|TOMATO OXYGEN SUPPLEMENTATION SUMMARY|
|Size||thru 9/16 (Good & Imperfect)||thru 10/14(Good & Imperfect)||Total Yieldthru 10/14 (Good, Imperfect, Green)|
|Total No Treatment||0.51||240||887||1508|
|Percent O2 Advantage||-1.1%||15.8%||8.4%||8.2%|
|Confidence Level %||--||83||89||84|
Cumulative total pounds of fruit during the harvest period through mid-September are shown in figure 1, and those through mid-October are shown in figure 2. Cumulative yields from plants provided with super-oxygenated water were greater than those from plants provided with untreated water throughout the study period. The differences between treated yields and untreated yields peaked in mid-September. The graph in figure 2 shows some slowing of the percentage difference after mid-September, as growth slowed and watering decreased.
Tomato crops showed an increase in yield when plants were treated with super-oxygenated water, while fruit size was unaffected. Cumulative yields were positive for super-oxygenated treated plants throughout the growing season, although individual harvests varied. The difference in total yields was most positive for treated plots thru mid-September, reaching nearly 16%. Since day-length and heat were decreasing after mid-September, plant growth and yield declined as did the differences between the treated and untreated plots. The difference between treated and untreated plots narrowed as growth slowed as expected since less water was being applied to the plants. Irrigation amounts dropped from nearly 50 gallons per day several times per week to less than 25 gallons one time per week as temperatures cooled. Total yield through mid-October, including all good, imperfect, and green fruit, showed a significant advantage for treated plots (8.2% with 84% confidence level). This yield advantage was maintained even though differences were narrowing between treated and untreated plots as growth slowed and much less water was supplied to the plants in the later part of September and in October.
One caveat for this study is that the plants were installed in the high tunnels somewhat late in the season, due to the cold spring growing conditions in zone 3b. One advantage of growing crops in high-tunnels is the ability to extend the growing season both in the spring and in the fall. These plants were not available for planting until mid-June, while tunnel temperatures may have permitted planting in May if supplemental heating was available. There was a substantial amount of green tomato fruit remaining when harvesting was terminated on October 14th, and adding the immature fruit yield to the total yield can provide an estimate of what may have been achieved if the growing season had been started earlier. The amount of immature fruit was substantial, at nearly 1300 pounds, and increased the differential advantage for treated plots from 74 pounds to 123 pounds at the end of the study.
Supplementation with super-oxygenated water is a very promising concept and deserves further consideration for high tunnel application. High tunnels are an ideal environment for such experiments, since water can be precisely controlled and rainfall is not an issue. Positive increases in yields were observed for tomatoes, and earlier planting to take advantage of the additional heat in the tunnel environment possibly may have resulted in even greater yield differentials.