Compiled by Joel Ransom (joel.ransom@ndsu.nodak.edu)

Experiments were conducted by North Dakota State University during the 2004 growing season with the objective of identifying practices that could be used to improve the productivity of wheat in North Dakota. These experiments varied somewhat in the factors that were studied but included one or more of the following: seeding rate, N rate, N timing, variety, and fungicide.

The intent of this report is to summarize the effect of selected management practices in a range of experiments so that farmers may have a better understanding of how these practices may impact production on their own farms.

A similar report was prepared in 2003 and the results of that report should also be reviewed when considering the results and recommendations presented here (the 2003 report is available online at: http://www.ag.ndsu.nodak.edu/aginfo/smgrains/IntensW04.htm).

Table 1 lists the experiments that were included in this review and the contact details of the principal investigators from whom additional information about the research can be obtained.

The experiments were designed so that the effects of each factor could be evaluated as well as the interactions between the various factors. Positive interactions between management practices are considered desirable, as it means that the output of two or more inputs is greater than the output of each input alone. Just as in 2003, however, there were few significant and consistent interactions between the various main factors, so this report will focus primarily on main factor responses. The cool, wet spring in the areas where this research was conducted was favorable for small grain development, and yields were well above average. However, yields at Langdon were reduced by frost prior to physiological maturity.  

Increasing the seed rate from the lowest rate used (1.0 to 1.2 million seeds per acre) to the highest rate (1.5 to 2.0 million seeds per acre) increased yields in three of the five experiments (Table 2). The increases were only in the range of 2 to 3 bu/acre, however. In two of the five experiments, increasing the seed rate reduced yield.

The effect of nitrogen rate and timing on grain yield and protein varied between experiments. Nevertheless, in general terms, the results indicate that when fertilizer rate was included as a variable in the experiment, applying all of the fertilizer pre-plant at the high rate was as effective as and often more effective than applying it in splits (Table 3).

At the lower fertilizer levels, or in experiments where just one level of N was used, grain yields were improved by splitting the fertilizer only in Carrington and Langdon. Grain protein tended to be higher when N was applied later but not consistently.

Only a single fungicide experiment at Carrington was included in this review. In this experiment, the fungicide treatment consisted of a single Folicur application at the early bloom stage. There was significant fungicide interaction by variety at this site. Reeder was much more responsive to the Folicur application than Granger (18 bu/acre vs. 8 bu/acre), due to its greater susceptibility to foliar diseases and leaf rust. The DON levels were higher in Reeder than in Granger, and were reduced significantly in both varieties with the application of Folicur.

Based on the results of these experiments and the data from 2003 (bear in mind that 2003 and 2004 were exceptional years for wheat yield) I would recommend the following: