A total of 15 projects were showcased at Scott Field Day July 17 including projects focused on agronomy, insects, and diseases. Dr. Kelly Turkington, pathologist with AAFC, talked about crop rotations being the first step to reduce disease followed by variety choice then fungicide application. When making the decision whether to use fungicides or not, knowing where yields comes from and what parts of the plant we want to protect is important.
In cereal crops, yield mainly comes from the top two leaves. The stem and head also provide nutrients, and support yield potential. Therefore, when applying fungicide we want to protect the top two leaves, as well as the stem and head. With leaf spotting diseases, control is warranted when disease is present on 20 to 25 per cent of the leaves. With fusarium head blight protection of the head is most important. Leaf rust is one of the major diseases to scout for. Turkington suggests striped leaf rust may be late this year, but do expect it to show up. If seeing a trace of striped rust in the field, then it is time to consider spraying fungicide, then wait two to three weeks before applying fungicide again. Turkington reminded everyone that current fungicides are xylem mobile which means they move with water in the plant. Water moves upward in the plant, hence fungicides move upward in the plant as well, and do not help with diseases at the bottom of the plant such as on lower stems or the roots. With both fungicide and insecticide applications it is important to watch the pre-harvest intervals.
Dr. Sabina Banniza, pulse pathologist with Crop Development Centre at the University of Saskatchewan, explained how seeding rate plays a big factor in disease development. If you have a thick canopy, disease can spread quickly because the canopy remains moist. Diseases do well in wet conditions. Root rots have been very problematic with pea crops over the past four years and this year is no exception. The organisms that cause the root rots are soil borne and they thrive under higher moisture situations and are not controlled by fungicide applications. Root rots tend to set in later in the season when seed treatments are no longer effective. Unfortunately there is nothing that can be done once the disease sets in, There have been whole fields lost from this disease, and it is becoming a real problem in wetter areas of the province.
Besides diseases, insects were a hot topic. Dr. Julie Soroka and Dr. Chrystel Olivier, research scientists with Agriculture and Agri-Food Canada in Saskatoon, gave an update on the insect situation. Soroka talked about how striped flea beetles are showing up more, and how they prefer mustard, but will eat canola as well. Flea beetles are more of a spring problem when canola is small and prefer warmer temperatures. Damage from cutworms has been seen this year, but their cycle should be complete. Fortunately diamond back moth numbers have been very low in the traps this year so we don't expect them to be a problem. The one to watch for is the bertha army worms. There are hot spots in the province in terms of high moth counts and Soroka expects the eggs will start hatching soon because of the hot days. This is one to be scouting fields for within the next couple of weeks.
Olivier is the aster yellow and leaf hopper expert and she commented that the leaf hopper numbers are down this year. This means the incidence of aster yellows should be lower than last year. The aster yellows disease is transmitted by leaf hoppers to plants. There are three ways the disease can be introduced each year. The virus can remain viable as long as it is in living tissue such as inside insect bodies or in the roots of plants that overwinter. The disease can also be blown in with leaf hoppers from the United States. Once in the plant, the disease causes the plant to grow abnormally and reduced seed set occurs. There are no control options for this disease.
Sherrilyn Phelps, Regional Crops Specialist with the Saskatchewan Ministry of Agriculture, , spoke about a project called the Pea Input Study. This project evaluates the effect of individual inputs and combinations of inputs and their effects on increased yield and economic returns. The inputs evaluated are seed treatment, seeding rate, inoculant, starter fertilizer, and fungicide. The largest yield increase from the individual inputs was with high seeding rate and double application of fungicide. Both inputs increased yields by approximately nine bushels. In the end, increasing the seeding rate from 60 to 120 seeds per square metre was the individual input that resulted in the greatest net return of $121.00 per acre. Phelps went on to talk about the combination of inputs and how important it is to use all the tools available. Where seed treatment, high seed rate, granular inoculant, and double application of fungicide were used together yields were increased by 22 bushels per acre and net returns by $265.00 per acre. If you are targeting high yields you need to use the inputs available. This is the second year of the project and Phelps looks forward to seeing the results this fall as do the growers in attendance.
Phelps also talked about factors that affect canola establishment. Seeding rate, seeding date, seeding depth, seeding speed, seed placed fertilizer, and seeder wind speed can all influence canola emergence. Seeding rate impacts emergence as the seed size combined with seeding rate determine the number of seeds that go in the ground and therefore limit the number of seeds that can emerge. Phelps comments that you cannot have more seeds come up than you put in the ground so doing some basic calculations at seeding time can give you a better idea of what to expect. Producers should be targeting 80 to 100 plants per square metre (eight to 10 plants per square foot) when calculating seeding rates. Research has shown that yields of canola can start to decrease when populations are below 45 plants per metre square so producers need to be sure they are well above 45 or they can start losing yield. Phelps did indicate that they saw an effect of seed size on emergence as the larger seed did have higher emergence rates than the smaller seed and that this may be something to do more work on.
Breanne Laturnus, graduate student from University of Alberta, spoke about a new herbicide called Pyroxasulfone. Pyroxasulfone is a group of 15 herbicides which is soil applied. Results show that the spring applied herbicide had better control than that applied in the fall. This new active ingredient controls grassy weeds, wild oats, and cleavers. Wheat, lentils and various other crops showed good tolerance so watch for this product in the future.
Neil Harker with Agriculture & Agri-Food Canada Research (AAFC), Lacombe, Alberta, discussed weed control from an integrated approach. Using agronomics to help with weed control is a great way to lower weed populations and increase yields. Higher seeding rates have been used by organic growers who cannot rely on herbicides. Other practices that Harker is evaluating include rotations with winter cereals and silage. The winter cereals help compete with wild oats as they are up earlier and are very competitive. Silage has been used for removing the wild oats before they disperse their seed which lowers the weed population for future years. Harker is demonstrating that a herbicide is not needed every year for wild oat control if you just use agronomics and do some planning.
In summary, there was a lot of information shared and many discussions. With over 200 people in attendance, great speakers, great food and great weather, it was a missed opportunity for those that didn't make it. Thanks to the Western Applied Research Corporation at Scott for hosting such as great day.
For more information on projects at Scott and to find out about the 2014 field day visit www.warc.ca or call Sherrilyn Phelps, Regional Crops Specialist, North Battleford at 306-446-7475.
- Olson is Agriculture Summer Student, North Battleford Regional Services Branch
