Vegetable Research at the North Willamette Agricultural Experiment Station, 1978

On-line version of Oregon Agricultural Experiment Station Special Report 541, 1979

CONTENTS

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AUTHOR:

Dr. Delbert D. Hemphill, Jr., Assistant Professor of Horticulture, has conducted research on vegetable crops culture and management since 1976 at Oregon State University's North Willamette Experiment Station, 15210 NE Miley Rd., Aurora, OR 97002-9543.

Primary emphasis is placed on the research needs of Portland-area fresh market vegetable growers, but research also continues on home garden vegetable culture, processing crops, and the safe and efficacious use of urban area organic wastes on agricultural land. Many of these research projects involve cooperation with agricultural scientists at Oregon State University in Corvallis, with scientists in western Washington, and vegetable growers in the Willamette Valley. Without these cooperators, much of the research reported here could not have been completed.

The first five sections of this report deal with trials which may help the market gardener or homeowner to choose those varieties most suitable for the Northern Willamette Valley. A few such trials are carried out each year; standard varieties known to perform acceptably are compared to new releases from seed companies and university breeding programs.

The next four sections deal with research on cultural or fertility practices with a goal of improved production of vegetable varieties already grown in the area.

The last two sections deal with more basic research on the effects of sublethal doses of herbicide on vegetable yield and quality and the suita­bility of sewage sludges and tannery wastes as vegetable fertilizers.

Summaries of findings from several of these projects are also scheduled for publication in the Oregon Vegetable Digest this year.

DISCLAIMER: The use of trade names does not constitute an endorsement by the Oregon State University Agricultural Experiment Station. Always check pesticide labels for currently registered uses.

In 1971, the North Willamette Agricultural Experiment Station obtained several selections from the forcing rhubarb varieties Victoria and German Wine from Washington State University as well as the variety Crimson and several breeding lines from Oregon State University, Corvallis, for a total of 24 lines. All lines were propagated by crown division and five plants of each maintained until 1977. Based on previous observation at WSU and OSU and field observations of vigor and quality at the North Willamette Station, 18 lines were selected in January 1978 for further observation. The lines OSU 12, 21, 22, 23, 34, and 183 were discarded at that time. Three crowns of each of the 18 lines were removed to a hot house for forcing and the remaining two crowns left in the field for propagation.

Methods

All crowns for forcing were dug on January 18, 1978, and washed with high pressure water. The crowns were then moved to a greenhouse bench and held at about 55°F for forcing. The entire forcing area was covered with black plastic drapes to exclude sunlight. Each crown was sprayed with two ounces of 250 parts/million gibberellic acid. Crowns were watered daily and 1 percent Captan was applied during the second week of harvest to control diseases. The crowns were harvested approximately every fifth day starting on February 8, 1978.

Results

The lines GWR1, GWP4, OSU 19, and OSU 216 rapidly proved to be inferior to the other lines and were discarded. The remaining two crowns of the other 14 lines were divided into three starts each and were replanted on February 15. The earliest lines to produce marketable spears were Victoria Bl, Victoria B8, Victoria H 10, Victoria I4, and Victoria A5, each with more than 15 percent of the spears harvested by February 13.

The highest total yields were obtained with Victoria A5, VI4, VH10, VC6, VB1, and VB8 in descending order (Table 1). The lines with the largest mean spear weight were German Wine Sasaki (N3), GWR1, Crimson, GWP4, Victoria H10, and GWP3. Best color was obtained with Crimson, OSU 358, and Victoria B8. Considering the combination of spear size, yield potential, and quality, the best lines were Victoria H10, Victoria B8, Victoria B1, Victoria A5, Victoria C6, and Crimson.

Table 1. Cumulative Rhubarb Forcing Yields - 1978                             
Variety or line    Marketable      Rank     Yield     Rank   Color   EarlinessZ
                  spears/crown             lb/crown                           
Crimson                92           9(tie)   9.0        7    excellent	ML
German Wine P3         72	   12	     6.6       12    poor-fair	ML
"        "  P4         46	   16	     4.2       15    poor-fair	L
"        "  R1         34          17        3.4       16    poor-fair  ML
"        "  T2         92           9(tie)   7.6       10    fair       ME
"        "  Sasaki(N3) 62          14        6.2       13    fair       L  
0SU 19                 28	   18	     2.0       18    poor-fair	L
OSU 216                48	   15	     3.0       17    poor-fair	L
"   358                82	   11	     6.8       11    good	ML
Victoria A5           158	    1	    12.2        2    fair	E
"        B1           124           5(tie)  11.0        4    fair       E
"        B8           124           5(tie)  11.2        3    fair-good  E
"        C6           128           4       10.8        5    fair       ME
"        E2           104           7        8.6        8    fair       ME
"        E10           96           8        8.0        9    fair       ME
"        Ell           68          13        5.6       14    poor-fair  ME
"        H10          136           3       12.6        1    fair       E
"        I4           150           2       10.6        6    poor-fair  E     
ZE, early; ME, mid-early; ML, mid-late; L, late.

