USPP32465P2 - Avocado rootstock named ‘Merensky 6’ - Google Patents
Avocado rootstock named ‘Merensky 6’ Download PDFInfo
- Publication number
- USPP32465P2 USPP32465P2 US16/602,696 US201916602696V USPP32465P2 US PP32465 P2 USPP32465 P2 US PP32465P2 US 201916602696 V US201916602696 V US 201916602696V US PP32465 P2 USPP32465 P2 US PP32465P2
- Authority
- US
- United States
- Prior art keywords
- merensky
- year
- rootstock
- hass
- avocado
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 235000008673 Persea americana Nutrition 0.000 title claims abstract description 23
- 240000002426 Persea americana var. drymifolia Species 0.000 title 1
- 244000025272 Persea americana Species 0.000 claims abstract description 23
- 241000233618 Phytophthora cinnamomi Species 0.000 abstract description 13
- 235000013399 edible fruits Nutrition 0.000 description 13
- 230000001488 breeding effect Effects 0.000 description 6
- 241000196324 Embryophyta Species 0.000 description 5
- 238000009395 breeding Methods 0.000 description 5
- 230000001186 cumulative effect Effects 0.000 description 5
- 239000002420 orchard Substances 0.000 description 5
- 240000001140 Mimosa pudica Species 0.000 description 3
- 241000233614 Phytophthora Species 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 229910052902 vermiculite Inorganic materials 0.000 description 3
- 235000019354 vermiculite Nutrition 0.000 description 3
- 239000010455 vermiculite Substances 0.000 description 3
- 201000010099 disease Diseases 0.000 description 2
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 2
- 230000000644 propagated effect Effects 0.000 description 2
- 238000012216 screening Methods 0.000 description 2
- 239000002689 soil Substances 0.000 description 2
- 241000894007 species Species 0.000 description 2
- 210000003462 vein Anatomy 0.000 description 2
- 241000283690 Bos taurus Species 0.000 description 1
- 241001133184 Colletotrichum agaves Species 0.000 description 1
- 241000321520 Leptomitales Species 0.000 description 1
- 235000007265 Myrrhis odorata Nutrition 0.000 description 1
- 241000233654 Oomycetes Species 0.000 description 1
- 240000004760 Pimpinella anisum Species 0.000 description 1
- 235000012550 Pimpinella anisum Nutrition 0.000 description 1
- 230000001154 acute effect Effects 0.000 description 1
- 229930002877 anthocyanin Natural products 0.000 description 1
- 235000010208 anthocyanin Nutrition 0.000 description 1
- 239000004410 anthocyanin Substances 0.000 description 1
- 150000004636 anthocyanins Chemical class 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 210000004907 gland Anatomy 0.000 description 1
- 238000003898 horticulture Methods 0.000 description 1
- 208000015181 infectious disease Diseases 0.000 description 1
- 230000008774 maternal effect Effects 0.000 description 1
- 210000001672 ovary Anatomy 0.000 description 1
- 244000052769 pathogen Species 0.000 description 1
- 230000001717 pathogenic effect Effects 0.000 description 1
- 244000000003 plant pathogen Species 0.000 description 1
- 230000010152 pollination Effects 0.000 description 1
- 230000027772 skotomorphogenesis Effects 0.000 description 1
- 230000017260 vegetative to reproductive phase transition of meristem Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01H—NEW PLANTS OR NON-TRANSGENIC PROCESSES FOR OBTAINING THEM; PLANT REPRODUCTION BY TISSUE CULTURE TECHNIQUES
- A01H6/00—Angiosperms, i.e. flowering plants, characterised by their botanic taxonomy
- A01H6/52—Lauraceae, e.g. avocado
- A01H6/525—Persea [avocado]
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01H—NEW PLANTS OR NON-TRANSGENIC PROCESSES FOR OBTAINING THEM; PLANT REPRODUCTION BY TISSUE CULTURE TECHNIQUES
- A01H5/00—Angiosperms, i.e. flowering plants, characterised by their plant parts; Angiosperms characterised otherwise than by their botanic taxonomy
- A01H5/08—Fruits
Definitions
- the present invention is generally directed to a new avocado plant, or variety of Persea americana Mill.
- the varietal denomination of the avocado rootstock of the present application is ‘Merensky 6’.
- Phytophthora is a genus of plant-damaging oomycetes (water molds), capable of causing enormous economic losses on crops worldwide.
- Phytophthora cinnamomi is a soil-borne water mold that produces an infection which causes a condition in plants called “root rot” or “dieback”.
