- Posted by: Gale Perez
From Growing Produce by | November 27, 2018
Field Scouting Guide: Palmer Amaranth
This month's field scouting guide concentrates on Amaranthus palmeri S. Watson.../h2>/span>
Richard Smith is a University of California Cooperative Extension Farm Advisor in Monterey County.
Leeks are in the onion family and are increasingly important crop in Monterey County. In 2017, there were 475 acres produced worth $8.6 million. They are mostly established by transplanting and days to maturity is generally 120+ days, but varies widely depending on the time of year and market demand. Given the long crop cycle and the lack of a dense crop canopy, leeks are susceptible to successive waves of weed emergence. Growers complain that leeks “blow up” weed populations by allowing a significant number of weeds to mature and set seeds.
The preemergent herbicides DCPA and...
From the Retail Nursery an Garden Center IPM News Fall 2018 newsletter
Managing Weeds in Landscapes
Nurseries and garden centers often sell a wide range of plants for use in gardens and landscapes. Your customers may manage a complex array of different landscape plantings, including woody trees and shrubs, woody ground cover beds, annual flower beds, herbaceous perennial beds, and mixed plantings (Figure 1). This complexity often makes weed management difficult. An integrated approach is the most economical and efficient way to control weeds, so knowing strategies for managing weeds in a variety of landscapes can help you advise customers.
Herbicides are the main means of controlling weeds. Recently, there has been increasing concern over the potential impacts of climate change, specifically, increasing temperatures and elevated carbon dioxide (CO2) concentrations, on the sensitivity of weeds to herbicides. A postdoctoral fellow in my lab, Maor Matzrafi, investigated the response of horseweed and lambsquarters to treatment with glyphosate under the higher temperatures and CO2 levels that are predicted to exist in northern California around 2050. Maor showed that the sensitivity of both weeds to glyphosate was reduced in response to increased temperature, elevated CO2 level, and the combination of both factors. He also found that...
- Author: Maor Matzrafi
- Posted by: Gale Perez
It is well known that herbicide efficacy is strongly associated with environmental conditions (Kudsk and Kristensen, 1992), and this is why applicators are required (by law) to spray under specific environmental conditions. In recent years, we have witnessed an increase in extreme weather events that have emphasized the importance of maintaining proper environmental conditions at, but more importantly after herbicide application. As part of my PhD project, I demonstrated that the first...