The clone AF 1753-16, a processing type variety licensed to Mc Cain Produce, Inc. last spring of 2003 was named “REEVES KINGPIN”. The name was chosen in honor of the potato breeder, Dr. Alvin Reeves, who was an avid bowler. AF 1753-16 clone is among his last selections before he passed away in 2001.
Reeves Kingpin is a high yielding new variety developed and selected at the University of Maine’s Aroostook Farm at Presque Isle, Maine. It is a mid-season variety that is earlier than Russet Burbank but later than Shepody and has yield advantage over these two commercially grown varieties, with yields ranging from 38 mt/ha to as much as 67 mt/ha in research trials. Its specific gravity on the average is about 1.093, ranging from 1.082 to 1.102 which is equal to or better than Russet Burbank. Reeves Kingpin is suitable for processing into french fries with comparable fry rating to Russet Burbank and Shepody. It has also good baking scores which may qualify it for fresh market. Reeves Kingpin plants are relatively taller, with greener leaves, more flowers and moderate to heavy fruit set compared to Russet Burbank which rarely set fruit. The tubers have netted to lightly russeted skin, are blocky and rarely exhibit the pointed and knobby tuber characteristics of Russet Burbank. The incidence of tuber sunburn and growth cracks could be higher in Reeves Kingpin, but the percent misshapen tubers could be lower compared to Russet Burbank and Shepody. Tubers of Reeves Kingpin are relatively tolerant to shatter bruise and black spot. The late season vigor of Reeves Kingpin is an advantage but its plants could be hard to vine kill. Reeves Kingpin is resistant to tuber net necrosis and moderately resistant to verticillium wilt. However, it is susceptible to golden nematode, late blight, common scab and corky ring spot virus.
EXECUTIVE SUMMARY
The program’s major goal is to breed
new varieties for processing and/or fresh market which are adapted and
acceptable in Maine and other eastern potato growing states. Types of varieties
selected in their order of priority are processing type-long russets for fries;
round whites for chips; table type and novel type (colored skin and flesh) for
fresh and special markets. Breeding objectives include high yield, resistance
to major pests and diseases, good processing traits, good storability and
superior eating and cooking qualities.
Promising clones include AF 1758-7, a high yielding medium late to late round white tablestock and AF 1808-18 which is a long russet mid-season clone that is suitable for fries processing and as a tablestock. AF 1753-16, a processing clone licensed to Mc Cain Produce Inc. in 2003 was named “Reeves Kingpin” in honor of Dr. Alvin Reeves. Commercial evaluation of this variety is continuing in Maine. Identified limitation to its widespread commercial production is the high incidence of external defects particularly, sunburn and growth cracks. A private company in Quebec has been granted an exclusive right to the old selection, AF 875-15 which is a chipping clone that is adapted in the colder areas of the eastern region. A plant breeder’s right for this clone has been applied for in Canada.
The breeding program conducted its regular activities for the year 2003 to 2004. True seeds developed from previous year’s crossing were planted in the greenhouse for tuberlet production. This year no hybridization work was conducted because of the greenhouse repair which took place during early winter to fall. About 29,000 single hills were evaluated which include new population with good processing traits and resistance to late blight from the USDA-Idaho breeding program. Field evaluation of early and middle generations together with five sets of yield trials were conducted at Gartley Farms. Field screening for resistance to scab and PVY were conducted at the Aroostook Research Farm for selected early and middle generation’s clones. Corresponding seed increase plots were planted at Gartley Farm for the different generations of selected clones. Seed clean-up and multiplication of promising clones through tissue culture and subsequent field multiplication of N1 and N2 tubers are conducted in collaboration with the state seed farm (Porter Farm) at Masardis, Maine under the Maine Potato Seed Board.
Other tests conducted are evaluation for processing traits (chips and fries), external defects (bruising, skinning, and black spot), greening, specific gravity, boiling (sloughing, after cooking darkening and texture), storage and sensory evaluations.
PROGRAM GOALS AND OBJECTIVES
“To
develop new varieties for processing and/or fresh market which are adapted in
Maine and other eastern potato growing states”
Types of varieties being
sought in their order of priority are processing types-long russets for fries;
round whites for chips; table types and novel types (colored skin and flesh)
for fresh and special markets.
Breeding objectives include
high yield, resistance to major pests and diseases, good processing traits,
good storability and superior eating and cooking qualities.
Promising Clones
AF 1758-7
· Medium-late to late round white tablestock
·
Good yielder (≥ than Kennebec and Superior; = Katahdin)
·
Low specific
gravity (≤ 1.070)
·
Good boiling
& baking scores
·
Tolerant to
blackspot but moderately susceptible to shatter bruise & skinning
·
Resistant to
golden cyst nematode, corky ring spot, verticillium wilt, common scab and
powdery scab
·
Can be hard to
top kill and very sensitive to post-emergence metribuzin
AF 1808-18
·
Long russet with
early to mid-season maturity
·
Good
yield and specific gravity (≥ to Russet Burbank)
·
Tolerant
to shatter bruise and skinning
·
Good
baking and cooking scores
·
Resistant
to verticillium wilt and net necrosis
·
Susceptible
to scab and late blight
·
Moderate
to high incidence of external defects (sunburn, knobs, growth cracks, misshapen
tubers)
Evaluation, Test & Yield Trial Results
Early and middle generations
About 43,000 true seeds were planted in the ME greenhouse for seedling tuber production, from which a total of 11,067 tubers were harvested. Out of 29,100 single hills planted, a total of 640 hills (2.2%) were selected; 78 of which were long white or russet clones which were selected from genotypes obtained from USDA-Idaho breeding program. Early generation selections were grouped into a long russet/white 8-hill or round red/white 12-hill plots. Out of the 240 entries in the long russet/white plots, 35 clones (14.6%) were selected while a total of 44 clone (18.2%) were selected out of the 242 round white/red plot entries(Tables 1 and 2). Eleven clones were selected (26.8%) from the 41 clones planted in 20-hill observational plots; all of which were selected from open-pollinated true seeds (Tables 3 and 4).
Yield Trials
Three stages of yield trials were conducted at Gartley Farms:: preliminary yield trial (36 entries); intermediate yield trials ( 12 long russet/white and 29 round white/red entries); and the advanced yield trials (4 long russet/white and 9 round white/red entries). Results are shown in Tables 5 to 9.
Seed Increase
Corresponding seed plots were planted at Gartley Farm for the different hill-stages of selected clones: 60 (early generation), 120 (middle generation), 200 (advanced selections) and 800 hills (promising clones).
Screening for Resistance to Diseases
Screening for resistance to common scab (41 entries + 5 check varieties) and PVY (58 entries + 7 check varieties) were conducted at the Aroostook Farm. Selected PVY and PLRV entries from last year’s were re-planted for further evaluation. Resistant clones were identified for each screening conducted but were not presented here.
Other Test and Evaluation
Other tests conducted are evaluation for processing traits- chips and fries (Table 10), external defects (bruising, skinning, and black spot), greening, specific gravity, boiling (sloughing, after cooking darkening and texture), storage and sensory evaluations.
Please note that results of early generation evaluations and disease screenings were not presented because of the very long list of entries.