Spacing Affects Yield, Size of Carrots

Transcription

1 RY $,,olurne XVII Oregon State University, July 1968 Number 3 - COLLECTION OWEGON QI Spacing Affects Yield, Size of Carrots No Vegeirable Crops Field Day This Year There will not be a general field day on the Vegetable Research Farm this year. However, those who wish to observe any particular research are welcome to visit the farm at any time. If the visitor's interest is in a specific research area, it is usually best to call in advance. The following personnel are those primarily involved. W. A. FrazierSnap bean, carrot, and onion breeding (Ph ). J. R. BaggettPea, broccoli, and cabbage breeding (Ph ). H. J. MackPhysiology and culture of various vegetable crops (Ph ). CrabtreeWeed control (Ph ). H. CrowellVegetable insect control (Ph ). Peas and beans are usually best to observe in late July to mid-august, while cole crops and carrots may be viewed in September and October. T7cT44ae,.. Spacing Affects Yield, Size of Carrots 1 No Vegetable Crops Field Day 1 Processors to Evaluate OSU 58 Bush Bean 4 OSU Bush Bean Lines Resist Yellow Mosaic Virus, Halo Blight 5 Higher yields and larger percentages of small roots of carrots were obtained when row spacings were reduced from 24 to 6 inches in tests at Corvallis during 1966 and In 1966 two fertilizer rates, and pounds N-P205-K20 per acre, were used in main plots replicated three times. Fertilizer was broadcast and disked in before planting. Row spacings of 24, 18, 12, and 6 inches were included at each fertility level. Red Cored Chanteflay carrots were planted May 19 and harvested October 3-7. Only one fertilizer rate was used in pounds N-P205-K2O per acre plowed down plus pounds N-P205-K20 per acre broadcast and disked in before planting. At each of the four row spacings (24, 18, 12, and 6 inches) three seeding rates were obtained by using Planet, Jr. plate holes 6, 9, and 12. Red Cored Chantenay carrots were planted May 25 and harvested September Carrots were harvested and topped by hand and yields and size distribution obtained. One or two center rows, 10 to 15 feet long, from each plot were used to minimize border effects. Yield of carrot roots was about 33% higher in 6-inch rows than in 24-inch rows in 1966 (Table 1). Yields at 6- and 12-inch row spacings were significantly higher than at 24 inches. Percentages of roots that were 1 to 1- inches in diameter averaged 12, 17, 23, and 42 for the 24, 18, 12, and 6 inch row spacings, respectively. Percentage of roots over 2 inches in diameter was highest at the 24-inch spacing. Number of roots per foot of row at harvest was lowest at the 6-inch spacings and highest at the 24-inch spacings although the seeding rate per linear foot of row was the same. (Continued next page)

2 Spacing of Carrots Table 1. Effects of fertilizer rates and row spacings on yield and sizes of carrots Fertilizer rate (N-P205-K20) Row spacing Roots/ft. (At harvest) Yield Size distribution of roots 1" 1-1k" lj-2" 2-2k" +2k" Lbs/A Inches No. T/A % % % % % Means: Fertilizer rates Row spacings 24" " " " Yield from the pounds N-P205-K20 fertilizer rate was slightly higher than at the fertilizer rate, although the difference was not significant. Yield in 1967 (Table 2) was increased 22% as row spacings were decreased from 24 to 6 inches. Yields tended to be lower at the heaviest seeding rate within each of the row spacings; however, this effect was not marked. Highest percentages of small roots were produced at the narrow row spacings and at the heaviest seeding rates (Table 2). Percentage of roots 1 to 1 inches in diameter at the 24, 18, 12, and 6 inch row spacings (three seeding rates averaged) were 29, 31, 37, and 48. Number of roots per foot of row at harvest was influenced markedly by row spacings and seeding rates, with highest numbers being obtained at the heaviest seeding rate (C) and widest row spacing (24 inches). The results indicate that decreasing the row spacing and/or increasing the seeding rate are a means of producing a higher percentage of small, high-value carrots. Efficiency and economics of processor utilization of various size grades would need to be considered if reduced row spacings and increased seeding rates were to be used to control size of carrot roots Further study needs to be done on effects of row spacings and seeding rates on competitive efficiency of other varieties, especially the new F1 hybrids, and the influence on yields, size, shape, length, and quality of carrots. Adequate weed control, fertilizer, and irrigation also would be essential. Machinery for precision seeding and for mechanical harvesting of carrots in narrow rows would seem to be one of the most limiting factors at present. H. J. MACK Department of Horticulture (Continued next page) Oregon Vegetable Digest is published four times a year by the Agricultural Experiment Station, Oregon State University, Corvallis, G. Burton Wood, Director. Address correspondence to the author concerned or to the Department of Horticulture. Material may he reprinted j)rovidiflg no endorsement of a commercial product is stated or implied. Please credit Oregon State University. To simplify technical terminology, trade names, of Products or equipment sometimes will be used. No endorsement of products named is intended nor is criticism implied of products not mentioned.

