EFFECT OF CCC ON GROWTH DISTRIBUTION AND FRUITING IN CITRUS
The mode by which dry matter is distributed among other plant organs, mainly the fruit, when growth is reduced, should serve as an additional indicator in testing the efficiency of chemicals applied. Using these criteria we investigated the effect of 2-chloroethyl trimethyl ammonium chloride (CCC) in young lemon trees. Trees were grown in pots during eleven months. CCC, at concentrations of 0, 500, 1500 and 3000 ppm was supplied to the root by irrigation, at weekly intervals.
Treatment with CCC induced an early start of flowering and improved fruit set. Total shoot extension lenght was lower in treated plants, resulting in a compact appearance of the tree. Branching was less affected by CCC, which also caused a decrease in the number of leaves per plant and improved leaf colour. The number of fruits initiated early and the final yield were increased by CCC treatments. Fruits from CCC-treated plants had a larger number of seeds than fruits from control plants. Total dry matter produced per whole plant was reduced only at the highest concentration of CCC, but relative distribution of dry matter to various plant parts was affected at all CCC levels. The fruit dry-matter as a proportion of total dry-matter was raised from 25.4 percent in the control to 43.5, 41.7 and 47.1 percent in trees treated with 500, 1500 and 3000 ppm CCC, respectively.
This increase was almost entirely at the expense of dry matter build-up in woody parts of the plants. Only a small relative decrease in dry matter was found in leaves and rootlets.