Improved soil-water relations through supplemental irrigation or the application of a soil conditioner can increase crop yield in semiarid regions. Barbary-Plante (BP) is a soil conditioner consisting of a sodium acrylamideacrilate copolymer with macro- and micronutrients and other components that improve nutrient availability, water retention, and aggregate stability in the soil. The efficacy of BP as a soil conditioner was tested on sweet corn (Zea maysL. cv. Sure Sweet) yield in the semiarid southwestern region of Puerto Rico (Lajas Valley). The soil at the experimental site is classified as Fraternidad clay (fine, smectitic, isohyperthermic Typic Haplusterts). The treatments consisted of three rates of BP (0, 50, and 100 kg/ha, without hydration) and three irrigation levels (corresponding to evapotranspiration replenishment of 0, 50, and 100%). Irrigation treatments were scheduled by using the Pan A evaporation method. Barbary-Plante was incorporated into the soil and supplemented with inorganic fertilizer to attain final rates of 150-50-150 kg/ha (N-P2O5-K2O). Sweet corn was planted on 20 February 2001 at a density of 64,000 plants per hectare. Drip irrigation treatments significantly affected marketable sweet corn yields. Marketable corn yield and cob number were unaffected by BP addition. Applications of 50 kg BP/ha under rainfed conditions produced the highest sweet corn emergence, although this effect was not significantly different from that in the untreated plots. Generally, BP effect on seed corn emergence was inconsistent.