- the plant pathogen is one of the world's most invasive species and is present in over seventy countries around the world. It is distributed worldwide and causes damage on hundreds of hosts. The disease affects a range of economic groups, such as food crops including avocados. It is a root pathogen that causes root rot and death of host plants.
- Phytophthora cinnamomi is the leading cause of damage to avocado trees amongst avocado farmers. Damaged trees generally die or become unproductive within three to five years.
- the discovery and utilization of avocado varieties, including rootstocks, which are resistant or have a tolerance to Phytophthora cinnamomi is highly desirable.
- This invention relates to a new and distinct avocado variety.
- the invention ‘Merensky 6’ is an avocado rootstock characterized by superior tolerance to Phytophthora root rot, as compared to ‘Duke 7’ (not patented).
- ‘Hass’ grafted onto ‘Merensky 6’ bears more fruits than ‘Hass’ grown on ‘Duke 7’ and ‘3-29-5’ grown on ‘Merensky 2’ (U.S. Plant Pat. No. 15,309).
- the avocado rootstock breeding block contained 20 different rootstocks which have shown superior performance under Phytophthora cinnamomi pressure (e.g. ‘D9’ (not patented), ‘Duke 7’, ‘Merensky 1’ (U.S. Plant Pat. No. 17,497) and ‘Merensky 2’). These trees were used as parent trees for breeding and underwent open pollination.
- Seeds from the breeding block were germinated and seedlings were screened for their tolerance to root rot by exposure to a virulent strain of Phytophthora cinnamomi in a mistbed.
- the seedlings were planted in Phytophthora cinnamomi infested vermiculite and evaluated for their root health after six weeks. Selected seedlings were then cloned and re-tested (10 of each) in the mistbed in comparison to ‘Duke 7’ (2000-2002) and ‘Merensky 2’ (2003-2005) clonal commercial rootstocks as described above. Rootstocks with better root health than ‘Duke 7’ and ‘Merensky 2’ respectively were selected in the second mistbed screening, asexually propagated and grafted with ‘Hass’ for field evaluation.
- ‘Merensky 6’ was developed at Tzaneen, Limpopo province, South Africa.
- the ‘Merensky 6’ rootstock variety originated from the avocado breeding block in 1993.
- the maternal parent is the ‘D9’ avocado variety.
- the pollen parent is unknown.
- Fruits were collected from the breeding block, the seeds removed and planted in vermiculite. The seedlings were grown under a shade net. When the seedlings were approximately 30 cm tall they were transplanted in Phytophthora cinnamomi infested vermiculite and evaluated for their root health after six weeks.
- ‘Merensky 6’ was selected as a single plant for further evaluation.
- Budwood was collected from the plant and grafted to stumps of adult avocado trees that had been cut down in the avocado genepool orchard.
- ‘Merensky 6’ grew into trees which provided budwood for producing clonal trees, using the nurse seed/etiolation system, for further testing.
- ‘Merensky 6’ differed from other varieties by having a high tolerance against Phytophthora root rot as well as high bearing capacity. The traits of ‘Merensky 6’ were found to be stable and progeny formed by asexual propagation is true to type.
- FIG. 1 is a photograph depicting a four-year-old, top-worked tree of the ‘Merensky 6’ variety while growing in Tzaneen, Limpopo province, South Africa
- FIG. 2 is a photograph depicting typical mature foliage of the ‘Merensky 6’ variety, above a tape measure in centimeters for size reference;
- FIG. 3 is a photograph depicting typical flush foliage of the ‘Merensky 6’ variety, above a tape measure in centimeters for size reference;
- FIG. 4 is a photograph depicting typical inflorescence of the ‘Merensky 6’ variety, above a tape measure in centimeters for size reference;
- FIG. 5 is a photograph depicting a typical external view of the fruit of the ‘Merensky 6’ variety, above a tape measure in centimeters for size reference;
- FIG. 6 is a photograph depicting typical internal views of the fruit of the ‘Merensky 6’ variety, with and without the seed, above a tape measure in centimeters for size reference.
- the trees are located in an experimental orchard at Tzaneen, Limpopo province, South Africa, and are grafted on a ‘Merensky 2’ rootstock.
- the ‘Merensky 6’ tree has an upright and vigorous growth habit.
- Table 1 data on the vigor of ‘Hass’ grafted onto the rootstock of ‘Merensky 6’ as determined by trunk diameter measurements, taken 20 cm from the soil line, from trees planted in an orchard with Phytophthora cinnamomi in Tzaneen, Limpopo province, South Africa.
