Vegetable Improvement Newsletter No. 9, February 1967

Compiled by H.M. Munger, Cornell University, Ithaca, New York

1. Some Correlation Studies in Asparagus as Related to Cumulative Season Yield

Dermot P. Coyne and Robert Fast

Department of Horticulture and Forestry, University of Nebraska, Lincoln, Nebraska

In evaluating the yield performance of asparagus varieties in trials or selected plants and in a breeding program, it has been considered necessary to obtain records of spear weight and of number of spears of row and/or individual plants for an entire harvest season over a number of years. This procedure is expensive and is time-consuming. Numerous other workers have studied the association of several plant characters with total yield evaluation of selected plants and /or varieties.

Simple correlations between early harvest productivity (weight and number of spears) of one-year-old asparagus seedlings in the nursery, earliness of spears emergence ratings of mature plants, and cumulative yield at each harvest date of mature plants with cumulative season yield of mature plants were studied in twenty-three asparagus "varieties" of diverse origin during the period 1961 to 1966. A significant high positive correlation was noted between cumulative yield and number of spears of the first two and five harvests and total season yield in 1965 and 1966. respectively. Ellison et al. (Proc. Amer. Soc. Hort. Sci., 72: 353-359, 1958; and 76:376-381, 1960) reported that a high correlation between the yield of the first two weeks of harvest and total season yield. In Lincoln about six to weight harvests would be made in that time in a normal season. The results suggest that in this area it is not necessary to harvest for as long as period as two weeks. There was no significant correlation between earliness of spear emergence ratings of mature plants observed at one date in 1963 and 1964 with cumulative season yield in 1965 and 1966. Apparently, a visual rating for earliness of spear emergence at the time the earliest varieties are ready for first harvest is not sufficiently accurate to have much predictive value for future season yields.

Significantly high positive correlations were observed for a the following characters between 1965 and 1966: total season yield, yield of first six harvest, number of spears for season and mean spear weight for season.

No significant relationship was observed between early yield, number of early spears of one -year-old asparagus seedlings of twenty-three varieties in the nursery in 1962 and cumulative season yield of mature plants in 1965 and 1966. Low correlations between seedling vigor and productivity of mature plants were observed by Scheer et al. (Proc. Amer. Soc. Hort. Sci. 76:370-375) and by Wellensiek (Hort. Abst. 1950, : 20, 113 and 1958, :28, 67). The type of measurements recorded in these studies differed from those recorded by the authors in the present study. However, Adam and Skiebe (Zuchter, 34:97-102, 1964) did note that seedling vigor could be used as an early study of productivity. Further studies should be undertaken to study seedling characters and mature plant yield in various environments.

2. Release of New Hybrid Cucumber Varieties

W.C. Barnes

Clemson University Truck Experiment Station, Charleston, South Carolina

The Clemson University Truck Experiment Station announces the release of two hybrid cucumber varieties for fresh market production. Both of these varieties have multiple resistance. Cherokee, recommended for use primarily in the South, has good resistance to downy and powdery mildew, anthracnose, and angular leafspot. Gemini will find its place in areas where scab and viruses are the major problems. These are confined to south Florida late winter production, Southern Mountain areas such as Western North Carolina, and t he Northern states. In addition to the good resistance to scab and cucumber mosaic virus, Gemini has moderate resistance to downy and powdery mildews, anthracnose, and angular leafspot.

Cherokee is earlier than Ashley while Gemini has about the same maturity. Both varieties produce a high percentage of their crop within the first 7-10 days which should be an advantage in marketing. this characteristics my be a disadvantage if the crop is under stress from adverse weather during this period.

Cherokee fruit color is equal to Ashley while Gemini is good except under very high temperatures. Fruit length of both varieties averages about 1/4 inch shorter than Ashley.

Seed supply will be limited for planting in 1967 and will be available only through the seed trade. Clemson has no seed for samples.

The two hybrids are produced by using the Clemson developed gynoecious 54. The original gynoecious (all female flowers) cucumber came from Korea and did not breed true. Gynoecious 54 produces no male flowers unless treated with the plant hormone gibberellin. The seed produced by using this hormone are planted in hybrid seed production fields with a pollen parent on every fourth row. The Clemson developed Poinsett is the pollen parent of Cherokee while the cornell University Sr Tablegreen is the pollen of Gemini. Such hybrid seed will cost only about 1/5 the price of that produced before the advent of the gynoecious material.

3. Male Sterility in the Cucumber

R.W. Robinson and W. Mishanec

New York State Agricultural Experiment Station, Geneva, New York

A survey of spontaneous mutation in the cucumber revealed that male sterility is much more common than we expected. Male steriles comprised the most ubiquitous type of mutant found in certain varieties. Approximately one plant in every 500 of the varieties Wisconsin SMR 18 and SMR 58 was male sterile, with male flowers aborting in the bud stage. Male sterility was less frequent in the other varieties tested.

Despite their frequent rate of occurrence, most male sterile mutants had the selective handicap of a high degree of female sterile mutants had the selective handicap of a high degree of female sterility. They were poor seed producers when cross pollinated, and did not appear useful as a practical means of producing hybrid seed.

Several male sterile mutants of Wisconsin SMR 18 were found to have the same single recessive gene for male sterility. Tests are in progress now to determine varieties and in those previously reported by other investigators.

4. Release of Eggplant Breeding Stocks Resistant to Verticillium Wilt

John Wiebe

Horticultural Research Institute of Ontario, Vineland Station, Canada

An eggplant breeding project carried at the Horticultural Research Institute since 1956 is being discontinued. The objective of this program was to find sources of resistance to verticillium wilt for eggplant and to incorporate this resistance into lines with good horticultural characteristics. The project has not been carried to completion. We are offering advanced breeding lines to other plant breeders. These lines are not yet fully stable but are a valuable source of field resistance combined with fairly good horticultural characteristics.

In every case the lines are the result of crosses between Black Beauty and lines obtained from the U.S.D.A. Plant Introduction Service (Regional Project NE-9, Geneva, N.Y., Dr. D.D. Dolan). The P.I. accessions carried some level of resistance to Verticillium albo-atrum under field conditions. A fairly complete progress report is given in the 1964 Report of the Horticultural Experiment Station, pages 91-94.

