Nutrient supply and container size effects on flowering, fruiting, assimilate allocation, and water relations of sweet pepper

The interaction of container size and nutrient supply on flowering and fruiting of sweet pepper was studied by a complete interactive experiment containing three volumes of containers (9, 18, and 33 dm³) and three concentrations of major nutrients at a constant ratio (3-0.5-1.25, 6-1-2.5, and 9-1.5-3.75 mM of N-P-K, respectively). The combination of small container volume (9 dm³) and low supply of nutrients (3-0.5-1.25 mM of N-P-K) induced an early flowering and short duration of flowering, which were succeeded by early fruit set and maturation of fruits. Increasing the nutrition supply to medium concentration (6-1-2.5 mM) significantly relieved the inhibition of root restriction imposed by small container volume to total fruit set and yield. Further increasing the nutrient supply from medium to high (9-1.5-3.75 mM) increased the fruit-set number and total yield of plant cultured only in the large volume container (33 dm³). Container size (<18 dm ³) became the predominant growth-limiting factor when nutrient supply was high. The restrictions of nutrient supply and root growth volume significantly increased partition of assimilates to the fruits. There was no significant effect of container size and nutrient supply on the water contents of all plant parts. Increasing nutrient and water supply could not sufficiently compensate the influences of extreme restriction of root volume imposed by container size. Relative large size of container combined with ample nutrition and water is needed for high yield production of pepper plant.