- Table 3 below provides the data on the typical canopy size of ‘Hass’ grafted onto the rootstock of ‘Merensky 6’ as determined by canopy volume measurements from trees planted in an orchard with negligible Phytophthora cinnamomi and salinity levels in Goleta, Calif., USA.
- the color of a one-year-old branch of ‘Merensky 6’ is yellow-green (RHS 146B).
- the bark of the one-year-old old branch is smooth.
- the lenticels of the one-year-old branch are inconspicuous.
- the color of the main stem is grey-brown (RHS 199A).
- the texture of the bark of the main stem is corky.
- the young shoot has a very weak intensity of anthocyanin coloration.
- the color of the young shoot is yellow-green (RHS 146A).
- the conspicuousness of lenticels is high.
- the lenticels of the young shoot are greyed-purple (RHS 185B).
- lenticels of ‘Duke 7’ are green (RHS 139B).
- the size of the lenticels of the young shoot of the ‘Merensky 6’ is approximately 1.0 mm long. There are approximately +/ ⁇ 20 lenticels per square cm.
- the color of the upper side of the young shoot is yellow-green (RHS 146A).
- the upper side of the young shoot has high glossiness.
- the lower surface of the young shoot has a yellow-green (RHS 146B) color.
- a mature leaf of the ‘Merensky 6’ variety has a length of approximately 19.0 cm and a width of approximately 6.0 cm, for a length/width ratio of 3.2.
- the shape of the mature leaf is lanceolate.
- the color of the upper side of the mature leaf is green (RHS 137A), and has a medium glossiness.
- the lower side of a mature leaf of the ‘Merensky 6’ leaf is green (RHS N138C). Veins are prominent and in relief on the lower side of the mature leaf.
- the color of the veins is yellow-green (RHS 151A).
- the mature leaves have a generally flat shape and cross-section.
- the color of the petiole of a mature leaf is yellow-green (RHS 144C).
- the length of the leaf petiole is approximately 3.7 cm.
- the mature leaf has a medium anise aroma.
- the margin of the mature leaf has a weak undulation. Reflexing of apex is present.
- the mature leaf apex shape and base shape are both acute. The leaves are held horizontally, i.e., approximately perpendicular to the shoot.
- the bud shape of the ‘Merensky 6’ flower is ovoid.
- the bud size is approximately 5 mm in length and approximately 4 mm in diameter.
- the bud color is yellow-green (RHS 145A).
- the flower belongs to Group “A”, with female opening occurring in the morning and ending before noon. The male opening occurs in the afternoon of the next day. The flower's opening cycle lasts approximately 30-36 hours.
- the petals of the flower are borne in two whorls of three perianth lobes.
- the single pistil with a slender style and small stigmatic surface has one carpel with one ovule.
- the ovary is superior.
- the pedicel is commonly approximately 2.3 mm in length and approximately 1.2 mm in diameter.
- the coloration of the pedicel is yellow-green (RHS 145A).
- the fruit of the ‘Merensky 6’ has a length of approximately 8.7 cm and a width of approximately 5.6 cm, for a ratio length/width of 1.6.
- the shape of the fruit is ellipsoid.
- the color of the skin of the fruit, when ripe, is yellow-green (RHS 146A).
- the texture of the skin of the fruit is smooth. Longitudinal ridges are absent.
- the thickness of the skin of the fruit is moderately thin.
- the main color of the flesh is yellow-green (RHS 154C).
- the color of the intensely colored area of flesh next to the skin is yellow-green (RHS 144A).
- the width of the intensely colored area of flesh next to the skin is approximately 3.0 mm. Fibers in the flesh are conspicuous.
- the seed of the ‘Merensky 6’ has a length of approximately 5.1 cm and a width of approximately 3.6 cm, on average.
- the shape, in longitudinal section, is ovate, and circular in cross-section.
- the color of the seed coat (fresh) is greyed-orange (RHS 166B).
- the fruit of ‘Merensky 6’ are not intended for market use. Instead, the variety is intended to be used as a vegetatively propagated rootstock onto which commercial varieties such as ‘Hass’, are grafted.
- Table 4 through Table 8 provide data on the yield of the ‘Merensky 6’ rootstock as compared to other rootstocks, for various scions and locations in South Africa and California. The data from these tables, taken from field trials, show that the ‘Merensky 6’ rootstock imparts a high bearing capacity to the scion.
