Jongte Lee

Title : A multiple regression model of wheat grain yield in response to meteorological conditions in Gyeongsangnam province, Republic of Korea

Abstract:

We analyzed climate change and the relationship between weather conditions and wheat yield from the 1990/1991 to the 2019/2020 growing seasons. Growth stages of wheat were classified as seedling (phase I, early Nov. to mid-Dec.), overwintering (phase II, late Dec. to early Feb.), tillering (phase III, mid-Feb. to mid-Mar.), stem elongation (phase IV, late Mar. to mid-Apr.), ripening (phase V, late Apr. to late May). Mean daily air temperature during the wheat growing season in 2011-2020 was 0.2 ? higher than that from 1991-2000. Mean daily air temperature at the tillering and stem elongation stages was 0.7?, 0.6? higher, respectively in 2011-2020 than in 1991-2000. Precipitation during the wheat growing season in 2011-2020 was 61.7 mm greater than that from 1991-2000. Maximum daily air temperature at the overwintering stage was positively correlated with wheat yield in simple linear regression (R2=0.231, P=0.015), while other weather conditions were not significantly correlated with the yield. A multiple regression model of wheat yield and weather conditions at each growing stage was estimated as follows; wheat yield (Mg ha-1 ) = 7.60-0.133*Tmax(I)+0.059*Tmax(II)+0.114*Tmax(III)-0.228*Tmax(IV)-0.118*Tmax(V)+0.380* Tmin(IV)-0.132*Tmin(V)+0.001*P(I)-0.005*P(II)+0.002*P(III)-0.007*P(IV)-0.001*P(V). The model parameters having a high variance inflation factor were excluded. A root mean squared error (RMSE) and an adjusted coefficient of determination (R2 ) for the model were 0.390 Mg ha-1 , 0.369, respectively. Considering the poor goodness of fit, other factors such as agronomic practices or a government policy should be necessary for predicting wheat yield.

Auidence Take Away Notes: 

• Climate change is a major issue in sustainability of agriculture. We evaluated changes in weather conditions for 30 years, analyzed correlation between wheat yield and weather conditions, and estimated wheat yield prediction model.
• The audience will know how weather conditions during the wheat growing season changed for past three decades in Republic of Korea
• The audience will be helpful to understand what climate change will affect wheat productivity.

Biography:

Dr. Jongtae Lee studied Agronomy at the Kyungbook National University, Republic of Korea and graduated as MS in 1998. He then joined the soil and fertilizer research group at the Chungcheongnam-do Agricultural Research and Extension Services (CNARES). He moved to Gyeongsangnam-do ARES in 2000 and joined onion research group. He received his PhD degree in 2019 at the Gyeongsang National University. He joined upland crops research group in 2020. He obtained the position of a Senior Agricultural Researcher at the GNARES. He has published more than 30 research articles in SCI(E) journals.