Cowpea (Vigna unguiculata L. Walp) is an important legume mainly used for human consumption worldwide, particularly in developing countries. Cowpea legume is rich in protein (25%), carbohydrates (70%), dietary fibre, minerals and vitamins. Cowpea comprises a range of varieties that breeders release based primarily on agronomic characteristics, such as yield, early maturity and drought tolerance. However, consumers do not always adopt all the released cowpea varieties. Cooking characteristics such as cooking time and sensory properties (i.e. appearance, texture, flavour) of cooked cowpeas are believed to be quality characteristics for legume acceptability by consumers. Physicochemical characteristics are known to influence cooking characteristics of cowpeas. These characteristics may be influenced by seed coat and cotyledon structure. The present study focuses on the effect of seed coat and cotyledon structure on cooking and sensory characteristics of cowpeas and how this in turn influences consumer acceptability of cowpeas. The influence of seed coat thickness and cotyledon compactness on cooking characteristics of four cowpea types (thick seed coat/compact cotyledon (Bechuana White), thick seed coat/porous cotyledon (IT82E 18), thin seed coat/compact cotyledon (Black Eye) and thin seed coat/porous cotyledon (California Black) was studied. Seed coat thickness was found to influence water absorption during soaking. Cowpeas with thin seed coats had higher rates of water absorption during soaking due to its amorphous cell layer that rendered the seed coat more permeable compared to the palisade cell layer found in cowpeas with thick seed coats. Cotyledon compactness influenced cooking time of cowpeas. Cowpeas with porous cotyledons cooked faster compared to cowpeas with compact cotyledon probably because of the structural arrangement of porous cotyledon cells that provide more intercellular spaces for rapid water entry, cell expansion and separation favouring a faster cooking process compared to compact cotyledon. Seed coat and cotyledon structures directly influenced very few of the cooking and sensory characteristics. Sensory attributes such as cooked cowpea flavour, degree of sweetness, degree of sweet aftertaste, and degree of mushiness positively contributed to consumers’ liking of cowpeas. Raw cowpea flavour, bitter taste, degree of bitter aftertaste and degree of firmness contributed to consumers’ disliking of cowpeas. Chemical composition of cowpeas probably influences sensory characteristics of cowpeas more than seed coat and cotyledon structures. It is recommended that breeders work together with food scientists in order to release cowpeas types that are preferred by consumers (i.e. cowpeas with good appearance (low percentage of splitting), good flavour and soft texture upon cooking. Please cite as follows: Penicela, L 2010, The influence of seed coat and cotyledon structure on cooking characteristics of cowpeas, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-06292011-154445/ > E11/438/gm / Dissertation (MSc)--University of Pretoria, 2010. / Food Science / unrestricted

The composition of seed banks of areas on the drained Kissimmee River floodplain (Florida, USA) that are currently pasture and formerly had been wet prairie, broadleaf marsh, and wetland shrub communities was compared to that of seed banks of areas that have extant stands of these communities. The species composition of the seed banks of existing wet prairie and former wet prairie sites were the most similar, with a Jaccard index of similarity of 55. Existing and former broadleaf marsh and wetland shrub communities had Jaccard indices of 38 and 19, respectively. Although existing and former wet prairie seed banks had nearly the same species richness, species richness at former broadleaf marsh and wetland shrub sites was higher than at existing sites. Mean total seed densities were similar in existing and former wet prairies (700 to 800 seeds m2). However, seed densities in former broadleaf marsh and wetland shrub sites were significantly greater than in comparable existing communities (>4,900 seeds m2 at former sites versus 200 to 300 in existing communities). The higher seed densities in former broadleaf marsh and wetland shrub sites was due to over 4,000 seeds m2 of Juncus effusus in their seed banks. Half of the species that characterize wet prairies were found in the seed banks at former and existing wet prairie sites. At existing broadleaf marsh and wetland shrub sites, most of the characteristic species were found in their seed banks. However, only one characteristic broadleaf species was found in the seed banks of the former broadleaf marsh sites, and no characteristic wetland shrub species were found in the seed banks of the former wetland shrub sites. The seeds of only two non-indigenous species were found in the seed banks of former wetland communities at very low densities. For all three vegetation types, but particularly for the broadleaf marsh and wetland shrub sites, re-establishment of the former vegetation on the restored floodplain will require propagule dispersal from off-site sources.