- Rootstock Year 2 Year 3 Year 4 Year 5 19.7 ⁇ 10.3 46.8 ⁇ 19.6 16.3 ⁇ 9.0 73.3 ⁇ 24.1
- ‘Merensky 2’ 13.4 ⁇ 10.5 42.2 ⁇ 14.6 19.9 ⁇ 12.0 59.8 ⁇ 24.1
- Yield (kg/tree) Rootstock Year 6 Year 7 Year 8
- Cumulative ‘Merensky 6’ 18.9 ⁇ 21.8 34.7 ⁇ 19.4 117.9 ⁇ 27.6 327.6 ⁇ 83.9
- ‘Merensky 2’ 21.9 ⁇ 23.5 21.8 ⁇ 21.2 78.5 ⁇ 18.6 257.5 ⁇ 77.1 Morebeng, Limpopo province, South Africa, with ‘3-29-5’ scion (n 45)
- the ‘Merensky 6’ variety and rootstock have shown a strong tolerance to Phytophthora cinnamomi.
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Physiology (AREA)
- Botany (AREA)
- Developmental Biology & Embryology (AREA)
- Environmental Sciences (AREA)
- Natural Medicines & Medicinal Plants (AREA)
- Breeding Of Plants And Reproduction By Means Of Culturing (AREA)
Abstract
A new and distinct variety of Persea americana tree imparting high bearing capacity and vigor to the scion cultivar when used as a rootstock. Further, this rootstock exhibits a high tolerance to Phytophthora cinnamomi.
Description
Latin name of the genus and species: Persea americana Mill.
Varietal denomination: ‘Merensky 6’.
The present invention is generally directed to a new avocado plant, or variety of Persea americana Mill. The varietal denomination of the avocado rootstock of the present application is ‘Merensky 6’.
Phytophthora is a genus of plant-damaging oomycetes (water molds), capable of causing enormous economic losses on crops worldwide. Phytophthora cinnamomi is a soil-borne water mold that produces an infection which causes a condition in plants called “root rot” or “dieback”. The plant pathogen is one of the world's most invasive species and is present in over seventy countries around the world. It is distributed worldwide and causes damage on hundreds of hosts. The disease affects a range of economic groups, such as food crops including avocados. It is a root pathogen that causes root rot and death of host plants. Phytophthora cinnamomi is the leading cause of damage to avocado trees amongst avocado farmers. Damaged trees generally die or become unproductive within three to five years. The discovery and utilization of avocado varieties, including rootstocks, which are resistant or have a tolerance to Phytophthora cinnamomi is highly desirable.
Currently, the main avocado variety grown and consumed in the world is ‘Hass’ (U.S. Plant Pat. No. 139, the contents of which are incorporated herein by reference). The main markets have year-round supply of ‘Hass’ avocados and end consumers are very used to buying ‘Hass’. Many other avocado varieties have been created and patented over the years, but none of them have been able to obtain important interest from growers, primarily due to the market still preferring the ‘Hass’ avocado fruit. It would be very desirable to be able to graft ‘Hass’ trees onto a rootstock which bear good yields.
This invention relates to a new and distinct avocado variety. The invention ‘Merensky 6’ is an avocado rootstock characterized by superior tolerance to Phytophthora root rot, as compared to ‘Duke 7’ (not patented). In addition, ‘Hass’ grafted onto ‘Merensky 6’ bears more fruits than ‘Hass’ grown on ‘Duke 7’ and ‘3-29-5’ grown on ‘Merensky 2’ (U.S. Plant Pat. No. 15,309).
To generate high yielding new avocado rootstocks tolerant to Phytophthora cinnamomi a breeding program was initiated at Tzaneen, Limpopo Province, South Africa in the early 1990s. The avocado rootstock breeding block contained 20 different rootstocks which have shown superior performance under Phytophthora cinnamomi pressure (e.g. ‘D9’ (not patented), ‘Duke 7’, ‘Merensky 1’ (U.S. Plant Pat. No. 17,497) and ‘Merensky 2’). These trees were used as parent trees for breeding and underwent open pollination. Seeds from the breeding block were germinated and seedlings were screened for their tolerance to root rot by exposure to a virulent strain of Phytophthora cinnamomi in a mistbed. The seedlings were planted in Phytophthora cinnamomi infested vermiculite and evaluated for their root health after six weeks. Selected seedlings were then cloned and re-tested (10 of each) in the mistbed in comparison to ‘Duke 7’ (2000-2002) and ‘Merensky 2’ (2003-2005) clonal commercial rootstocks as described above. Rootstocks with better root health than ‘Duke 7’ and ‘Merensky 2’ respectively were selected in the second mistbed screening, asexually propagated and grafted with ‘Hass’ for field evaluation.
