**4. Conclusion**

78 Soybean Physiology and Biochemistry

Fig. 11. Linear relationship between annual potential evapotranspiration (ETp) (Y axis) estimated by Thornthwaite (TW) (top) and annual moisture index (Iu) (Y axis) estimated by TW (down), with the potential intensity of soybean rust estimated by FLS (X axis), for the observations of monthly average temperature in January, at 39 INMET weather stations in Minas Gerais and surrounding states, with the leaf wetness period fixed at 12 hours.

Similarly, Morales & Jones (2004) used GIS to study the ecology and epidemiology of whitefly (*Bemisia tabaci* Gennadius 1889), transmitting geminiviruses in tropical crops in Latin America, at 304 georeferenced locations, where the whitefly and geminiviruses have caused significant damage. For this, it was developed a mathematical model including two climatic variables, temperature and precipitation, to map the probability of occurrence of favorable areas for pests. Later, using the Köeppen climatic classification, it was possible to verify that 55% of the localities affected by geminiviruses were located in the tropical wetdry, 22% in humid-dry tropical regions, subtropical and local remnants of humid equatorial climates, with frequent coastal winds. According to the authors, based on the results, it was It was possible to develop, validate and implement a fuzzy logic system to estimate the monocyclic process of soybean rust, regarding Conquista, Savana and Suprema cultivars, based on temperature, leaf wetness and area under disease progress curve. The co-kriging method was more accurate and precise than the ordinary kriging method for mapping rust intensity.

FLS was better applied then non linear regression models to estimate the potential disease spatial progress.

The moisture index and potential evapotranspiration of Thornthwaite were significantly correlated with the estimates of the soybean rust intensity.

Leaf wetness up to 12 hours and temperatures around 20 °C, determined higher rust intensity. Temperatures above 30 ºC and 15 ºC as well as leaf wetness below 6 hours, reduced the rust intensity.
