Response of pale swallowwort (Vincetoxicum rossicum) to multiple years of mowing

2019 ◽  
Vol 12 (03) ◽  
pp. 169-175
Author(s):  
Jeromy Biazzo ◽  
Lindsey R. Milbrath
Keyword(s):  
United States ◽  
Seed Production ◽  
Cropping Systems ◽  
Growing Season ◽  
Stem Density ◽  
Percent Cover ◽  
Mechanical Control ◽  
Vincetoxicum Rossicum ◽  
Crown Density ◽  
Broadleaf Species

AbstractPale swallowwort (Vincetoxicum rossicum), as well as its congener, black swallowwort (Vincetoxicum nigrum), is a European viny milkweed that has become invasive in natural areas and perennial cropping systems in the northeastern and midwestern United States and southeastern Canada. Mechanical control over 1 to 2 yr has not been effective, but studies of a longer duration are needed. We measured effects of mowing (no mowing or three or six times per growing season) on stem and root crown densities, percent cover, and follicle (seed pod) production of V. rossicum and percent cover of other vegetation over a 7-yr period. Stem density, root crown density, and percent cover of V. rossicum were reduced after 3 to 5 yr of mowing regardless of mowing frequency. Cover of other, mostly nonnative, broadleaf species increased. Follicle production was eliminated in all years of the study. In our environment, mowing three times at monthly intervals during the growing season can prevent seed production. However, mowing must occur for at least 3 yr to reduce, but not eliminate, stands of V. rossicum.

Glyphosate-Resistant Palmer Amaranth (Amaranthus palmeri) Morphology, Growth, and Seed Production in Georgia

Weed Science ◽  
2015 ◽  
Vol 63 (1) ◽  
pp. 264-272 ◽  
Author(s):  
Theodore M. Webster ◽  
Timothy L. Grey
Keyword(s):  
United States ◽  
Seed Production ◽  
Growing Season ◽  
Palmer Amaranth ◽  
Competitive Balance ◽  
Potential Growth ◽  
Southeast United States ◽  
Alternative Means ◽  
Soil Seedbank ◽  
Crop Competition

Herbicide-resistant Palmer amaranth has become the most economically detrimental weed of cotton in the southeast United States. With the continual marginalization of potential herbicide tools, research has expanded to include alternative means of affecting future Palmer amaranth populations by altering safe sites and reducing inputs to the seedbank population. The influence of delayed Palmer amaranth establishment on seed production potential has not been investigated in the southeast United States. Studies were conducted to evaluate the influence of time of Palmer amaranth establishment on morphology, growth, and seed production. The experiment was a factorial, with five levels of Palmer amaranth transplanting (0 to 12 wk after cotton planting) and two levels of crop type (cotton and noncrop). In the absence of crop competition, the first cohort of Palmer amaranth produced 446,000 seeds per plant. This potential seed production was reduced 50% when Palmer amaranth plants were established nearly 6 wk later. In contrast, the first Palmer amaranth cohort growing in competition with cotton produced 312,000 seeds, 30% less than was produced in the absence of competition. Interference from cotton shifted time to 50% seed production to nearly 4 wk earlier in the growing season, relative to plants without crop competition. Delayed establishment of Palmer amaranth simulates premature loss of herbicide efficacy and alters the competitive balance between cotton and Palmer amaranth. Although the planting time that resulted in 50% reduction in Palmer amaranth plant height at the end of the season was not affected by the presence of cotton, 50% reduction in plant width and biomass occurred within the first 3.8 wk of the growing season when growing with cotton, more than 4 wk earlier than Palmer amaranth growing without a crop. This suggests that early season weed control programs will have a large effect on Palmer amaranth potential growth and seed production, as well as crop yield. To implement soil seedbank reduction strategies effectively, information on mechanisms that regulate Palmer amaranth persistence in the soil seedbank is needed.

scholarly journals Rattail fescue (Vulpia myuros) interference and seed production as affected by sowing time and crop density in winter wheat

Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Seed Production ◽  
Yield Components ◽  
Field Experiments ◽  
Growing Season ◽  
Sowing Time ◽  
Growing Seasons ◽  
Crop Density ◽  
Wide Range

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.

scholarly journals Seed production of barnyardgrass (Echinochloa crus-galli) in response to time of emergence in cotton and rice

