Potential Rootstocks For 'Redblush ' Grapefruit In The Desert

Effects of 12 rootstocks on yield, yield efficiency, bearing potential and quality of Redblush ' grapefruit were measured and potential rootstocks recommended for the arid climate of southwest Arizona. Trees on `Palestine ' sweet lime and 'Volkamer ' lemon produced high cumulative yield but small fruit. Trees on Macrophylla (Alemow)produced higher yields after 5 years of planting and had significantly higher mean yield efficiency than trees on other rootstocks. Thus, Macrophylla rootstock could be a good choice for 'Redblush'at the standard spacing and perhaps at high density spacing in southwest Arizona. Fruit of trees on ` Carrizo ' and `Troyer ' citranges were largest. Trees on `Savage ' citrange had lowest yield thinnest peel and highest levels of total soluble solids and soluble solids /acid ratio. Fruit of trees on 'Swingle ' citrumelo or C.P.B. 4475 rootstock consistently had higher percentage acid than those on other rootstocks. Considering yield and /or various quality factors, Vol/tamer' lemon, rough lemon, 'Palestine ' sweet lime, 'Oklawaha ' sour orange and particularly ' Carrizo ' citrange are suitable for 'Redblush ' grapefruit in the arid Southwest. 'Savage' citrange, *hang ' pummelo, `Cleopatra ' mandarin, and `Swingle ' were poor yielding rootstocks for 'Redblush ' grapefruit, and therefore undesirable for planting under the standard spacing of this experiment. 'Savage ' and `Swingle ' might be good choices at higher densities because they have yield efficiency, high maximum bearing potential and quality