Relation of Hydrocyanic Acid Potential of Leaf Samples to That of Whole Plants of Sorghum¹

Abstract

The relationships between the hydrocyanic acid potential (HCN‐p) of leaves and whole plants were studied in ‘Piper’ sudangrass, Sorghum bicolor var. sudanense (L.) Moench, and ‘Suhi‐l’, sorghum‐sudangrass hybrid, S. bicolor ✕ S. bicolor var. sudanense, subjected to three cutting managements. The results were: Leaf and whole plant samples from Suhi‐1 were usually higher in HCN‐p than samples from Piper at all harvest dates for the three cutting managements. Plants cut at 10 cm when they reached the early bloom stage had significantly lower average HCN‐p than plants cut at 8 and 20 cm when they reached a height of 50 and 75 cm, respectively. Differences in average HCN‐p for the two latter cutting management were not signifant. There were no significant differences among average HCN‐p of the whorl and the first and third leaves of Piper. For Suhi‐1, no significant difference was found between the average HCN‐p of the whorl and the first leaf. Both the whorl and the first leaf were significantly higher in HCN‐p than the third leaf. There were no consistent trends in HCN‐p associated with successive harvest dates during the season. Most of the simple correlation coefficients between HCN‐p of leaf samples and of whole plants were highly significant, indicating that leaf samples could be used to rank varieties for HCN‐p. Ratios of leaf to whole plant HCN‐p were inconsistent; therefore, such samples are not suitable for estimating the total amount of HCN‐p of whole plants.

Amount and Distribution of Hydrocyanic Acid Potential during the Life Cycle of Plants of Three Sorghum Cultivars1

“…and modified by . As suggested by and Benson, Gray, and Fribourg (1969), confidence intervals were used in preference to the analysis of variance for comparing sample means.…”

Título en español

“…Leaf tissue was analyzed for HCN-p with the spectrophotometric method described by Gorz et al (5) with modifications in sample preparation. The third leaf from the distal end of the plant was sampled prior to each cutting, according to the suggestion of Benson et al (1). Samples were obtained at random over the length of the blade, excluding the midrib with an ordinary hole puncher.…”

“…Few reports are available in Puerto Rico concerning the use of forage sorghums, in spite of their great potential for production throughout the year_ In studies conducted in the Lajas Valley, Vazquez et al (18) reported dry forage yields of over 35 tons per hectare with "Millo Blanco" (MB), a local forage-sorghum variety. Sotomayor-Rios and Telek (14) obtained dry forage yields of 17 tons per hectare from hybrid CK-60 X MB, with an average crude protein content of 17.6% during a 211-day period at Isabela_ On the basis of cuttings at a 30-day interval Sotomayor-Rios and Santiago (16) reported dry forage yields of 20 tons per hectare in 140 days or 143 kg•ha- 1 • day-\ with an average crude protein content of about 14.3%. Morales (10) evaluated a series of hybrids offorage-sorghum and sorgo-sudan at Isabela, and reported yields of over 40 tons of dry forage/ha yearly when harvested at a 45-day interval.…”

Effects of Ensiling on the Hydrocyanic Acid Potential of Sorghum Plants1

“…As suggested by Wattenbarger et: a!. (1968) andB(:nson, Gray, andFribourg (1969), confidence intervals were used to compare treatment means.…”