Abstract: The effect of three new plant growth regulating compounds (Bioproduct XH, Bioproduct XL and Product AG) on Russet Burbank and Shepody plant growth and tuber yield was studied during the 1999 growing season. The Bioproducts were sprayed and Product AG dusted on seed tubers the day before planting. Bioproduct XL at one-quarter strength increased tuber yields of Shepody and Russet Burbank. Performance of plants treated with quarter-, half- or full-strength Bioproduct XH was not different from that of the control. Shepody appeared to be more responsive than Russet Burbank. Dusting Product AG on seed tubers at the recommended rate was toxic to the potato tubers and inhibited emergence, retarded plant growth and decreased tuber yields. Product AG was also applied to the foliage of Russet Burbank and Shepody plants at tuber hooking stage and hooking stage plus 19 days. No significant effects upon tuber yield were found with either foliar treatment or cultivar tested. The warm weather experienced during the 1999 growing season may have influenced the outcome of this trial. Additional field trials are needed to fully explore the potential and usefulness of these products.
1Potato and Horticulture Branch, NBDARD, Wicklow, NB E7L 3S4