Effects of Accumulated Growing Degree Days (GDDs) on Sesame (Sesamum indicum) Growth and Yield under Greenhouse Condition in the Mekong Delta, Vietnam

Abstract

Sesame has high nutritional value, sesame seeds contain oil, protein, sugar, water, ash, and two kinds of oleic acid and linoleic acid; sesame is commonly used in the diet or as a vegetable oil. Sesame is grown in many tropical countries, and the optimum temperature for sesame growth is 25-30 °C. Due to climate change, the temperature is increasing, in the Mekong Delta of Vietnam, the temperature in summer can reach nearly 35 °C. The research question is whether high air temperature affects sesame growth and yield. To answer the above question, the study was conducted in greenhouse conditions in An Giang province with different temperature conditions, including 3 extreme chambers from 32.7, 32.9, and 34°C; automatic fan and a misting system for to control temperature. Black sesame plants were grown in 42 pot (34 x 28 x 28cm), each chamber with 4 plants per pot. All pots were filled with the same amount of alluvial soil (Fluvi Mollic Gleysols). Results showed that accumulated growing degree days in chambers 1, 2, and 3 were 2115, 2019, and 1994 GDDs, respectively. At 2115 GDDs gave the highest value of fresh biomass (1417g/pot), dry biomass (276 g/pot), dry weight capsule (109 g/pot), and dry seeds (51 g/pot). Regarding harvest index, chamber 3 with 1994 GDDs gave the highest harvest index of 0.22; the other chambers were in the range of harvest index of 0.18-0.20. In conclusion, under greenhouse conditions with 2115 GDDs is ideal for the growth and yield performance of black sesame.