In the table below are given the 1966 field number, the original P.I. parent, brief field notes of 1966 and the amount of seed available for release.

Because all resistant material came from the U.S.D.A. Plant Introduction Service it is important to keep track of all these lines and to give U.S.D.A. credit when varieties are named.

If varieties or hybrids are named which trace back to this material, credit should be given to the Horticultural Research Institute of Ontario and the Plant Introduction Service of the U.S. Department of Agriculture.

5. Introducing Green Seeded Fordhook Bush Lima Bean

Robert E. Wester

Crops Research Division, ARS, U.S. Department of Agriculture, Beltsville, Md.

Green Seeded Fordhook lima bean (tested under U.S. 861), which is resistant to downy mildew strain A, was released to lima bean seedsmen in the spring of 1966. This is the first green-seeded Fordhook variety released to the trade.

Parents. The parents of Green Seeded Fordhook are P.I. 164155, early Thorogreen, Concentrated Fordhook, and Fordhook 242. Resistance to downy mildew strain A was contributed by P.I. 164155, a speckled-seeded pole lima bean from India; Early Thorogreen, the green cotyledons and dark-green leaves; Concentrated Fordhook, the concentrated pod set, compact plant and short racemes; and Fordhook 242 contributed heat resistance. Seed size was obtained by backcrossing to Fordhook 242 five times before pure lining was started.

Plant habit. The plants of Green Seeded Fordhook are compact, a few inches shorter and not as bushy as Fordhook 242, being about 13 to 16 inches tall with a spread of 18-20 inches. The racemes protrude slightly above the foliage and are shorter than those of Fordhook 242. A concentrated set of pods are produced in the crown of the plant that reach prime condition 4-6 days later than Fordhook 242.

Yield. Under favorable growing conditions in the Middle Atlantic States when downy mildew is absent, Green Seeded Fordhook will usually yield about 10% less than Fordhook 242, but when downy mildew is present, it will out yield it by 30 to 60%.

Other characters. The new variety vines as satisfactorily as does Fordhook 242. The beans, while are slightly smaller than Fordhook 242, remain in a succulent condition in the field 5-8 days longer than Fordhook 242, which is a very desirable characteristic.

Amount of seed. In 1966 seedsmen produced about 18,000 pounds of seed of Green Seeded Fordhook. The variety will be further increased in 1967 and only a limited amount will be available for processor trials.

6. Notice to Seedsmen and Processors Concerning the Naming and Release of Snap Bean Variety Bonus

Crops Research Division, ARS, U.S. Department of Agriculture, Beltsville, Md.

The snap bean, B3125-X-5-2, supplied to seedsmen for trial and increase under release notice dated February 4, 1963, is hereby named Bonus and is formally released for immediate unrestricted commercial use.

Bonus originated at the U.S. Vegetable Breeding Laboratory at Charleston, South Carolina. It is resistant to the type strain and the New York 15 strain tolerance to powdery mildew, rust, and Rhizoctonia root-rot.

Bonus has been grown in the Southern Cooperative Snap Bean Trails in 133 tests.It performed well in these trials even though it was usually evaluated and compared with fresh market types. Since it is a white-seeded bean, it has been grown in commercial canner trials in several Northern States including New York, Delaware, Pennsylvania, Missouri, and Maryland. IT was highly rated in these tests as having very desirable canning quality for both whole pack and cut beans because of its white seeds and its preferred size, shape, color, and eating quality. the extra refined appearance of the pod is an outstanding Bonus characteristic.

The variety Bonus is distinct and not currently available variety is apt. to be confused with it. The length of time to harvest is 50 to 52 days. Pods are round and straight, but can be slightly curved when produced under poor growing conditions. Pod length is uniform from year to year, averaging 5.0 inches in all trails. Pod color is similar to that of the variety Tendergreen. The pods are smooth when harvested at the proper stage for processing or for fresh market. Seeds are white and average 100 to an ounce. Plants average 16 inches in height with a spread of 18-20 inches, and are well adapted to mechanical harvest. The plants produce a strong, vigorous root system, a characteristic usually associated with good top growth and high yields.

Yields have been consistently high in a wide range of locations and have averaged 7,000 pounds per acre. The variety grows equally well in southern areas during spring and fall, and in northern areas during the summer months. Bonus is recommended not only for processing, but also is suitable for home garden and fresh market use, and should reach good demand in areas where multiple purpose snap bean is desired.

Bonus seed will be distributed through commercial seed channels. the USDA has no seed for distribution, but information on sources of seed can be obtained by writing to Dr. J.C. Hoffman, U.S. Vegetable Breeding Laboratory, P.O.Box 3348, Charleston, South Carolina 29407.

7. A Powdery Mildew Resistant Honey Dew Muskmelon

G.W. Bohn and T.W. Whitaker

Crops Research Division, ARS, U.S. Department of Agriculture, La Jolla, California

Strains of Honey Dew muskmelon currently available to growers in Arizona and California are likely to be erratic performers in the many different environments found in these areas. The vines are susceptible to powdery mildew and extremely susceptible to the cucurbit mosaic viruses. Common defects of the fruit are: poor exterior appearance; odd shape and sizes; low soluble solids; thin flesh, becoming watery prior to best edibility; and poor flavor.

With the idea that some of these defects could be corrected, or at least ameliorated, an original cross was made with Honey Dew and none of our best powdery mildew resistant lines of cantaloupe in 1646; F₃ (PMR 45 x Resistant Cantaloupe) x P.I. 124, 111. From this original cross we have isolated Honey Dew line 61090-M4, which in our opinion has considerable merit and will be in trial in several areas on a sufficiently large scale to judge its acceptability during the coming growing season. H.D. 61090 has performed well in trials in California and Texas during two seasons, in plantings both for spring and fall harvest.

H.D. line 61090-M4 is highly resistant to powdery mildew. It has a mildew rating of 4.0 on our scale (1.0 = completely susceptible; 5.0 = immune). Comparable ratings are: Honey Dew = 2.0; PMR 45 = 2.0; PMR 6 = 3.0. Sizes and shapes are good and under growing conditions in the Imperial Valley the line is highly productive. The skin is smooth, turning creamy white with yellow blotches when mature. The flesh is thick, greenish, and of excellent quality; soluble solids averaged about 16.5% in a fall crop grown in Imperial Valley.

