Potassium Gibberellate

Potassium gibberellate (Gibrel, a solution of potassium gibberellate supplied by Merck Co., Inc.) was applied three times (September 17, October 1, and October 15). These spray treatments consisted of 10, 20, 30, 40, 50, and 100 p.p.m. of potassium gibberellate plus an unsprayed check. These plots, as well as all others in the field studies, were kept under observation until the winter mulch was applied in December 1958, and observations were continued in the spring of 1959 when the mulch was removed. 

Flowers appeared in the autumn of 1958 on plots treated with 40, 50, and 100 p.p.m. of potassium gibberellate and petiole elongation was noted on plants sprayed with 100 p.p.m. When the plants started to bloom in the spring, more flowers opened earlier on the plants sprayed with 10 and 20 p.p.m. of potassium gibberellate than on the unsprayed check plants. Plants in all plots started to bloom at about the same time. No other effects of the sprays were noted until harvest. 

Table I. Effect of Rate of Potassium Gibberellate Application to Strawberry Plants...

Table II presents yield data from this study. Three applications of 20 p.p.m. of the material caused a highly significant increase in early yields with no significant reduction in total yields. The single application on October 15 and the two applications started October 1 significantly reduced total yields. Under conditions of this study it would appear that three applications of potassium gibberellate are needed to increase early yields.

Table II Effect of Number of Potassium Gibberellate Spray Applications to...

Table IV. Effect of Spray Applications of Potassium Gibberellate upon Strawberry Fruit Size and Yield...

These field studies indicate that sprays of potassium gibberellate in the autumn change the pattern of fruit production the following spring. It would appear that the flowers had all reached a similar stage of development at the bloom period on plots treated with 10 and 20 p.p.m. of the material. This is carried through to the harvest period, when more fruit is harvested early from the plots receiving these treatments. 

At the time the field studies were in progress, greenhouse investigations were initiated. The Sparkle variety only was used. Greenhouse-grown, potted dormant strawberry plants were placed under a 16-hour photoperiod and sprayed with 0, 10, 20, 40, 80, and 160 p.p.m. of potassium gibberellate, applied first on October 13 and repeated on October 20 and 27, 1958. Each plot included four plants... 

The results of the chromatographic analysis are reported in Table V. The presence of IAA in vegetative strawberry tissue was confirmed, but no simple relationship between free extractable IAA and applications of potassium gibberel-late could be observed. The compositing of plant tissues prevented the statistical analysis of these data. 

To gain information on the effect of potassium gibberellate on the number... 

Flowers were produced by the unsprayed plants that were exposed for only 30 short days. This confirms that flowers had been initiated in the crowns of plants when sprays were applied after 30 short days and that these plants represented a different population from those sprayed immediately on placement under short-day conditions. One clearly evident result was a sharp reduction in number of flowers produced. The plants treated with 10 p.p.m. of potassium gibberellate, regardless of time, produced about one half as many flowers as the control plants. This was not observed in the field studies at the 10-p.p.m. concentration, but 40 p.p.m. of potassium gibberellate used three times in the field reduced yields by about one half. 

Potassium Gibberellate occurs as a white to slightly off white, crystalline powder. It is soluble in water, in alcohol, and in acetone. The pH of a 1 20 aqueous solution is about 6. It is deliquescent. 

Uses Emulsifier, stabilizer, thickener in foods Regulatory FDA 21 CFR 172.660 Potassium gibberellate CAS 125-67-7... 

DIhydroxyacetone Phytase Xylanase enzyme activator, barley malting Potassium gibberellate enzyme activator, brewing Gibberellic acid... 

Phenothiazine Poloxamer 101 Poloxamer 105 Poloxamer 108 Poioxamer 122 Poloxamer 123 Poloxamer 124 Poloxamer 181 Poloxamer 182 Poloxamer 183 Poloxamer 184 Poloxamer 185 Poloxamer 188 Poloxamer 212 Poloxamer 215 Poloxamer 217 Poloxamer 231 Poloxamer 234 Poloxamer 235 Poloxamer 237 Poloxamer 238 Poloxamer 282 Poloxamer 284 Poloxamer 288 Poloxamer 331 Poloxamer 333 Poloxamer 334 Poloxamer 335 Poloxamer 338 Poloxamer 401 Poloxamer 402 Poloxamer 403 Poloxamer 407 Polyethylene glycol Potassium gibberellate... 

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