Hm. Flint et al., EFFECTS OF THE PLANT-GROWTH REGULATOR MEPIQUAT CHLORIDE ON SILVERLEAFWHITEFLY (HOMOPTERA, ALEYRODIDAE) INFESTATIONS ON COTTON, Journal of entomological science, 31(1), 1996, pp. 112-122
Cotton, Gossypium hirsutum L., plants were treated with the plant grow
th regulator mepiquat chloride (Pix(TM)) in, greenhouse and field plot
tests to determine its effect on infestations of the silverleaf white
fly, Bemisia argentifolii Bellows and Perring. In the greenhouse, Pix-
treated plants were significantly shorter and had thicker leaves than
untreated plants by the end of the second week following application.
Most of the Pix treatments caused significant reductions in adults, eg
gs and nymphs on leaves by fourth and final week of the test. In a sep
arate test, leaf water potentials were equal for Pix-treated and well-
watered plants which were significantly lower than for water-stressed
and control plants. Pix-treated plants in two field plot tests showed
the same changes in plant morphology observed in Pix-treated plants in
the greenhouse. However, leaf water potentials were the same as in un
treated plants and no reductions in whitefly infestations were found d
uring the 6 to 7 wk test periods. Pix-treated plants in a third field
plot test showed no changes in plant morphology or in whitefly infesta
tions. The reduced whitefly infestations of Pix-treated plants in the
greenhouse, but not in field plots, may have been due to reduced leaf
water potentials in Pix-treated greenhouse plants but not in field pla
nts.