The original cross was followed immediately by two backcrosses to Honey Dew. In all there were 4 backcrosses to Honey Dew, 8 generations of selfing, one generation in which open selections were made and finally 4 generations of mass selection.

This program was carried out in cooperation with the Department of Vegetable Crops, University of California, Meloland Station, El Centro, California.

8. Hand Pollination of Cantaloupes

John L. Bowers

Department of Horticulture and Forestry, University of Arkansas, Fayetteville, Arkansas

We have had excellent results from the use of 2% solution of benzyladenine in lanolin paste applied to base of calyx area on flowers of cantaloupes to induce better fruit set in hand pollinated flowers in this field. We had been experiencing very poor success in previous seasons in obtaining either selfs or crosses in the field.

9. Variable Outcrossing in Cucurbita Pepo

H.M. Munger

Department of Plant Breeding and Biometry, Cornell University, Ithaca, New York

An incident described by a seedsman several years ago and a situation we encountered recently, both suggested the presence of self-incompatibility in Cucurbita pepo. Our own experience arose from increasing a line of bush table Queen (Cornell 60-4) at East Ithaca in 1963. We knew there was summer squash in a nearby garden but it was several hundred yards away and out of sight behind buildings and trees. Furthermore there were only 4 or 5 hills of summer squash vs. 24 hills of Table Queen. To our surprise, we found man outcrosses, when the increased Table Queen seed was used in 1964, perhaps 10%.

To get some evidence as to the reason for the unexpected amount of outcrossing, reciprocal crosses were made in 1965 between the Table green and Seneca Prolific. To get a 50% mixture of pollen, one androecium of each was put in a glass vial, stirred with a camel's hair brush, and applied with the brush. An 80% androecium mixture was similarly obtained by mixing an androecium of one with one-fourth of an androecium of the other cut off with shears. The mixture estimated as 90% was obtained by touching an anther of Seneca Prolific to one spot of the Table Queen stigma and then covering the entire surface with self or sib pollen.

the results in table 1 show that 5 out of 6 fruits of Seneca Prolific gave offspring with less outcrossing than expected from the type of pollination made while all 4 fruits of Table Queen had more outcrossing. Apparently self-incompatibility is not involved since the Table Queen pollen regardless of the parent on which it was used. The explanation remains to be investigated, but the data do indicate that some varieties are more subject to contamination from foreign pollen than others.

Table 1 . Amount of crossing in seed resulting from 1964 mixed pollinations in two varieties of Cucurbita pepo.

10. Water Imbibition Method of Identifying Pea Genotypes Applied to F₂ Seeds

H.H. Marshall

Research Branch, Experimental Farm, Brandon, Manitoba

Double wrinkled peas may be identified in segregating lines by their capacity to absorb water prior to germination. In earlier work this was applied to seed of F₃ or later lines whose genotype was more or less known. Since both new wrinkled and classical wrinkled are expressed on the genotype of the embryo, it seemed possible to apply the test to seed of F₁ plants, that is at the beginning of the F₂ generation.

Two hundred F₂ seeds of Supersweet (double wrinkled) x P.I. 210637 (classical wrinkled) were tested for water absorption. The range of absorption indices obtained was 2.03 to 3.63 or somewhat greater than expected. Since each seed was potentially different from most others, this could not be checked by the replication. However, several of the more extreme readings were checked by re-weighing the wet seed, drying it and weighing again. No errors were found.

All seed was dried and returned to storage. Later samples representing those with the lowest, two intermediate and the highest absorption indices were sown in a sterile medium. Throughout the test and germination there was a loss of 7.7% dead and 1.5% hard seeds.

11. The Prevention of Rodent Damage in Breeding Plots

W.H. Lachman

Department of Plant and Soil Sciences, University of Massachusetts, Amherst, Mass.

For several years, squirrels, skunks, woodchucks and raccoons stripped the ears from plants and ruined about one-third of the crop grown for our sweet corn breeding project. During three years, we attempted to catch the animals responsible for the damage. Using canned sardines as bait in appropriate traps, we were successful in capturing many animals. even with the removal of these trapped rodents, however, damage to the corn did not subside.

At the suggestion of Dr. E.V. Wann of the U.S. Vegetable Breeding Laboratory at Charleston, S.C., we decided to try a special electric fence for protecting the corn from various small animals.

During 1965 and 1966 we attempted to protect an area of about two and one-half acres of sweet corn. An electric fence consisting of three wires, one 5. another 10 and still another 15 inches above the soil, was found effective in keeping all the bothersome rodents out of the sweet corn breeding nurseries here at Amherst. The fence was fitted with a 6-volt battery operated electric fence charger and was in operation during the period between silking stage of the corn ears until harvest. No loss of the crop was experienced during the 1965-1966 seasons.

For maximum effectiveness, border areas where the fence is to be installed must be reasonably level and kept free of weeds. The fence should be activated before rodents have begun using the field as a feeding area, usually about silking time.

12. Tomato Breeding Lines for Release

E.A. Kerr and J.H.L. Truscott

Horticultural research Institute of Ontario, Vineland Station, Canada

In the last 20 years tomato lines with specific desirable characteristics have been developed. Vineland numbers have been assigned to 28 of them. All have one or more undesirable characteristics which make them unsuitable for commercial production. Most have been used in the Institute breeding programs for early processing tomatoes or for increased Vitamin C. A descriptive list giving parentage, Vitamin C, season, crack resistance, color, specific genes firmness etc. is available. These lines are available to any plant breeder who wants them. If any are used in the development of a cultivar we request that credit be given to the Horticultural Research Institute of Ontario.