Methods

The seedbed was rototilled in early July, and 1 ton/acre dolomite, 1,000 pounds/acre of 10-20-10, and 1 pound/acre of boron were broadcast and incorporated. Trifluralin at 0.75 pounds/acre and dyfonate at 2.0 pounds/ acre were incorporated into the top three inches of soil. No other weed or insect control measures were needed except for one shallow cultivation in October and application of 0.5 pounds/acre of diazinon on February 2, 1978. Seedlings were thinned to about 12 inches within-row spacing on September 1. Between-row spacing was 42 inches. Irrigation by overhead sprinkler was used as needed through September. An additional 225 pounds/acre of ammonium nitrate was applied on February 2, 1978. First harvest of overwinter types was on March 16, 1978. Snow Crown and the Moran lines headed in November and December and no yield data were taken.

Results

Table 2. Yield of overwinter cauliflower varieties, spring 1978            
Cultivar         Total yield  EstimatedY    Head size   MeanZ   Harvest span
                   lb/plot    tons/acre      lb/head    grade              
Armado April        41.5         10.8           1.9      1.3    3/22 - 4/05 
Armado May          35.0          9.1           1.1      1.5    3/31 - 4/12 
Armado Quick        46.0         11.9           2.2      1.05   3/16 - 3/31 
Armado Tardo        34.0          8.8           1.4      1.4    3/31 - 4/17 
June                19.9          5.2           1.0      2.1    4/17 - 5/08 
Markanta Walcherin  36.9          9.6           1.3      1.6    3/31 - 4/12 
Pinnacle            28.0          7.3           1.1      1.7    4/12 - 5/08
ZGrade 1 = 1.0 pound minimum (4.5 inch diameter), tight, free of defects. 
 Grade 2 = less than 1 pound or overmature, ricey, discolored, etc. 
 Grade 3 = combination of small size and severe defects.
YYield/acre estimated by scaling up results from these 84 square foot plots.

Armado April and Armado Quick were of highest overall quality with excellent head size, color, firmness, and flavor. However, texture after freezing is somewhat poorer than most fall-harvested varieties, with a tendency toward mushiness (easy to overcook).

April and Quick also had the least variability in head size with about 80 percent of heads falling within 25 percent of the mean. All other varieties produced smaller (average) center heads and one to several small side heads, greatly resembling sprouting broccoli in this respect. Part of the high quality rating of April and Quick may be due to their early harvest, prior to onset of warmer weather and insect and disease problems.

All varieties were adequately self-blanching, particularly the Markanta Walcherin. The plants survived temperatures to 21°F and one severe ice storm in which a half-inch layer of ice broke off the oldest leaves. Quality of June was totally unacceptable because of a tendency to riciness and formation of leaves in the heads.

Methods

The cultivars evaluated included Presto, Dragon Eye, Express Yellow, Imai, Kaizuku Extra, Keep Well, Senshyu Yellow Globe, Hatif de Paris, Hatif de.Vaugirard, Printanier Parisien, Mulhouse de Selestat, Mulhouse Auxonne, Paille des Vertes, and Advance. Seed sources were Moran Seed Co. (Advance), Vilmorin (French lines), and Takii (all others). Plots were seeded on August 1, August 20, and September 20. There were four replications of each treatment (variety) at each planting date. Plots were a 10-foot section of a single row. Initial fertilizer application consisted of 1,700 pounds/acre of 10-20-10 incorporated into the seedbed along with 4 pounds/acre of diazinon. Dacthal at a rate of 9 pounds/acre was applied and irrigated in immediately after planting. An additional 300 pounds/acre of ammonium nitrate was applied on January 27 and again on March 8. All plots were harvested on June 30.

Results

Although there was considerable variability in rate and percent of emergence of the various lines, an acceptable initial stand was obtained in every case. However, the third planting was killed during the winter. Apparently the plants had not achieved sufficient size to overwinter success­fully. Both the first and second plantings overwintered successfully but there were considerable losses and damage from diseases and apparent fertilizer burn. Consequently, the yield data obtained did not include four reps for each variety and were not subjected to statistical analysis. Unlike the 1976-77 experiments, all varieties experienced a significant degree of seed-head formation in the spring. On April 21, Express Yellow, Kaizuku Extra Early, and Advance had the highest percentage (>30) of bolters while Mulhouse Auxonne and Senshyu Yellow Globe had the smallest percentage (<10).

Yield data for the best replicate for each variety in the first planting are shown in Table 3. Data for the second planting are in Table 4. The varieties Presto, Advance, and Senshyu Yellow Globe were the highest yield­ers at both planting dates. Yield was much smaller at the second planting date except for the varieties Hatif de Paris and Keep Well. Largest bulb size was obtained with the varieties Senshyu Yellow Globe, Presto, Keep Well, and Express Yellow, but very acceptable size and quality were obtained with several other varieties. Bulb size was much smaller at the second planting except for Hatif de Paris and Presto. All varieties had tops down at harvest except for those noted in Table 3 as having unusually large necks. Planting date did not greatly affect degree of bolting. The earlier planting data gave superior yields, at least for this season.

