Conservation of crop genetic resources is now considered an important component of sustainable agricultural development. If conservation of genetic resources for agriculture is to be successful, a more complete understanding of the dynamics affecting traditional (landrace) crop populations is needed. We conducted a study of maize-based agriculture in the Central Highlands of Mexico in communities at 2400, 1700, 1400, and 1200 masl to assess the status of traditional varieties in an area characterized by thorough integration into the national economy. Our research contradicts the view that modern varieties persist because of marginal conditions, deficient infrastructure, weaker markets, or traditional attitudes. One or two landraces dominated highland maize populations and farmers appeared to be more conservative in terms of their emphasis on traditional maize varieties than at lower elevations. The dominance of traditional varieties in the highlands is well known but poorly explained, and the coexistence of traditional and modern varieties in the mid-elevations was unexpected. Our highland study area has good roads, is near Mexico City, and is less than 50 km away from four major crop research institutes that have done maize breeding since 1950’s. We suggest that in situ conservation of maize genetic resources in the highlands is sustained because the landraces there have good agronomic performance and are highly valued by farmers for their end-use qualities. At the mid-elevations, competition between local and modern maize was sharpest, and farmers have found that both landraces and improved varieties suit their needs, hence enhancing genetic diversity. Interventions and incentives would appropriately be carried out here to assure in situ conservation of locally adapted landraces of maize.

Conservationists of crop genetic resources have feared that in situ conservation was not viable for agriculture precisely because of changes resulting from introduction of new varieties of existing crops, new crops, and new farm practices. In addition, conservation within farming systems necessarily implies a constantly changing crop population resulting from the processes of crop evolution. Even though in situ conservation of crop genetic resources is now generally understood to be dynamic, there are few examples of how evolution takes place in farmers fields. This study describes several changes in maize landraces in four communities along an altitude transect in Central Mexico (1200 to 2400 masl). While true modern varieties have not been widely adopted in the study region, farmer management results in numerous changes in maize landrace populations. Five types of dynamic management were observed: (1) purposeful hybridization between traditional and modern maize types, (2) possible creation of a new maize landrace by directional selection of the progeny of hybridization between two traditional landraces, (3) displacement of a local landrace by the introduction of a modern variety and a non-local landrace, (4) maintenance of stable populations of a locally dominant landrace, and (5) market-driven selection for a minor variety. We concur that in situ conservation of crops must be conceived as an open process where the objective is not to maintain historic varieties or static genetic conditions. Rather, in situ conservation of crops is totally in the hands of the farmer, although interventions may be designed to influence farmers' management of agrobiodiversity.

Indigenous Peruvians have used totora (Schoenoplectus californicus: Cyperaceae) vessels or caballitos for fishing along the coast of Peru since pre-Inca times. Presently, caballito use and construction are declining in numerous fishing towns. Participant observation techniques were employed to investigate aspects of caballito construction. S. californicus stems were used to make four bundles to serve as the caballito body. The bundles were lashed together with single and double twist rope made from Furcraea andina (Agavaceae) leaves. The stem of Guadua angustifolia (Poaceae) was used as a paddle for the vessel. Caballito construction has varied little through time. We documented a decline in the use of traditional plant materials due to their scarcity. Huanchaco fishermen have played an important role in maintaining the tradition of building caballitos.

The Sierra Norte de Puebla, Mexico, is a region with biological and cultural diversity, where the use of local natural resources was increased by the relative isolation of the region until recent decades. There are more than 600 useful plants reported. In the Sierra Norte de Puebla at least six Begonia species are used as food. The objective of this paper is to report such species that are utilized for self-supply and for sale in local markets. The management includes gathering among wild populations, transplanting of rhizomes and vegetative propagation by leaves to establish and increase populations in home gardens and in coffee plantations.

Hippocratea excelsa and Hippocratea celastroides have therapeutic and insecticide applications in Mexican traditional medicine. The toxicity of H. excelsa root cortex has been previously demonstrated against the stored grain pest Sitophilus zeamais. To identify the active compounds, several extracts (petroleum ether, CH₂Cl₂, acetone, methanol, and water) and compounds were obtained from the roots, and tested (1% w/w) with a force-feeding assay against S. zeamais. All H. excelsa extracts showed high antifeedant activity, and elicited moderate mortality. The triterpenoid pristimerin and a mixture of sesquiterpene evoninoate alkaloids, isolated from the hexane and methanol extracts, respectively, strongly reduced the insect feeding capacity. Other triterpenoids (friedelin, β-sitosterol, canophyllol) isolated from the hexane extract, and the alditol galactitol obtained from the water extract, were innocuous or its activity was not statistically significant. The organic extracts from H. celastroides only showed moderate antifeedant activity, while the water extract was innocuous. Galactitol was also obtained from this extract.

There is increasing pressure from communities neighbouring protected areas in KwaZulu-Natal, South Africa, to harvest resources from these areas. For example, Hyphaene coriacea Geartn. (vegetable ivory palm) leaves are extensively used by Zulu people for commercial and subsistence craftwork. This study investigates the effect of varying leaf harvest intensities on leaf production of Hyphaene coriacea in the Greater St Lucia Wetland Park in KwaZulu-Natal, South Africa, and aims to provide some management guidelines for sustainable use. Replicate plots subjected to three different harvest intensities were established and numbers and lengths of unopened leaves were monitored over four years. Results suggest that a harvest intensity of one leaf stem⁻¹ year⁻¹ would be sustainable. This is equivalent to 34% of calculated annual production. The 650 ha harvest area is estimated to produce 191 750 leaves year⁻¹ (4793 bundles) which could be harvested sustainably.

