GROWTH ANALYSIS OF MINI-WATERMELON GENOTYPES IN HYDROPONIC SYSTEM

The aim of the present work was to characterize the growth dynamics (dry mass production and partitioning) and the growth rates of mini-watermelon genotypes grown in hydroponic system in a greenhouse in the south of Rio Grande do Sul State, Brazil. The plots were composed by the four genotypes and the subplots by 11 plant evaluation dates. The genotypes expressed a growing tendency in relation to the accumulation of total plant dry mass (DM), with a sigmoidal growth curve. For all genotypes, the crop relative growth rate decreased in relation to plant age. The 'Extasy' cultivar showed a higher vegetative growth after the middle of the crop cycle, and the fruit growth intensity was lower in the early part of the crop cycle and higher at the end, as compared to the others. Until half crop cycle, leaves were the main assimilate sinks. Fruits comprised 1 to 5% of the total plant DM production at the beginning of fruiting and 70 to 76% of the total plant DM at the end of the crop cycle. The 'Extasy' cultivar showed a higher vegetative growth, a higher leaf area index from the half of the crop cycle and a lower initial relative growth rate of fruits in hydroponic system in a greenhouse.