‘Merensky 6’ was developed at Tzaneen, Limpopo Province, South Africa. The ‘Merensky 6’ rootstock variety originated from the avocado breeding block in 1993. The maternal parent is the ‘D9’ avocado variety. The pollen parent is unknown. Fruits were collected from the breeding block, the seeds removed and planted in vermiculite. The seedlings were grown under a shade net. When the seedlings were approximately 30 cm tall they were transplanted in Phytophthora cinnamomi infested vermiculite and evaluated for their root health after six weeks.
Based on its tolerance to the disease, ‘Merensky 6’ was selected as a single plant for further evaluation. Budwood was collected from the plant and grafted to stumps of adult avocado trees that had been cut down in the avocado genepool orchard. ‘Merensky 6’ grew into trees which provided budwood for producing clonal trees, using the nurse seed/etiolation system, for further testing.
During screening and field evaluation, ‘Merensky 6’ differed from other varieties by having a high tolerance against Phytophthora root rot as well as high bearing capacity. The traits of ‘Merensky 6’ were found to be stable and progeny formed by asexual propagation is true to type.
The accompanying photographs show specimens of the tree and plant parts of the new ‘Merensky 6’ variety.
The following is a detailed description of the new ‘Merensky 6’ variety, which was taken from approximately 4-year-old mature trees, with the exception as a rootstock for a specific scion when reference is made to root rot tolerance and yield. The trees are located in an experimental orchard at Tzaneen, Limpopo Province, South Africa, and are grafted on a ‘Merensky 2’ rootstock.
In those instances where precise color assessment could be made, The Royal Horticulture Society (R.H.S.) color numbering system (R.H.S. Colour Chart published by The Royal Horticultural Society, London 2001) is used herein for the color description of the rind, seed, bark, leaf, flower, flesh color and other characters of the ‘Merensky 6’ avocado tree. In other instances, generally, color terms are used in accordance with an ordinary dictionary significance.
With reference now to FIG. 1 , the ‘Merensky 6’ tree has an upright and vigorous growth habit. Below in Table 1 are data on the vigor of ‘Hass’ grafted onto the rootstock of ‘Merensky 6’ as determined by trunk diameter measurements, taken 20 cm from the soil line, from trees planted in an orchard with Phytophthora cinnamomi in Tzaneen, Limpopo Province, South Africa.
TABLE 1 | |
Trunk diameter (cm) |
Rootstock | Year 2 | Year 3 | Year 4 | Year 5 | Year 6 |
‘Merensky 6’ | 7.1 ± 1.1 | 8.6 ± 1.4 | 11.4 ± 1.7 | 13.7 ± 2.0 | 16.2 ± 2.2 |
‘Duke 7’ | 5.6 ± 1.0 | 6.5 ± 1.1 | 8.2 ± 1.3 | 9.3 ± 1.5 | 10.8 ± 1.7 |
Tzaneen, Limpopo Province, South Africa, with ‘Hass’ scion (n = 24) |
Below are data on the vigor of ‘Hass’ grafted onto the rootstock of ‘Merensky 6’ as determined by trunk diameter measurements, taken 5 cm from the soil line, from trees planted in an orchard with Phytophthora cinnamomi in Goleta, Calif., USA.
TABLE 2 | ||
Trunk diameter (cm) |
Rootstock | Year 2 | Year 3 | Year 4 | |
‘Merensky 6’ | 6.1 ± 3.8 | 9.4 ± 0.7 | 11.2 ± 1.0 | |
‘Merensky 2’ | 6.8 ± 3.1 | 8.4 ± 2.7 | 11.4 ± 1.2 | |
Goleta, California, USA, with ‘Hass’ scion (n = 15) |
Table 3 below provides the data on the typical canopy size of ‘Hass’ grafted onto the rootstock of ‘Merensky 6’ as determined by canopy volume measurements from trees planted in an orchard with negligible Phytophthora cinnamomi and salinity levels in Goleta, Calif., USA.