Table 3. Yield per plot and mean bulb weight of overwintered onions, first
         planting (8/1)                                                            
Variety                Yield       Rank    Mean bulb    Rank    Comments
                     lb/20 feet            size, lb                                
Advance                50.6          2        0.55       6      Med. large,
                                                                yellow,globe
Dragon Eye             46.3          3(tie)   0.58       4(tie) Med. large,
                                                                yellow,squat
Express Yellow         23.2         10        0.58       4(tie) Med. large, yellow,
                                                                squat to globe
Hatif de Paris         22.8         11        0.34      11      Med., very 
                                                                white, squat
Hatif de Vaugirard     30.3          9        0.47       7(tie) Med. large,
                                                                green-white, squat
Imai                   16.1         13        0.67       3      Large,yellow, squat
Kaizuku Extra Early    31.8          8        0.47       9      Med. large, yellow,
                                                                squat to globe
Keep Well              14.3         14        0.89       1      Very large,
                                                                yellow, globe
Mulhouse de Auxonne    39.6          5        0.27      14      Small bulb, large
                                                                neck, yellow globe
Mulhouse de Selestat   35.2          6        0.42      10      Small bulb, large 
                                                                neck, yellow globe
Paille des Vertes      20.8         12        0.33      12      Small bulb, large
                                                                neck, yellow globe
Presto                 62.6          1        0.47       7(tie) Med. large, yellow
                                                                squat
Printanier Parisien    34.6          7        0.27      13      Small, white, squat
Senshyu Yellow Globe   46.3          3(tie)   0.68       2      Large,yellow,
                                                                squat to globe     


Table 4. Yield per plot and mean bulb weight of overwintered onions, 
second planting (August 20)                                           
Variety                     Yield       Rank      Mean bulb    Rank
                          lb/20 feet              size, lb            
Advance                     34.0          2         0.28       6 (tie)
Dragon Eye                  14.6          8         0.28       6 (tie)
Express Yellow              16.1          6         0.40       3
Hatif de Paris              21.6          4         0.32       5
Hatif de Vaugirard          15.6          7         0.20      11 (tie)
Imai                        10.0         10         0.28       6 (tie)
Kaizuku Extra Early          4.4         14         0.22      10
Keep Well                   19.4          5         0.37       4
Mulhouse de Auxonne          6.1         12         0.14      13
Mulhouse de Selestat         7.6         11         0.24       9
Paille des Vertes            5.5         13         0.12      14
Presto                      41.0          1         0.46       1
Printanier Parisien         12.1          9         0.20      11 (tie)
Senshyu Yellow Globe        26.4          3         0.41       2      

Methods

All varieties were seeded in a heated greenhouse on March 20 and trans­planted to the field on June 1. Plants were grown on 40-inch raised beds covered with black plastic mulch. Fertilizer consisted of 1,000 pounds/acre of 10-20-10 and 1,000 pounds/acre of dolomite incorporated into the sandy loam soil before bed shaping. Plants received one cup of 1 ounce/gallon 10-30-20 at transplant and 1 cup of 2 ounce/gallon calcium nitrate on June 30. Drip irrigation was provided by Viaflo tubing. No pesticides were used. All plants were tied to stakes but were not pruned. Plant spacing was 18 inches between plants and 40 inches between rows or about 8700 plants/ acre. Each variety was replicated four times with three plants per replicate. Fruit was harvested weekly from mid-July until first frost in late October except that the chile peppers and four bell types were not harvested until fully red-ripe.

Results

Data on total yield, mean fruit weight, and earliness are reported in Table 5. Only the top 10 varieties in each class are reported for the sweet peppers picked green. Highest yielding sweet peppers were Canape, Calwonder, Miss Belle, New Ace, Early Niagara Giant, and Pip. Varieties producing the largest fruit were Pip, Yolo Wonder L, Atlas, Keystone Resistant Giant, Calwonder, Bell Boy, Miss Belle, and Early Canada Bell. Highest overall fruit quality was achieved with Atlas, Bell Boy, Calwonder, Keystone Giant, Miss Belle, Yolo Wonder L, and Pip. Considering the combination of yield, fruit size, earliness and fruit quality, the outstanding varieties were Pip, Calwonder, Miss Belle, and Bell Boy.

Among the early ripening bell-type sweet peppers, Midway was the highest yielder but did not ripen until October. Shepherd was the best yielder of the remaining varieties and ripened half its fruit in September. All four varieties successfully ripened most fruit before first killing frost, but October was unusually warm and dry and Midway might not ripen any fruit in a normal autumn.

Among the moderately hot Anaheim or California green chile types, none of the New Mexico lines exceeded the standard Anaheim in overall yield or quality. These varieties were picked ripe but Anaheims are often used green for chiles rellenos or canning, and all varieties produced acceptable yields of green fruit by mid-August. The hot variety Jalapeno produced a good yield of green chiles but was slow to ripen and very susceptible to sunburn. The very hot Serrano is a low yielder but very attractive as an ornamental.

