# Classification of Potato Varieties Drought Stress Tolerance Using Supervised Learning
## 3 Results  
### The Climatic Water Balance Determination  
The results were statistically processed using the ANOVA software. The analysis of variance for the value of the CWB was carried out using [PERSON]'s test at the confidence level of \(\alpha=0.05\) for the period 2005-2015. Over the 11 years, the analysis showed a significant influence of years and months and interactions between years and months. For the growing season May-August in the studied years, an analysis of the distribution of the CWB in the form of a histogram and distribution series was performed, and then, the water conditions in the studied periods were classified. Based on those calculated for each year, the Climatic Water Balance  
Based on the climatic conditions during the growing season in 2005-2015, the climatic water balance for the individual years was determined. Very dry, dry, optimal, and wet years are distinguished. In the group of very dry years, there were 2 years; these are 2005 and 2015. In the group of dry years, there were 3 years; these are the years 2006, 2008, and 2014. In the group of optimal years, there are 4 years; these are the years 2007, 2009, 2012, and 2013. Two years were included in the group of wet years; these are the years 2010 and 2011. As it could also be observed in Figure 2, the measured values of the relative yield decrease are not so easy to distinguish when one uses only climatic water balance values (b), and even data split using the resistance classes overlap to some extent (c). The bright difference between the relative yield decreasing measurements that can be spotted in Figure 2a also does not let one split that data precisely. For instance, the average relative yield decrease in the wet years was 20.78 (Table 3) and so were the 25% measurements of the very dry years and a significant part of the measurements of the other years. \begin{table}
\begin{tabular}{c c c c c c c} \hline
**Climatic Water Balance** & **Year** & **V** & **VI** & **VII** & **VIII** & **V–VIII** \\ \hline very dry & 2015 & \(-13\) & \(-60\) & \(-8\) & \(-85\) & \(-166\) \\  & 2005 & 26 & \(-32\) & \(-22\) & \(-71\) & \(-99\) \\ \hline dry & 2006 & \(-22\) & \(-24\) & \(-109\) & 123 & \(-32\) \\  & 2014 & \(-12\) & 14 & \(-49\) & 29 & \(-18\) \\  & 2008 & 2 & \(-45\) & 0 & 28 & \(-15\) \\ \hline optimal & 2013 & 69 & 41 & \(-72\) & 27 & 65 \\  & 2012 & \(-11\) & 38 & 18 & 30 & 75 \\  & 2009 & 13 & 20 & 27 & 24 & 84 \\  & 2007 & 27 & 50 & \(-5\) & 24 & 96 \\ \hline wet & 2010 & 147 & \(-10\) & 27 & 63 & 227 \\  & 2011 & \(-33\) & \(-36\) & 255 & 21 & 207 \\ \hline \end{tabular}
\end{table} 
Table 2: Classification of the precipitation condition with the climatic water balance (mm) of the potato growing season in Jadwisin for months (columns: V, VI, VII, and VIII and summary: V–VIII) in particular years of 2005–2015. \begin{table}
\begin{tabular}{c c c c c c c c} \hline
**(a) Climatic Water Balance** & **Min** & **Max** & **Mean** & **Std** & **Q.25** & **Q.5** & **Q.75** \\ \hline very dry & \(-3.49\) & 48.06 & 27.85 & 10.86 & 20.91 & 28.77 & 35.34 \\ dry & 2.64 & 61.43 & 33.09 & 14.51 & 23.23 & 33.90 & 41.86 \\ optimal & 1.02 & 56.83 & 35.12 & 10.71 & 28.54 & 35.24 & 42.45 \\ wet & 0.50 & 61.64 & 20.78 & 10.37 & 15.45 & 19.84 & 24.64 \\ \hline
**(b) Tolerance to soil drought** & **Min** & **Max** & **Mean** & **Std** & **Q.25** & **Q.5** & **Q.75** \\ \hline Group I & \(-3.49\) & 43.16 & 21.81 & 10.23 & 15.83 & 22.25 & 28.59 \\ Group II & 43.16 & 56.83 & 31.02 & 9.68 & 24.96 & 32.36 & 35.92 \\ Group III & 21.81 & 61.64 & 41.62 & 8.82 & 38.05 & 42.02 & 47.33 \\ \hline \end{tabular}
\end{table} 
Table 3: Descriptive statistics for the measured relative yield decrease concerning: (a) climatic water balance classes, (b) decrease for cultivar groups of tolerance to soil drought, and (c) for cultivar groups of tolerance to soil drought and climatic water balance classes.