2011 ◽  
Vol 150 (6) ◽  
pp. 717-724 ◽  
Author(s):  
M. V. BAGAVATHIANNAN ◽  
J. K. NORSWORTHY ◽  
K. L. SMITH ◽  
P. NEVE
Keyword(s):  
United States ◽  
Seed Production ◽  
Herbicide Resistance ◽  
Crop Production ◽  
Integrated Management ◽  
Resistance Management ◽  
Simulation Models ◽  
Effective Resistance ◽  
Southern United States

SUMMARYThe spread of herbicide resistance in barnyardgrass (Echinochloa crus-galli(L.) Beauv.) poses a serious threat to crop production in the southern United States. A thorough knowledge of the biology of barnyardgrass is fundamental for designing effective resistance-management programmes. In the present study, seed production of barnyardgrass in response to time of emergence was investigated in cotton and rice, respectively, in Fayetteville and Rohwer, Arkansas, over a 2-year period (2008–09). Barnyardgrass seed production was greater when seedlings emerged with the crop, but some seed production was observed even if seedlings emerged several weeks after crop emergence. Moreover, barnyardgrass seed production was highly variable across environments. When emerging with the crop (0 weeks after crop emergence (WAE)), barnyardgrass producedc. 35 500 and 16 500 seeds/plant in cotton, andc. 39 000 and 2900 seeds/plant in rice, in 2008 and 2009, respectively. Seed production was observed when seedlings emerged up to 5 WAE (2008) or 7 WAE (2009) in cotton and up to 5 WAE (2008, 2009) in rice; corresponding seed production wasc. 2500 and 1500 seeds/plant in cotton, andc. 14 700 and 110 seeds/plant in rice, in 2008 and 2009, respectively. The results suggest that cultural approaches that delay the emergence of barnyardgrass or approaches that make the associated crop more competitive will be useful in integrated management programmes. In the context of herbicide resistance management, it may be valuable to prevent seed return to the seedbank, irrespective of cohorts. The findings are vital for parameterizing herbicide resistance simulation models for barnyardgrass.

scholarly journals Effect of Heat Resource Effectiveness Change on Rice Potential Yield in Southern China

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 896
Author(s):  
Qing Ye ◽  
Xiaoguang Yang ◽  
Wenjuan Xie ◽  
Junmeng Yao ◽  
Zhe Cai
Keyword(s):  
Southern China ◽  
Cropping Systems ◽  
Reduction Rate ◽  
Growing Season ◽  
Scientific Basis ◽  
Yield Reduction ◽  
Percentage Increase ◽  
Potential Yield ◽  
Effective Heat ◽  
Rice Growing Season

During the rice growing season, farmers’ decisions about cropping systems and seed varieties directly affect the utilization of heat resource, and eventually affect the potential yield. In this study, we used the hourly accumulated temperature model to calculate the available heat resource as well as the effective heat resource in southern China. We conducted a spatiotemporal analysis of the heat resource effectiveness during rice growing season and an impact assessment of heat resource effectiveness on rice potential yield and cereal yield reduction. The results showed that, during the period of 1951–2015, heat resource effectiveness generally declined in the rice cropping area of southern China. And this decrease worsened during the most recent three decades compared with the period of 1951–1980. A strong correlation was detected between heat resource effectiveness and rice potential yield in the study area. When the effective heat resource during the growing season increased by 1 °C·d, rice potential yield would increase by 14 kg ha−1. For each percentage increase in heat resource effectiveness, the rice potential yield reduction rate would go down by 0.65%. This agro-climatological study aims to offer a scientific basis for rice production decisions in southern China, such as when to plant, which varieties to choose and so on.

Early growth of lodgepole pine after establishment of alsike clover–Rhizobium nitrogen-fixing symbiosis

1992 ◽  
Vol 22 (8) ◽  
pp. 1089-1093 ◽  
Author(s):  
R. Trowbridge ◽  
F.B. Holl
Keyword(s):  
Forest Floor ◽  
Lodgepole Pine ◽  
Nitrogen Concentration ◽  
Growing Season ◽  
Early Growth ◽  
Percent Cover ◽  
Foliar Nitrogen ◽  
Growing Seasons ◽  
Pine Seedlings ◽  
Needle Mass

