English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The commercial sources of rotenone at present are the roots of certain species of Derris and Lonchocarpus. These are tropical plants grown in areas outside the continental United States. The U. S. Department of Agriculture has been interested for several years in the possibility of developing a source of rotenone which could be grown economically in the continental United States and Puerto Rico. Various plant parts of 16 Tephrosia species were evaluated for rotenoid content (5). The highest rotenoid content was found in leaves of T. vogelii Hook. f. Subsequent studies (3,6) demonstrated significant differences in rotenoid content among plant introductions and breeding lines. Nevertheless, it is necessary to increase the rotenoid content of T. vogelii leaves before commercial production is feasible. Although Tephrosia grows vigorously in the southeastern United States, the climatic conditions required for flowering and seed production make it necessary to conduct all breeding programs in Puerto Rico. Barnes et al. (3) in a previous study demonstrated that varietal comparisons based on percentage rotenoid content were not influenced by latitude; i.e., plants selected for high rotenoid content in Puerto Rico also produced high rotenoid content in the continental United States. Plant rotenoid content was unaffected by planting distance. However, plant growth characteristics such as plant height, leaf-to-stem ratio, and total yield of stems and leaves per hectare, were influenced by within-row spacing and latitude. Because of these significant interactions, the same authors concluded that additional crop management studies were needed at each latitude before the most profitable crop production practices could be determined. This paper reports results of an experiment designed to study the effect of plant spacing and time of planting on the production of T. vogelii grown in Puerto Rico. The plant characteristics studied included rotenoid content

Effect of Planting Date and Plant Spacing on the Rotenoid Production of Tephrosia vogelii in Puerto Rico