- Author: Richard Smith
- Posted by: Gale Perez
Onions is a challenging crop in which to achieve good weed control. They are planted in high density configurations that preclude the effective use of cultivation. Cultural practices such as locating plantings in fields have low weed populations, as well as preirrigating up a flush of weeds followed by killing them with shallow cultivation can be effective in minimizing the population of weeds that emerge during the crop cycle. In general, excellent weed control for many of the common cool and warm season vegetables can be accomplished by a combination of the registered pre and post emergence herbicides. The weed control challenges in onions occurs with weeds that are not well controlled by currently registered herbicides. It is...
- Author: Rob Wilson
Happy New Year! It’s too cold in Tulelake for field work, so I’m busy summarizing 2013 research results. Today I posted a progress report on the Intermountain Research and Extension Center (IREC) website summarizing results for our 2013 onion weed control research. The study was conducted at IREC to evaluate rates of DCPA (Dacthal) alone and combined with pendamethalin (Prowl H20) applied at loop stage for control of kochia in onions grown on silty clay soil with high organic matter. Sulfentrazone (Zeus), an unregistered herbicide in onions, was tested at various rates as a preemergence and postemergence herbicide on the same soil type. Prowl H20 application timing was also evaluated by comparing applications...
- Author: Richard Smith
Weed control in onions can be challenging. Onions have various challenges that make weed control difficult. They grow slowly early in the crop cycle and never achieve a good competitive crop canopy to suppress weeds. Also, given the high density plantings, it is not possible to effectively cultivate the beds. In addition, given the close spacing between plants, it is difficult to hoe out weeds without risking damage to the onion stand. In conventional onion production there are a number of materials that can provide excellent weed control (see Figure 1). The timing of application of the materials can be tricky because some weeds may grow quickly and be difficult to control by the time the onions reach the 2nd...