`Umatilla Russet' and `Russet Legend' Potato Yield and Quality Response to Irrigation

Abstract

`Umatilla Russet' and `Russet Legend', two newly released potato ( Solanum tuberosum L.) cultivars were compared with four established cultivars (`Russet Burbank', `Shepody', `Frontier Russet', and `Ranger Russet'). Potatoes were grown under four, season-long, sprinkler irrigation treatments in three successive years (1992-94) on silt loam soil in eastern Oregon. At each irrigation, the full irrigation treatment received up to the accumulated evapotranspiration (ET c ) since the last irrigation. Three deficit irrigation treatments had progressively less water. The new cultivars `Umatilla Russet' and `Russet Legend' performed as well as or better than the other cultivars in the full irrigation treatment, with `Umatilla Russet' showing a higher yield potential at the higher water application rates than `Russet Legend'. All cultivars produced more U.S. No. 1 tubers than `Russet Burbank', except in 1993, an unusually cool and wet year. `Russet Legend' was the only cultivar showing a tolerance to deficit irrigation. In two out of the three years, `Russet Legend' was as productive of U.S. No. 1 yield over most of the range of applied water as `Shepody', `Frontier Russet', and `Ranger Russet' were at the higher end of the applied water range. Chemical names used: 0,0-diethyl S -[(ethylthio) methyl] phosphorodithioate (phorate); N -(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin); and 2-chloro- N -(2-ethyl-6-methylphenyl)- N -(2-methoxy-1methyl-ethyl) acetamide (metolachlor).