odder is the common name for the group of plants in the genus Cuscuta· It is a serious weed in nearly all the legume seed producing areas of southern and western United States (5). Dodder is of major economic importance in the production of alfalfa, lespedeza, clover, and of less importance in such crops as flax, onions, sugar beets, and some ornamentals.

Previous studies have indicated that certain alfalfa varieties and clones are more resistant than others to alfalfa seed chalcid damage. This resistance varies in all cases and data on infestations indicate that agronomic characteristics may be responsible for some of the apparent resistance. Since this is a major pest in alfalfa seed producing areas, and cultural and chemical controls have been essentially ineffective, it was decided to determine if resistance was associated with certain pod characteristics in order to find a partial solution to the problem.

The overall objective of this study was to quantify the effects of dominant grass propagule source (i.e., cultivar vs. non-cultivar) and seeded diversity of propagules on community structure and ecosystem function during prairie restoration. Two field experiments, and two chronosequences were used to investigate this main objective. The two field experiments were established at the same latitude separated by 620 km (corresponding to a precipitation gradient from eastern Kansas to western Illinois), and consisted of a split plot design, with dominant grass source as the whole-plot factor (2 levels) and seeded dominance of grasses as the subplot factor (5 levels). Percent cover of each species in each treatment combination was quantified during the first five years of restoration. Total plant species richness and diversity were not adversely affected by cultivars in Kansas or Illinois. The effect of the dominant grass population source on the cover of focal grasses, planted species, and volunteer species were contingent upon location. By the fifth year of restoration, diversity and richness were greatest, and cover of volunteer species was lowest in the low grass dominance (i.e., high diversity) treatment. ANPP, as well as total, microbial, and mineralizable pools of C and N were measured to quantify ecosystem function in these two field experiments. Changes in ecosystem function in Kansas and Illinois were primarily driven by time and regional abiotic differences, not propagule source or seeded diversity. The effect of plant species diversity on ecosystem function was further investigated at a landscape scale by developing and sampling two chronosequences of high (HDC; n=20) and low diversity (LDC; n=15) prairies spanning over two decades of restoration in northwestern Illinois. In general most metrics of ecosystem function in both chronosequences moved towards levels measured in remnant prairies. While the constituent prairies of the HDC had higher species richness, diversity, and more rapidly increasing root biomass than the fields of the LDC, recovery of other important ecosystem functions including aboveground net primary productivity, total, microbial, and mineralizable soil C, and soil aggregate mean weighted diameter were achieved equally well with either high or low diversity prairie plantings.

Weed control is challenging for Mississippi peanut producers. Research was established during 2017 and 2018 at the Delta Research and Extension Center in Stoneville, Mississippi, to evaluate herbicide programs for weed control and reducing weed seed production in Mississippi peanut production. Treatments were combinations of acetochlor, clethodim, flumioxazin, lactofen, paraquat, and S-metolachlor with their respective adjuvants if needed. Treatments were applied: PRE, early-POST (EPOST), and/or mid-post (MPOST). All treatments included a PRE application followed by (fb) application of EPOST and/or MPOST application. Flumioxazin PRE fb lactofen plus clethodim MPOST provided greatest weed control and peanut yield. This treatment provided 88 to 100% control of barnyardgrass, hemp sesbania, Palmer amaranth, pitted morningglory, and prickly sida. Additionally, this treatment reduced total weed seed production 88% compared to the nontreated control. Flumioxazin PRE fb lactofen plus clethodim EPOST fb acetochlor MPOST provided similar weed control and peanut yield as flumioxazin PRE fb lactofen plus clethodim MPOST. This treatment provided 88 to 100% control of all weed species present and reduced total weed seed production 93%. Sequential applications of PRE, EPOST, and/or MPOST herbicide treatments provided the best season-long control of weeds and weed seed suppression in Mississippi peanut.