13. Combined Root knot and TMV Resistance in Tomato

J.C. Gilbert and Jack S. Tanaka

Department of Horticultural, University of Hawaii, Honolulu, Hawaii

Since the release of our first commercial-type root knot resistant tomatoes in 1955, the addition of tobacco mosaic virus tolerance to these lines has been a major breeding objective here. Concentric fruit cracking was more severe in the earlier selections in both the TMV and root knot programs and so this combinations was difficult to improve for tolerance to concentric cracking here. This has now been done, however, to the extent that the newest TMV-root knot resistant variety (Healani) is slightly more tolerant to concentric cracking than our previous standard commercial varieties in Hawaii (i.e., The "island lines" Maui, Kauai, Oahu, etc. released by Frazier in 1949). Radial cracking has never been a problem with this material.

In addition to the tolerance to TMV which is best expressed in the earlier stages of the plants' growth, this combination now has some resistance to physiological gray wall or vascular browning produced in Hawaii by overcast, humid weather in the absence of air movement around and under the plants. The new TMV-root knot resistance is also combined with some tolerance to Alternariadiseases and resistance to Spotted wilt virus, Stemphylium solaniand Fusarium wilt in Hawaii. This determine inbred with uniform ripening immature green fruit color originated from a cross of Hawaii 6351 and STEP 305 in 1959. Its resistance to spider mite defoliation appears somewhat intermediate between the resistant Hawaii varieties, Anahu and Kalohi, and the more susceptible mainland types Vinequeen, Homestead, Rutgers, etc. New crosses made recently have been carried out to improve its spider mite tolerance and add resistance to bacterial wilt eventually.

Although F₁ hybrids made with one Florida parent and one Hawaii parent have offered combined resistance to both TMV and root knot and have been the most widely grown commercial types in Hawaii, Healani is our first inbred variety carrying both Florida and Hawaii with this combination of disease resistance.

TMV symptoms can be produced on Healani under certain conditions in older plants, but field tests here for five years have demonstrated its ability in Hawaii to escape symptoms in growing plants when standard varieties show severe mosaic form the same inoculation.

14. Evaluation of Lycopersicon species, Plant Introductions and Varieties For Resistance to 2, 4-D Injury

D.P. Coyne, O.C. Burnside and W.C. Whitney

Department of Horticultural and Forestry, University of Nebraska, Lincoln, Nebraska

Sixty tomato varieties and/or breeding lines and 448 plant introductions were evaluated for resistant to 2, 4-D spray injury in an observation trial at Lincoln, Nebraska, in 1966. The 2, 4-D diethyl amine formulation was used and sprayed on the plants at the rate of 9 ounces actual 2, 4-D per acre. Most of the lines showed severe and/or very severe plant injury six days after spraying and 394 lines died at a later time. Some lines showed early moderate injury and new vigorous growth free from 2, 4-D symptoms developed on almost all of the plants in the following 6 PI lines: 118778 (Brazil), 190858 (Argentina), 203229 (Australia), 124036 (Argentina), 129131 (Panama), and 272636 (Costa Rica). Fruit set was heavy on these lines but maturity was delayed. PI 129131 may be a useful parent to use in a breeding program for a source of resistance to 2, 4-D injury. A detailed report may be obtained by writing the senior author.

15. A Source of Tolerance in Lycopersicon Esculentum to Bacterial Spot Pathogen

D.P. Coyne and M.L. Schuster

University of Nebraska, Lincoln, Nebraska

Bacterial spot of tomatoes, a disease caused by Xanthomonas vesicatoria (Doidge) Dows. is a serious disease in some tomato growing areas. No resistance or tolerance to the bacterium has been reported in commercial varieties of tomatoes grown in the United States. Slepneva (Rev. Appl. Myc. 40:434, 1961) reported tolerance in some USSR tomato varieties and Alexander et al., (Plant Dis. Reptr. Suppl. 136:51-84, 1942) found resistance in some plant introduction (PI) lines of Lycopersicon species. The reaction of the foliage of the USSR varieties mentioned by Slepneva and some of the PI lines reported by Alexander et al., to the Nebraska isolates of the bacterium was studied in the field in 1965 and 1966 respectively. Other Lycopersicon PI lines were tested in 1964 with an isolate obtained from Dr. R.E. Stall, University of Florida.

The first inoculations were made when the green fruit was in the early stages of development. The plants were inoculated with a bacterial suspension by means of a power sprayer at ca 150 p.s.i. L. esculentumx L. pimpinellifolium PI 126923 was considered to possess the best foliage tolerance in the field tests. This PI may provide a high enough level of tolerance for use in a breeding program. Alexander, et al. also found this line tolerant to the bacterium but all the other lines reported as tolerant were found to be susceptible in our tests. All of the USSR plant introductions (PI) previously reported by Slepneva as moderately resistant were found to be highly susceptible to the Nebraska isolate. Severe fruit infection developed in 1965 but very little fruit infection was observed in the 1964 or 1966 tests. Gardner and Kendrick (J. Agr. Res. 21:123-256, 1921) reported that while foliage infection was stomatal, fruit infection developed through injury or puncture. Perhaps the surface of the fruit was not injured by spraying in these particular years.

16. Evaluation of Lycopersicon Species, Plant Introductions and Varieties for Resistance to 2, 4-D Injury

D.P. Coyne, O.C. Burnside, and W.C. Whitney

University of Nebraska, Lincoln, Nebraska

2,4-D is widely used to control weeds in lawns, alongside roadsides and in many important agronomic crops. The drift from these spray applications often cause considerable damage to tomatoes grown in commercial fields and in home-vegetable gardens. In some cases the injury may be severe resulting in curling of leaves, stem distortion, stunting of plant growth, failure of fruit set and/or development of malformed fruit. In town gardens where 2,4-D is used on adjacent lawns almost all tomato plants show some response to 2,4-D. If the injury is slight the plants generally recover and produce a satisfactory tomato crop. Differences in varietal resistance to 2,4-D injury have been observed by the authors.

The present study was conducted to determine (a) if there were sources of resistance in Lycopersicon species and varieties to a high concentration of a 2,4-D spray, (b) the effect of a moderately low rate of 2,4-D on the yield of 50 varieties, (c) the relation of initial plant injury and yield.