An overdense lodgepole pine (Pinuscontorta Dougl. ex Loud.) stand was knocked down and the site was prepared by broadcast burn, windrow burn, or mechanical forest floor removal. Inoculated alsike clover (Trifoliumhybridum L.) was seeded at 0, 10, 20, and 30 kg/ha for the three different site preparation treatments to determine the effects of (i) site preparation on infection and effectiveness of the clover–Rhizobium symbiosis and clover percent cover and (ii) the clover–Rhizobium N2-fixing symbiosis on survival, early growth, and foliar nitrogen concentration of lodgepole pine seedlings. The N2-fixing symbiosis established well in all treatments. Clover percent cover increased with increasing rate of seeding, although by relatively few percent in the clover seeded plots. Broadcast burning, windrow burning, and mechanical forest floor removal did not affect the establishment of the N2-fixing symbiosis or clover percent cover. Lodgepole pine survival was not affected by the seeding treatments in any year, nor were height measurements during the first three growing seasons. Seedling height was slightly less in clover-seeded plots compared with controls in the fourth growing season. Lodgepole pine seedlings on clover-seeded plots had decreased diameter growth compared with controls during the first three growing seasons, but incremental diameter growth no longer showed this effect by the fourth growing season. Needle mass (g/100 needles) was less in clover-seeded plots at the end of the second growing season, but this effect was reversed by the fourth growing season, when both needle mass and foliar nitrogen concentration in lodgepole pine foliage were greater in clover-seeded plots.

scholarly journals Identifying maize yield and precipitation gaps in Uganda

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Terence Epule Epule ◽  
Driss Dhiba ◽  
Daniel Etongo ◽  
Changhui Peng ◽  
Laurent Lepage
Keyword(s):  
Cropping Systems ◽  
Growing Season ◽  
Maize Yield ◽  
Sub Saharan Africa ◽  
World Bank Group ◽  
Precipitation Data ◽  
Yield Data ◽  
Yield Gaps ◽  
Maize Yields ◽  
Growing Season Precipitation

AbstractIn sub-Saharan Africa (SSA), precipitation is an important driver of agricultural production. In Uganda, maize production is essentially rain-fed. However, due to changes in climate, projected maize yield targets have not often been met as actual observed maize yields are often below simulated/projected yields. This outcome has often been attributed to parallel gaps in precipitation. This study aims at identifying maize yield and precipitation gaps in Uganda for the period 1998–2017. Time series historical actual observed maize yield data (hg/ha/year) for the period 1998–2017 were collected from FAOSTAT. Actual observed maize growing season precipitation data were also collected from the climate portal of World Bank Group for the period 1998–2017. The simulated or projected maize yield data and the simulated or projected growing season precipitation data were simulated using a simple linear regression approach. The actual maize yield and actual growing season precipitation data were now compared with the simulated maize yield data and simulated growing season precipitation to establish the yield gaps. The results show that three key periods of maize yield gaps were observed (period one: 1998, period two: 2004–2007 and period three: 2015–2017) with parallel precipitation gaps. However, in the entire series (1998–2017), the years 2008–2009 had no yield gaps yet, precipitation gaps were observed. This implies that precipitation is not the only driver of maize yields in Uganda. In fact, this is supported by a low correlation between precipitation gaps and maize yield gaps of about 6.3%. For a better understanding of cropping systems in SSA, other potential drivers of maize yield gaps in Uganda such as soils, farm inputs, crop pests and diseases, high yielding varieties, literacy, and poverty levels should be considered.

scholarly journals Quantifying seed production by volunteer canola (Brassica napus) and Sinapis arvensis

2011 ◽  
Vol 29 (3) ◽  
pp. 489-497
Author(s):  
E Soltani ◽  
A Soltani ◽  
S Galeshi ◽  
F Ghaderi-far ◽  
E Zeinali
Keyword(s):  
Brassica Napus ◽  
Seed Production ◽  
Cropping Systems ◽  
Plant Size ◽  
Quantitative Information ◽  
Sinapis Arvensis ◽  
Soil Seed Banks ◽  
Sowing Dates ◽  
Wide Range ◽  
Close Relationship

