Mepiquat-chloride (Pix) is a synthetic plant growth regulator effective in controlling vegetative growth of cotton. This physiological response usually results in uniform early maturity. There are reports of yield increase through the use of Pix, however, these results are sporadic and environmentally dependent.

Today with an increase in the use of Pix, on commercial cotton fields, researchers will need to know its impact on phytophagous cotton pests in order to optimize IPM strategies. Our objectives were to measure the impact of Pix on host-plant resistance to Heliothis zea in cotton.