The main problem for growers of crops that are harvested continually is to ensure that their crops continue to produce new leaves while also producing high yields.
In the research discussed here, sweet pepper plants were grown from December to June in a glasshouse in Spain. Plants were removed at intervals and divided into different fractions, which were dried and weighed. As well as leaf dry weight, their area and nitrogen content were also measured.
One measure of the storage potential of a leaf is its weight per unit leaf area. This ratio increased at first but then fell, as did the nitrogen content of the leaves and the weight of the whole root system.
The falls coincided with increases in the weight of fruit on the plants - and the leaves nearest the fruits showed the biggest changes. The weight of fruit then declined as fruit were harvested but this pattern of increases in fruit weight and decreases in leaf attributes was then repeated during a second fruiting flush.
Evidently, both the leaves and the roots store materials that can be diverted to developing fruits when required, suggesting that the roots play some part in the regulation of fruit growth.
Influence of Fruit Load on Dry Matter and N-Distribution in Sweet Pepper Plants by Gonzalez-Real, Baille and Liu (2008). Scientia Horticulturae 117: 307-315. The contents of issues of Scientia Horticulturae and abstracts of papers are provided at www.elsevier.com/locate/scihorti.