TABLE 3 | ||
Canopy volume (m3) |
Rootstock | Year 2 | Year 3 | Year 4 | |
‘Merensky 6’ | 9.2 ± 2.2 | 11.1 ± 2.3 | 15.2 ± 1.1 | |
‘Merensky 2’ | 7.7 ± 3.0 | 10.5 ± 2.9 | 17.0 ± 1.9 | |
Goleta, California, USA, with ‘Hass’ scion (n = 15) |
With reference now to FIGS. 2-4 , the color of a one-year-old branch of ‘Merensky 6’ is yellow-green (RHS 146B). The bark of the one-year-old old branch is smooth. The lenticels of the one-year-old branch are inconspicuous.
The color of the main stem is grey-brown (RHS 199A). The texture of the bark of the main stem is corky.
The young shoot (flush) has a very weak intensity of anthocyanin coloration. The color of the young shoot is yellow-green (RHS 146A). The conspicuousness of lenticels is high. The lenticels of the young shoot are greyed-purple (RHS 185B). By comparison, lenticels of ‘Duke 7’ are green (RHS 139B). The size of the lenticels of the young shoot of the ‘Merensky 6’ is approximately 1.0 mm long. There are approximately +/−20 lenticels per square cm. The color of the upper side of the young shoot is yellow-green (RHS 146A). The upper side of the young shoot has high glossiness. The lower surface of the young shoot has a yellow-green (RHS 146B) color.
A mature leaf of the ‘Merensky 6’ variety has a length of approximately 19.0 cm and a width of approximately 6.0 cm, for a length/width ratio of 3.2. The shape of the mature leaf is lanceolate. The color of the upper side of the mature leaf is green (RHS 137A), and has a medium glossiness. The lower side of a mature leaf of the ‘Merensky 6’ leaf is green (RHS N138C). Veins are prominent and in relief on the lower side of the mature leaf. The color of the veins is yellow-green (RHS 151A). The mature leaves have a generally flat shape and cross-section. The color of the petiole of a mature leaf is yellow-green (RHS 144C). The length of the leaf petiole is approximately 3.7 cm. The mature leaf has a medium anise aroma. The margin of the mature leaf has a weak undulation. Reflexing of apex is present. The mature leaf apex shape and base shape are both acute. The leaves are held horizontally, i.e., approximately perpendicular to the shoot.
The bud shape of the ‘Merensky 6’ flower is ovoid. The bud size is approximately 5 mm in length and approximately 4 mm in diameter. The bud color is yellow-green (RHS 145A). The flower belongs to Group “A”, with female opening occurring in the morning and ending before noon. The male opening occurs in the afternoon of the next day. The flower's opening cycle lasts approximately 30-36 hours. The petals of the flower are borne in two whorls of three perianth lobes. The petals possess entire margins and petal coloration is yellow-green (RHS 145C). There are commonly nine fertile stamens, each having two basal orange nectar glands and three staminodia. The anthers are tetrathecal. The single pistil with a slender style and small stigmatic surface has one carpel with one ovule. The ovary is superior. The pedicel is commonly approximately 2.3 mm in length and approximately 1.2 mm in diameter. The coloration of the pedicel is yellow-green (RHS 145A). There are approximately 60-80 flowers per inflorescence. Generally, ‘Merensky 6’ has been found to bloom in July at Tzaneen, Limpopo Province, South Africa. The flowering time in California, USA, has been found to be between March and April.
The fruit of the ‘Merensky 6’ has a length of approximately 8.7 cm and a width of approximately 5.6 cm, for a ratio length/width of 1.6. The shape of the fruit is ellipsoid. The color of the skin of the fruit, when ripe, is yellow-green (RHS 146A). The texture of the skin of the fruit is smooth. Longitudinal ridges are absent. The thickness of the skin of the fruit is moderately thin. There is an intermediate adherence of the skin to the flesh of the fruit. The main color of the flesh is yellow-green (RHS 154C). The color of the intensely colored area of flesh next to the skin is yellow-green (RHS 144A). The width of the intensely colored area of flesh next to the skin is approximately 3.0 mm. Fibers in the flesh are conspicuous.
The seed of the ‘Merensky 6’ has a length of approximately 5.1 cm and a width of approximately 3.6 cm, on average. The shape, in longitudinal section, is ovate, and circular in cross-section. The color of the seed coat (fresh) is greyed-orange (RHS 166B).
The ‘Merensky 6’ fruit ripen in February in Tzaneen, Limpopo Province, South Africa; and in September in California, USA. The fruit of ‘Merensky 6’ are not intended for market use. Instead, the variety is intended to be used as a vegetatively propagated rootstock onto which commercial varieties such as ‘Hass’, are grafted.
