- Author: Mark Bolda
- Author: Alejandro del Pozo
Interesting farm call this morning. A strawberry grower near Watsonville reported a large group of worms (caterpillars) migrating north out of the mixed cover crop including barley and mustard.
These worms were identified by our new UCCE entomologist Alejandro del Pozo as being a species of armyworm, for which this sort of behavior is not unusual. One distinct characteristic to ID these worms is the ‘Y' shaped suture on their forehead. For instance, the beet armyworm,Spodoptera exigua, could be a problem in strawberries when high infestations are left unmanaged. You could read more about the beet armyworm as pest of strawberries on the UCIPM guidelines at http://ipm.ucanr.edu/PMG/r734300611.html
Knowing that these creatures do feed on strawberries, the advice to the grower is to mow and disk the cover crop to destroy the majority of these worms. Yes, the grower is forfeiting some of the benefit of the cover crop he expected to keep going until the end of August, but the risk to his strawberry crop of this large population of armyworms is greater.
- Author: Mark Bolda
This meeting put on by colleagues Richard Smith, Michael Cahn and Eric Brennan has been put together with the intent of helping growers, especially berry growers, retain some of the expected rainfall from this year's predicted El Niño system and gain some benefit by recharging a bit of our groundwater.
They've actually planted some cover crops out so you can see what it looks like. I'll be on hand to address management of these cover crops in strawberry.
- Author: Romy Basler
- Author: Mark Bolda
A cover crop can be a useful way to prevent weeds in anchor rows.
Cover crops in anchor rows can suppress weed growth and additionally help to minimize soil erosion and nutrient and sediment loss when it rains. Densely planted cover crops can outcompete weed seedlings germinating from the soil and prevent wind-dispersed seeds from reaching the wet soil surface. Have a look at the newly revised weed section in the Caneberries Pest Management Guidelines on the UC IPM web site.
As readers know, tunnels used for caneberry cultivation have the advantage that even when it rains caneberries remain dry which helps with fruit quality and yield. However, during rains, the water drains from the plastic cover of the tunnel and down into rows that contain the anchoring posts of the tunnel structure. The accelerated runoff in these post rows can cause soil erosion, sediment and nutrient loss. As such, the persistent soil moisture in post rows also promotes weed growth. These weeds, while maybe not competing directly with canes, can reproduce and quickly spread into neighboring cane rows.
Cover crops in the anchor rows are especially helpful when managing weeds that are difficult to control with fumigation because of their hard impermeable seed coats (mallows and filaree), or that have developed resistance to herbicides such as glyphosate and paraquat (hairy fleabane and horseweed).
Cover crops can be managed with mowing or herbicides to avoid seed production.
