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Moser Park is a property in Allen County, Indiana, managed by New Haven Parks and Recreation. We conducted a plant survey within the forested section of the park, identifying and quantifying abundance of understory, midstory, and overstory plants. We calculated species richness and Shannon's index for all three strata and tested for relationships with environmental variables (i.e., canopy cover, soil compaction, litter depth, and light availability). The majority of understory species are typically associated with disturbed habitats, with very little resemblance to natural, pre-settlement habitat (i.e., low coefficient of conservation values). Understory cover was dominated by Rubus allegheniensis. Midstory stratum was less diverse than the understory and was dominated by an abundance of Fraxinus pennsylvanica, which was also an important species in the overstory. The forest at Moser Park matched the Hackberry–American Elm–Green Ash forest type. There was a lack of both Quercus and many Acer spec...

Traits associated with root morphology and nutrient uptake rate may contribute to the competitive ability of invasive species by determining their access to soil nutrients and their ability to extract those resources. Here, we tested the hypotheses that (a) exotic woody shrubs would be superior belowground competitors for nitrogen in heterogeneous soil resulting from key aspects of root architecture and (b) larger plants would be superior belowground competitors. We tested these hypotheses using two native shrubs, Rubus allegheniensis and Viburnum dentatum, and two invasive exotic shrubs, Rubus phoenicolasius and Berberis thunbergii, all four of which can become abundant in plant communities in the eastern United States. We grew replicate plants from each species with interspecific competitors, with intraspecific competitors, and individually in a randomized layout in a greenhouse in two temporal blocks. Each experimental container had a central soil patch amended with 15N-labeled litter. We meas...

Flyspeck disease caused by the Ascomycete fungus Schizothyrium pomi is a major component of a summer disease complex that has become an increasing problem on apple in the northeastern United States. This study describes the development of thyriothecia of S. pomi on one of its major reservoir hosts, wild blackberry, and suggests that temperature drives thyriothecium maturation. An empirical model relating thyriothecium maturity to degree-days from apple leaf budbreak in Massachusetts had a high coefficient of determination, R2 = 0.90. Ninety percent of thyriothecia matured between 540 and 1,625 degree-days from the budbreak biofix. S. pomi produced one generation of asci per year on blackberry. This discrete maturation period occurred well before signs of disease developed on apple fruit and before production of conidia. Considering that fungicide applications for scab management in commercial apple orchards also will protect fruit from flyspeck during early fruit development, it is unlikely that ascospores produced on reservoir hosts directly infect fruit. Instead, they probably initiate infections in reservoir hosts adjacent to commercial orchards, which produce conidia that are the inoculum which infects apple fruit in commercial production.

Rubus often becomes the most prominent vegetation within 2–3 years following heavy overstory disturbances at mesic sites within temperate forests of northeastern North America. This review draws together available literature about its dynamics and effects, focusing primarilyon raspberry (Rubus idaeus L.) and blackberry (Rubus allegheniensis Porter). It covers some key ecologic functions of raspberries related to nutrient leaching, microclimate near the ground, and organic matter decomposition. It also summarizes published information about the potentialinterference with desirable tree regeneration at northern hardwood sites within the region. The review concentrates on raspberry (Rubus spp.) dynamics and effects following clearcutting, shelterwood method, and other heavy overstory disturbances. Findings indicate that raspberries commonlydevelop into a dense cover after cutting and other overstory disturbances reduce the stocking of northern hardwood stands by 40% or more. Ecologically, they shade the ground, intercept and transpire water, and reduce the rate of litter decomposition and nutrient cycling, all of whichreduce leaching from a site. On poorly drained, droughty, and shallow soils, raspberries have reportedly delayed the development of hardwood regeneration. However, by 5–7 years, rapidly developing hardwood species have normally grown through the Rubus at most other sites, andthe emerging tree community has formed a closed canopy by 10–15 years. The presence of abundant, well-developed, and well-distributed advance tree regeneration ensures prompt restocking of new hardwoods, seems to minimize the potential for interference by raspberries, and precludes anyneed to release the tree seedlings from a raspberry cover. North. J. Appl. For. 23(4):288 –296.

