Evaluation of a sprayable elemental sulfur fertilizer under field conditions in Alberta

Elemental sulfur (ES) fertilizers have high S content but may not be effective in the year of application due to the time required to oxidize. Rapid oxidation may be possible if the ES has a large surface area in contact with the soil. We evaluated the efficacy of Sulgro 70, a micronized ES fertilizer that is sprayed onto the soil surface, in eight field trials in southern and central Alberta over a 2 yr period. Under dry conditions in southern Alberta, the relative efficacy of Sulgro 70 to increase S supply to ion-exchange membranes was 22% during the first 4 wk period after seeding and 53% during the second 4 wk period after seeding, compared with ammonium sulfate (AS) sprayed on the soil surface. Under wetter conditions in central Alberta, the relative efficacy of Sulgro 70 to increase S supply was variable (51%–201%) during the first 4 wk period after seeding and 56% during the second 4 wk period after seeding. Based on increases in biomass S concentration in three trials where the unfertilized control had low S concentration (<3 g S·kg−1), the relative efficacy of Sulgro 70 was 34%. Canola seed yield was not increased by application of AS or Sulgro 70 in any of the trials. Sulgro 70 sprayed on the soil surface oxidized appreciably during the first 8 wk after seeding and, with suitable management, has the potential to meet canola S requirements in the year of application.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

INTER-ROW STUBBLE SEEDING AND PLANT GROWTH REGULATORS TO IMPROVE FIELD PEA STANDABILITY AND PRODUCTION

Field pea (Pisum sativum) is an important economic and rotational crop in Alberta, Canada. However, standability problems are a major barrier to increasing seeded area in highly productive growing environments. Field experiments were conducted from 2015 to 2017, at three sites in the central and Peace regions of Alberta to determine if: i) pea standability and production can be improved using inter-row seeding into untilled standing wheat stubble; ii) pea standability and production can be improved using chlormequat chloride (CCC), trinexapac-ethyl (TXP) or ethephon (ETH) plant growth regulators (PGRs); and iii) PGR responses are cultivar specific. Depending on the site-year there were 16 to 17 inter-row seeding, PGR, cultivar treatment combinations arranged in a randomized complete block design. Relative to the no stubble control, inter-row seeding into 20 or 30 cm tall, untilled wheat stubble significantly improved standability between 6 to 23% under conditions when lodging occurred. It also reduced days to maturity and increased 1000-seed weight, but had no effect on yield. Individual PGR treatments, CCC, TXP and ETH, generally had small and inconsistent impacts on agronomic traits, yield and seed quality. In dry conditions, PGRs reduced yield. CDC Meadow was slightly more responsive to PGR treatments than AAC Lacombe indicating responses may be cultivar specific. Because of small and inconsistent responses, PGRs have little value as an agronomic tool on field pea. Alternatively, inter-row seeding into standing wheat stubble is a low cost, easy to implement practice for improving field pea standability.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Evaluation of disease, yield and economics associated with fungicide timing in Canadian Western Red Spring wheat

Protection from fungal plant pathogens is key for optimizing the yield and quality of wheat (Triticum aestivum). However, current grower practices and historical research do not always align with respect to optimum fungicide timing to maximize disease control, yield, quality and profitability of Canadian Western Red Spring (CWRS) wheat. Six fungicide treatments were evaluated at eight site-years across Alberta in 2018 and 2019 to determine the optimum time for fungicide application. The treatments included early fungicide applications at BBCH 22-23 (herbicide timing), early to mid-season application at BBCH 30-32 (plant growth regulator timing), ‘traditional’ timing at BBCH 39-45 (flag leaf), and head timing at BBCH 61-63 (fusarium head blight timing), and were compared with a non-treated control. Yield responses to fungicide treatments occurred at 50% of the site-years when disease pressure was 32% higher than in non-responsive site-years. Responsive site-years were characterized by higher relative humidity (65.4 - 74.0%) and an average 273 mm of precipitation. At responsive site-years, McFadden leaf spot disease severity ratings were 50% greater in early August when fungicides were applied at BBCH 22-23 and 30-32 versus at BBCH 39-45. At responsive sites, yield and thousand-kernel weight were 9.3% and 5.2%, higher, respectively, for fungicide applications at BBCH 39-45 and BBCH 61-63 compared with fungicide applications at BBCH 22-23 and BBCH 30-32. The most economically beneficial practices were applications of propiconazole, benzovindiflupyr and azoxystrobin (Trivapro A+B) at BBCH 39-45 or prothioconazole and tebuconazole (Prosaro XTR) at BBCH 61-63 when environmental conditions were conducive for disease development.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author