Europa: Test grubbing delivers lower yields than expected
In Mid-September, the Verenigde Telers Akkerbouw or VTA did a test potato grubbing according to a set protocol among its members.
This Dutch growers association has been performing these yield measurement since 2001. It is still carried out at the same time every year.
Average yield per hectare
The average yield of the samples was fixed at 47.088 kg per hectare. In 2017, this was 58.507 kg per ha. This amount means that, up to now, the yield per hectare is 19,5% lower than last season. Compared with the five-year average, the hectare yield is 12,5% less. Both these percentages are shown in the graph below.
Test grubbing and regrowth August -- September
As indicated in the trial grubbings done in August already, there are major differences in the yields. The lowest is now at 21,3 ton/ha and the highest at 84,6 ton/ha. These differences in yield can occur due to the plants being irrigated or not. Water damage to plots also play a role.
It must also be noted that most of the participating farmers come from clay areas in the Netherlands. This year, in the sandy regions of the country, the results lag significantly behind other years. This lag may be even more significant than in traditionally clay areas. However, partly due to the major differences in (the possibility of ) irrigation, no hard and fast conclusions can be drawn.
Of course, there are differences between the varieties. Only a few samples of certain varieties were received. Because of this small sample, it would be statistically incorrect to draw firm conclusions. When the total regrowth was calculated, the association used a weighted average. This calculation amounted to 10.622 kg/ha. On average, this regrowth was at 10.378 kg/ha in the same period over the previous five years.
Significant differences were also recorded when it came to the growth potential. A large number of the samples indicated that the crop has already been dumped, grubbed or completely ruined. In contrast, there were also farmers who reported that their plants were still green.
Percentage of 50 mm and up
The portion of 50 mm and up was determined to be 61%. In 2017, this was 70%, while the five-year average was 69%. Here, vast differences between fields were observed.
With 178 tubers, the average number of per sample (2x3 meter) was relatively low. Last year, this number was 185. The five-year average was 190.
Click here for the press release with larger images.
Fuente: http://www.freshplaza.com/article/9032284/test-grubbing-delivers-lower-yields-than-expected/