Table 4 through Table 8 provide data on the yield of the ‘Merensky 6’ rootstock as compared to other rootstocks, for various scions and locations in South Africa and California. The data from these tables, taken from field trials, show that the ‘Merensky 6’ rootstock imparts a high bearing capacity to the scion.
TABLE 4 | |
Yield (kg/tree) |
Rootstock | Year 2 | Year 3 | Year 4 |
‘Merensky 6’ | 0.3 ± 0.5 | 4.6 ± 5.3 | 0 |
‘Duke 7’ | 0.3 ± 0.6 | 1.2 ± 1.1 | 0 |
Yield (kg/tree) |
Rootstock | Year 5 | Year 6 | Cumulative |
‘Merensky 6’ | 40.7 ± 12.4 | 38.0 ± 19.3 | 83.6 ± 28.6 |
‘Duke 7’ | 16.9 ± 10.3 | 6.3 ± 11.8 | 24.7 ± 17.5 |
Tzaneen, Limpopo Province, South Africa, with ‘Hass’ scion (n = 24) |
TABLE 5 | |
Yield (kg/tree) |
Rootstock | Year 2 | Year 3 | Year 4 | Year 5 |
‘Merensky 6’ | 19.7 ± 10.3 | 46.8 ± 19.6 | 16.3 ± 9.0 | 73.3 ± 24.1 |
‘Merensky 2’ | 13.4 ± 10.5 | 42.2 ± 14.6 | 19.9 ± 12.0 | 59.8 ± 24.1 |
Yield (kg/tree) |
Rootstock | Year 6 | Year 7 | Year 8 | Cumulative |
‘Merensky 6’ | 18.9 ± 21.8 | 34.7 ± 19.4 | 117.9 ± 27.6 | 327.6 ± 83.9 |
‘Merensky 2’ | 21.9 ± 23.5 | 21.8 ± 21.2 | 78.5 ± 18.6 | 257.5 ± 77.1 |
Morebeng, Limpopo Province, South Africa, with ‘3-29-5’ scion (n = 45) |
TABLE 6 | |
Yield (kg/tree) |
Rootstock | Year 2 | Year 3 | Year 4 | Year 5 |
‘Merensky 6’ | 31.3 ± 7.4 | 17.5 ± 18.6 | 48.7 ± 22.5 | 74.1 ± 26.9 |
‘Merensky 2’ | 23.5 ± 9.0 | 19.0 ± 15.9 | 34.9 ± 18.3 | 50.6 ± 26.1 |
Yield (kg/tree) |
Rootstock | Year 6 | Year 7 | Year 8 | Cumulative |
‘Merensky 6’ | 72.8 ± 47.3 | 26.2 ± 35.0 | 157.0 ± 47.2 | 427.6 ± 87.3 |
‘Merensky 2’ | 26.3 ± 25.4 | 23.3 ± 20.0 | 107.0 ± 41.1 | 284.6 ± 88.5 |
Morebeng, Limpopo Province, South Africa, with ‘Hass’ scion (n = 45) |
TABLE 7 | |
Yield (kg/tree) |
Rootstock | Year 2 | Year 3 | Year 4 |
‘Merensky 6’ | 22.4 ± 10.6 | 12.6 ± 14.0 | 19.5 ± 11.7 |
‘Merensky 2’ | 14.9 ± 11.5 | 12.2 ± 11.4 | 16.4 ± 13.9 |
Yield (kg/tree) |
Rootstock | Year 5 | Year 6 | Cumulative |
‘Merensky 6’ | 11.9 ± 11.3 | 15.6 ± 15.7 | 81.9 ± 21.4 |
‘Merensky 2’ | 7.4 ± 9.5 | 8.9 ± 10.1 | 59.8 ± 31.0 |
Santa Paula, California, USA, with ‘Hass’ scion (n = 10) |
TABLE 8 | |
Yield (kg/tree) |
Rootstock | Year 2 | Year 3 | Year 4 | Cumulative |
‘Merensky 6’ | 8.3 ± 5.5 | 23.0 ± 14.1 | 14.0 ± 14.1 | 45.3 ± 17.1 |
‘Merensky 2’ | 4.2 ± 5.3 | 23.7 ± 10.0 | 14.0 ± 9.5 | 41.8 ± 16.5 |
Goleta, California, USA, with ‘Hass’ scion (n = 15) |
As shown in Table 9 and Table 10 below, which represent data of tree health of the ‘Hass’ scion on ‘Merensky 6’ as compared to using ‘Merensky 2’, ‘Hass’ trees on the ‘Merensky 6’ rootstock are healthier than those on the ‘Merensky 2’ rootstock.
