Effects of successive applications of maneb and benomyl on growth and yield of five wheat varieties of different heights.


  • J.H.J. Spiertz




Wheat cv. Juliana (culm length 117 cm), Manella (82 cm), Lely (80 cm), Mex-cross (69 cm) and Gaines (79 cm) were sprayed twice before flowering with 2 kg maneb/ha and twice after flowering with 1 kg benomyl/ha. Combined treatment greatly delayed the spread of Septoria tritici and S. nodorum in the crop, the flag leaf remained green longer, the grain filling period was lengthened, and the growth rate of the grain between the milk stage and the dough stage was increased from 204 to 230 kg/ha day; effects were greater in the susceptible cultivars Lely and Gaines. Increases in grain yield were 14, 23, 32, 16 and 42% for the 5 cultivars, respectively. The green area of the flag leaf accounted for 85% of the variance in grain yield. The degree of disease infection was not significantly correlated with culm length or amount of leaf area. ADDITIONAL ABSTRACT: Spraying with maneb at 2 kg/ha twice before flowering and with benomyl at 1 kg/ha twice after flowering greatly delayed the spread of Septoria tritici and S. [Leptosphaeria] nodorum and increased yields, particularly in the 2 susceptible cvs. (Abstract retrieved from CAB Abstracts by CABI’s permission)