No variety exhibited serious disease or insect problems and physiological and nutritional disorders were absent. Comments and seed sources are listed in Table 6.

Table 5. Yield of Pepper Varieties, North Willamette Station, 1978                   
Variety             Yield     Variety         Mean fruit   Variety        % harvested
                  tons/acre                   weight (lb)                   by 8/02
A. Sweet types picked green
Canape              29.0      Pip                .28       Early Calwonder    18 
Calwonder           28.2      Yolo Wonder L      .26       Miss Belle         14 
Miss Belle          27.9      Atlas              .25       New Ace            14 
New Ace             27.7      Keystone Giant     .25       Ace                12 
Early Niagara Giant 27.1      Calwonder          .24       Bell Boy           10 
Pip                 26.6      Bell Boy           .24       Yellow Sweet Long  10 
Early Canada Bell   26.1      Miss Belle         .24       Early Canada Bell   9 
Bell Boy            24.8      Early Canada Bell  .24       Staddon's Select    9 
Staddon's Select    24.2      Early Calwonder    .23       Canape              8 
Burpee's Fordhook   24.0      Staddon's Select   .23       Pip                 7
------------------------------­------------------------------­--------------------
B. Sweet types,picked ripe                                 % ripe by 9/30 
Midway              18.3      Midway             .29       Stokes Early       74 
Shepherd            17.1      Shepherd           .23       Earliest Red Sweet 60 
Stokes Early        14.6      Stokes Early       .22       Shepherd           47 
Earliest Red Sweet  13.0      Earliest Red Sweet .21	     Midway 	       0 
---------------------------------------­-----------------------------------------
C.Anaheim types,picked ripe
Anaheim             15.5      Big Jim            .18       Big Jim            38 
New Mexico 6        13.2      Anaheim            .17       Anaheim            32 
Sandia              11.5      New Mexico 6       .14       New Mexico 6       23 
Big Jim             9.0       Rio Grande         .12       Sandia             23
Rio Grande          8.1       Sandia             .11       Rio Grande         17     
LSD (.05) Yield = 2.0 tons/acre; LSD (.05) fruit weight = 0.03 pounds.


Table 6. Comments and Seed Sources                                           
Variety           Source      Comments 
A. Sweet types picked green
Ace                 6         Very compact plant; small fruit, elongated 3 or
                              4-lobe bell, thin wall
Atlas               1         Low vigor, late seedlings; compact; large 
                              fruit, 3 or 4-lobe long smooth, thick wall
Bell Boy            7         Low vigor, late seedlings; compact; med. fruit,
                              fair yielder, thick wall
Burpee's Fordhook   2         Tall, open, spindly plant; long, small, smooth
                              fruit, thick wall
Calwonder           5         Med. size plant; large fruit, 4-lobed bell,
                              thick wall
Canape              5         Med. size plant; good yielder but small fruit;
                              tapered, 3-lobe, thick wall
Early Calwonder     4         Compact; early; med. size fruit, 3 or 4-lobe
                              smooth, thick wall
Early Canada Bell   6         Med. plant; 3-lobe blocky, thick wall
Early Niagara Giant 6         Large plant, high yield of med. size fruit,
                              thick wall, 3-lobe blocky
Keystone Giant      5         Large plant; low yield of large, 3 or 4-lobe,
                              thick walled blocky fruit
Miss Belle          4         Very compact; early; good yielder of large 
                              fruit, blocky, thick wall
New Ace             2         Compact, early; good yielder of small fruit, 3
                              or 4-lobe taper, thin wall
Pip                 1         Very vigorous, early seedlings; compact; large
                              fruit, 4-lobed, thick wall, early
Staddon's Select    6         Med. plant; slightly tapered 3 or 4-lobe fruit,
                              thick wall
Yolo Wonder L       5         Med. plant; low yield; large 3 or 4-lobed
                              blocky, thick wall
-----------------------------------------------------------------------------
­B. Sweet types picked red
Earliest Red Sweet 6          Very vigorous, early seedlings; med. plant; 
                              early; small, thin-walled fruit
Midway             6          Very vigorous, early seedlings; med. plant; 
                              thick walled, large blocky fruit; late
Shepherd           6          Med. plant; highly tapered, conical, thick
                              walled fruit
Stokes-Early       6          Compact; elongated -3 or 4lobed-bell, thick wall
----------------------------------------------------------------------------- 
C. Anaheim types
Anaheim            4          Tall, spindly plant; good yield and size, early;
                              7-10 inches long x 1-1/2 inches at shoulder 
Big Jim            3          Very vigorous and early seedlings; med. plant,
                              spreading; early, 8-10 inches tapered fruit 
New Mexico 6       3          Very vigorous, early seedlings; tall plant,
                              good yield, smaller fruit, 6-9 inches long
Rio Grande         3          Tall plant; poor yield of small fruit 
Sandia             3          Tall plant, spindly; fair yield of small fruit   
Seed Sources: 1. Asgrow Seed Co., 2. W. Atlee Burpee Co., 3. Department of 
              Horticulture, New Mexico State University, Las Cruces, N. M.
              4. Ferry Morse Seed Co., 5. Harris Seed Co., 6. Stokes Seeds Inc.
              7. Otis Twilley Seed Co.