Sixty tomato varieties and/or breeding lines and 448 plant introductions were evaluated for resistance to 2,4-D spray injury in an observation trial at Lincoln, Nebraska, in 1966. The 2,4-D diethyl amine formulation was used and sprayed on the plants at the rate of 9 ounces actual 2, 4-D per acre. Most of the lines showed severe and/or very severe plant injury six days after spraying and 394 lines died at a later time. Some lines showed early moderate injury and new vigorous growth free from 2, 4-D symptoms developed on almost all of the plants in the following 6 PI lines: 118778 (Brazil), 190858 (Argentina), 203229 (Australia), 124036 (Argentina), 129131 (Panama), and 272636 (Costa Rica). Fruit set was heavy on these lines but maturity was delayed.

Fifty tomato varieties were evaluated for plant injury and "one shot" harvest yield after a spray treatment of 2,4-D at the rate of one ounce actual 2,4-D per acre at the time the first flower cluster was in bloom in the majority of the varieties. The majority of the varieties showed severe initial plant injury. The following varieties showed only slight plant injury: Superman (Harris), Moreton Hybrid (Harris), Heinz 1439, Roma (Asgrow), Marion (Asgrow). The majority of the varieties showed excellent recovery from the injury and in general the plant vigor was only slightly less than those of the check varieties. It was also interesting to note that only three varieties VF 145-21-4 (Asgrow), Grandpak (Asgrow), and Starfire (Stokes) showed a significant yield reduction due to the spray. This was a surprising result but should be treated with caution as these are only one year's results. In general, however, it appears that many tomato varieties have a high ability to recover from moderately severe 2,4-D injury and produce a good tomato crop.

17. Attempts to Find the Changes Necessitated in the Tomato So That it Will Successfully Outdoor Sow Under Cool Conditions

T.O. Graham and Ian McKenzie

University of Guelph, Guelph, Ontario, Canada

Short season areas are being forced to look seriously at the breeding of tomato varieties which are suitable for outdoor direct seeding. It has become apparent that in the success of such a program, two problems must be faced. These are to introduce varieties which will germinate in cool soils and also to locate types with the ability to withstand a reasonable degree of frost while growing outdoors in the seedling stage.

Earliness is a serious consideration in short season areas. Because of this an effort has been made in the report which follows, to allow an estimate between the different types under test as to their speed of germination. This has not progressed to a point where one can state that a correlation exists between earliness and speed of germination.

Brief mention will be made to past work on the ability of the tomato to set fruit during both cool and warm periods. With outdoor seeding in the north, this takes on a new emphasis. Outdoor seeded types flower three weeks later than transplants at Collingwood, which is on the southern shore of the Georgian Bay. If transplants at Collingwood commence to flower on June 15th, the mean temperature at this date is approximately 63?F. However, this would give the outdoor seeded types, which will commence to flower approximately 3 weeks later, a mean temperature of close to 67?F. For the first time short season areas may be presented in their breeding programs with the problem of fruit-set under warmer conditions.

Fortunately for short season areas, there is a degree of evidence supporting the fact that if a tomato plant sets its flowers during cool periods, it may have the ability to set fruit during warm spells as well. This point was illustrated in studies reported by Curme (1) and Schaible (10) in which they found that the Filipino tomato known as Narcarlang had the ability of superior fruit setting at high as well as low temperatures respectively. Filipino #2, which is almost identical to Narcarlang, has been the pivot point of the breeding program at Guelph (3).

The fact that resistance to heat sterility may be associated with resistance to cold sterility has been further strengthened by Young (11) while working at the Tomato Disease Laboratory at Jacksonville, in East Texas. He tested the short-season Canadian varieties at Cold Set, Early Alberta, Early Lethbridge, Earlinorth, and Swift. He found these could set fruit in Eastern Texas in the summer at a time when it is normally too hot for tomato flowers to become fertilized and the plants go into a period which is described as summer dormancy. It has been fairly well proven by others that the Canadian varieties tested by Young are resistant to cold sterility and will set fruit under controlled conditions as low as 45?F. and in some cases as low as 40?F., (1,4,5,7,8).

If the five varieties Cold Set, Early Alberta, Early Lethbridge, Earlinorth and Swift germinate in cool soils, then there is a good case towards stating that the above-ground tolerance of a plant from the fruit setting standpoint to both heat and cold is directly associated with its tolerance to cool soil temperatures at the time of germination. Unfortunately, there is only readily at hand at Guelph, information as to the germination of the Cold Set variety, as well as a closely related type known as High Crimson. In Alberta the varieties Swift, Earlinorth and Cold Set germinate in cold soils. Early Lethbridge has not been adequately tested as yet (9).

At Guelph the testing for fruit set under cool conditions is carried out in a greenhouse which, during the winter, can be kept fairly well at night under temperature control. Very few plants set fruit possessing seed. For example, during the winter of 1963-64, one hundred and four different types were tested at 45?F. Only 12 of these set seed. Under the circumstances, both Cold Set and High Crimson varieties have repeatedly set seed.

The Cold Set variety (5) is a cross between Fireball and Filipino #2. Both these parents are resistant to heat and cold sterility. High Crimson (6,3) traces back to four parents, one of which is Filipino #2. As stated previously, Filipino #2 is almost identical with the Narcarlang tomato type. Information follows as to how well in 1965 the High Crimson variety germinated in a cool soil when compared to 98 other types. In each case, 200 seeds were sown on June 13 in soil filled flats and placed in a growth chamber where the soil temperature was held as far as possible at a constant 48?F. Of the one hundred types tested, only 17 germinated. Mention will not be made to the 83 varieties which did not germinate, or the 13 varieties which had a total of less than five seeds germinate.

Germination in Soil Held at 48?F, 1965.

A summary of the second germination test follows. This test made in 1966 is similar to the one made in 1965, except that in the second test the flats were watered with distilled water to prevent a building up of salts which happened in the first test. This accumulation slowed germination. The soil temperature was 48?F. in 1965 and was lowered to 43?F. in 1966. In the second test the first seedlings emerged in 25 days, but the experiment was allowed to run another 27 days to give a more complete picture than obtained in 1965.

In the table which follows, mention is made to plant import or 'PI' seed received at Guelph from the United States Department of Agriculture. In some of these cases germination is compared as between Geneva, New York and Guelph (2).

