Extending the Season in Northern Wisconsin Through Processing Vegetable Production

2018 Vegetable Trial Results

Carrots.  Tables 1-4 below show the carrot yields of the five varieties across the four trial locations.  Values within a column with a different letter are statistically different at the P=0.05 level.  Bolero and Cupar tended to have better germination resulting in a greater number of carrots per plot (Table 1).  The percent of the carrots that were merchantable tended to be the same within a given location but varied widely across locations with only 62% merchantable at Great Oak, buy nearly 100% at Yoman Farm, for example (Table 2).  Individual carrot weights also varied by location, but also by variety.  Belgrado tended to be the largest and Bolero the smallest (Table 3).  Total merchantable plot yields varied widely across sites with the lowest yields at Great Oak due to the lower stand counts and lower individual carrot size.  There was no statistically significant differences among the varieties for total yields at the Great Oak, Yoman, or Northcroft sites, but at the River Road site Cupar was the highest yielding and Cambera the lowest.  In general, looking across all the sites, Bolero and Cupar had the highest merchantable yields and Cambera and Naval had the lowest yields.

Green Beans. Table 5-6 shows the per plant green bean yields for the entire season.  There were no statistically significant difference among the varieties except at Northcroft Farm were Jade 2 and Momentum had higher yields than the other three varieties.  In general, the green bean trials showed that yields were pretty similar and thus variety selections could be based on other factors such as flavor or bean size.

Fall Broccoli. The primary interest in the fall broccoli trials was average head size, which translates into high total yields.  Table 6 shows the average weight of the harvested heads at the four locations for each variety.  The head size varied significantly across the locations with River Road producing the largest heads, on average.  In general, average head size was fairly similar for the different varieties at each location with the exception of Emerald Star, which tended to produce the smallest heads. 

2019 Vegetable Trial Results

Carrots. Tables 7-9 report the 2019 field carrot trial results for the same varieties trialed in 2018.  Establishment success was better than in 2018 with higher plant numbers per plot (Table 7).  Interestingly, Bolero and Cupar tended to have better germination and higher stand counts in both 2018 and 2019.  Individual carrot size again varied considerably across the varieties with Belgrado and Cambera tending to be the largest and Bolero the smallest (Table 8).  As in 2018, Bolero and Cupar tended to have the highest plot yields due mainly to the higher germination rates (Table 9).

Green Beans.  Season total green bean yields in 2019 varied considerably across the three trial locations, due in part to deer browse damage.  Jade2 followed the typical pattern for Jade of poor germination, which contributed to the low per plot yields.  At River Road where plants were most vigorous and yields were highest, Momentum and Sybaris tended to yield more than the other varieties.

Fall Broccoli. Table 10 shows the average head size for the five broccoli varieties at the four trial locations in 2019.  Head size was remarkably similar across the locations and varieties.

Potatoes.  The potato trials in 2018 failed due to historic rainfall, but in 2019 the trials were a success.  Total tuber count tended to be highest for Bintje and lowers for Norland Red at each location (Table 12).  Average tuber weight tended to be lowest for Bintje (Table 13).  Despite the smaller size, Bintje had the highest plot yields and from the flavor surveys it made the best french fries.

2020 Vegetable Trial Results

Tables 15-18 show the results of the snacking pepper trials.  Table 17 is of perhaps most interest in that it shows the relatively low merchantability of the peppers at two of the three locations, particularly for the HMS Orange Picnic and Mini Red Bell varieties.  Most of the peppers were deemed just too small for commercial sale.  Doe Hill and Snackabelle Red tended to produce the largest of the peppers.

High Tunnel Carrots.  Table 19 shows the high tunnel carrot yields at the Great Oak Farm and Northcroft Farm sites in 2020.  Carrots are typically only grown in the high tunnel when sold as early season green-top bunching carrots that can command a higher price.  At both sites, the performance of the five varieties were fairly similar though Nectar and Napoli tended to have higher plot yields and slightly larger carrots. 

Field Carrots. Table 20 shows the number of merchantable and non-merchantable carrots harvested on average per plot for each variety and location.  It was not a good year for the carrots as many were small, forked, or otherwise misshapen.  Merchantability was highest for Yaya at Great Oak and highest for Romance and Negovia at Northcroft.  As shown in Table 21, the higher merchantability result in higher average plot yields for Yaya at Great Oak and Negovia at Northcroft.

Spring Broccoli.  Each plot started with 12 plants.  Flea beetle damage at Great Oak farm reduced survival and deer browse severely damaged the plots at River Road.  However, survival and harvests at Northcroft were good.  In general, Belstar produced the largest heads at all three locations. Head size at all three locations was not particularly large in part due to early flowering and the need to pick before flowering occurred.

Fall Broccoli. The size and weight of the broccoli heads varied by planting location (Table 23).  At the Northcroft Farm site, the varieties had a similar head diameter, except for 'Diplomat', which was slightly smaller.  'Eastern Magic' tended to produce the largest heads.  At the Yoman Farm site, Emerald Crown tended to produce the largest heads. 

Butternut Squash.  Table 24 shows the results of the 2020 butternut squash trials.  The planting at Northcroft Farm suffered from significant deer browse and yields were considerably reduced.  The planting at River Road Farm did very well.  Nutterbutter and Hamilton had the highest yields due in part to the larger fruit size.  Ripening butternut in far northern Wisconsin has always been a challenge.  At the River Road trial the reason for un-merchantable fruit was immaturity at harvest.  Brulee, Butterbaby, and Hamilton all had good maturation, and with the high yields, Hamilton was the all-around winner.  However, at Great Oak Farm, Butterbaby was the overall winner.

Objective 2 - Frozen Veg Taste Testing

2018 Tasting Results
After harvesting, the producer was hydro-cooled and shipped to Northland College where it was washed, chopped, frozen, and vacuum-packed.  Three tasting events were held.  Two for the 2018 harvest and one for the 2019 harvest.  The plan was to do two for the 2019 harvest, but Covid-19 restrictions at Northland College prevented us from doing so.

Broccoli. Figure 1 shows the taste attributes of the broccoli varieties harvested in 2018, frozen, and tasted at 1 month and 4 months after harvest.  Tasters rated the intensity of each flavor attribute from 1-5 with 5 being the most intense.  "Overall Flavor" is the tasters' overall preference of the the variety.  As the data show, the 2018 broccoli was rated is highly bitter and overall flavor preference was low. No single variety tasted better than others and there was not consistent change in flavor from 1 month to 4 months.

Carrots. Figure 2 shows the taste attributes of the frozen (then steamed) carrots at 1 month and 4 months after harvest.  In general, the intensity of the flavor components and the overall flavor preference decreased from 1 month to 4 months.  Bolero and Naval rated as having the overall highest quality flavor.

Green Beans.  Figure 3 shows the flavor attributes of the frozen green beans (then steamed) at 3 months and 7 months after harvest.  As with the carrots, the overall flavor declined during storage with the Nov ratings tending to be higher than the Feb ratings.  BAO958 had the highest rating for overall flavor and sweetness.

Butternut Squash.  Figure 4 shows the flavor attributes of butternut squash varieties grown at the Spooner Agricultural Research Station.  At the November tasting the Waltham and Nutterbutter had the highest rated overall flavor.  In general, however, there was not consistent differences among the varieties with respect to flavor.  Havana was included in the blind taste testing as a measure of variability and the differences in the two samples reflects the overall variability and lack of differences among the varieties.