Evaluation of Sweet Corn Varieties at Two Grower Locations in Ohio

Robert J. Precheur, Jim Doran, David Schacht, Clarence Renk, Michael Haddix and Joe Davlin.

Department of Horticulture and Crop Science, Grower Cooperators: New Albany, OH, Canal Winchester, OH, Manager and staff at the Western Branch, South Charleston, OH

Sweet Corn is Ohio's number one fresh market vegetable with between 15,000 to 17,000 acres planted depending on the year. In the US, Ohio ranks 6^th in fresh market sweet corn production. Sweet corn is produced throughout OH, in the southeast along the Ohio River, in many counties around Cincinnati, and also throughout central and northern OH.

Objectives

To identify sweet corn cultivars with good emergence, high marketable yield and excellent quality under OH growing conditions.

Methods

At Canal Winchester, ten SE varieties were planted on April 20^th, 29^th and May 22, 2006. Eleven SE varieties were planted on May 4^th in New Albany. Eight SH2 varieties were planted in Canal Winchester on May 22, 2006 and eleven SH2 varieties were planted on May 25^th in New Albany. Plots consisted of either: 4, 6 or 8 row blocks, 30 in apart and approximately 500 or 1000 ft long depending on location. In row spacing averaged 9 inches in Canal Winchester and 11 inches in New Albany. The middle two rows (total 20 linear feet) at three random locations in the block were used for yield data. Data collected included early plant vigor, plant and ear characteristics, and marketable yield. Sweetness was determined by a purely subjective evaluation of raw eating quality. Each variety was also evaluated for percent germination at ten different temperatures on the thermo-gradient table. Complete thermo gradient results, saturated salt accelerated ageing, (SSAA) seed tests, and pictures are available at the VegNet website: http://vegnet.osu.edu

Results

As in 2005, warm April weather allowed for early planting and good germination but was followed by a prolonged period of very cool, wet weather. This is reflected in that the days to maturity for the se varieties ranged anywhere from 6 to 19 days later than the ‘Predicted Maturity’ for a particular variety. In the bicolor se’s, Luscious, Precious Gem and Trinity had the best early plant vigor 2-4 weeks after emergence. Whiteout, Denali, Augusta and Sugar Queen had good early plant vigor for the white se varieties.

In the bicolors, Brocade, Luscious and Accord had the best yield in Canal Winchester. Native Gem and Trinity had high yields in New Albany. For the highest yielding varieties, Trinity and Brocade had the best flavor. Revelation and Reflection had good flavor but lower yields. Luscious had significant tip fill problems at one location. Revelation and Precious Gem also had tip fill problems at one location with less than 0.5 inches of the ear tip unfilled. Revelation had a significant amount of Stewart’s bacterial wilt which led to a 20% reduction in plant stand. Untreated sample seed was mixed with Gaucho treated seed for this planting. Revelation is a good tasting early variety but the Stewart’s susceptibility removes it from our recommended list.

For the white se’s, the best yielding varieties were Augusta, Sugar Queen and at one location Chantilly. All white se’s tested were rated as having good flavor at both locations except for Whiteout and Sugar Pearl which got a lower medium to good rating at one of the two locations. Chantilly also had a significant amount of Stewart’s Bacterial Wilt at both locations reducing plant stand by about 20-25% after stand counts were made on 6/22/06.

In the SH2 varieties, days to maturity more closely matched predicted maturity and a heat wave near harvest time pushed maturity of several varieties together and slightly ahead of predicted maturity.

Overall, yields were very good and the highest yielding bicolor sh2’s were: Optimum, Holiday (both augmented SH2’s), Mirai 334 BC, Mirai 301 BC, Xtra Tender 282, and Mirai 308 BC. At one location Cavalry (HMX 2374) had the highest yield producing over 2000 dozen ears per acre. However, this variety was extremely tough with very poor flavor. Mirai 334 BC, at the Canal Winchester (CW) location had a tip fill problem with 0.5 to 1 inch of the ear left unfilled. Most of this planting was unmarketable. At New Albany, Mirai 334 BC had good tip fill. The problem at CW is puzzling since there was no stress and all plantings received timely irrigation unless the overhead irrigation affected pollination.

Flavor was rated as very good for most of the sh2 varieties and there was an occasional good or good to very good rating for 3 varieties. One variety that was outstanding in flavor, texture and quality was Optimum. Quality and performance were equal for both locations.

Visit theVegNet website: http://vegnet.osu.edu for pictures of these varieties.

The accelerated aging test is a common and important seed vigor indicator for many large-seeded crops, but its utility for sweet corn (Zea mays L.) evaluation may be limited because of the anatomical and compositional differences among su, sh2 and se genotypes. The recent use of saturated salts in accelerated aging tests to reduce water uptake, microflora growth, and slow seed deterioration (Jianhua and McDonald, 1996) may also be useful in more accurately testing sweet corn genotypes. Pericarp damage and pathogen levels in (or on) sh2 seed are especially troublesome (Borowski et al., 1991; Parera et al., 1996). Use of a saturated salt accelerated aging (SSAA) test is to more accurately evaluate sweet corn seeds. The SSAA test should (1) reduce water uptake, (2) minimize microflora growth, and (3) slow overall seed deterioration, thereby allowing a more precise and repeatable measurement of sweet corn seed vigor.

Table 1. Saturated Salt Accelerated Aging¹, 2006

ID #	Variety	Color	Percent Germination
	SE's
1	Native Gem^1	Bi	84
4	Trinity^1	Bi	94
5	Luscious	Bi	80
6	Accord	Bi	59
7	Precious Gem	Bi	72
10	Chantilly	W	89
11	Sugar Pearl^1	W	84
12	Whiteout^1	W	81
13	Augusta	W	87
14	Denali	W	51
15	Sugar Queen	W	82
	SH2's
18	Mirai 308 BC^1	Bi	75
19	Mirai 334 BC^1	Bi	75
20	Mirai 301 BC^1	Bi	79
21	Mirai 350 BC^1	Bi	51
22	Optimum^1	Bi	78
23	Surpass^1	Bi	74
25	Holiday	Bi	77

1. Average of 4 replications.

Table 2. Summarization of 2006 Sweet Corn Cultivars on The Thermo-Gradient Table

			Percent Germination
	Temperature Range		12-16^oC 57 - 61 ^oF				18-20^oC 64 - 68 ^oF				22-30^oC > 72 ^oF
	Days on Table		3	5	7	10	3	5	7	10	3	5	7	10
ID #	Variety	Type
	SE's
1	Native Gem^1	Bi	0	0	5	20	0	13	30	43	56	93	94	95
4	Trinity^1	Bi	0	0	0	20	3	40	55	70	68	96	98	99
5	Luscious	Bi	0	0	3	6	6	38	53	68	47	94	91