The effects of leaf harvest, even at maximum harvest rate, on leaf production over the four year study period appear negligible although there was a slight decline over time in leaf production of trees subjected to high harvest intensity. A slight increase in leaf production was observed at moderate levels of harvest intensity.

For the long term sustainable use of H. coriacea leaves, an adaptive management approach is recommended. This approach should be formulated with the users to include access rights and responsibility, economic benefit to the harvesters and monitoring of plant response to leaf harvest.

Biases in the ethnohistoric literature of the Maohi have resulted in a misconception that cultivation practices were not well developed in the Society Islands. Though observations of cultivation practices are indeed few and far between in these sources, taken together they clearly indicate the importance of cultivated plants to many aspects of Maohi life. This paper documents 47 taxa, and many more varieties, that the Maohi relied on for food and technology. Cultivation techniques ranged from minimum tillage, to major modifications of the landscape. Few of these crops, and their associated cropping techniques, are used by the Maohi today.

The use of botanical insecticides based on the neem seed (Azadirachta indica var.siamensis Valeton) shows strong potential in the fight against important agricultural pests. Unfortunately, its use in rural Thailand is extremely limited. This study examines the efficacy of neem extracts processed under rural conditions; identifies factors that influence local farmers’ adoption of neem products; and proposes recommendations to promote the use of neem insecticides. The principal findings are: in field trials conducted under typical rural conditions, neem did not adequately control major pests of yard-long beans (Vigna sesquipedalis); and intensity of vegetable production, knowledge of neem insecticides and availability and accessibility of neem products strongly influence farmers’ adoption of neem products for pest control.

Many of the edible wild plants that are included in local food baskets have both therapeutic and dietary functions. Such medicinal foods have been part of Eastern medicinal theories since ancient times and have recently received attention in the USA and Europe within the fields of functional foods, neutraceuticals and phyto-nutrients.

We report the inhibition of the causative agents of dental caries, Streptococcus mutans and other oral streptococci, by the antimicrobially active ingredients of the hop plant (Humulus lupulus L.). The hop constituents studied were purified beta acid, xanthohumol, iso-alpha acid and tetra iso-alpha acid. Cruder hop extracts were also investigated. The antimicrobial activity of these hop constituents was tested against four strains of Streptococcus mutans as well as one strain each of Streptococcus sanguis and Streptococcus salivarius and compared to antimicrobial essential oils used in mouthwashes in two independent assay systems. We found that all tested hop constituents inhibited the Streptococci. The minimum inhibitory concentration at pH 7.5 ranged from 2 to 50 µg/ml depending on the microorganism and hop phytochemical tested. Contrary to a previous report, there was no activity enhancement by ascorbic acid over and above the enhancement due to pH lowering. There was no resistance development to beta acid after 10 passages in a subinhibitory concentration of this acid. Antimicrobial activity of hop constituents was found to be greater than other plant products such as thymol, nerol, cinnamon oil, oil of clove, menthol and eucalyptol. The possibilities of using hop constituents in mouthwashes are discussed.

Fifteen years after a symposium on economic plants projecting to the year 2000, what predictions and remarks of the speakers with reference to ethnobotany and medicinal plants proved prophetic and what others fell short? Certainly they predicted a continuation of acculturation, biodiversity loss, and technology advances. They also foresaw the need for collaborative, multidisciplinary research and major government funding, and changes in regulations governing an expanded industry in botanicals, nutriceuticals, and phytopharmaceuticals, all of which occurred. However, many technologies were in their infancy or unknown, such as gene amplification and recombinant procedures, high-throughput screening, gene chip technology, and combinatorial chemistry, and are only now being used in research and development in the discovery of new therapeutics. Likewise, who would have foreseen worldwide devastating effects of mutant microorganisms resistant to drugs of choice for treating important diseases, such as malaria and tuberculosis? Research data involving these two infections illustrate the value of finding activity based on collections specifically targeted by indigenous users (antimalaria) and those generally used medicinally together with chemotaxonomic selections (antituberculosis). A discussion of research beyond 2000 addresses the future of ethnobotanical research, acculturation and biodiversity losses, collaborative research, regulation and/or standardization of pharmaceuticals, nutriceuticals, and phytopharmaceuticals, and new technologies.

Nepeta cataria L., the catnip plant, is important in the pet industry for cats and as an herbal medicinal treatment for the fevers, diarrhea, insomnia, and lacking menstruation of humans. A natural mutation of N. cataria produced a novel morphology that warranted investigation to determine how the mutation affected the microscopic features, including catnip's ethnobotanical storehouse of glandular hairs. The morphology, anatomy, and physiology of this mutant are compared to that of the wild type of catnip to document the major differences. The secondary plant metabolites which facilitate catnip's ethnobotanical uses are stored in microscopic glandular hairs (trichomes). The trichomes on the mutant and wild type catnip leaves were not shown to differ (scanning and transmission electron microscopy). The feliobotany (use by cats) of N. cataria is discussed in relation to catnip trichomes.