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The disease ratings IFSI employs differ depending on the disease. For most corn diseases, hybrid responses will range from highly resistant to highly susceptible. Because of the quantitative nature of these responses, hybrids do not fall into distinct classes. However, reactions can be grouped and placed into categories. The categories used by IFSI are resistant (R), moderately resistant (MR), moderate (M), moderately susceptible (MS) and susceptible (S). This categorical system is used for northern corn leaf blight (Exserohilum turcicum), Goss's wilt (Clavibacter michiganensis susbp. nebraskensis), and Stewart's wilt (Pantoea stewartii). This differs from adopted standards of the International Seed Federation, which are often used. Under these standards, only two levels of resistance are classified (high resistance (HR) and intermediate resistance (IR)) and varying levels of susceptibility are not separated. This is a small number of classes, which does not differentiate levels of susceptibility. As a result, IFSI felt it beneficial to continue a similar system to that used by Dr. Jerald Pataky, long time sweet corn pathologist at the University of Illinois, which has five categories (R, MR, M, MS, S). This provides dealers and growers with a greater separation of hybrid reactions.

For common rust caused by Puccinia sorghi and maize dwarf mosaic (MDM) caused by Maize dwarf mosaic virus, single major genes or a combination of a few genes are used for resistance. While without these major genes, hybrids vary quantitatively, which would be similar to the diseases described in the first paragraph above. With the presence of major genes, we find there is limited value in assessing the quantitative nature of these two diseases. For rust we provide information on the Rp gene(s) that are present in the hybrid (i.e. RpGDJ). These genes provide complete resistance as long as virulent races are not present. For classifying MDM, resistant hybrids are labeled as resistant, while susceptible hybrids are not labeled. For MDM, moderately resistant (MR) is occasionally used for hybrids that have the major gene mdm1, but lack other necessary resistance loci. Under disease inoculations, these MR hybrids display a reduction in disease incidence over susceptible hybrids, but have increased incidence over the hybrids placed in the R category.

Supersweet sweet corn varieties carry the shrunken-2 (sh2) gene. This gene causes very slow conversion of sugar into starch. Consequently, hybrids that carry sh2 maintain their sweetness for a long time, up to 21 days when cooled to 32 - 34°F. Seed should be handled with care and soil conditions should be as close to optimum as possible (soil temperature at least 60°F and adequate but not excessive moisture). Source: https://extension.udel.edu/weeklycropupdate/?p=142

There are two distinct isolation groups in sweet corn, those containing sh2 and those containing su1 genes. To avoid starchy kernels, each group should be isolated from each other as well as popcorn and field corn. Sweet corn hybrids containing sh2 may be identified as supersweet, shrunken, IFSI Reserve™ , Xtra-Tender™ , Xtra-Sweet™, augmented, and Gourmet Sweet™. Sweet corn hybrids containing su1 that should be isolated from sh2 hybrids include; sugary enhanced (se), normal sugary (su), and synergistic.

All IFSI sweet corn varieties are supersweet (sh2). To avoid starchy kernels, isolate from the genotypes sugary enhanced (se), normal sugary (su) and synergistic by ≥300 feet or ≥12 days in silking.

IFSI Reserve™ sweet corn is the elite of elite eating quality in sweet corn. IFSI Reserve™ brand is reserved for the most tender and sweet varieties in the industry.

All hybrid sweet corn seed produced by IFSI has been developed by using traditional plant breeding techniques. These varieties were not developed by using genetic transformation or other forms of genetic manipulation.

Our seed dealers are an excellent resource when determining the right hybrid fit for each grower. You'll find on our website Sample Growing Plans that illustrate the suggested positioning for many of our hybrids.

When one of our breeders develops a new population, targeted to improve a set of characteristics important for growers and/or consumers, it takes approximately 8 years before that improved hybrid will be planted in a grower's field. 3-4 years of this cycle is spent in a breeding nursery fixing the characteristics, screening for and selecting disease resistance as well as other traits. The next 3 years are spent testing the newly developed material in diverse conditions. During this process only the best material is advanced - more than 95% of the newly developed hybrids will be culled for inadequate performance within the first 2 years of hybrid testing. The last year is spent increasing parent seed and growing the first hybrid seed production. IFSI is constantly evaluating and adopting technologies to accelerate this process and to increase the amount of improvement per breeding cycle.