*4.5. Models Based on Main Crops Production*

Both wheat and maize production proves to significantly influence the total Moldavian agriculture production. The model representing the relation between wheat production and total plant production (Figure 9) has a high R-square. The residuals display a normal distribution (Figure A1), being independent from one another. As the value of the wheat production increases, the value of total plant production increases (one unit of wheat production leading to a 2.17 unit increase in total plants production). The relation between maize production and total plant production is strongly linear (Figure 10), showing an R-square of 88.00%, higher than the one found when modelling wheat production–total plant production. The residuals also display a normal distribution, being independent from one another (Figure A3). As maize production value increases, the value of total plant production increases (one unit of maize production leading to a 2.07 unit increase in total plant production). The models can be used in order to assess the total agriculture production indicators by variating both the maize and wheat production quantity.

Therefore, in order to grow the agricultural production, the maize and wheat production capacity must be maximized. Thus, it is recommended that a significant share of government financial resources be used in order to develop and implement better growth technologies for these crops, as well as to implement proper technical measurement for maintaining the optimum technological requirement of them during the entire year's production cycle.

**Figure 9.** Wheat production–total plants production.

**Figure 10.** Maize production–total plants production.

#### *4.6. Models Based on Main Crops Production Value*

Wheat production–wheat production value follows a linear positive trend (Figure 11). The model describes this while having the regression *p*-value at 0.01, an R-square of 60% and independence of the residuals. This, according to the histogram and normal probability plot (Figures A5 and A6) are right skewed (working with a low number of samples usually has an effect over the residuals histograms as a histogram is most effective when there are 20 or more data points. If the sample is too small, then each bar on the histogram does not contain enough data points to reliably show skewness or outliers). This model emphasizes the stability and high liquidity of the wheat market. Therefore, the wheat market is characterized by high trading activity and high wheat supply and demand. Thus, Moldavian wheat production will sell fast, without any constrains related to price, in order to make this crop production more attractive for buyers. The grape production value–maize production value scenario is characterized by no variation and no correlation of the residuals (Figure A7). The model explains 65% of the maize production value variance by using the grape production value (Figure 12). The *p*-value for the grape production value is 0.008, below the 0.05 threshold (Figure A8). The equation shows that for every unit increase in the grape production value, the maize production value will increase with 2.09 units. Thus, the model emphasizes the complementarity between both the grape and maize markets in terms of the prices established for both crops during the analyzed nine-year period.

**Figure 11.** Wheat production–wheat value.

**Figure 12.** Grape value–maize value.
