The Growth and Development of Five Waterhemp (Amaranthus tuberculatus) Populations in a Common Garden

Weed Science ◽  
2017 ◽  
Vol 65 (2) ◽  
pp. 247-255 ◽  
Author(s):  
Joseph M. Heneghan ◽  
William G. Johnson

Waterhemp is a weed indigenous to the midwestern United States and is problematic in agronomic crop production. This weed is well suited to inhabit minimally tilled environments and is increasing in prevalence across many agricultural production areas and systems. A common garden experiment was established in Indiana in 2014 and 2015 with waterhemp populations from Indiana, Illinois, Missouri, Iowa, and Nebraska to compare the growth and development of waterhemp from these regions. Three establishment dates (May, June, and July) were used each year to simulate discontinuous germination. Mean biomass accumulations from the May (1,120 g plant−1) and June (1,069 g plant−1) establishment dates were higher than from the July (266 g plant−1) establishment date. There were no differences in biomass accumulations between the five populations in the May and June establishments, but biomass accumulations ranged from 195 to 338 g plant−1in the July establishment. Mean seed yields were higher from the May (926,629 seeds plant−1) and June (828,905 seeds plant−1) establishment dates compared with the July (276,258 seeds plant−1) establishment. In the May and June establishments, seed yields ranged from 469,939 seeds plant−1to 1,285,556 seeds plant−1. The Illinois population flowered the latest of all the populations yet also grew the tallest. The July establishment flowered the most rapidly after establishment, accumulated less biomass, and also had the largest seeds. This study demonstrated differences among waterhemp populations when grown in a common environment and the effect of establishment timing on waterhemp growth and development.

EDIS ◽  
2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Yuvraj Khamare ◽  
Chris Marble ◽  
Robert Stamps

Benghal dayflower is listed among the world’s worst weeds, affecting over 25 crops in 29 countries (Holm et al., 1977). Benghal dayflower has many characteristics that make it a very troublesome weed in Florida landscapes, nurseries and other agricultural production areas. It was first recorded in Florida in 1928 and was designated as a legally noxious weed by the U.S Department of Agriculture in 1983 (Faden, 1993). Due to its status as a legally noxious weed, presence of benghal dayflower on nursery property can lead to quarantines, so identification and management is critical for nurseries. This 5-page article is written for green industry professionals and others to aid in the identification and management of benghal dayflower in and around ornamental plants. Major revision by Yuvraj Khamare, Chris Marble, and Robert Stamps, and published by the UF/IFAS Environmental Horticulture Department. Previous version: Stamps, Robert. 2011. “Prevention, Early Detection, and Eradication of Benghal Dayflower in Field Nurseries”. EDIS 2011 (5/6). https://journals.flvc.org/edis/article/view/119299.


EDIS ◽  
2020 ◽  
Vol 2020 (5) ◽  
pp. 5
Author(s):  
Thomas Smith ◽  
Chris Marble ◽  
Shawn Steed ◽  
Nathan Boyd

Garden spurge is a prostrate (low-growing), herbaceous, short-lived, warm-season annual weed commonly found growing in Florida landscapes, container nurseries, and other agricultural production areas. This article is written for green industry professionals and others to aid in the identification and management of garden spurge in and around ornamental plants.


2021 ◽  
pp. 1-6
Author(s):  
Jessica S. Ambriz ◽  
Clementina González ◽  
Eduardo Cuevas

Abstract Fuchsia parviflora is a dioecious shrub that depends on biotic pollination for reproduction. Previous studies suggest that the male plants produce more flowers, and male-biased sex ratios have been found in some natural populations. To assess whether the biased sex ratios found between genders in natural populations are present at the point at which plants reach sexual maturity, and to identify possible trade-offs between growth and reproduction, we performed a common garden experiment. Finally, to complement the information of the common garden experiment, we estimated the reproductive biomass allocation between genders in one natural population. Sex ratios at reaching sexual maturity in F. parviflora did not differ from 0.5, except in one population, which was the smallest seedling population. We found no differences between genders in terms of the probability of germination or flowering. When flowering began, female plants were taller than males and the tallest plants of both genders required more time to reach sexual maturity. Males produced significantly more flowers than females, and the number of flowers increased with plant height in both genders. Finally, in the natural population studied, the investment in reproductive biomass was seven-fold greater in female plants than in male plants. Our results showed no evidence of possible trade-offs between growth and reproduction. Despite the fact that female plants invest more in reproductive biomass, they were taller than the males after flowering, possibly at the expense of herbivory defence.


2011 ◽  
Vol 150 (6) ◽  
pp. 717-724 ◽  
Author(s):  
M. V. BAGAVATHIANNAN ◽  
J. K. NORSWORTHY ◽  
K. L. SMITH ◽  
P. NEVE

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.


2011 ◽  
Vol 12 (1) ◽  
pp. 34 ◽  
Author(s):  
Craig G. Webster ◽  
William W. Turechek ◽  
H. Charles Mellinger ◽  
Galen Frantz ◽  
Nancy Roe ◽  
...  

To the best of our knowledge, this is the first report of GRSV infecting tomatillo and eggplant, and it is the first report of GRSV infecting pepper in the United States. This first identification of GRSV-infected crop plants in commercial fields in Palm Beach and Manatee Counties demonstrates the continuing geographic spread of the virus into additional vegetable production areas of Florida. This information indicates that a wide range of solanaceous plants is likely to be infected by this emerging viral pathogen in Florida and beyond. Accepted for publication 27 June 2011. Published 25 July 2011.


2018 ◽  
Vol 425 ◽  
pp. 35-44 ◽  
Author(s):  
Timothy J. Albaugh ◽  
Thomas R. Fox ◽  
Chris A. Maier ◽  
Otávio C. Campoe ◽  
Rafael A. Rubilar ◽  
...  

2017 ◽  
Vol 60 (5) ◽  
pp. 1669-1680 ◽  
Author(s):  
Daniel Steven Andersen ◽  
Laura M. Pepple

Abstract. During the twentieth century, U.S. agriculture strived to achieve increased food production in order to satisfy both local and export demands. In many cases, this led to increased farm sizes and an operational separation of crop and livestock production. The trend of increasing centralization and industrialization of agriculture, specifically animal agriculture, has resulted in the concentration of waste products associated with animal production (manures and wash-down water) over relatively small geographic areas that are spatially segregated from crop production areas. Because the distance that manure can be economically hauled for land application has practical limits, the public is concerned that this spatial separation of crop and animal production areas could lead to over-application of manures near animal feeding facilities, and thus potentially increase the transport of nutrients to ground and surface waters. An aggregated analysis (statewide) of crop and animal production in Iowa suggests that about 30% to 40% of current nitrogen and phosphorus requirements for crop production could be supplied from manures and litters generated from livestock production, while about 50% of potassium requirements could be supplied. However, neither livestock nor crop production in Iowa is uniformly distributed across all counties. This unequal distribution suggests that a more disaggregated analysis of crop nutrient requirements and manure nutrient supply is necessary to estimate the risks of excess nutrient loss to the environment. Thus, we evaluated crop nutrient demand and manure and litter production at the county level to determine if excess manure generation is of concern and to locate areas where additional manures could be used. Results showed that several counties are becoming manure rich, but most locations maintain sufficient capacity to use manure nutrients effectively. Keywords: Crop nutrient capacity, Manure management, Manure production, Nutrient balance, Nutrient management.


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