Fully satisfactory varieties have not been available to Oregon growers. It would be helpful for both fresh market and processors to have a high quality summer crop. The possibility exists for double cropping, particu­larly if combined with overwintered cauliflower.

The research involved comparing common autumn-harvest varieties with several experimental lines for August harvest.

Methods

Eleven varieties or lines of cauliflower were seeded in Jiffy-pots containing a peat-vermiculite soil mix on May 18 and placed in a screen­house. Seedlings were transplanted to the field on June 19. Land prepara­tion included broadcast and incorporation of 1 ton/acre dolomite, 1,000 pounds/acre of 10-20-10, 1 pound/acre boron, 0.75 pound/acre trifluralin, and 2 pounds/acre dyfonate. Diazinon, as a 1 pound/acre drench, was applied on July 12 when root maggot damage became apparent. A sidedress application of 200 pounds/acre calcium nitrate was applied on July 14. Heads were harvested over the period August 10 - September 6.

Results

The summer of 1978 was not particularly well-suited to a cauliflower heat tolerance trial. Daytime temperatures reached 90°F for only two short periods; July 20-25 (average high = 93°) and August 6-9 (average high = 97°). The latter brief spell of high temperatures immediately preceded the first harvest and may have resulted in lower quality for Snow Crown and MSU-817, the only varieties harvested as early as August 10. High temperatures for the rest of the harvest period averaged 72°. Average low temperature for July and August was 57°. Thus, most varieties matured during relatively mild weather. Largest head size was obtained with Imperial 10-6 but White Top and White Empress had higher total yield per plot due to slightly higher plant populations. Highest quality curds were obtained with Self­Blanche, White Top, and White Empress.

Table 7. Yield Data, Summer Cauliflower                                  
      Harvest Date:   8/10    8/17     8/25      9/06    Total
Cultivar  Source                                                         
                      -------------kilograms/plot-------------  gram/head
Snowball D     1Z      -      3.29     2.28      3.56     9.13     652 
Snowball Y     1       -      6.60     4.24      5.90    16.74     837 
Snow Crown     1      9.42    1.20     0.12      0.43    11.17     576 
Self-Blanche   1       -      4.66     7.52      1.53    13.71     914
Imperial 10-6  1       -      8.18     8.62      1.43    18.23    1215
White Top      2       -      6.14     8.97      4.94    20.05    1002 
White Empress  3       -      16.20    2.01      3.67    21.88    1152
MSU-817        3      6.62     -        -         -       6.62     441 
Moran 15       4       -      1.82    10.27      2.43    14.52    1117
Moran 23       4       -      5.45     8.85      0.78    15.08     943
Moran 32       4       -       -      10.10      5.31    15.41     982   
ZSource 1 = Harris Seed Co.; 2 = Sluis & Groot; 3 = Dr. Shigema 
 Honma, Michigan State University; 4 = Moran Seed Co.


Table 8. Comments on Heat-Tolerant Cauliflower Varieties                         
Variety          Description                                                     
Snowball D       All heads of poor quality because of small purple 
                 leaves growing through curd.
Snowball Y       Large, well-formed heads; slightly ricey by time first heads  
                 reached marketable size; some leaves in curd; quality fair.
Snow Crown       Early; fair to poor curd quality.
Self-Blanche     Lovely, large white heads; nice curd.
Imperial 10-6    Very large heads, good yield; but became ricey 
                 very rapidly and many leaves in head.
White Top        Large, well-formed heads; high quality.
White Empress    Large heads, good quality; concentrated maturity. 
MSU-817          Very early, matured rapidly; ricey, poor quality; small heads.
Moran 15         Fair quality; good head size, but off-color and leaves in curd.
Moran 23         Large, well-formed heads, slightly ricey; many heads
                 have small purple leaves in curd; fair quality overall.
Moran 32         Late maturity, fair quality.                                    

The purpose of these experiments was to investigate cultural methods for establishing earlier and higher percentage stands of several vegetable crops and to encourage more vigorous seedling growth during periods of suboptimal air and soil temperatures. Phosphoric acid (PA), a possible emergence stimulator and anticrustant, was applied at planting as an over-the-row banded spray. This technique, if successful, would allow production of crops at earlier than normal dates, taking advantage of possible premium prices. Better stand establishment could allow direct seeding of presently transplanted crops or eliminate the need for over­seeding and subsequent thinning of some crops.

