Pokeweed (Phytolacca Americana)

Pokeweed (Phytolacca Americana)
Author: Arnold Krochmal
Publisher:
Total Pages: 12
Release: 1970
Genre: Molluscicides
ISBN:

S2Pokeweed, a plant abundant in Appalachia, exhibits some chemical similarities to a related species that has shown molluscicidal properties. Because this suggests that pokeweed, Phytolacca americana L. (P. decandra L.), has potential for controlling fresh-water snails, we have compiled this report of its chemical composition, uses, propagation methods, and other potentially useful species of the genus Phytolacca. The related species, Phytolacca dodencandra L'Her, was found to be the source of a molluscicide, which could pIay an important role in control of bilharziasis, a parasitic disease of humans widespread in Puerto Rico, Africa, and other tropical areas (22). Dead snails and small fish were observed in waterways in areas of Ethiopia where people washed their clothes with this Phytolacca's fruit, which is rich in saponins. Some distance downstream and immediately upstream from the washing places, abundant live snails were present, suggesting that the fruit contained a toxin acting as a molluscicide. This was subsequently confirmed by laboratory tests; tap-water extracts of the dried and powdered fruit had an LC100 (lethal concentration) of 10 parts per million against snails (Biomphalaria, Bulinus: and Lymnea spp.) after 24-hour exposure at 23OC. Furthermore, it was shown that molluscicidal potency was not affected by the presence of soil or vegetable matter, an important factor when the molluscicide is used under natural conditions. S3.

Common Pokeweed (Phytolacca Americana L.) Management in Pennsylvania Field Crops

Common Pokeweed (Phytolacca Americana L.) Management in Pennsylvania Field Crops
Author: Kelly Patches
Publisher:
Total Pages:
Release: 2014
Genre: Pokeweed
ISBN:

Common pokeweed (Phytolacca americana L.) is a perennial broadleaf weed with a large persistent taproot that is also capable of abundant seed production. It has become a frequent problem in agronomic crops in Pennsylvania. Traditionally, plowing was used to manage pokeweed; however, the wide-spread adoption of conservation tillage, a decline in the use of soil residual herbicides, and a decrease in diverse cropping rotations may have allowed pokeweed populations to increase in recent years. This research was conducted in order to identify opportunities to better manage pokeweed in corn, soybean, and other Northeast U.S. cropping rotations and shows that an integrated approach which includes both cultural and chemical tactics enables successful management of pokeweed in conservation tillage systems.Experiments were conducted in order to investigate the biology of common pokeweed in order to better time control tactics. In a pokeweed seedling emergence timing experiment, seedlings emerged throughout the summer, but peak emergence occurred in mid to late May. By August, pokeweed seedling emergence ceased. Both above- and below-ground pokeweed biomass decreased with delayed emergence and plants which emerged in late July did not produce mature berries by the end of the season. Experiments were also conducted to assess herbicide efficacy on pokeweed control. In corn, glyphosate, plant growth regulators, and other herbicides provided at least 80% control in trials conducted over a 3-year period. In soybean, glyphosate provided the best control of pokeweed; all treatments including glyphosate provided at least 80% control, while non-glyphosate treatments provided less than 62% control. Other glyphosate experiments examined herbicide rate, nozzle selection, carrier volume, and application timing. Air induction and flat fan nozzles provided the same level of control and in one of two years, 93 L/ha carrier provided better control than greater carrier volumes. The highest rates of 1.27 and 1.73 kg ae/ha provided the best control 12 weeks after application (WAA), but at 44 WAA, there was no difference in control due to glyphosate rate. Glyphosate application after mid-June provided better control than earlier in the summer. Even though pokeweed is a challenging weed to control, the results from this research show that there are options for controlling pokeweed in Pennsylvania field crops. Understanding the emergence pattern and current herbicide options has provided insight on how to better time control tactics and reduce this problematic weed. In order to control pokeweed, an integrated approach must be taken. Crop rotation and selection and timing of herbicide application are important for effective control.