3 Spacing of Carrots... Table 2. Effects of seeding rates and row spacings on yield and sizes of catrots Roots/ft. Row spacing Seeding rate* (At harvest) Yield * A, B, C-Planet, Jr. hole numbers 6, 9. and 12 respectively. AAA Size distribution of roots -1" 1-1k" 1+-2" 2-2+" +2+" Inches No. T/A % % % % % 24 A B C A B C A B C A B C Means: Seeding rates A B C , Row spacings 24" " " " K. P. Buchholtz and R. E. Doersch reported in Weed Science (Vol. 16, 1968) that corn plots receiving broadcast spray applications of triazine herbicides without cultivation yielded as much as plots receiving the standard two cultivations for weed control. One cultivation resulted in an average 6% increase in yield on herbicidetreated plots. This yield increase probably was due to improved weed control. In some experiments, increases in corn yield due to improved weed control by cultivation on plots treated with herbicides were less than expected increases based on weed growth reductions. This disparity may have been due to injury to the corn by cultivation. R. E. Wester reported in Amer. Soc. Hort. Sci. (Vol. 91) that exposure of pods to daylight was necessary for chlorophyll development in mature beans of the 'Thaxter' bush lima. When daylight was prevented from reaching the beans by covering 4 to 6-day-old pods with soil or aluminum foil, the beans which grew to maturity in complete darkness were completely white. This was the first report that daylight was necessary for the development of green color in lima bean seed. Bitumen-impregnated black fiber pots were found to retard the gro Lii of tomato seedlings Maas and Adamson reported in Amer Soc Hort Sci (Vol 91) that the use of vermiculite in place of peat in the potting mix and the supplemental use of calcium nitrate increased growth sufficiently to compensate for the toxic effects, but did not eliminate them. Black fiber pots are less expensive than peat pots.

4 Processors to Evaluate OSU 58 Bush Bean Processors of snap beans in the Willamette Valley will have the opportunity this summer to evaluate OSU bush green pod bean line 58. Pilot plantings of 1 to 10 acres will be made by growers for most processing companies in the area. The OSU 58 selection oiiginated from bulk (massed) progeny of complex crosses of several bean lines, predominantly derived from crossing to Blue Lake pole. It represents a major step in combining better growth habit with many of the pod qualities of Blue Lake pole beans, especially taste, color, and tenderness. It is the only selection (involving approximately 18 years of breeding effort, and observation of several million bean plants in segregating populations) which possesses those particular characteristics. The original plant selection was made in the summer of 1965; small single plots were observed in 1966; many single plant selections were made in these plots. The single plant selections provided sub-lines for observation in greenhouse and field in the early spring and summer of Seeds of the best sub-lines were massed and sent to New Zealand for winter increases Four hundred pounds of seed was increased to approximately 6,000 pounds there, and it is this seed which is being used for pilot plantings by processors. An approximately similar increase is being made in the U. S. this summer (1968). A conditional preliminary release of OSU 58 has been made for observation and breeding purposes; the line is so new that no formal release and no authorization of seed increase is deemed advisable until the 1968 field trial results have been evaluated. Additional notes on 58 follow: Quality: The 58 pod, when processed, can be considered as a close approximation to the Blue Lake pole pod. Taste, color, and texture were given satisfactory scores in panel tests by most individuals. It may tend to slough more than Blue Lake. The 58 quality appears especially promising in large sieve sizes-6 on through 7 sieve; color remains distinctly above average and, under good culture, seed sizes are not excessive. Seeds are larger than those of Blue Lake. There is moderate irregularity (seed skips) of pod in 58; young pods are slightly rough in appearance; older pods (larger sieves) are above average in smoothness and tend to curve. Sieve sizes: The line, inherently fleshy, develops into large sieve sizes very rapidly. If left in the field to secure heavy yields, sieve sizes would be well beyond the generally desired range of 50% sieve 4 and under. A preliminary small plot test, at spacings of 6 inches on the square, indicated that the line may be capable of producing heavier yields of relatively smaller sieve sizes at this spaing than at conventional spacings in which rows are 36 to 38 inches apart. Pod set and maturity: Repeat plantings of 58 were made throughout the summer of 1967 to observe set of pods and growth habit. The line set well throughout the summer. In general, the line was three to six days earlier than Gallatin 50. Growth habit: Growth habit of 58 is considerably better than the earlier-released OSU lines 949 and 2065, but not as desirable as Gallatin 50. It could therefore be classed as an intermediate growth habit type. The line also appears less sensitive to day-length changes and to. high temperatures than 949 and Mutants: Several mutants, for large and small, flats or ovals, characteristic of Blue Lake, have already been noted in 58. The early evidence is, therefore, that this tendency has been inherited from Blue Lake. Yield: Small plot tests have shown yields of 2 to 10 tons per acre, at 38-inch row spacings and plants 3 to 10 inches in the row. Spacings in the row were generally wide in order to secure maximum seed increases from the limited seed available in the spring of At the low yield, sieve sizes were small; at the heavy yield, sieve sizes were distinctly large. It appears that, at current commonly used spacings and good culture, the variety should yield 4 to 6 tons per acre, with sieve sizes tending to be large. More data are needed on yield potential, and pilot tests on farms are, of course, the final answer. Mechanical harvest: Only about 50 feet of a row was harvested in 1967with a Borge harvester. This extremely limited observation indicated satisfactory mechanical harvest potential, but limitations of such a test must be recognized. Further tests: It is cautioned' that OSU 58 still must undergo further critical testing at our research farm, in the Food Tech, laboratory, on the farms, and in the processing plants. The line has been increased very rapidly. Potential: It is of distinct interest because it combines, for the first time, a moderately good growth habit with close approach to the Blue Lake pod. These new combinations are not only of possible immediate value commercially, but form a valuable base for further improvement in the round-pod bush green bean. Crosses with many other bean varieties and lines were made in 1966 and A few F4 lines are being grown in the greenhouse and large numbers of F2 and F3 progeny are being grown on the Vegetable Crops Research Farm in Major objectives for further improvement of the line are a slimmer pod, less tendency for seed skips, straightness, and disease resistance. Disease resistance: OSI'J 58 is relatively resistant to rust strain 33, prevalent in the Willamette Valley, when compared to 949, 2065, FM-i, and FM-1K, but

