High Tunnel Garlic Variety Study

Varieties Evaluated: Mediterranean, Inchelium Red, German Red, Purple Red, Gambinao Italian Purple, French Alsace Loraine, German White, Large Pink -Clove Selection, Romanian Red, Mchadidzhuari, Xian, "Tony Felice's Variety" .
Bed Preparation: Raised Beds/Bare ground
Plant Date: 10/25/00 (all varieties except Mchadidzhauri and Xian - planted on 10/31/00)
Plot Size: 2 - 32-foot rows per bed. 6 inch spacing within row; 8 inch spacing between rows.
Fertigation: 6Ibs/A of Ammonium sulphate on 4/22/01 and 5/19/01
Irrigation: Drip irrigated approximately a total of 30 hours throughout the growing season.

Brief Summary:
Variety trial was conducted in one of the 36 X17 ft high tunnels at the Penn State High Tunnel Research Park. Cloves were planted approximately 1-2 inches beneath the surface. Drip irrigation was used starting mid March 2001. Soil tests showed no need of additional fertigation, however ammonium sulphate was applied in two split applications (4/22/01 and 5/19/01). Irrigation was terminated once the stalks/leaves begun drying and turning brown. Plant growth parameters, including germination, and plant vigor were evaluated across the varieties. All garlic varieties were harvested late June, expect for Xian, which matured 2 ½ weeks earlier. Bulbs were tied in bundles and allowed to dry. Following harvest, number, weight and size were measured. Bulbs selected for seed were stored in mesh bags.


Results:
Germination percents were extremely high ranging between 85 to 100 percent for all varieties except "Tony Felice" and Gambiano Italian Purple, which had germination percents of 70 and 65 respectively (See Table 1).

Overall, German White, Romanian Red and Mchadizhauri, showed the highest Vigor (5, 5, and 4 respectively). Mediterranean, Inchelium Red, Gambinao Italian Purple, and Xian, had the lowest vigor (Table 1).

In general, growth across varieties was sporadic especially in the early months, except for the varieties, Romanian Red, German White, and Inchelium, which exhibited uniformity throughout the growing season. Xian was the earliest variety to mature, and was harvested 18 days before other varieties. All other varieties matured later, differing only slightly in the maturity dates.
While there were differences in bulb size amongst the varieties, it should be noted that bulb and clove size seemed to be directly related to the size of seed planted. It was evident that bulbs grown in the tunnel were slightly larger than field-grown garlic (conversation with Tony Hartifield). More work however, needs to be done to explore the various benefits of growing garlic in tunnels including earliness and improved quality.

Growing garlic in a tunnel environment proved successful. One of the benefits of growing under the tunnel environment, would be the reduced fluctuation in temperatures leading to decreased thawing and freezing of the ground. This obviously promoted a more favorable growing environment for the bulbs. Future work will include side-by-side comparison between field and tunnel grown garlic, as well as economic analysis.

Acknowledgement: Anton C. Hatfield-Nicholson Juniata Stinking Rose for providing most of the garlic seed.

Table 1.

Variety Total # Bulbs Harvested/5 ft area Vigor Size/inches Weight lbs/10 bulbs AverageWeight (lbs)
Mediterranean 20 2 1.6 1.6 0.16
Inchelium Red 20 2 1.4 2 0.2
German Red 20 3 2.6 2.8 0.28
Purple Tip 20 3 1.5 1.2 0.12
Gambinao Italian Purple 13 2 1.6 2.3 0.23
French Alsace Loraine 20 3 1.8 1.4 0.14
German White 17 5 2 1.7 0.17
Large Pink Clove Selection 20 3 1.5 1.7 0.17
Romanian Red 18 5 1.7 1.7 0.17
Mchadidzhuari 19 4 1.5 1.3 0.13
Xian 20 2 1.3 0.6 0.06
Tony Felice* 14 3 2.8 2.1 0.21

*Note: Variety name unavailable for this variety: Source: "Tony Felice"