Publication Date

1985

Location

Kyoto Japan

Description

Forage sorghums (Sorghum bicolor) provide high-quality pasture during the summer, but because of their rapid rate of growth quickly become mature and unacceptable for grazing. Maintaining their growth in a more juvenile stage could be expected to improve forage quality and utilization by livestock. Our objectives were to determine the effects of the plant growth regulator meflidide (N-[2,4-dimethy-5-[[(trifluoromethyl) sulfony]amino]phenyl] acetamide) on vegetative growth and root production of a hybrid forage sorghum. In two greenhouse experiments different rates of mefluidide (0, 0.035, 0.07, 0.14 and 0.28 kg/ha) were applied to 'Dekalb ST6+ ' hybrid forage sorghums and plant responses measured up to 35 days following treatment. Plant heights and top yields were reduced by mefluidide, but number of tillers per plant was increased. Root weights were less for treated plants in one experiment. Top/root ratios were not different for treated and control plants after 28 or 35 days. Root weight differences over time appeared to be more a function of the amount of top growth present than a direct effect of mefluidide on roots. This supposition is supported by top/root ratio data, single and multiple regression analyses, and path coefficient analysis. By releasing apical dominance and stimulating new tiller production, mefluidide maintains the plant longer in a more juvenile stage of growth.

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Effects of Mefluidide on Vegetative Growth and Root Production of Forage Sorhum

Kyoto Japan

Forage sorghums (Sorghum bicolor) provide high-quality pasture during the summer, but because of their rapid rate of growth quickly become mature and unacceptable for grazing. Maintaining their growth in a more juvenile stage could be expected to improve forage quality and utilization by livestock. Our objectives were to determine the effects of the plant growth regulator meflidide (N-[2,4-dimethy-5-[[(trifluoromethyl) sulfony]amino]phenyl] acetamide) on vegetative growth and root production of a hybrid forage sorghum. In two greenhouse experiments different rates of mefluidide (0, 0.035, 0.07, 0.14 and 0.28 kg/ha) were applied to 'Dekalb ST6+ ' hybrid forage sorghums and plant responses measured up to 35 days following treatment. Plant heights and top yields were reduced by mefluidide, but number of tillers per plant was increased. Root weights were less for treated plants in one experiment. Top/root ratios were not different for treated and control plants after 28 or 35 days. Root weight differences over time appeared to be more a function of the amount of top growth present than a direct effect of mefluidide on roots. This supposition is supported by top/root ratio data, single and multiple regression analyses, and path coefficient analysis. By releasing apical dominance and stimulating new tiller production, mefluidide maintains the plant longer in a more juvenile stage of growth.