Methods

Crops tested were cauliflower, bush beans, carrots, cucumber, and head lettuce at the Station, rutabaga, parsnip, and turnip at Montecucco Farms north of Canby, carrots at Casale Farms, Aurora, and leaf lettuce, Romaine lettuce, spinach, and green onions at the Sambuceto farm, Lone Elder. At the Station, the plot area was prepared by plowing, disking, incorporation of 1,000 pounds/acre of 10-20-10 plus 500 pounds/acre of dolomite and harrowing to achieve final seedbed. The cauliflower area also received 4 pounds/acre dyfonate incorporated into the top three inches of the seedbed along with 0.75 pounds/acre of trifluralin. The bean and cucumber plots received 4 pounds/acre dinitroamine and the carrot area, 1.5 pounds/acre linuron, all preemergence.

Seeding of cauliflower, beans, cucumbers, and carrots and PA application was on April 10 and all plots received 100 pounds/acre of 18-46-0 banded at planting. PA was applied at seeding to the appropriate plots (40 row feet) at a rate of 20 gallons/acre of 17 percent PA in a 2-inch band over the row. This is roughly equivalent to 600 pounds of P205/acre within the sprayed band. Applications at grower's farms were on April 10 and April 11. In these cases, the PA was applied within 48 hours of seeding but before emergence of the crop. Each crop was seeded and grown according to the particular grower's usual cultural practice. The head lettuce experiment was seeded on June 2. All experiments were replicated at least four times. Stand data were obtained for all crops except cucumber. Yield data were obtained for Station crops only.

Results

An over-the-row band of PA at or shortly following planting tended to increase stand for all crops except leaf and Romaine lettuce (Table 9). However, statistically significant (95 percent probability) increases in early stand were obtained only for spinach and cauliflower while crisphead lettuce and onion stands were significantly improved only at the 90 percent confidence level. High variability among blocks was the key factor in the lack of statistically significant stand differences for most crops. In the case of bush beans, the variability was directly attributable to birds eat­ing the emerging seedlings. The cucumber crop was destroyed by birds eat­ing the seed. The high variability among plots for Station carrots was caused in part by an apparent failure to properly seed one check plot.

The increased stands of cauliflower, crisphead lettuce, and onion were reduced to non-significant levels within four weeks after seeding (Table 10). This was caused in part by a combination of damping off and insect damage which led to increased variability among blocks and also to late emergence of seedlings from untreated plots. Average daily temperature during the period April 10 to May 1 was 50°F, average daily soil temperature at 2-inch depth was 53°, clearly suboptimal for most of these crops. Total precipita­tion was 0.5 inches but little crusting was observed at any location except Casale Farms. Although crusting was not a major factor, the low air and soil temperatures should have provided a nearly ideal test of any emergence and growth stimulating properties of the PA.

Cauliflower and lettuce crops were thinned to a final stand and seed­ling weights were obtained shortly before or at thinning. Seedlings from PA sprayed plots weighed significantly more than seedlings from non-sprayed plots for crisphead and leaf lettuce (Table 11). In addition to these effects on mean seedling weight, PA treated plots of cauliflower and lettuce exhibited a lower degree of among-blocks variation as seen in the smaller coefficients of variability for PA treatment means.

Stand establishment, within limits, is assumed to be related to yield. Unfortunately, of the crops which showed significant stand differences, no yield data were obtained for onions or spinach and the cauliflower and crisphead lettuce were thinned to a nearly uniform stand. However, it should be noted that the stands of cauliflower and crisphead lettuce from PA-treated plots approached the 90-100 percent level needed for direct ­seeding to final stand.

Of the crops for which yield data were obtained, PA treatment significantly increased yield only for carrots (Table 12). The increased carrot yield was due primarily to improved stand. Mean root size was increased by 11 percent but this difference was not statistically significant. For crisphead lettuce, the 6 percent increase in mean head weight for plants from PA plots was not statistically significant but the head size variability (per head basis) was 28 percent smaller on PA treated plots. This degree of improvement could be important for a mechanically harvested crop, particularly as it may reflect more concentra­ted maturity. Cauliflower head size variability was not similarly affected.

Table 9. Early Stand Counts as Affected by PA Spray            
Crop             Days after     Seedlings/plot     Significant
                  seeding       +PA       -PA      difference  
Bean                 21         39.0      27.3         -
Carrot (Casale)      19         78.0      75.6         -
Carrot (Station)     21	       177.3     138.0         -Z  
Cauliflower          17	       150.8     133.6	       **
Lettuce, crisphead    6	        53.5      46.2         *
Lettuce, leaf        15         48.8      48.7         -
Lettuce, Romaine     15         28.0      30.7         -
Onion                19        223.0     205.5         *
Parsnip              16         52.8      46.5         -
Rutabaga             16         18.2      17.8	       -
Spinach              15         80.3      69.7        **
Turnip               18         36.4      33.8         -      
ZHighly variable among blocks.
**Significantly different at 95 percent confidence level. 
*Significantly different at 90 percent confidence level.


