Charles A. Mullins

Plants of ‘Prime Plus’ and ‘Attribute GSS 0966' were taller and yields were higher than the other cultivars. Ears of ‘Xtra Tender 276A’ were heavier and longer than ears of most other cultivars. The five cultivars performed well.

Supersweet sweet corn (SH₂) is the major corn type used for shipping sweet corn markets, and is sometimes grown in home gardens and for local markets. The first supersweet cultivars that were developed were somewhat difficult to grow, seed was difficult to store, and the kernels had a crisp texture. Many of the problems have been overcome in newer cultivars. Numerous supersweet cultivars have been evaluated by University of Tennessee researchers in recent years. An experiment was conducted at the Plateau Experiment Station at Crossville in 2000 to evaluate performance of five Supersweet type sweet corn cultivars.. The cultivars included two standard supersweet cultivars, ‘Millennium’ and ‘Prime Plus’, a genetically engineered numbered isoline of ‘Prime Plus’ with the Bt gene which was named ‘Attribute GSS 0966' and two cultivars with more tender kernels, ‘Xtra Tender 271A’ and ‘Xtra Tender 276A’.

The site was prepared for planting using conventional tillage in late April. Fertilizer was broadcast at 600 lb/A of 15-15-15 before final disking on May 3. Plot size was one row, 20 ft long, and rows were spaced 30 inches apart. Seed of the cultivars was obtained from commercial seedsmen, and was planted on May 4 at the rate of 70 seed per row using a cone-type mechanical planter. Experimental plot design was a randomized complete block with four replications. Herbicides applied on May 5 were atrazine (Aatrex) at 1 lb ai/A and metolachlor (Dual II) at 2 lb ai/A. Insecticides were applied on a 3 to 5 day frequency and included esfenvalerate (Asana) at 0.05 lbai/A and lambda-cyhalothrin (Warrior T) at 0.03 lb ai/A.

Records taken included plant stand, plant height, ear height, ear diameter, number and weight of ears, ear length, ear diameter, external ear appearance, internal ear appearance, % fill, ear cover, and insect damage rating. All data were analyzed by analysis of variance procedures, and cultivar means were separated by Duncan’s multiple range tests at the 0.05 level of probability.

Plant stand was not significantly different due to cultivar (Table 1). Plants of ‘Prime Plus’ and ‘Attribute GSS 0966' were taller than plants of all other cultivars. Plant diameter and ear height were not significantly different due to cultivar. ‘Prime Plus’ and ‘Attribute GSS 0966' produced more ears than all other cutivars. Ears of ‘Xtra Tender 76A’ weighed more than ears of all cultivars except ‘Millennium’.

Ears of ‘Millennium’ were longer than ears of all other cultivars (Table 2). Ear diameter and shuck cover were not significantly different due to cultivar. ‘Xtra Tender 271A’ had the highest external rating, and ‘Xtra Tender 276A’ had the highest internal rating of ears of all cultivars. ‘Millennium' had the least ear fill of all cultivars.

Table 1. Plant characteristics and yield of Supersweet sweet corn cultivars evaluated at The University of Tennessee Plateau Experiment Station at Crossville, 2000.