THE EFFECT OF CROPPING ON THE GROWTH AND FLOWERING OF BLACK CURRANTS

Partly or totally deblossomed bushes of black currants were compared with normal fruiting ones in 1983 and 1984. In 1983, where the yield in the low cropping bushes was reduced to 25 per cent of the yield in normal cropping ones, the growth of leaves and current year’s shoot in the latter case was restricted to at least 60 per cent of the values in low cropping bushes.
In 1984, the reduction in normal cropping bushes was even greater, as they were here compared to deblossomed bushes, and the growth in branches and roots was depressed too, even the reduction in roots was less than in the top parts.
During the period of fruit development the effeciency of the leaves was higher in the full cropping bushes.

Following 1983 the number of racemes on normal cropping plants was reduced and this was closely related to the previous reduction in the total length of current year’s shoot.
This relationship was also obvious in the following year, even some compensation now took place due to flowering on short laterals.
The total yield in the first three cropping years was reduced to 78–89 per cent of the yield in normal cropping plants by poor cropping in one or two of the three years.
The current year’s extension growth was proportionally greater after full cropping compared to no cropping in the previous year.

The results are discussed and compared to a similar investigation in apples.

IV International Rubus and Ribes Symposium

P. Hansen

https://doi.org/10.17660/ActaHortic.1986.183.46