New early navel oranges

New early navel oranges

23 July 2019

Dr Dave Monks and Andrew Creek, NSW DPI

In the last few years a number of new, early Navelina orange sports have been evaluated in Australia, with maturity 4 to 6 weeks earlier than standard Washington navel.

Leng, Pasin and Newhall navel oranges are all considered early navels, however Navelina clones and the more recent sports are the earliest maturing.

Now Australian citrus growers seeking early fruit can choose from Navelina, M7, FJ Navel and Rayno. These varieties are available through Auscitrus or specific variety managers.

Navelina 7.5 from Spain is the Navelina clone mostly planted in Australia. Fruit shape is variable and more oval compared to Washington Navel.

A rounder Navelina 315 clone from Italy is planted less as fruit size is considerably smaller. Navelina, picked at maturity, is a great eating piece of fruit.

Many growers will say their favourite eating orange is a Navelina that missed picking, suggesting full flavour develops after acceptable BrimA benchmarks are met.

M7 is an early navel with exceptional eating quality. It is round, has high Brix, good acid and juice% and was found as a limb sport on a Naveline 7.5 tree in Kenley, VIC. M7 reaches full colour in the 2nd week of May, and is sold into premium markets.

However, the variety owner and some growers have described management issues that require overcoming, specifically variable size and basal splitting.

“I’ve been picking my M7 for 3 years now,” said Frank Battistel, Griffith.

“I am happy with the way they colour at least two weeks earlier than my Navelina. A very sweet and juicy piece of fruit that is much rounder than the Navelina. I must follow a program strictly to prevent splitting.

“I also found my trees needed more copper to prevent deficiency. Yields have been lower for me, however I speak to other growers from different regions and their yield is fine. Maybe the citrange stock is not best for my soil.”

“Seven years ago, we decided to go with some M7 as it has a superior eating quality: not only earlier but as a navel period,” David Steven, Ellerslie, said.

“The first trees we had experience with were topworked over from Thomson navel on both citrange and rough lemon stock (trees were 30 years old in good health).

“So far, we have been harvesting M7 off these topworks for five seasons but are still a long way off full production. External fruit quality has been a mixed bag, with small fruit one season to very large rough fruit the next.

“Splitting has also been an issue when fruit is larger. If the fruit is left until full colour or later we have found the fruit to still be in very good condition.

“Internal quality has always been excellent, but trying to achieve an acceptable packout has so far eluded us with lots of blemish and unfavourable size ranges. Most people I speak with are trying very hard to make this variety work as its timing and eating quality fit so well into our markets. Hopefully success is just around the corner.”

Kenley-based Greg Chislett, M7 Variety Owner, says: “As the Variety Owners, we have invited citrus growers to an annual M7 open day where updates on our M7 Orchard Protocol have been discussed. There has been considerable progress made over the years in understanding the particular requirements involved in growing the variety.

“More effective foliar copper products have been identified which have significantly improved performance both in the nursery and orchard. The feedback from most growers is now quite positive and fruit marketers and retailers acknowledge the high eating quality of the variety.”

FJ is a good quality early navel that was found as a limb mutation in Leeton, NSW.

FJ reaches full colour in the 4th week of May. It has good Brix, acid and juice%. FJ is round, has consistent yield and fruit are of good size.

A grower visiting the Dareton evaluation site recently commented that FJ ‘just fits in with our usual farm practices’, compared with M7 which required special attention.

“I’ve been picking 250 trees of FJ Navel for 5 years now,” said Mick Cuzzillo, Stanbridge.

“FJ is a nice piece of fruit that packs rounder than my Navelinas. The FJ colours naturally better and quicker than Navelina. Internally the fruit is sweet and juicy.”

Rayno is a good quality early Navelina sport from South Africa. Rayno reaches full colour in the 4th week of May. It has good Brix, acid and juice%.

Rayno has a neck and most fruit are oblong, however one packer/grower said he didn’t mind the shape and thought he could find a market for it. Rayno has produced a high yield of mid-small fruit in the first two years of production from topworked trees.

It is too early to give a fair impression of the fruit size, but we will follow it through next season.

Rootstock incompatibility is an important factor to consider with Navelina and these Navelina sports.

Since the initial plantings in 1990s, it has been found that Navelina is incompatable with Swingle Citrumelo and C35 citrange.

Navelina planted on C35 roostock began to die from about 15 years of age at the Loxton Research Centre (Gallasch and Skewes). Carrizo citrange has also shown some incompatibility symptoms and a sweet orange interstock is recommended for a long lived tree.

Table: Juice results at harvest maturity 2019, Dareton, NSW.

	Full colour	Brix	Acid	B:A ratio	BrimA	Juice %
M7	10-May	14.0	1.0	14.0	160	42
Navelina	20-May	12.5	0.9	13.8	145	45
FJ	20-May	12.0	0.9	13.5	140	45
Rayno	25-May	11.5	1.0	11.5	120	50