Gibberellin Studies with Sugarcane. III. Effects of Rate and Frequency of Gibberellic Acid Applications on Stalk Length and Fresh Weight1
- Paul H. Moore and
- Harold Ginoza2
Sugarcane (Saccharum spp. hybrids) stalk length, fresh weight, dry weight, and sucrose content, normally reduced when plants are grown under reduced sunlight (250 Langleys/day) and cool temperatures (mean daily temperature 23 C), can be increased with foliar applications of gibberellic acid (GA3). Maximum increases in lengths and fresh weights of seven Hawaiian commercial cultivars were a function of cultivar treated, the amount of GA3 applied, the number of applications, and the interval between applications.
Lowland cultivars produced the largest gains in response to the largest quantities of GA3; highland cultivars produced smaller gains. The effects of two applications of 1.0 mg GA3 per stalk depended on the interval between applications. Least growth gains occurred when the intervals were 0 and 45 days; greatest growth gains occurred when the interval between applications was 15 days. The effect of a 30-day interval was nearly equal to the 15-day interval, but the 30-day interval did not result in as great a loss of stalks as occurred at the 15-day interval. Three and four applications of 0.5 mg GA3 per stalk at 15-day intervals were less effective in increasing stalk length and fresh weight than were three and four applications of 0.5 mg GA3 per stalk at 30-day intervals. Greatest gains in fresh weight in response to 2.0 mg GA~ per stalk were in response to the greatest number of applications, four, if they were at 30-day intervals.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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