From the methanol extract of the fruits of the blackberry (Rubus allegheniensis Port.), four triterpenoids – pomolic acid (1), tormentic acid (2), euscaphic acid (3) and 1β-hydroxyeuscaphic acid (4) – were isolated, while six triterpenoids – 2, 3, myrianthic acid (5), ziyu glycoside II (6), sericic acid (7) and 19-hydroxy-2,3-secours-12-ene-2,3,28-trioic acid 3-methyl ester (8) – were obtained from the methanol extract of the leaves of this plant. Their structures were determined on the basis of spectral data. Compounds 1–8 were examined for their inhibitory activities on foam cell formation in human monocyte-derived macrophages induced by acetylated low-density lipoproteins at a 50 μM concentration. Among the tested compounds, 1 showed the strongest activity, with the inhibitory effect being 90%. The inhibitory activities of 2–8 were evaluated to be 30%, 32%, 33%, 4%, 48%, 4% and 24%, respectively. Further, the structure–activity relationship of these compounds was investigated.

Summary 1 Seed banks are dynamic entities, with input occurring through dispersal and loss occurring through germination and various sources of mortality. Measures of abundance of seeds in the soil at one point in time cannot distinguish those seeds destined to germinate or die in the next growing season from those entering the long-term seed bank, and cannot therefore reveal the proportion of seeds that are carried over from year to year. 2 We studied seed bank dynamics in a 2.5-ha deciduous forest gap by following the fate of a single year’s cohort of seeds over 2 years. Seed input for 1 year, subsequent in situ germination and survivorship were measured at 60 locations. We examined how temporal changes in seed bank composition were affected by the presence of the dominant gap colonizing species Rubus allegheniensis. 3 Over the course of 2 years, both mean seed density and its variance declined. The temporal changes in density were not, however, accompanied by detectable changes in diversity. 4 Three species (R. allegheniensis, Phytolacca americana and Paulownia tomentosa) dominated the seed bank. Seed bank accumulation patterns in Rubus and Phytolacca showed contrasting responses to the presence of Rubus, with Phytolacca excluded from seed banks in such patches through reduced input and increased mortality. 5 First year germination and post-dispersal mortality interact with seed input to influence the spatial distribution of density and diversity in the long-term seed bank. Substantial long-term seed banks do form within temperate forest gaps and patterns of above-ground vegetation can have substantial effects on their dynamics.

Control and regrowth of hemp dogbane, wild blackberry, and triazine-resistant common lambsquarters (TR-CHEAL) were studied in no-till corn from 1992 to 1994. Hemp dogbane, wild blackberry, and TR-CHEAL population increased 10, 123, and 177%, respectively, between 1992 and 1994 in plots treated with PRE applications of paraquat, atrazine, and metolachlor (weedy checks). POST applications of tank mixtures of 35 g ai/ha nicosulfuron or 20 g/ha primisulfuron with 280 g/ha 2,4-D or 140 g/ha dicamba, and 560 g/ha dicamba applied alone controlled hemp dogbane, wild blackberry, and TR-CHEAL 67 to 98%. These treatments reduced the population or prevented expansion of these weeds the year following treatment. In 1992, corn yield response to weed control was inconsistent. In 1993 and 1994, all plots treated with POST herbicides yielded higher than the weedy check. Corn yield of plots treated with combinations of nicosulfuron or primisulfuron with 2,4-D or dicamba and 560 g/ha dicamba applied alone were 102 to 149% and 124 to 153% higher than the weedy check in 1993 and 1994, respectively. Nomenclature: Atrazine, 6-chloro-N-ethyl-N'-(1-methylethyl) -1,3,5-triazine-2, 4-diamine; dicamba, 3,6-dichloro-2-methoxybenzoic acid; metolachlor, (2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-meth- oxy- 1-methylethyl) acetamide); nicosulfuron, 2-(((((4,6-dimethoxy-2-pyrimidinyl)amino)- carbonyl) amino)sulfo nyl)-N,N-dimethyl-3-pyridinecarboxamide; paraquat, 1,1 '-dimethyl-4,4'-bipyr- idiniumion; primisulfuron, methyl 2-(((((4,6-bis (difluoromethoxy)-2-pyrimidinyl) ami

Hemp dogbane and wild blackberry have become significant weed problems in no-tillage corn production in Maryland. Nicosulfuron (31 to 62 g ha−1) plus crop oil concentrate (COC) gave 67% or more hemp dogbane and wild blackberry control. There was no difference in hemp dogbane or wild blackberry control between 31 and 94 g ai ha−1nicosulfuron. Tank mixtures of 2,4-D or dicamba with nicosulfuron gave 72 to 100% hemp dogbane and wild blackberry control. Hemp dogbane control following applications of 560 g ha−12,4-D was 97% in 1989 and 63% in 1990. Wild blackberry control with 2,4-D was 40% both years. Dicamba at 280 g ha−1gave 70 and 55% control of hemp dogbane and 75 and 65% control of wild blackberry in 1989 and 1990, respectively. Triclopyr plus 2,4-D provided 72 to 98% hemp dogbane control and 92 to 98% wild blackberry control. However, triclopyr plus 2,4-D applied at 280 plus 560 g ha−1injured corn, and corn yields were reduced compared with weedy controls in 1990.

