Performance and Fruit Ripening of Red Orange Tree Grafted onto Two Rootstocks

The cultivar Sanguínea de Mombuca (Citrus sinensis [L.] Osbeck) bears lycopene-rich fruits with attractive red pulp and high nutritional value; thus, this cultivar has the potential to diversify orchards for the production of fruits for natural consumption and juice. Therefore, studies on the productive performance in combination with rootstocks are required. This study evaluated the phenological cycles, yield, ripening curve, and fruit quality of this cultivar grafted onto 'Rangpur' lime and 'Swingle' citrumelo. The study was conducted in the Midwest of the state of São Paulo, in the subtropical region of southeastern Brazil, and the field experiment was performed over two consecutive seasons. Rootstocks had little effect on the duration of the phenological cycles. The fruit ripening curve predicted the time of harvest as approximately 240 days after anthesis, regardless of rootstock. Fruits harvested from trees grafted onto 'Swingle' citrumelo showed higher levels of soluble solids and sugars and higher technological indices. The larger number of fruits and greater fresh weight confirmed that better yield performance occurred with the trees grafted onto the 'Rangpur' lime as opposed to the 'Swingle' citrumelo rootstock.