James E. Boudreaux and Alan Fuller1, David Yount Jr.2, Matt A. Martin Jr.3, Glen E. Daniels, Matthew Foster 4 and Denyse Cummins5
Sweet corn is one of the most popular summer vegetable crops for Louisiana’s vegetable growers. It is a high-demand item that brings customers to roadside stands and farmers markets. Sweet corn is not a high-income-producing crop for Louisiana growers. It is a relatively low-yielding crop for the amount of land that it requires for production.
Louisiana growers are looking for sweet corn varieties that make large ears with a good flag leaf that fills out the whole ear. The consumer of today also is looking for sweet corn that is free of worm damage. Worm-free corn requires spraying with an insecticide every 2 days from the time the silks appear until the silks dry (20-24 days, 10-12 sprayings). The spraying adds to the cost of production and requires significant attention by the grower. Just missing one spraying will result in worm damage to the ear. The use of Bt sweet corn varieties will free the grower from the expense of spraying and reduce the stress of a rigid spray schedule.
Eight Bt sweet corn varieties were planted in the spring of 2008 at Ed Lester Farms in Coushatta, Robbie Poole Produce Farm in Cheneyville, La., Riverview Plantation in Vidalia and Scott Ryan Farms in Dixie, La. The growers chosen had the ability to plant with vacuum seeders to plant single seeds at the desired spacing and to irrigate to ensure tip fill.
All the plots were planted in mid- to late April and matured the end of June and early July. Three rows, 200 feet long of each variety were planted. The plots were evaluated in late June and early July
The plants were evaluated for plant size and ear height. Twelve ears of each variety were harvested, and six ears were shucked for evaluation. The condition of the flag leaf and the ends of the ears were noted. The ear length, ear diameter and the degree of tip filled were evaluated from the shucked ears.
The top variety in the test was the yellow super sweet GSS 0969. This variety was well ahead of all the other varieties in the test. Its main attribute was the large 8x1¾- inch ears. It is a medium-late-maturing variety. The ears were tight on the ends with only a fair-to-good flag leaf. The plants were medium tall with the ears being made at a medium-high level on the plants. The kernels filled out to the tip of the ear.
Two of the bicolor varieties, BSS 0982 and BSS 0977, were tied for the top spot. BSS 0982 is a medium-maturing super sweet variety that had a good flag leaf and a tight end. It made 7x1¾-inch ears which filled out to the tip. The plants were medium tall and produced ears at a medium-low level on the plant.
The variety BSS 0977 is a medium-early super sweet. The plants were medium tall with ears produced at the medium-high level. The flag leaf was only fair, but the ends of the ears were tight. It made a 7x1½-inch ear that filled out to the tip.
The top white variety was WSS 0987. It is a medium-maturing super sweet that made 1¼- to 1½-inch ears. The flag leaf was only fair to good, and all the ends of the ear were tight. The kernels filled out to the tip of the ear.
Growers are encouraged to try the Bt varieties a on small scale before planting large plantings to determine how they performed under the conditions of their farm.
The proper use of irrigation is a must to be successful with the Bt varieties. Failure to irrigate will result in small ears that do not fill out to the tip. It was also noted by one of the cooperators that the Bt varieties tended to fall over in high winds easier than other sweet corn varieties.
1Professor and Student Worker, LSU School of Plant, Environmental and Soil Science, 155 J C Miller Hall, Baton Rouge, La. 70803; 2Assistant County Agent, Red River Parish, Coushatta, La.; 3County Agent, Rapides Parish, Alexandria, La.; 4County Agent and Summer Intern, Concordia Parish, Vidalia, La.; 5Area Horticulture Agent, Shreveport, La.