Weed Control J 2024; 23: e202400847

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Interference and economica threshold level of ryegrass in rye crop

DOI: 10.7824/wcj.2024;23:00847

Abstract:

Background:

Ryegrass (Lolium multiflorum) is one of the most detrimental weeds to rye (Secale cereale) grain yield, as it competes for limited and essential resources needed for crop growth.

Objective:

To identify explanatory variables for determining the competitive ability and economic damage level (EDL) of ryegrass infesting rye crops.

Methods:

The field experiment was conducted during the 2018 growing season using a completely randomized design. Treatments consisted of rye genotypes (BRS Serrano, IPR 89, BRS Progresso, and Crioulo) and 12 ryegrass densities competing with the crop, ranging from 0 to a maximum of 68 plants m^-2. Thirty days after emergence, plant density, leaf area, soil cover, and shoot dry mass of ryegrass were evaluated. In rye, grain yield, selling price, control cost, and control efficacy were determined.

Results:

The BRS Serrano and IPR 89 genotypes were the most competitive, while BRS Progresso and Crioulo were the least competitive in the presence of ryegrass. BRS Serrano and IPR 89 exhibited higher competitive performance and ETL, with values ranging from 2.28 to 8.23 plants m^-2, respectively.

Conclusions:

Grain yield, market price, herbicide efficiency, and control cost influence ETL values, with the highest values observed for BRS Serrano and IPR 89 genotypes (2.28 to 8.23 plants m^-2) and the lowest for BRS Progresso and Crioulo (1.15 to 2.48 plants m^-2 of ryegrass).