Table 10. Late Stand Counts as Affected by PA Spray          
Crop              Days after   Seedlings/plot     Significant
                   seeding      +PA      -PA      difference 
Beans                25         45.8     38.3             - 
Beans                30         76.3     62.5             - 
Carrots (Station)    28        161.0    117.3             - 
Cauliflower          25        144.8    130.0             - 
Lettuce, crisphead   12         50.2    48.8              -  


Table 11. Seedling Weight at Thinning as Affected by PA Spray                 
Crop            Days after     +PA                 -PA             Significant
                  seeding   Fresh weight        Fresh weight       difference
                           (mg/seedling) C.V.  (mg/seedling) C.V.             
Cauliflower         37	       1150      10%      1160        21%      -
Lettuce, crisphead  25	        998       2	   745         4      **
Lettuce, leaf       40	        720       6	   510         9      **
Lettuce, Romaine    40          760       4        660         7       -      


Table 12. Vegetable Yields as Affected by PA Spray                     
Crop                        +PA              -PA            Significant
                         Mean fresh       Mean fresh        difference
                           weight    C.V.   weight    C.V.             
Beans, kg/plot              6.51     41%     6.82      41%        - 
Carrots (Station), kg/plot  5.73     32      4.36      50        ** 
Carrots (Station), g/root     72     11        65      11         - 
Cauliflower, g/head          569     30       580      31         - 
Lettuce, crisphead, g/head   611     13       576      18         -
_______________________________________________________________________________________________
ZThis C.V. is among heads.

The purpose of this experiment was to investigate methods for establish­ing earlier and more complete stands and more vigorous corn seedling growth during periods of suboptimal air and soil temperatures. Phosphoric acid (PA) was applied alone and in combination with banded treble superphosphate (banded P) and clear plastic mulch in an attempt to enhance early seedling growth. These techniques might allow production of sweet corn at earlier than normal harvest dates, taking advantage of possible premium prices, and increase yields at relatively little expense.

Methods

The experiment was designed as a 2x2x2 factorial (± plastic, ± PA, f banded P) in a randomized block design with four replications of each of the eight combinations of factors. PA was applied to the appropriate plots immediately after seeding as a 3-inch band of 15 percent acid, 16 ounces of dilute acid per 25 feet of row. Banded P was applied two inches to the side and two inches below the seed at a rate of 270 pounds P 0 /acre. Plastic mulch was 12 mil clear polyethylene covering single rows of the appropriate plots. Plot size was three rows wide with 30-inch row spacing and 25-foot length. The middle row of each plot was used for all stand counts, seedling weights, and yield.

After plowing, two hundred pounds/acre of 0-0-52.5 and 400 pounds/acre of treble superphosphate were broadcast and incorporated. On May 4, the plots were seeded, banded P applied, 1.25 pounds/acre atrazine and 2.0 pounds/acre alachlor were applied, and PA sprays applied. Seeding was at a rate which would give nearly 40,000 plants/acre assuming 100 percent stand. Plastic mulch was applied on May 5. On May 19, the plastic was slit to allow emergence of the seedlings. On June 6 all record rows were thinned to eliminate multiple seedlings per hole and fresh weights were obtained. Nitrogen, as 450 pounds/acre of 34-0-0,was applied to all plots on May 30.

Results

During the three weeks after seeding, the average daily air temperature was 52.5°F and soil temperature at 2-inch depth was 58°, clearly less than optimal for corn germination and growth. Plastic mulch increased average air temperature at ground level by 9° and 2-inch soil temperature by 6°. The other treatments had little or no effect on air or soil temperature except that PA without plastic appeared to raise soil temperature within the band by 0.5°. Fifty percent emergence occurred on May 10 for all combinations of plastic-covered seed and on May 16 for all treatments with­out plastic.

A stand count was taken on June 6 after all treatments showed maximum emergence (Table 13). No single treatment alone had a significant effect on stand. However, statistical analysis of the multifactor inter­actions revealed that the check plots had a significantly lower stand than the average of all other treatments (95 percent confidence level), the combination of plastic, PA, and banded P resulted in higher stand than the average of all other treatments (90 percent level), and that there was a significant PA x plastic interaction. The latter interaction is manifested in the fact that plots with PA alone had the best stand in the absence of plastic mulch while PA alone resulted in the poorest stand in the presence of plastic. None of these effects on stand has any practical significance for a corn crop with the plant density obtained in this experiment.

The main effects of the treatments on seedling growth are best reflec­ted in seedling weight at thinning (Table 14). Seedlings from plastic covered plots weigh more than four times as much as non-covered seedlings. PA treatment resulted in a slight increase in seedling weight and banded P resulted in a slight decrease in seedling weight on plastic-covered plots.

The yield of Grade 1 ears was affected primarily by the plastic mulch (Table 15), with a nearly 6-fold yield difference. However, all plots were harvested on the same day. Non-mulched treatments would have yielded much higher if allowed to stand an additional one or two weeks since maturity was the primary factor in assigning a No. 1 grade. Phosphoric acid also produced a small increase in yield of Grade 1 ears and, considering non­mulched plots only, there was a significant increase in yield because of the combination of PA and banded P. The plastic effect on total ear weight (Grade 1 and 2, Table 16) was much less striking and is probably much closer to the true effect of the mulch on corn yield potential. PA-treated plots again had a slightly higher yield and the three-way interaction of PA, banded P, and plastic also was significant.

