Fusarium head blight (FHB) has become a major limitation to cereal crop production across much of the prairies in recent years, particularly for bread and durum wheat growers, and the disease is also impacting barley growers. Managing this disease with fungicides and resistant cultivars is not sufficient. A third important strategy of FHB management is the selection and inclusion of non-host crops in the rotation. In this study, our objective is to determine the impact of preceding crop choices on FHB of wheat (spring and durum) and barley, at select locations across western Canada. Crop choices will include common cultivated crops (cereals, pulses and oilseeds), as well as corn, which is increasingly popular in western Canada, particularly in Manitoba at present, and is expected to increase rapidly in Saskatchewan and Alberta over the next decade. The study will document the FHB severity and Fusarium spp., yield and quality (amount of fusarium damaged kernels, toxin content, TKW, TW, protein content and other important grading factors depending on the crop) of the affected cereal crops in each crop sequence. From this information, cereal growers will have information on which to base crop sequence decisions that minimize FHB in cereals in western Canada.
To determine optimum crop sequences to minimize fusarium head blight in wheat.
Targeted plant populations to determine seeding rates:
Wheat 250 (HRS wheat or CPS); 210 (durum)
Seeding date: early to late May depending on region, weather and crop
Previous crop stubble: Canola stubble if possible, but note the rotation on the field the previous 2 to 4 years if known
Soil Sample: 0-6” and 6-12”
Fertilizer rate: Side band fertilizer based on 100% of soil test results and target yield (see chart below, yields are only examples, use a target based on your experience at a particular site)
NOTE the following is an example use actual soil test results and recommendations for each site:
Weed control: this will require careful planning so there are no cropping restrictions for the Year 2 crops (and in Year 2 for the Year 3 crop)
Pre-seed burnoff with glyphosate
Seeding equipment: varies with location
Harvesting: The plots should be straight cut with the combine and dried to a constant moisture content.
Experimental design: split-block, also known as a strip plot design (36 to 81 treatments in Years 2 and 3, depending on crops included 6 to 9)
Plot size: Saskatoon – 2 x 10 M in Years 2 and 3
Retain 10-15 flag or penultimate leaves (whichever have leaf spot symptoms) for possible plating to identify pathogens. Collect into a paper envelop and let dry. These can be a composite sample of the 3 reps for Year 1. Can be forward to U of S after harvest with spike/panicle samples and 500 gram grain sample (see points 3 and 5)
Evaluate 100 spikes/panicles of each cereal crop for FHB symptoms. For wheat and barley use the Stack and McMullen scale attached (incidence and severity to get FHB index). Retain 50 spikes of each for plating to determine species.For oat and canaryseed assess 100 panicles for symptoms (incidence) if possible, retain 25 oat panicles and 50 canaryseed panicles for plating and seed evaluation.