Melogold - Citrus grandis × C. Paradisi/Citrus maxima/Citrus grandis

Origin  University of California, Riverside

The Melogold or Melogold grapefruit (Citrus grandis Osbeck × C. Paradisi Macf.) is a citrus hybrid similar to the oroblanco; both result from a cross between the pomelo and the grapefruit and is a fruit similar to a sweet grapefruit.

The intent was to obtain a grapefruit-like cross that is less bitter or acidic than grapefruit, instead achieving sweetness similar to the pomelo. It was to be smaller than the pomelo, and more flavourful, with characteristics linked to the grapefruit.

The breeders intentionally used a tetraploid grapefruit and a diploid pomelo, with triploid progeny and seedless.

Similar to oroblanco, Melogold can be eaten with a Grapefruit spoon, or peeled as an orange. They are ripe when still green.

Melogold was once said to be preferred as a cash crop over oroblanco, since melogold has thinner skin, which is preferred by consumers. Oroblanco is still more special in flavor.

Exterior peel color is slower to develop than in Marsh grapefruit, but late in the season is comparable. Exterior peel texture is smooth to slightly pebbled. Average peel thickness is slightly greater than Marsh, but as a percentage of fruit diameter is equal to Marsh and thinner than Oroblanco; interior color and texture are the same as Oroblanco.

As with Oroblanco the central core hollow is greater than Marsh at maturity. The flesh is tender and juicy, separating well from the segment membranes. Percent juice has been equal to Marsh and slightly higher than Oroblanco.

In 1958, CRC 2240 (pomelo) Robert K. Soost and James W. Cameron crossed with a seedy, white, tetraploid grapefruit. Two of the triploid offspring had particularly favorable characteristics. One was released in 1980 as 'Oroblanco'.

The second was released as Melogold. Oroblanco was more similar to grapefruit, while Melogold was more similar to pomelo.

Melogold was much larger than Marsh grapefruit and Oroblanco at all test locations. Weight at Riverside from 1967 through 1975 averaged 470 grams for Melogold, 360 grams for Oroblanco and 280 grams for Marsh.

Parentage/origins: Melogold is a triploid hybrid of Acidless pummelo and a 4N seedy Marsh grapefruit.  It was developed at the University of California, Riverside by Drs. Cameron and Soost.  It is a sibling of Oroblanco grapefruit hybrid and was released in 1986.  Mellow flavor (low acid) = Melo, gold for the deeper color of the rind than Oroblanco, hence Melogold. Patent on this cultivar is held by the University of California.

Rootstocks of accession: Carrizo citrange, C-35 citrange, Troyer citrange

Season of ripeness at Riverside: Early December to March

Season of ripeness at Lindcove: Early November through February

In 1958, an essentially acidless pummelo, CRC 2240, which had been shown to impart low acidity to its progenies, was crossed as seed parent with a seedy, white, tetraploid grapefruit. The small population from this cross consisted of 1 tetraploid and 6 triploids, which were field planted in 1962.

Two of the triploids had particularly favorable characteristics and were propagated for further testing. One of these was released in 1980 as 'Oroblanco'. The second is was released as Melogold. The general characteristics of the fruit resemble those of white-fleshed grapefruit cultivars, but are more pummelo-like than 'Oroblanco'. Fruit size is much larger than 'Marsh' grapefruit and 'Oroblanco' at all test locations.

Weight at Riverside from 1967 through 1975, averaged 470 grams for 'Melogold', 360 grams for 'Oroblanco', and 280 grams for 'Marsh'. Shape is comparable to 'Marsh' and 'Oroblanco' with a slight tendency to obconate fruit. Exterior peel color is slower to develop than in 'Marsh' grapefruit, but late in the season is comparable. Exterior peel texture is smooth to slightly pebbled.

Average peel thickness is slightly greater than 'Marsh', but as a percentage of fruit diameter is equal to 'Marsh' and thinner than 'Oroblanco'; interior color and texture are the same as 'Oroblanco'. As with 'Oroblanco' the central core hollow is greater than 'Marsh' at maturity. The flesh is tender and juicy, separating well from the segment membranes.

Percent juice has been equal to 'Marsh' and slightly higher than 'Oroblanco'. 'Melogold' may have a slight bitterness, particularly early and late in the harvest season. In taste tests, 'Melogold' has always been preferred by a wide margin over 'Marsh', but usually was a very close second to 'Oroblanco'.

At Riverside, solids have consistently been slightly lower than 'Oroblanco', but at Lindcove they have sometimes been slightly higher. Acidity at Riverside has also been consistantly slightly lower than 'Oroblano', but has fluctuated at Lindcove. As with 'Oroblanco', acidity is much lower than 'Marsh' at all sampling dates through the season at all test locations.

The low acidity with moderate solids produces a ratio that is much higher than 'Marsh' at all sampling dates. Fruit from Coachella Valley and South Coast Field Station also have acidity and moderate solids even early in the season. However, fruit from Coachella Valley have been rather insipid, and fruit from South Coast Field Station generally have been slightly bitter and lacking in flavor.

As with 'Oroblanco', 'Melogold' appears to be best adapted to the inland citrus areas of California. At Lindcove, the season of use is from early November to February, just slightly earlier than 'Oroblanco'. At Riverside, maturity is from early December into March. As with grapefruit, 'Melogold' can be utilized as a breakfast or salad fruit, but the flavor will be unique.

My opinion, for what it might be worth, regarding Oroblanco vs Melogold, is this: For maximum returns as a cash crop, plant your acreage to Melogold; but save one space near your back door for a tree of Oroblanco for your own use.

Melogold trees grow vigorously to a large size with a somewhat spreading form.  Melogold fruits are oblate in form with a slightly flattened base.  The rind is smooth and medium to dark yellow at maturity and thinner than Oroblanco for a similarly-sized fruit.

The large fruits typically average one pound in weight. The flesh is pale yellow in color, seedless, tender, and juicy.  The flavor is mild, sweet and reminiscent more of pummelo than of grapefruit.  Melogold is early in its maturity and holds well on the tree.

Availability: Commercially available in California through the Citrus Clonal Protection Program.