- Author: Carl E. Bell
- Posted by: Gale Perez
Plant growth and development and herbicide efficacy, part 1
In the 1920's and 30's field bindweed (Convovulus arvensis) was a major weed in the western US; so much so that coordinated research was undertaken by the most prestigious Agricultural Universities from California to Oklahoma to figure out what to do. And this was before the advent of herbicides, so scientists and farmers had to rely on other methods, especially cultivation. After much work, it was discovered that the pernicious bindweed could be eradicated from a field by regular cultivation for just two seasons. They used duck-foot cultivators; a collection of several flat triangular blades that overlapped and ran horizontally about 2-4 inches below the...
- Author: Carl Bell
- Posted by: Gale Perez
A recent blog post titled–Plant growth and development and herbicide efficacy discussed herbicides like glyphosate and imazapyr that move through plants in the sugar conducting tissues (aka phloem or symplastic system).
There are some herbicides that move in the water conducting tissue (aka the xylem or apoplastic system). These herbicides, mostly in older classes of chemicals, enter plants through the roots and travel upward to the leaves where you see their effect. Many of these herbicides are only used in crops, so it is unusual that anyone working in a natural area will ever encounter them.
Others, such as diuron or bromacil are used to some in roadsides, under pavement, industrial areas, railroad beds, and...
- Author: Richard Smith
- Posted by: Gale Perez
From the UC Cooperative Extension Monterey County Crop Notes newsletter (March/April 2014)
Excellent weed control is essential for economically producing cilantro and parsley. Both crops have had various weed control challenges over the last few years. Cilantro and parsley are in the celery family and both are small acreage crops (cilantro 980 acres and parsley 533 acres in Monterey County in 2012) that are important to the local economy. In our modern production systems, both crops are planted in dense plantings (24-33 seedlines) on 80-inch wide beds. Parsley has been mechanically harvested for...
- Author: Oleg Daugovish
Growers and pest control advisors look at strawberry plants daily and see problems often. Some problems like salt injury are frequent while others, like frost injury are only seen once in a few years. With over 60 pathological, physiological and nutritional problems it is important not to overlook injury from herbicides. In collaboration with UC strawberry workgroup members we recently launched a bi-lingual web site that displays injuries and disorders from chemical and other causes.
The site is a work in progress as we continue to add images of problems, translation into Spanish and update the content of existing pages with new information. We hope that with improved access to images and descriptions the site can be useful in...
- Author: Richard Smith
Each of the past several years, we have received samples of tomato plants from small growers and homeowners that have severe leaf deformity. The leaves of affected plants have the following symptoms: the leaves are distorted with cupping and twisting (Photos 1 & 2), as well as strapping or shoe string symptoms (Photo 3); the leaves can also have distinctive flaring along the edges (Photo 4). In addition, the leaves can be tightly curled (Photo 5). We examined these samples for the presence of viruses, but have never found viruses associated with these symptoms. In addition, the symptoms do not fit classic virus symptoms such as mottling (blending of dark green and yellowing). The symptoms on these tomatoes most closely fit with...
