2.1.2. Tobacco yield estimation and monthly variations

The previous model was used to predict tobacco dry weight per plant as a function of temperature. Hourly temperature (60 cm above ground level) data in Homestead, Florida was obtained from the Florida automated weather network (FAWN) database for three consecutive years (2017–2019). The model predicts tobacco dry weight at day 27 after emergence of seedlings (assuming a constant initial dry weight of 0.5 g/plant seedling), starting at the first hour of the first day of every month and ending on the 23rd hour of the 27th day of the same month. Assuming that germination occurs over the course of 15 days, the model predicts the dry weight yield at day 42 post seeding.

Fig. 4 shows the model results for each year at the end of 27th day of each month. The average of the monthly yield over 3 years is also displayed as a solid green line, indicating a slight drop in yield during the month of July, most likely due to the consistently elevated temperature. The average dry weight yield was 21.28 ± 2.37 g/plant. This 11% standard deviation from the mean reflect a low variation in temperature ranges due to seasonal changes in Homestead, Florida. However, this model can be further improved by incorporating other weather factors such as photon flux, ambient CO₂ concentration, plant nutrients availability, wind, and humidity. Germination efficiency as a function of these variables should also be considered to produce a more robust model.

Tobacco dry weight prediction based on historical Homestead, FL weather data from three consecutive years. (For interpretation of the references to color in this figure, the reader is referred to the web version of this article).