especially for the ‘continental-undisturbed-thin’ population. Dormancy cycling, with dormancy at its lowest in October, was observed for the ‘oceanic-arable-thick’ population, whilst a slow decrease without clear seasonal pattern was found for the other population. These results indicate different ways of regulating seed persistence in the soil, which might be taken into account when building demographic models. These differences could be due to interactions between fruit wall thickness and the other factors; it is possible that a thicker fruit wall increases longevity by promoting dormancy by physical restriction, but depending on temperature. Thinner fruit walls would make plants display other adaptive strategies to maximize survival time in the soil seed bank. Studies involving more populations and isogenic material are needed to address this specific question.

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Seed and vegetation dynamics in an alpine herb field: effects of disturbance type

Canadian Journal of Botany ◽

10.1139/b93-052 ◽

1993 ◽

Vol 71 (3) ◽

pp. 471-485 ◽

Cited By ~ 68

Author(s):

Jeanne C. Chambers

Keyword(s):

Seed Bank ◽

Vegetation Cover ◽

Soil Seed Bank ◽

Vegetative State ◽

Seed Rain ◽

Life History Strategies ◽

Small Scale ◽

Pocket Gopher ◽

Growing Seasons ◽

Highly Correlated

Relationships among the aboveground vegetation, seed rain, and seed bank were examined on a late seral herb field characterized by pocket gopher disturbance and on an early seral gravel borrow that had been severely disturbed 35 years ago on the Beartooth Plateau, Montana. Aboveground vegetation cover was assessed by species in twelve 5-m2 plots. Seed rain was sampled during the 1988, 1989, and 1990 growing seasons with pitfall traps, and the soil seed bank was sampled in fall 1989, spring 1990, and fall 1990. The seed rain (filled seeds) on the borrow area ranged from 7730 to 14 009 seeds/m2 and was higher than that found on other alpine sites; that on the Geum turf ranged from 3375 to 6179 seeds/m2 and was similar to that for other alpine sites. Although highly variable among dates on the borrow area, the seed banks were similar to those of comparable alpine sites. Seed bank density ranged from 1980 to 6003 seeds/m2 on the borrow area and from 3202 to 4647 seeds/m2 on the Geum turf area. The Geum turf area had higher vegetation cover than the borrow area (87 vs. 25%) and higher numbers of species in the aboveground vegetation, seed rain, and seed bank. Relationships among the aboveground vegetation, seed rain, and seed bank were largely determined by the disturbance characteristics of the different sites and the life-history strategies of the dominant species. Medium-lived species, primarily grasses, with high production of small and compact seeds had colonized the borrow area. Despite establishment of other species, 35 years after disturbance the medium-lived species still dominated the aboveground vegetation, seed rain, and seed bank. Species abundances in the three different components were all highly correlated. In contrast, on the Geum turf area there were no correlations among the aboveground vegetation, seed rain, or seed bank. Long-lived forbs that produced low numbers of relatively large seeds dominated the aboveground vegetation and persisted on the area primarily in the vegetative state. The same medium-lived species that dominated the borrow area had the highest abundance in the seed rain on the Geum turf area and appeared to persist by colonizing small-scale disturbances caused by gopher burrowing. Short-lived species with small, long-lived seeds existed on the site primarily through a highly persistent seed bank. The relationships among the aboveground vegetation, seed rain, and seed bank on the Geum turf and borrow areas are compared with those observed for more temperate systems following disturbance. Key words: alpine, herb field, Geum turf, disturbance, vegetation cover, seed rain, seed bank, colonization, establishment, succession.

