Evaluation of a Rapid Technique for Measuring Soluble Solids in Corn Stalks¹

Abstract

Soluble solids in corn (Zea mays L.) stalks were measured by multiplying the refractometer reading in percent Brix of a small sample of expressed juice by the moisture lost in drying a stalk sample. This method was evaluated by comparison with total sugar determination by the Shaffer‐Somogyi method on the same samples. For individual internodes sampled over the growing season the correlation was r = +0.93**. The ratio of total sugars : soluble solids over a range of genotypes and populations varied from 0.48 to 0.66More rapid estimates of soluble solids in the stalk were obtained by sampling one internode near the ear with the refractometer and multiplying the Brix reading by the moisture lost in drying the entire stalk. Results obtained by using refractometer readings from the ear internode, the internode above the ear, and the internode below the car were highly correlated (r = +0.92**, +O.SO*+, and 0.90**, respectively) with the total sugar content of the stalks.The refractometric technique was an inexpensive, rapid means of determining levels of soluble metabolites in corn stalks and also provided useful estimates of total sugar levels.

Harvest Methods for Estimated Ethanol Yields from Relative Fermentable Carbohydrate Accumulation in Maize Hybrids1

“…Assuming equality of refractometer readings and percent fermentable carbohydrates was unnecessary as only relative comparisons were made. They are proportional and thus correlated (2,8 (7). In 1983, the internodes used for refractometer readings were also quickfrozen and sent to the Northern Regional Research Center, Peoria, IL, for sugar analyses on a dry-weight basis for comparison with estimates based on refractometer readings.…”

Caracteristicas biométricas e fisiológicas de três cultivares de milho

“…Vários autores mostraram que os sólidos solúveis acumulados nos colmos, quando a capacidade de crescimento dos grãos é limitada, após o florescimento, quando a demanda é grande, são mobilizados para o crescimento dos grãos, podendo representar até 20% do seu peso final (DAYNARD et alii, 1969;CAMPBELL & HUME, 1970;HUME & CAMPBELL, 1972;DUNCAN, 1975;MACHADO et alii, 1982). Tal comportamento possivelmente esteja relacionado com a diferença entre a capacidade fotossintética da planta e a capacidade de enchimento de grãos nesse período (DAYNARD et alii, 1969;DUNCAN, 1975;MACHADO et alii, 1982).…”

Accounting for Increases in the Harvest Index of Sweet Corn following Early Leaf Clipping1

“…Intemodes were collected in early morning (sunrise to 1 hr past sunrise) and immediately taken to the laboratory for determination o f total solids with a Bausch and Lomb " Abbe HI" refractometer. Intemode samples were oven-dried and values were adjusted to equal moisture and converted to percent soluble solids (2).…”