Of the 46 types placed under test and sown in cool soil on April 26th, only those which ended up with a total germination of over 20% are listed. There were 28 types with a germination of less than 20%. It will be noted that Cold Set and High Crimson, on the basis of comparison, gave a high percentage of germination when sown in cool soil.

Germination in Soil Held at 43?F, 1965

In 1965 the Cold Set seed used for outdoor sowing germinated 98% from controlled indoor optimum test. This seed was directly seeded outdoors on May 18 at the rate od 15.7 seeds per foot, and at a depth of 1 1/4 inches.

The seed on 1/4 acre germinated in 8 days and experienced 32.5% outdoor germination as against 40% germination when this same seed was sown indoors and kept under control at a soil temperature of 43?F.

In 1966 the Cold Set seed used for field seeding was harvested from the previously mentioned 1965 yield. One-quarter acre was sown direct in 1966. Another quarter acre was directly sown with Ottawa 60 using this variety as a check. Previously Ottawa 60 did not germinate under a controlled soil temperature of 48?F. in 1965, but it experienced 21% germination in 1966 at a soil temperature of 43?F. The Ottawa 60 variety did not germinate in 1966 when sown directly outside.

In 1966 the Cold Set seed used germinated 82% under controlled indoor optimum test. It was directly seeded outdoors on May 3 at the rate of 22 seeds per foot and at a depth of 1 1/2 inches. Germination took place in 3 weeks at 6.6%. The question is did the seed which could not stand up in a cold soil kill out in 1965 and 1966?

In 1965 the outdoor sown Cold Set variety survived frost on May 30, May 31, June 1, June 4, June 13 and June 26. Verbal word has been received from the Experimental Farm at Smithfield, Ontario that there appears to be a difference between varieties as to their resistance to frost when in the seedling stage. It is not known as yet whether such types as Cold Set are more resistant than average.

As long as the breeding program is not too far removed from the Narcarlang type, it is likely that the three forms of resistance, namely to heat sterility, cold sterility, and a lack of germination in cool soils can all be combined. It may be that germination in cool soils can be used as a seedling marker for all three attributes.

Literature Cited:

1. Curme, J.H. 1962. Effect of low night temperature on tomato fruit set. Proc. Plant Sci. Symposium, Campbell Soup Company: 99-108.
2. Dolan, D.D. 1966. Percentage germination of tomato introductions in 5-6 weeks at 10?C plus others characteristics. Paper given in mimeograph form at Tomato Breeders Round Table, Chicago, February 24.
3. Graham, T.O. 1959. NARCARLANG tomato type from the Philippines. Report of the Tomato Breeders Round Table, Chicago, February 24.
4. Graham, T.O. 1961. Adaptability in the tomato of multiple factors to a certain range of climatic conditions. Proc. Canadian soc. Hort. Sci. 2:21-24.
5. Graham, T.O. 1966. Cold and Heat Sterility - New Types which help combat adverse floral set. Report of the Tomato Genetics Co-operative 16:56-28.
6. Graham, T.O. 1966. Crimson Gene Combination- Breeding record at Guelph. Report of Tomato Genetics Co-operative 16:59-62.
7. Kemp, G.A. 1965. Inheritance of fruit set at low temperature in tomatoes. Proc. Amer. Soc. Hort. Sci. 86:565-568.
8. Kemp, G.A. 1966. Fruit set at low night temperatures. Report of the Tomato Genetic Co-operative 16:13.
9. Kemp, G.A. 1966. (Research Station, Lethbridge, Alberta, Canada). Correspondence.
10. Schaible, L.W. 1962. Fruit setting responses to high night temperatures. Proc. Plant Sci. Symposium, Campbell Soup Co: 89-98.
11. Young, P.A. 1963. Two-way varieties for hot or cold climes. Amer. Vegetable Grower. May: 3.

18. Stocks Desired

Okra : Breeding material or varieties for resistance to root-knot nematodes. Le Vern Lorenz, Box 52, Isabella, Oklahoma 73747.

The following is a request from Dr. Attia, FAO Regional Adviser for Vegetable Improvement and Seed Production, for stocks of vegetables much needed in the various new Eastern countries. The seed may be sent to Dr. M.S. Attia, care of Plant Production and Protection Division, Food and Agriculture Organization of the United Nations, Via delle Terme di Caracalla, Rome, Italy.

Tomato: Red, round, large, smooth fruits.

• Early maturing, preferably determinate growth type and good foliage cover to fruits. resistant to root knot nematode and/or Fusarium wilt.
• Suitable for mechanical harvesting, in addition to resistance to the above diseases.
• Resistance to TMV and leaf-roll virus.
• Tolerant to high temperature and have the ability to set fruits under high temperatures.
• Resistance to early blight.

Onion: White flesh, high in dry matter content, able to set bulbs under relatively short day (about 12-12 hrs. ) and relatively cool temperature (20-25 degrees C.).

• Resistance to pink root and smut, good keeping quality, early maturity high uniformity and low degree of splits.

Peas: Resistance to downy and powdery mildew, early maturity, less susceptibility to mineral deficiencies under alkaline soils.

• Late maturity, sweet, not wrinkled, high yields and resistance to powdery mildew.

Melons: Resistance to powdery mildew and TMV. Excellent juicy flesh, large size fruits.

Cucumber: Resistance to powdery and downy mildew, relatively heavy bearing under high temperature. Smooth, spineless fruits which may still be marketed when reaching relatively large sizes.

Chilies : high yielding, high pungency and resistance to Alternaria fruit rot.

Pepper: High yielding and resistance to Alternaria fruit rot.

19. Uncatalogued Vegetable Varieties Available for trial in 1967

This list is aimed at facilitating the exchange of information about potential new varieties, or new varieties which have not yet appeared in catalogues. Persons conducting vegetable variety trials who wish seed of items on this list should request samples from sources indicated.

It is the responsibility of the person sending out seed to specify that it is for trial only, or any other restriction he may want to place on its use.

Crops are listed alphabetically. For each entry the following information is given: Designation, source of trial samples, outstanding characteristics, variety suggested for comparison (not given separately if mentioned in description), status of variety (preliminary trial, advanced trial, to be released, or released), and contributor of information if different from source of trial samples. Where several samples are listed consecutively from one source, the address is given only for the first.

