- Author: Lynn M. Sosnoskie
Field bindweed (Convolvulus arvensis) is a perennial vine native to the Mediterranean region of Europe and Northern Africa that has become naturalized throughout much of the world. The species can reproduce vegetatively (through the spread of rhizomes) and via seed production. Field bindweed seedlings can be distinguished from emerging perennial vines by the presence of two square- to kidney-shaped cotyledons. Leaves are arrow-shaped and alternate along the developing stem. The true leaves of seedlings resemble those on mature vines (just being smaller in size to start). Within six weeks of emergence, the seedlings have developed a taproot and a significant number of lateral roots. For more information about field bindweed,...
- Author: Lynn M. Sosnoskie
2019 Automated Weeder and Thinner Demonstration and Field Day
The 2019 Automated Weeder and Thinner Demonstration and Field day will take place on Tuesday, May 21, from 10:00 a.m. to 12:00 noon at the USDA Spence Research Field Station, 1572 Old Stage Road in Salinas. Automated technologies are helping to fill the gap in the supply of labor that is occurring in the farming community. At this field day weeders and automated lettuce thinners developed by a number of companies will be demonstrated on lettuce plantings. Both driven and autonomous machines that use a variety of different mechanisms to remove unwanted plants will be available for viewing. These technologies are useful to both conventional and organic...
- Author: Lynn M. Sosnoskie
Abutilon theophrasti (commonly known as velvetleaf) is a summer-emerging, annual, broad-leaf weed native to Asia. The species can be found mainly in the Central Valley (and mostly in the Sacramento Valley) in agronomic crop systems, along roadsides, in orchards and vineyards, and in other disturbed areas.
Cotyledons (approximately 1/2 inch (12 mm) long and wide) are rounded to heart-shaped in appearance. The first true leaves are heart-shaped with with shallow and rounded-toothed margins. Velvetleaf cotyledons, leaves and petioles are covered with fine, soft hairs (hence the name 'velvetleaf').
Images are included in a printable PDF document at the end of the post. For more...
- Author: Lynn M. Sosnoskie
Growers (mainly pistachios) and crop consultants in the southern and western parts of the San Joaquin Valley have recently reported the spread of alkaliweed from low-lying saline or alkaline soils (including seasonal wetlands and floodplains) into irrigation ditches, orchards, and some agricultural fields (Figure 1).
Now, some of you may be asking 'What is alkaliweed?'
Alkaliweed (Cressa truxillensis) is a native, perennial plant in the morningglory family (Convolvulaceae), the same family of field bindweed (Convolvulus arvensis) and dodder (Cuscuta spp.). The species has a prostrate to ascending growth habit, rarely exceeding a foot in height. The species produces grey-green,...
- Author: Lynn M. Sosnoskie
The summer annual weeds are starting to emerge and I am using this blog over the next few weeks to introduce readers to the seedlings of important species.
Black nightshade (Solanum nigrum) is an annual (or sometimes a short-lived perennial) species that is common throughout much of the state inhabiting: tree and vine systems, agronomic and horticultural crop fiels, roadsides, gardens, and other disturbed sites.
The seedlings have cotyledons that are ovate (oval) to lanceolate (lance-shaped) with pointed tips that can become purplish in color. Leaves are ovate to triangular in shape, also with pointed tips. Early leaves have simple margins whereas older leaves possess margins that are wavy to...