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Population Distribution of Wild Radish (Raphanus Raphanistrum L.) Weed and Soil Depth of Seed Bank Across Different Land-Use Types in Horro District, Western Oromia, Ethiopia

10.21203/rs.3.rs-629597/v1 ◽

2021 ◽

Author(s):

Geleta Shone ◽

Fikiru Wakoya ◽

Zerihun Jaleta ◽

Hirpha Legese

Keyword(s):

Land Use ◽

Seed Bank ◽

Soil Depth ◽

Soil Seed Bank ◽

Wild Radish ◽

Raphanus Raphanistrum ◽

Weed Species ◽

Land Use Types ◽

Significant Difference ◽

Weed Flora

Abstract Background: Wild radish (Raphanus raphanistrum L.) is an invasive weed in Ethiopia and hurting different land use types in the Horro district of the study area and fact, more research has not been done yet on the weed is highly infested and persisted for three decades. Therefore, this study was conducted to assess the weeds flora and seed bank status across different land use types in the Horro district of western Oromia, Ethiopia. Three locations and from each location five different land use were purposively selected and a 1m2 area of quadratic sampling techniques was used to record weed flora. From each quadrat, soil samples were taken having two soil depth levels (0-15cm and >15-30cm) to evaluate the soil seed bank of weeds. Results: The data of wild radish weed in different location and different land use types both field survey and greenhouse experiments were found a statistically significant difference (p<0.05) among the target action of land use types but there was found no significant difference among soil depths. More all less, the highest wild radish population was recorded from grazing land land followed by wheat crop land and among the locations, Gitilo Dale has the highest weed density. Among the weed flora, again wild radish was highly dominated weed species than the other weed species in all land use types and locations. From soil seed bank status of soil depth, high weed population was recorded at 0-16cm of second season weed emergence from pot and Gitilo Dale was the highest infected location at this season, while barley crop land was the highest infected among land use types in first season of weed emergence from pot. Among the weed species were recorded from soil depth, again wild radish was highly dominated in both seasons. The population of weed flora per quadrat was directly proportion with population recorded from soil depth that emerged from pot. Conclusions: This study has highly verified that this area has highly infected by wald radish (Raphanus raphanistrum) and there could be a source of weed seed. Generally, the concerned bodies should have to be given attention which should need immediate intervention strategies to mitigate the negative impacts of weed otherwise the area will be out of production soon. Therefore, an extensive integrated weed management strategies should be applied in all phases of cropping systems to sustain environment and reduce this weed in the future.

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Necromass as seed reservoir in macroforb meadows with varied moisture conditions

Acta Agrobotanica ◽

10.5586/aa.1693 ◽

2016 ◽

Vol 69 (4) ◽

Cited By ~ 1

Author(s):

Magdalena Franczak ◽

Bożenna Czarnecka

Keyword(s):

Seed Bank ◽

Vegetation Cover ◽

Soil Seed Bank ◽

Plant Cover ◽

Lythrum Salicaria ◽

Plant Parts ◽

Dead Plant ◽

Moisture Conditions ◽

And Storage

Necromass, i.e., dead plant parts, has a great impact on the spatial patterns of populations and communities. Depending on its thickness and the degree of decomposition, it may constitute a space-blocking physical barrier and impede recruitment of individuals due to, e.g., autotoxication. The aim of the study was to determine the role of the necromass layer in formation of the soil seed bank of variously moist meadow communities and its influence on the efficiency of generative reproduction. The authors paid special attention to the possibility of capture and storage of seeds of species occurring in the vegetation cover by necromass. Additionally, selected features of seeds of species present on the necromass were analyzed in order to identify species that can potentially contribute to formation of the necromass seed bank.The plant cover comprised 52 species in total. Seedlings of 21 taxa appeared on the necromass and their number ranged from 10 to 13, depending on the patch. The density of the seedlings ranged from 339 to 4923 m−2. In all patches, Lythrum salicaria and Lysimachia vulgaris seedlings were most numerous. These two species were characterized by the highest frequency as well. The low values of Jaccard’s index (0.28–0.36) imply a low share of taxa that are common for the necromass and the vegetation cover. This result should be explained by the occurrence of large disproportions in the number of all species identified on the necromass and among the vegetation. The seeds are typically characterized by small sizes and usually have smooth or finely striated and/or ribbed surface texture. The presence of additional structures, e.g., pappus and hairs, in the largest and heaviest seeds (Crepis paludosa, Geum rivale, and Cirsium spp.) may help seeds capture in the necromass.

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