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Primates have important ecological roles as seed dispersers and seed predators in tropical forests. Orangutans are large-bodied frugivores that consume a high diversity of plant species, however, relatively little is known about their ecological roles. Ecological interactions are critical processes for ecosystem dynamics, structures, and functions. This dissertation investigated Bornean orangutans’ (Pongo pygmaeus wurmbii) ecological roles by studying orangutan patterns of frugivory, seed dispersal, and seed predation, dispersed seed spatial patterns, and seed fate outcomes. This research was conducted at the Cabang Panti Research Station in Gunung Palung National Park, Borneo, Indonesia. Chapter 2 analyzes orangutan seed dispersal behavior using the seed dispersal effectiveness framework to identify which fruits orangutans are most effectively dispersing. Orangutans predated seeds more frequently than they spat or swallowed seeds. Additionally, the fruits preferred most by orangutans were highly predated. Despite the prevalence of seed predation, orangutans also frequently dispersed seeds, 71.8% of fecal samples contained seeds with a mean of 28 seeds (>2mm) per fecal sample. Chapter 3 models orangutan seed dispersal distances to understand how far orangutans are dispersing seeds across the landscape and if seeds are dispersed across habitat types. This study found orangutans dispersed seeds, on average, 400-650m. There were occasional long distance seed dispersal events, and the maximum dispersal distance was 2.2km. Both male and female orangutans dispersed seeds long distances (>1km). Unflanged male orangutans dispersed seeds the longest mean distances of the age-sex classes with the farthest mean maximum distances at the 80-hour gut retention time. In Chapter 4, the fate of seeds dispersed by orangutans is investigated along with the variation underlying the fate of dispersed seeds. Camera traps and seed tracking studies revealed the orangutan primary seed shadow was heavily reshaped post-dispersal. By 6-months post dispersal, most orangutan dispersed seeds (86-87%) had been removed, mostly by seed predators, and almost all of the remaining seeds (11-14%) had died. This dissertation reveals orangutans are involved in important ecological interactions. Orangutans disperse and predate high quantities of seeds from many plant genera, and the loss of the orangutan would likely negatively affect their natural ecosystems. / 2026-10-31T00:00:00Z

Anthropogenic habitat disturbance is the leading cause of global biodiversity decline. Urbanization in particular is one of the most drastic forms of habitat disturbance, and it is associated with a decrease in both plant and animal diversity. Changes in biodiversity can affect the interactions between the remaining species within an ecosystem, which can, in turn, affect the provision of essential ecosystem services such as seed dispersal and pollination. Despite the wealth of studies examining the effects of urbanization on biodiversity, however, relatively few studies have investigated how urbanization impacts the interactions between species and the ecosystem services provided by them. Seed dispersal is one such ecosystem service which provides an ideal study system for investigating these effects. The goal of this study was to assess the impact of urbanization on avian seed dispersal networks in southern Appalachia. Specifically, we investigated the impact on species richness, interaction richness, and several network metrics related to ecosystem function (H2, interaction evenness, and weighted nestedness). The study was conducted across two fall – winter observation periods to coincide with the period of peak fruit production, from September – January in 2021-2022 and 2022-2023. Data was collected from 9 study sites during multiple visits via direct observation of bird-fruit interactions, with a total of 635 interactions recorded from 32 bird species on 18 fruiting plant species. Although data analysis is currently ongoing, initial results seem to indicate that there is no significant difference in species richness or interaction richness between natural and urban sites. This has interesting implications, as it suggests that plant-frugivore networks are relatively robust to disturbance caused by urbanization, which is promising for the continued provision of ecosystem services in urban areas.

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