Agronomic response of six-row barley cultivars to supplemental fertilization and late-season fungicide treatments

Abstract

Management practices such as the use of fertilizers and fungicides can have positive effects on grain yield and quality of cereals, especially where diseases are a concern. Six cultivars of six-row barley (Hordeum vulgare L.) were tested at two fertility levels (standard and high) with a late-season application of the foliar fungicide Tilt (propiconazole) to determine their agronomic responses to these management practices. In 1988, when yields were limited because of early season drought, only Leduc showed a positive yield response to the Tilt, even though it has the highest level of genetic resistance to scald and net blotch of the cultivars tested. In 1989, when yields were again limited by adverse environmental conditions, no response to Tilt was found. In 1990, when growing conditions during the season were excellent, Empress, Noble and Samson had positive responses to Tilt application. Tilt had no effect on grain protein, maturity, or harvest index; it slightly improved test weights and kernel weights and decreased percent thins; and it had variable effects on height, number of viable tillers m−2, and kernel number spike−1. Yield response to Tilt was not affected by fertility regime. High fertility (112 kg ha−1 N 37 kg ha−1 P) resulted in an overall increase in yield of 0.62 t ha−1 from the standard fertility treatment (84 kg ha−1 N 27 kg ha−1 P); decreased harvest index; delayed maturity in 1989 only; increased height, number of viable tillers m−2, and kernel number spike−1; increased protein content of the grain in 1988 only; and had no effect on test weight, kernel weight and percent thins. Because of the variability of response from year to year and cultivar to cultivar, the economic feasibility of Tilt application may be limited.Key words: Hordeum vulgare L., propiconazole, soil fertility, management