Predicting soybean phenology in Manitoba

Crop Soybean
Start Date2017
End Date2020
Principal InvestigatorLawley, Yvonne, University of Manitoba
MPSG Financial Support$192,800
Total Project Funding$192,800
ReportYear 1 – MPSG ANNUAL Extension Report

Research Objectives

The objective of this new project will be to confirm differences in soybean phenologial development in Manitoba and then use this information to develop a more accurate model to predicting critical growth stages for farmers and agronomists. This model will be based crop heat units, photoperiod (latitude), and soybean maturity group. The model could be used by farmers and agronomists to accurately predict critical growth stages of soybean in Manitoba.

Project Description

Soybean requires short days (<14 hours) to stimulate flowering. Maturity group classifications (often not established in Manitoba) are usually based on time (days) or Crop Heat Units (CHUs) to maturity and do not always accurately predict critical crop growth stages (such as the beginning of flowering or maturity) in Manitoba. There are 13 soybean Maturity Groups or MG in North America. In Manitoba, MG 000 to MG I can be grown depending on the amount of CHUs received. Each MG classification is further sub-divided into decimal units.
Earlier work by Morrison et al. (unpublished) from 2008 to 2010 comparing soybean varieties varying in maturity classification from MG 000.9 to MG 1.3 grown in Morden and Ottawa revealed that the greater day length during spring and early summer in Manitoba dramatically lengthened the vegetative period (17 to 23 days) and reduced flowering for soybeans relative to Ottawa. These changes in soybean phenological development in Manitoba happened even for varieties found to be day length insensitive in Ottawa.