• Bean
  • Bonus. J.C. Hoffman, U.S. Vegetables Breeding Laboratory, P.O. Box 3348, St. Andrews Branch, Charleston, S.C. 29407. Pods are very attractive, being smooth, straight and suitable for whole pack. Plants produce a strong vigorous root system, a characteristic usually associated with good growth and yields. Compare with Tendercrop. Released. Seed available from several seedsmen.
  • Lika Lake. Robert J. Snyder, Dept. of Horticulture, Univ. of Maryland, College Park, Maryland 20742. Bush Blue Lake type. Dark green pod; excellent texture and flavor, smooth, straight pod. This variety was entered in the All-America Selections trials 1966 and came close to being awarded a Bronze medal. It has been evaluated at several canning companies and found to have excellent flavor and quality. To be released in 1968.
• Beet
  • Pacemaker(Hybrid). E.W. Scott, Joseph Harris Co., Moreton Farm, Rochester, New York 14624. Processing beet with hybrid vigor and uniformity. Bred by Dr. Gabelman of Wisconsin. Compare with Ruby Queen. Released.
  • 87 SR (Hybrid). E.W. Scott. Processing and/or market type but with hybrid vigor and uniformity. Monogerm.
• Broccoli
  • F₁ #83883. Robert C. Tang, Dessert Seed Co., P.O. Box 181, E1 Centro, Calif. 92244. Early, extra large central head, very uniform maturity, fine beads, good color, excellent quality. Compare with Prime Hybrid. Advanced trial.
• Cabbage
  • Market Dawn (Hybrid). E.W. Scott, Joseph Harris Co., Moreton Farm, Rochester, New York 14624. First early, uniform market type cabbage. Compare with Golden Acre. To be released.
• Carrot
  • 12H (Hybrid). E.W. Scott, Joseph Harris Co., Moreton Farm, Rochester, New York 14624. Uniform size and shape. Good color for processing. Compare with Royal Chantenay. To be released.
  • ENH (Hybrid). E.W. Scott. Long smooth with good color and quality for market or "slices." Compare with Long Imperator. Advanced trial.
  • EN82 (Hybrid). E.W. Scott. Long Nantes type and better quality , also better color. For market or slicing. Compare with Scarlet Nantes. Advanced trial.
  • F₁ #9517 (Hybrid). Robert C. Tang, Dessert Seed Co., P.O. Box 181, El Centro, California 92244. Long Chantenay type, very smooth, excellent dark orange color; coreless red inside. Sweet, excellent quality. Compare with long Chantenay . Advanced trial.
• Cucumber
  • 916s (Gynoecious hybrid). E.W. Scott, Joseph Harris Co., Moreton Farm, Rochester, New York 14624. Slicer with filed resistance to scab, mosaic and mildew. Heavy early yield. Advanced trial.
  • SC-6 (Gynoecious hybrid). E. Wilbur Scott. Dark green slicer with resistance to downy and powdery mildew, scab and mosaic. Combination suggested by Dr. Barnes. Compare with Gemini. Advanced trial.
• Eggplant
  • F₁ #423 (hybrid). Robert C. Tang, Dessert Seed Co., P.O. Box 181, El Centro, California 92244. Oval-round shape black color fruit. Very prolific, early, good vigor. A hand-pollinated F₁ hybrid. Compare with New Hampshire Hybrid. Advanced trial.
• Lettuce
  • MSU-21 (Leaf). S. Honma, Dept. of Horticulture, Michigan State University, East Lansing, Mich. 48823. 7-10 days earlier than Grand Rapids, slightly darker green than Grand Rapids. Greenhouse type. To be released.
  • MSU-8, MSU-15, MSU-16 (semi-heading). S. Honma. For greenhouse or outside planting, 2 weeks earlier than Bibb in greenhouse. Firmer leaves than May King. Compare with Buttercrunch, Bibb, Boston type. To be released.
• Lima Bean (Phaseolus lunatus)
  • Green Seeded Fordhook Bush Lima Bean. Robert E. Wester, Crops Research Div., ARS, U.S. Dept. of Agriculture, Plant Industry Station, Beltsville, Maryland, 20705. Plants are compact, a few inches shorter and not as bushy as Fordhook 242, 13-16" tall with spread of 18-20". Racemes protrude slightly above foliage and are shorter than Fordhook 242; resistant to downy mildew strain A; first green-seeded Fordhook variety released to the trade; beans slightly smaller than Fordhook 242 and remain in succulent condition in the field 5-8 days longer than Fordhook 242. Released in spring of 1966.
• Southern Peas
  • Ark. 203, Ark. 206, Ark 208. John L. Bowers, Dept. of Horticulture, University of Arkansas, Fayetteville, Ark. 72701. The Ark, 203 and Ark. 206 are bush types; concentrated pod set. Ark. 208 is extremely dwarf type and concentrated pod set. Compare with Princess Anne Blackeye. Each of these lines are members of the Blackeye group and each possesses the easy-shell character and freedom of seed coat split.
• Squash
  • 66-35 (C. moschata). H. M. Munger, Dept. of Plant Breeding, Cornell University , Ithaca, N.Y. 14850. Bush Butternut type (runners 4-3 feet long), good quality, earlier than Butternut but smaller fruit. Preliminary trial.
  • 64-103 (C. Pepo). H.M. Munger. Bush Table Queen type (runners about 4 feet long), large fruit, good quality, uniform shape and size. Compare with Royal Acorn. Advanced trial.
  • F₁ P-10 (hybrid). Robert C. Tang, Dessert Seed Co., P.O. Box 181, El Centro, Calif.92244. Bush scallop type summer squash, early, very prolific, uniform, good vigor, good green color fruit. Compare with Early bush scallop. Advanced trial.
• Sweet Corn
  • Early Golden Giant. W.H. Lachman, Dept. of Plant and Soil Sciences, University of Massachusetts, Amherst, mass. 01002. Early, large ear, good quality. Compare with North Star. Advanced trial.
• Tomato
  • Del. 65S7 - Eugene P. Brasher, Dept. of Horticulture, University of Delaware, Newark, Delaware 18711. Concentrated set ; Fusarium and crack resistant. Compare with Heinz 1350. Advanced trial.
  • Healani. J.C. Gilbert, Dept. of Horticulture, Univ. of Hawaii, 1825 Edmondson Road, Room 137, Honolulu, Hawaii 9682. Multiple disease resistant to Alternaria diseases. Untried in northern areas. Compare with Bounty or Fireball (Physiol. type). To be released.
  • Puunui. J.C. Gilbert. Determinate, resistant to Fusarium, Stemphylium, Rootknot, Spotted Wilt. Smooth, globe fruits, good set under lowland tropical and subtropical conditions. Well adapted to Guam and other Pacific islands in these latitudes. Compare with Bounty, Fireball. To be released.
  • Nematex. A. L. Harrison, Plant Disease Experiment Station, Rt. # 3, Box 307, Yoakum, Texas 7795. Resistant to Fusarium wilt (race 1), root knot, collar rot, gray leaf spot and cracking. Vines similar to Homestead; fruits slightly smaller. Released in 1966.
  • Summertime, A. L. Harrison. Will set fruit under high night temperatures (high 70's). Adapted to Central and South Central Texas. Small erect compact plants. Smooth fruit 1- 11/2 inches diameter, resistant to cracking and blossom-end rot. Compare with Improved Porter. Released.
  • V 6512.E. A. Kerr, Horticultural Research Institute, VINELAND STATION, Ontario, Canada. Verticillium resistant; productive; good appearance and internal quality. Compare with Galaxy. Either V 6512 or a sister line, V 663, to be released.
  • Chico Grande. P.W. Leeper, Texas Agricultural Experiment Station, Weslaco, Texas 78596. Large fruited pear or paste type, for machine harvest; determinate, resistant to Fusarium and Stemphylium. Processing type. Compare with Chico, Roma, Red Top. Released 1966.
  • El Monte. Paul W. Leeper. Determinate; large round fruit; resistant to Fusarium and Stemphylium. Fresh market or processing. Released 1966.
  • La Pinta. Paul W. Leeper. Large fruited pink; determinate, resistant to Fusarium wilt and Stemphylium. Fresh market type. Adapted to vine-ripe harvest. Released 1966.
  • Pope. Joe McFerran, Horticulture Dept., University of Arkansas, Fayetteville, Arkansas 72701. Small fruited (olive shape); wilt resistant developed for pickling. Compare with Yellow Plum. To be released.
  • UNH-11-1-66. L.C. Peirce, Dept. of Plant Science, University of New Hampshire, Durham, N.H. 03824. Large fruit, early, heavy fruit set on medium small vine. Shows some stylar scar. Determinate, uniform ripening, very consistent in performance. Disease susceptibility not determined. Compare with Fireball. Preliminary trial.
  • UNH-5-3-66. L.C. Peirce. Earlier, smaller fruit size than 11-1-66. Shows some stylar scar. Very heavy fruit set consistently; determinate, uniform ripening. Disease susceptibility not determined. Compare with Fireball.
  • 903 - R.W. Robinson, Vegetable Crops, N.Y.S. Agricultural Experiment Station, Geneva, N.Y. 14456. Possible use for mechanical harvesting because of concentrated ripening, little shattering, and high proportion of stem free fruit. Verticillium resistant; compact determinate plant with good foliage cover; midseason maturity; small spherical fruit with shallow stem attachment. Advanced trial.
  • 6419 F-1. Paul Thomas, Peto Seed Company, P.O. Box 138, Saticoy, Calif. 93003. Medium early indeterminate; resistant to verticillium, fusarium, and nematode. Medium large fruit. Compare with Moreton Hybrid or Fantastic Hybrid. Advanced trial.
  • 6426 F-1. Paul Thomas. Medium season vigorous determinate; resistant to verticillium, fusarium wilt, and nematode. Compare with Homestead 24. Advanced trial.
  • 6427 F-1. Paul Thomas. Medium early indeterminate; resistant to verticillium, fusarium wilt, and nematode. Medium large fruit. Compare with Indian River. Advanced trail.
  • 6428 F-1. Paul Thomas. Medium season, indeterminate; resistant to verticillium and fusarium wilt and nematode. Large fruit. Compare with Manalucie. Advanced trial.