Volunteer canola (Brassica napus) and Sinapis arvensis are well identified weeds of different cropping systems. Quantitative information on regarding seed production by them is limited. Such information is necessary to model dynamics of soil seed banks. The aim of this work was to quantify seed production as a function of the size of those weeds. A wide range of plant size was produced by using a fan seeding system performed at two sowing dates (environments). Plant size varied from 3 to 167 g per plant for canola and from 6 to 104 g per plant for S. arvensis. Seed production ranged from 543 to14,773 seeds per plant for canola, and from 264 to 10,336 seeds per plant for S. arvensis. There was a close relationship between seed production per plant and plant size which was well-described by a power function (y = 130.6x0.94; R² = 0.93 for canola and y = 28x1.27; R² = 0.95 for S. arvensis). There was also strong relationships among the number of pods produced in individual plants and the quantity of seeds produced (g per plant) with the size of the plant. The relationships found in this study can be used in dynamic seed bank models of volunteer canola and S. arvensis.

scholarly journals Soil microbial biomass and function are altered by 12 years of crop rotation

2016 ◽  
Author(s):  
Marshall D. McDaniel ◽  
A. Stuart Grandy
Keyword(s):  
Microbial Community ◽  
Microbial Biomass ◽  
Crop Rotation ◽  
Soil Microbial Biomass ◽  
Cropping Systems ◽  
Growing Season ◽  
Plant Biodiversity ◽  
Soil Microbial ◽  
Catabolic Potential ◽  
And Function

Abstract. Agriculture-driven declines in plant biodiversity reduce soil microbial biomass, alter microbial functions, and threaten the provisioning of soil ecosystem services. We examined whether increasing temporal plant biodiversity (by rotating crops) can partially reverse these trends and enhance microbial biomass and function. We quantified seasonal patterns in soil microbial biomass, respiration rates, extracellular enzyme activity, and catabolic potential three times over one growing season in a 12-year crop rotation study at the W.K. Kellogg Biological Station LTER. Rotation treatments varied from one to five crops in a three-year rotation cycle, but all soils were sampled under corn to isolate historical rotation effects from current crop effects. Inorganic N, the stoichiometry of microbial biomass and dissolved organic C and N varied seasonally, likely reflecting fluctuations in soil resources during the growing season. Soils from biodiverse cropping systems increased microbial biomass C by 28–112 % and N by 18–58 % compared to monoculture corn. Rotations increased potential C mineralization by as much as 64 %, and potential N mineralization by 62 %, and both were related to substantially higher hydrolase and lower oxidase enzyme activities. The catabolic potential of the microbial community, assessed with community-level physiological profiling, showed that microbial communities in monoculture corn preferentially used simple substrates like carboxylic acids, relative to more diverse cropping systems. By isolating plant biodiversity from differences in fertilization and tillage, our study illustrates that crop biodiversity has overarching effects on soil microbial biomass and function that last throughout the growing season. In simplified agricultural systems, relatively small increases in plant biodiversity have a large impact on microbial community size and function.

scholarly journals Results of the weed control in onion (Allium Cepa L.) field

2021 ◽  
Vol 1 (3) ◽  
pp. 1-9
Author(s):  
O. Ariunaa ◽  
T. Erdenenzorig ◽  
B. Dondov
Keyword(s):  
Weed Control ◽  
Seed Production ◽  
Experimental Research ◽  
Plant Protection ◽  
Growing Season ◽  
Crop Damage ◽  
Weed Species ◽  
Domestic Production ◽  
Allium Cepa L ◽  
Production Demand

Our country has provided about 52% of vegetables from domestic production, the rest part imported others from outside. Thus, imports of potatoes and vegetables have been reduced last year, for this reason, main vegetable seeds, were produced domestically and provided over 80 percent of the country’s demand. In the future domestic production demand of vegetable goal set working to provide by 100 percent from government our country in this connection issues urgent need to solve sowing seeds, variety supply, seed production, and plant protection. According to our research, during the growing season, 150-350 weeds growing per 1m2 of rounded onions shows that the amount of crop damage is relatively high. For the purpose of control against weeds in the onion field with 3 repetitions of 7 variants of 2 types of herbicides are conducted experimental research. These include; pre-emergent Estamp (Stomp) herbicide applied in doses 2.5; 3.5 l/ha that controls all types of weeds, but showed results of 65.2-72.4%. The growing season during a selective post-emergent of Gaur herbicide in doses 0.7; 0.9l/ ha used against broadleaf and grassy weeds that became clear of weed species density reduced by 92.7-93.4%. It was tested in this study Pendimethalin, 33% + Oxyfluorfen 24 % mixture herbicides have reduced the number of weeds by 92.4-94.1%.

Sign in / Sign up

Export Citation Format

Share Document