What are the effects of picking 55% of the leaves?

"In the project 'The new crop,' a more than normal amount of leaves were picked from tomato plants (55% instead of 33%). At the request of the large advisory commission, it was noted by growers that the crop at Wageningen UR is still in a vegetative state. The differences that could be seen were in the growth length, which was clearly less where there was a lot of leaf picked.

The crop with more leaf picked was a lot more open and the plants were more uneven. It is questioned whether this unevenness through the much more open structure of the crop is an advantage. In the discussion, it was expressly chosen to continue with the expiriment, therefore they will continue the leaf picking because the crop still makes enough leaves. The leaf picking also has an effect on the total water usage of the crop. In a really open glasshouse, this was about 10% less than in a standard glasshouse.

The large advisory commission had, at the request of Wageningen UR, previously looked at one of the practice businesses where a test on leaf picking had already been carried out at the testing ground Zwaagdijk. The tests were carried out on the coarse variety Merlice and the cocktail tomato Brioso. Also in practice, it was possible to see big differences between the leaf strategies. We can see now that the crop development was really put under strain, whereby extra leaf picking can't be justified. The plant really needs its 'lungs' with increasing light. We need to work with the crop.

The different approaches of Wageningen UR and the practice business are really informative. They show that leaf picking is a technique that has a place in cultivation management and can contribute to the further optimalisation of the more exposed crop. The tests are continuing, at Wageningen UR and at the practice business, but now with different approaches.