High Tunnel Tomato Variety Trial

During the season, all varieties grew well and achieved relatively good yields.


  • Ultra Sweet, Mountain Spring, Mountain Fresh, Royal Mountie, Sunbeam, Seedway10250, Daybreak, NC Grape.

Bed Preparation

  • Flat culture/Black plastic

Date seeded

  • 3/29/00 into 72 cell Speedling flats

Date Transplanted

  • 5/4/00


  • Randomized with 4 replications

Plot size

  • 20 plants per row (2 varieties per row) 80 plants per rep/house 1.5ft between plants in row 3.5ftbetween rows Total area planted /tunnel ~ 0.006acres


  • 15lbs/A of 20-20-20 on 5/15/00 and 6/19/00.


  • Drip irrigated approximately a total of 33 hours through the season.


Brief Summary

During the season, all varieties grew well and achieved relatively good yields. Plants were staked using the Florida weave system. Tomatoes were tied three times except for NC Grape* and Ultra Sweet*, which were tied four times (5/19, 5/30, 6/13, 6/23*). The plants were pruned a two different times. The NC Grape variety was topped/trimmed mid July to help manage the vigorous growth. Early and mid season, the crop was virtually free of insect pests and/or disease. However late in the season there was an outbreak of powdery mildew, followed by an infestation of white fly. In each tunnel it was observed that the mildew started in the middle rows and then quickly spread to the outer rows. Lack of sufficient air movement throughout the house may have contributed to the rapid spread of the mildew.

Two applications of Bravo (2lb/A) were applied to help manage the mildew, however the profuse foliage made it difficult to spray and attain good coverage. Consequently control was minimal. Attempts were made to promote as much air movement through the tunnel by letting the sides up as much as possible. Overall NC Grape and Seedway seemed to have fair amount of tolerance to the mildew. Ultra Sweet and Daybreak seemed the most susceptible (See Table 1).

Encarisa Formosa (bio-control) and insecticidal soap were used to help control whitefly infestations.

Powdery Mildew Rating
Powdery Mildew Rating
Powdery Mildew Rating
Ultra Sweet 1.8 3.1 4.6
Sunbeam 0.0 2.0 4.1
Mt.Fresh 1.1 1.5 2.6
Mt.Spring 1.2 2.2 3.1
RoyalMountie 0.0 3.7 3.5
NC Grape 0.0 1.1 2.3
Daybreak 2.1 3.0 3.8
Seedway 0.0 1.2 2.5

Significance y * * *
LSD (0.05)z 0.2 0.6 0.3

x Powdery mildew rating on a scale of 1-5: 1=least mildew on most leaves, 5= severe mildew on most leaves y Treatment effects were significant at 5% (*) probability levels z Least significance difference at the 5% level


NC Grape was the first to flower and fruit followed by Daybreak and Ultra sweet. NC Grape flowers had to be pinched off twice, to allow for crop maturation prior to fruit production. Harvest of the crop commenced on 7/20/00. A total of 15 harvests were made, most harvests occurring twice a week. The last harvest was made on 10/10/00. However most of the varieties continued bearing and still had fruit on them until the first hard frost (10/28/00). Overall the Mountain fresh had the highest marketable yield (weight) while Sunbeam had the lowest. Ultra Sweet produced the highest number of marketable fruit, however, most of the marketable fruit consisted of US #3 and #4 (Table 2). Ultra sweet had a significantly high cull compared to all other varieties. Most of the cull was as a result of misshapen fruit, cat facing, sun scalding, and blotch ripening. We also observed other defects including zippering, mouse damage, soft rot, (BER) blossom end rot, cracking and as well as both mouse and bird damage.

NOTE: Please note on the tomato study, instead of 10/28 for first hard frost, it should read 10/29 when outside min. temperatures read 26.3F and the min. temps in the tunnels read an average of 29.8F.

Table 2. Tomato Variety Yield

Variety Total Yield
Total Yield
Marketable Yield
Marketable Yield
Marketable Yield
% by Grade
Marketable Yield
% by Grade
Marketable Yield
% by Grade
Marketable Yield
% by Grade
Cull Yield
Cull Yield
Cull Yield
Ultra Sweet 2239 875.2 1886 708.3 19.6 16.5 24.8 23.3 353 166.9 15.8
Mt. Spring 1578 850.1 1419 780.9 49.2 21.4 13.2 6.1 159 69.2 10.1
Mt. Fresh 1921 906.2 1783 862.8 45 23.1 17 7.7 138 43.4 7.2
Royal Mountie 1432 808 1303 744 45.8 24.3 14.9 6 129 64 9
Sunbeam 1301 748.8 1183 689.7 58.6 18.1 10.3 3.9 118 59.1 9.1
Seedway 1566 816.7 1398 743.1 47.4 21.4 14.6 5.9 168 73.6 10.7
Daybreak 1670 840.5 1562 790.8 46.1 18.8 19.7 8.9 108 49.7 6.5
lsd .05
412 63
229 70

99 61
NC Grape*


*NC Grape data not subjected to statistical analysis **Note:A replication effect with replications 2 and 4 having significant higher yields compared to reps 1 and 3 was noted in the analysis. However this effect did not produce enough variation to diminish the overall effect of the variety on crop yield. Since we could not amend the soil this last season, I recommend taking soil tests in the four tunnels (probably in all others as well) and amend soil accordingly, prior to next cropping. Rep. effects are probably due to the fertilization study in 1999.