- Author: Jose Luiz Carvalho de Souza Dias
- Author: Nicholas Clark
- Author: Konrad Mathesius
- Author: Sarah Light
- View More...
Common chickweed (Stellaria media) (Figure 1) is a winter annual found throughout California and considered to be one of the most common broadleaf weeds infesting cereal crops (also referred as small grains) in the state (Wilen 2006). Herbicides can provide effective control of chickweed; however, overreliance on a single herbicide (or group of herbicides with the same site of action), is likely to result in resistance to that herbicide (or group of herbicides) (Tranel and Wright 2017). Even though herbicide-resistant common chickweed populations have not been confirmed in California, lack of effective control with post-emergence applications of the ALS-inhibiting herbicides pyroxsulam (Simplicity) and tribenuron (Express...
- Author: Konrad Mathesius
- Contributor: Thomas Getts
- Contributor: José Luiz Carvalho de Souza Dias
- Editor: Brad Hanson
- View More...
Concerns about a growing resistance to herbicides
In Mediterranean or arid climates, particularly in areas with marginal soils, crop rotations are often limited to a narrow range of hay, pasture, a handful of winter legumes, or rainy-season grasses. Arid conditions and weathered soils drove Australia's rainfed grain growers to adopt no-till strategies earlier than their counterparts in California. While beneficial from a water use perspective, successful no-till systems depend on herbicides to control weeds that were traditionally kept in check with tillage.
Dependence on herbicides alone in these systems has resulted in weeds with resistance to multiple modes of action. In Australia, there is one...
- Author: Taylor Nelsen
- Author: Gabriel Rosa
- Author: Justin Merz
- Author: Mark Lundy
Weather patterns are highly variable across the state of California. They change from year to year and across locations. While parts of the state may be experiencing drought conditions this year (Figure 1), each location can have dramatically different weather. For growers and agronomists, location-specific weather information is essential to understand plant growth and water use. It is also important for planning field management activities such as fertilization and irrigation.
We have created a new interactive website where users can access their location-specific precipitation and temperature data:
- Author: Konrad Mathesius
- Author: Taylor Nelsen
- Author: Mark Lundy
Seeding rate is an important consideration for small grain growers at planting. There are a number of agronomic factors that help to determine the ideal seeding rate such as whether a field will be irrigated, the potential for weed pressure or lodging, the planting date, crop type, and seed germinability. In addition, there can be a large range of seed weights among different small grain varieties and from one seed lot to the next. To achieve full yield potential under irrigated conditions in California, 25 to 30 plants per square foot is a good target density for wheat. As a seeding rate this translates to approximately 1.2 million seeds per acre with a seed weight of 40 gram per thousand seeds. However, adjustments to the seeding...
- Author: Nicholas Clark
- Author: Thomas Getts
- Author: Giuliano C. Galdi
- Author: Taylor Nelsen
- View More...
This is the third post in a blog series focused on improving nitrogen (N) use efficiency in California small grains. This post discusses two hand-held devices that indicate plant N levels in small grains to help optimize fertilizer decisions. The tools help determine plant vigor by measuring light reflected from the whole plant canopy or absorbed by a single leaf. Comparing measurements made in and immediately outside of N rich zones in representative areas of the field helps determine if the crop is likely to respond to more N fertilizer. The plant N levels indicated by the hand-held devices complement other important information, which are...