• Watermelon
  • Kansas 66-1. Charles V. Hall, Horticulture Dept., Kansas State University, Manhattan, Kansas 66502. Sister line to Crimson Sweet but a long cylinder fruit shape. Resistant to races 1 and 3 Anthracnose and Fusarium wilt. Late maturing with excellent fruit quality. Compare with Garrisonian. Preliminary trial.

The following material was received a couple of weeks after the Feb. 1 deadline:

• Cabbage
  • Pee Wee
  • Little Leaguer
  • Junior
    • C. Walkof, Canada Research Station, Morden, Manitoba, Canada. All three varieties are dwarf comparable in size to baseballs or softballs. Pee Wee 1/2 lb. per head, Little Leaguer 1 lb., and Junior 1 1/2 to 2 lbs. The 3 dwarf varieties provide a range of head sizes which will help to limit wastage of food as often occurs when a large conventional-sized cabbage is used in part and the remainder deteriorates before it is used again. Also, the dwarf type heads can be cooked and served whole thereby retaining the aromatic flavors which may be lost when cut cabbage is cooked. Compare with Golden Acre No. 84. To be released.
• Carrot
  • 66-651. C.E. Peterson, 101 Horticulture Bldg., Michigan State University, East Lansing, Mich. 48823. Long, smooth, good interior color. Uniform-tapered, package type. Compare with Gold Pak. Advanced trial.
• Cucumber
  • MSU 527. C.E. Peterson. Resistant to CMV and scab. Vigorous, early, F₁ gynoecious. Compare with Triumph. To be released.
• Tomato
  • VR Gardener. H.M. Hunger, Plant Breeding Department, Cornell University, Ithaca, N.Y. 14850. A composite of seven F₄ progenies homozygous for Verticillium wilt derived from 7 backcrosses to Gardener. Comparable to regular Gardener in earliness, flavor, freedom from blotchy ripening, and softness of flesh. Fruit may be slightly larger. Not officially named; release under consideration.