Grower Field Trials

2006-7 OSU Canola Field Test Plot Locations

Fall planting conditions were marginal due to unusually dry weather. There were periods of limited rainfall in mid-September and again in mid-October but no significant, continuous rainfall until the first days of November. For optimum survival, past practice has shown that canola should be planted in the Willamette Valley by the middle of September and should have adequate soil moisture to germinate and begin rapid growth. This was not the case in fall 2006. Fall stands at all sites were marginal to adequate. In addition to low rainfall, high heat (90 F+) shortly after germination of the south Valley fields led to additional plant losses.

January weather was warmer than average and plant size increased but in late-January and early February there was a period of eight days were days times temperatures were near 50F and night time temperatures near 25F. Soils were at field capacity in most areas. This period of freeze thaw cycles lead to ice formation and the soil phenomenon called ice lensing were significant plant heaving occurs. Stands in all grower fields were damaged. Matt Rice’s field – the latest planted – was lost entirely. A portion of Chuck Sherman’s field was lost as well as that at Larry Venell’s. Sherman took out more than half of his field. Rice and Venell decided to abandon their fields due to the poor stands and to plant other crops in the spring planting window. These canola fields were not the only crops lost due to the fall and winter weather. A significant number of fall planted grass seed crops were also lost.

Site 1 – Venell Farms 

Planted September 22. The field was significantly thinned due to winter injury and was removed and replanted to spring wheat.

Site 2 – A2R Farms

Planted September 27. The field was damaged by winter injury but was maintained. The field average yield was 2647 lb/a based on harvest weight and a 20-acre harvested area. A replicated spring nitrogen rate trial (three replications) was embedded in the field. Rates of 100 and 150 lb/a spring nitrogen were used. There was no difference in yield between N rates in this field.

Treatment (lb/a spring N) Seed yield (lb/a)
100 2843
150 2580
Average 2712
Difference between means (PLSD) Not significant

Site 3 – VanLeeuwen

Planted September 20, windrowed June 19, combined July 5-6. This field was planted just after the first significant precipitation event of the fall and was the earliest planted field in the trial set. There was some winter injury but less than observed at other trial sites. The field average yield was 3394 lb/a based on harvest weight and a 20-acre harvested area. A replicated spring nitrogen rate trial (four replications) was embedded in the field. Rates of 100 and 150 lb/a spring nitrogen were used.

Treatment (lb/a spring N) Seed yield (lb/a)
100 3333
150 3372
Average 3353
Difference between means (PLSD) Not significant

Site 4 – Rice

Planted November 1. This was the latest planted field in the trial set. It was planted after significant rainfall had been obtained and had the most uniform stand at the end of December, however, plants were very small. Nearly all plants were heaved from the ground in the ice lensing weather event and the field was lost. The field was replanted to a spring seed crop.

Site 5 – Sherman

Planted October 4, windrowed July 1, combined July 9. This field had a mixed stand and suffered from winter injury. The weakest portion of the field was removed. The field average yield was 3155 lb/a based on harvest weight and an 8-acre harvested area. A replicated spring nitrogen rate trial (two replications) was embedded in the field. Rates of 100 and 150 lb/a spring nitrogen were used. While there was a large difference in yield between the nitrogen treatments, this difference was not statistically different due to the reduced replication.

Treatment (lb/a spring N) Seed yield (lb/a)
100 2442
150 3853
Average 3148
Difference between means (PLSD) Not significant

These field trials demonstrate the risk associated with planting fall canola in western Oregon. As indicated, a mid-September planting date is desired, but as in fall 2006, there may be years in which significant rainfall is not received until late September or October. In these instances, depending on winter weather, fields may be a risk for stand reduction or loss. If irrigation is possible, pre-irrigating a field prior to planting should allow timely planting and assure crop establishment and survival in most instances.

The yields obtained in the three fields that were maintained in crop were somewhat surprising. Stands had been significantly reduced in the Sherman and Robinson fields to a level were yield reduction was anticipated. But spring weather was favorable and moisture adequate and remaining plants compensated for reduced stands. Such compensation would not be expected in all years especially those with dry and/or hot periods at flowering.

While small plot work on Hyslop Farm has shown a yield advantage to higher nitrogen rates, these field scale trials did not show an advantage in the current year. If additional replication had been present at the Sherman site, the difference observed there would likely have been statistically and economically significant.

2008 Grower Field Trials

2009 Grower Field Trials