The effect of unincorporated and incorporated litter and extracts of broom-sedge, fescue, and blackberry on the mycorrhizal development and growth of black walnut seedlings was investigated in two greenhouse experiments. Seedling growth varied with method of litter application. Only fescue extract decreased growth in the extract experiment, but unincorporated and incorporated broom-sedge litter significantly (P ≤ 0.05) reduced seedling total dry weight below that of mycorrhizal control seedlings. The total dry weight of seedlings in incorporated fescue litter was reduced by 47%. The number of mycorrhizal infected root segments on seedlings grown in unincorporated litter was more than twice the number of infected roots on seedlings grown in incorporated litters. Significantly fewer mycorrhizal roots were found on seedlings grown with fescue and broom-sedge litters than on mycorrhizal control seedlings. On the average, incorporation of litter increased the percentage of leaf phosphorus, but the shoot absorption of phosphorus was considerably less for seedlings grown in incorporated fescue litter compared with unincorporated fescue litter. Seedlings grown in fescue extract had 33% less phosphorus than control seedlings. Except for possible interference with mycorrhizal development when litter was incorporated, there was no evidence to suggest that blackberry litter contains substances that are allelopathic to black walnut.

APOMIXIS WAS FOUND in northeastern American polyploid blackberries during the course of breeding experiments conducted by Einset (1951). Twenty-four species and clonal varieties of blackberries (subgenus Eubatus, basic chromosome number 7) with somatic chromosome numbers ranging from 21 to 63 were selfed, open-pollinated, or crossed with a blackberry plant having a different chromosome number. Pollination was essential for seed set in every case. IChromosome counts showed that 80100 per cent of the seedlings of 21-, 35-, 49or 63chromosome seed parents possessed the same chromosome number as the female parent, whether it had been selfor open-pollinated or crossed with a male parent of a different chromosome number. When 28-chromosome seed parents were crossed with odd-ploid pollen parents 80 per cent of the seedlings were tetraploid. These seedlings were assumed to have developed from unfertilized, unreduced eggs. Seedlings having more than the somatic chromosome number of the female parent made up 0-7 per cent of the total progenies of the seed parents of each level of ploidy. Most of these were considered to have arisen from fertilized, unreduced eggs. Twenty-eight-chromosome seed parents produced 14-chromosome offspring totalling 6.3 per cent of the progenies, indicating that a reduced egg could develop parthenogenetically. Many aneuploid seedlings of polyploid seed parents conceivably originated from the union of reduced eggs and sperm, one or both having an aneuploid chromosome number. Seedlings resulting from the development of fertilized reduced eggs undoubtedly composed part of the tetraploid progeny of open-pollinated 28-chromosome seed parents, but could not be detected by somatic chromosome counts. The present paper will describe the development of the embryo sac in a diploid species of blackberry which reproduced sexually (Einset, unpublished data) and in six polyploid species which behaved pseudogamously (Einset, 1951). The terminology used will be that of Maheshwari (1950). MATERIALS AND METHODS.-Embryological material was collected from Rubus allegheniensis Porter (2x), R. canadensis L. (3x), R. localis Bailey (3x), R. beltobatus Bailey (Kittatinny) (4x), R. abactus Bailey (5x), R. meracus Bailey (7x), and R. flagellaris Willd. (9x). Rubus allegheniensis was growing wild in a hedgerow in Geneva, N. Y. The rest of the material was gathered from either the same plants or vegetative propagations of the same plants in the collections of the New York State

Diploid Rubus allegheniensis Porter and R. rusticanus Merc. shoot tips were proliferated in tissue culture and treated with 0.02 to 0.08% colchicine to induce non-chimeral polyploidy. About 20 shoot tips of each treatment were transferred to test tubes containing modified Anderson's medium for shoot proliferation. Shoots at the 3- or 4-leaf stage were transplanted into Jiffy-7 peat pellets and placed under intermittent mist for rooting. Root tip squashes were made for chromosome counts. Thirteen R. allegheniensis and 7 R. rusticanus plants proved to be autotetraploids (28 chromosomes). Stomata of the autotetraploids were significantly larger than those of the diploids but stomatal conductance of CO2 and photosynthesis rate were reduced significantly as compared to diploids. Pollen grains in tetraploid were larger than those in diploid R. allegheniensis plants. These results indicate that tissue culture can facilitate the production of non-chimeral colchiploids in Rubus spp.