TABLE 9 | ||
Tree Health | ||
Rootstock | (0-10; 10 = Dead) | |
‘Merensky 6’ | 0.1 ± 0.3 | |
‘Merensky 2’ | 3.2 ± 0.8 | |
Santa Paula, California, USA, with ‘Hass’ scion, 6-year-old trees (n = 10) |
TABLE 10 | ||
Tree Health | ||
Rootstock | (0-10; 10 = Dead) | |
‘Merensky 6’ | 1.1 ± 1.8 | |
‘Merensky 2’ | 1.9 ± 3.6 | |
Goleta, California, USA, with ‘Hass’ scion, 4-year-old trees (n = 15) |
The ‘Merensky 6’ variety and rootstock have shown a strong tolerance to Phytophthora cinnamomi.
Claims (1)
1. A new and distinct rootstock variety of avocado tree having the characteristics as described and illustrated herein.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US16/602,696 USPP32465P2 (en) | 2019-11-20 | 2019-11-20 | Avocado rootstock named ‘Merensky 6’ |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US16/602,696 USPP32465P2 (en) | 2019-11-20 | 2019-11-20 | Avocado rootstock named ‘Merensky 6’ |
Publications (1)
Publication Number | Publication Date |
---|---|
USPP32465P2 true USPP32465P2 (en) | 2020-11-17 |
Family
ID=73263794
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US16/602,696 Active USPP32465P2 (en) | 2019-11-20 | 2019-11-20 | Avocado rootstock named ‘Merensky 6’ |
Country Status (1)
Country | Link |
---|---|
US (1) | USPP32465P2 (en) |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
USPP15309P3 (en) | 2001-09-07 | 2004-11-09 | Koehne Josef Stefan | Avocado tree named ‘Merensky 2’ |
USPP17947P3 (en) | 2005-05-11 | 2007-08-28 | Westfalia Technological Services | Avocado rootstock named ‘Merensky 1’ |
-
2019
- 2019-11-20 US US16/602,696 patent/USPP32465P2/en active Active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
USPP15309P3 (en) | 2001-09-07 | 2004-11-09 | Koehne Josef Stefan | Avocado tree named ‘Merensky 2’ |
USPP17947P3 (en) | 2005-05-11 | 2007-08-28 | Westfalia Technological Services | Avocado rootstock named ‘Merensky 1’ |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
USPP24279P3 (en) | Avocado rootstock named ‘Steddom’ | |
USPP32465P2 (en) | Avocado rootstock named ‘Merensky 6’ | |
USPP27144P3 (en) | Sweet orange tree named ‘B9-65’ | |
USPP32464P2 (en) | Avocado rootstock named ‘Merensky 5’ | |
USPP33655P2 (en) | Mandarin tree named ‘Star Cott 3’ | |
USPP33534P3 (en) | Avocado tree named ‘BL 5-552’ | |
USPP35444P2 (en) | Avocado tree named ‘BL516’ | |
USPP33563P2 (en) | Mandarin tree named ‘Star Cott 1’ | |
USPP21578P2 (en) | Apple tree named ‘Burnett cultivar’ | |
USPP35225P3 (en) | Apple tree named ‘MD-TAP1’ | |
USPP23933P3 (en) | Apple tree ‘DS 22’ | |
USPP35367P3 (en) | Apple tree named ‘MD-TAP2’ | |
USPP32768P2 (en) | Mangifera plant named ‘Orange Star’ | |
USPP29438P3 (en) | Lemon tree named ‘Code 3X97’ | |
USPP29552P3 (en) | Lemon tree named ‘3 ELS 0’ | |
USPP14239P3 (en) | Avocado tree named ‘3-29-5’ | |
USPP14238P3 (en) | Avocado tree named ‘Harvest’ | |
USPP29440P3 (en) | Lemon tree named ‘7 ELS C3’ | |
USPP29439P3 (en) | Lemon tree named ‘7B97’ | |
USPP22613P3 (en) | Almond tree named ‘Zohar’ | |
USPP29791P3 (en) | Sweet orange tree named ‘Florida EV1’ | |
USPP27778P3 (en) | Mandarin tree named ‘Bingo’ | |
USPP24608P3 (en) | Lemon tree named ‘7ELS1’ | |
USPP28595P3 (en) | Apple tree named ‘CP 101’ | |
USPP22458P3 (en) | Almond tree named ‘Matan’ |