5 OSU Bush Bean Lines Resist Yellow Mosaic Virus, Halo Blight For the past two growing seasons (1966, 1967) OSU bush bean lines 189 and 190 have shown high resistance in the field to natural infection by yellow mosaic virus (bean virus 2). These lines are of special interest because they combine resistance to this virus with pod qualities closely approaching Blue Lake pole; they are deep green in color, low in fibre, and approach Blue Lake in taste and pod refinement. They are relatively small diameter types when compared, for example, to OSU 58, discussed elsewhere in this issue of Oregon Vegetable Digest. They do not, however, have as desirable growth habit as 58. Low infection of these two lines, when compared to 949, Rogers 206 (Tempo), Salem, and Gallatin 50 is shown in Table 1. Puregold Wax also had very high resistance in this disease-plot area on the Vegetable Research Farm, where beans are planted adjacent to rows of gladiolus, host plant for the virus. The high resistance oi this line has been noted in previous years. OSU 189 and 190 also possess some tolerance to mixed-race inoculation with the halo blight bacterium. The resistance is of the tolerant type characteristic of pole Blue Lake, one of the parents. The two lines are being tested in small single-row plots by a few processors. Extent of increase for possible pilot trial will depend upon evaluation of the lines this summer. The disease resistance and to some extent small pod diameter are assets, but plant habit might limit their usefulness. Plants and leaves in the two lines are smaller than is characteristic of OSU 949, released a few years ago. They also tend to be more productive. Many crosses have been made between OSU 58 and these two lines with the hope of combining desirable A AA characters of the parents into a single line. The 189 and 190 have also been crossed with pole bean lines resistant to yellow mosaic virus to decrease fibre in these pole types. W. A. FnizIER and.j. R. BAGGETT Department of Horticulture - GEORGE VARSEVELD Department of Food Science and Technology Table 1. Percent of yellow mosaic virus infection, bush beans, field, Corvallis, 1967' Variety Total plants No. hifected Infection2 Gallatin (b) OSU (c) Rog (c) Salem (c) OSU (c) Puregold Wax (a) OSU 189 4, (a) OSU 190 2, (a) Data from nine randomly replicated plots of each variety or breeding line. 2 (a) significantly higher level of resistance than (b) and (c), at.01 level; (b) lower level of resistance than (a) but significantly higher level than (c) at.01 level; (c) high susceptibility, compared to (a) and (b). lines involving Blue Lake germ plasm. Resistant lines 189 and 190 considered near Blue Lake in pod quality, with growth habits intermediate between 949 and 58. OSU 58 Bush Bean not as resistant as Gallatin 50 and many other bush beans. It is rather similar to most bush beans in susceptibility to root rot, halo blight, and white mold. Extensive greenhouse tests are under way to determine resistance or susceptibility to common mosaic virus. Some sub-lines are susceptible; it now appears that others may be resistant. If so, the seed stocks now available would show both resistant and susceptible plants. These tests will be continued, since resistance to this organism is highly desirable. Many of the ciosses involving OSU 58 have been made to lines possessing resistance to common mosaic and/or halo blight. Systematic testing is under way, along with backcrossing, to insure resistance to common mosaic and tolerance to halo blight. We believe that a major bottleneck in improvement of the bush beanthe combination of habit with Blue Lake taste, color, and tendernesshas been broken; although the 58 line, itself, may not be ideal, it should open the way for more rapid advances in bush green bean improvement. W. A. FRAZIER, J. R. BAGGETT, H. J. MACK, A. A. DUNCAN Department of Horticulture - GEORGE VARSEVELD Department of Food Science and Technology E. K. VAUGHAN Department of Botany and Plant Pathology R. BULLOCK North Willamette Experiment Station J. B. RODGERS, D. BOOSTER.Department of Agricultural Engineering