The results for total ear weight confirm that the primary effect of plastic mulch is to promote early maturity while the PA and banded P may more directly affect total yield potential. The number, as opposed to-weight, of Grade 1 ears was increased 6-fold by plastic and to a far lesser degree by banded P (Table 17). Again, this was primarily due to earliness. Table 18 presents results for the total number of ears, which includes all ears showing any kernel development. Plastic mulch significantly increased the number of ears produced, but the effect is small compared to the increase in weight or number of Grade 1 ears. PA also had a small effect. Plastic mulch significantly increased the average size of individual Grade 1 ears (Table 19), but the size increases were small compared to the plastic effects on earliness. No treatment or combination had any significant effect on corn silage fresh weight (Table 20).

Effects of plastic, PA, and banded P treatments in 1977 were similar except that the plastic treatment effect on weight of Grade 1 ears was much larger in 1978 than in 1977, probably because of an earlier 1978 harvest which accentuated maturity differences. The results can be summarized as follows: Clear plastic mulch will produce a small increase in sweet corn yield, but, more importantly, will increase earliness by as much as two weeks for early plantings. Banded P and PA effects are much smaller and less consistent in these experiments, but the banded P and PA combination, particularly in the presence of plastic, produces a significant increase in yield and earlier maturity.

Table 13. Effect of Plastic Mulch, PA, and Banded P on Stand of Sweet Corn 
Treatments             Check    Banded P  PA   Banded P + PA  Mean, plastic 
                       ------------Number of seedlings/25 feet-------------
With plastic           56.5       53.3    51.3      57.5          54.6
No plastic             48.0       54.0    54.8      51.8          52.1
Mean, + or - PA:       -PA        53.0    +PA       53.9
Mean, + or - Banded P: -Banded P  52.7    +Banded P 54.2                   


Table 14. Effect of Plastic Mulch, PA, and Banded P on Sweet Corn 
Seedling Weights One Month after Seeding                                   
Treatments             Check    Banded P  PA   Banded P + PA  Mean, plastic 
With plastic            6.3        5.0    6.7        6.1           6.0Z
No plastic              1.3        1.3    1.4        1.6           1.4
Mean, + or - PA:        -PA        3.5    +PA        4.0Y
Mean, + or - Banded P: -Banded P   3.9    +Banded P  3.5Y
____________________________________________________________________________________________________ 
ZMeans for plastic treatments significantly different at 99.9 percent 
 confidence level.
YMeans for PA treatments and Banded P treatments significantly different 
 only at 90 percent level.


Table 15. Effect of Plastic Mulch, PA, and Banded P on Fresh Weight of Grade 1 
Ears of Sweet Corn                                                            
Treatments             Check   Banded P  PA   PA+Banded P  Mean, plastic      
                       -Grade 1 earsZ, tons/acre fr. wt., including husks-
With plastic            8.1       8.4    8.3       9.3         8.5Y
No plastic              1.1       1.0    1.3       2.4         1.5
Mean, + or - PA:        -PA       4.7    +PA       5.3X
Mean, + or - Banded P:  -Banded P 4.7    +Banded P 5.3                        
ZGrade 1 ears are completely filled ears having at least 80 percent mature kernels.
YMeans for plastic treatments significantly different at 99.9 percent confidence level.
XMeans for PA treatments significantly different at 90 but not 95 percent level.


Table 16. Effect of Plastic Mulch, PA, and Banded P on Fresh Weight of 
Total Ears (Grade 1 plus Grade 2) of Sweet Corn                          
Treatments             Check   Banded P  PA   Banded P+PA  Mean, plastic 	
                       -Total ears, tons/acre fr. wt., including husks-
With plastic           10.9      10.3   10.4      11.6        10.8Z
No plastic              6.8       7.6    8.6       8.8         8.0
Mean, + or - PA:        -PA       8.9    +PA       9.9Z
Mean, + or - Banded P:  -Banded P 9.2    +Banded P 9.6                   
ZMeans for plastic treatments and PA treatments significantly different at 
 99 percent confidence level.


Table 17. Effect of Plastic Mulch, PA, and Banded P on Number of Grade 
Number 1 Ears of Sweet Corn Produced                                      
Treatments              Check   Banded P   PA   Banded P+PA  Mean, plastic
                        -------Number of Grade 1 ears/25 feet--------
With plastic            33.8      35.3    32.0       40.3       35.4Z
No plastic               4.8       4.5     5.5       10.8        6.4
Mean, + or - PA          -PA      19.6     +PA       22.2
Mean, + or - Banded P   -Banded P 19.0    +Banded P  22.7Y
___________________________________________________________________________________________________
ZMeans for plastic treatments significantly different at 99.9 percent 
 confidence level.
yMeans for banded P significantly different at 95 percent level.


Table 18. Effect of Plastic Mulch, PA, and banded P on Total Number
of Ears of Sweet Corn Produced                                              
Treatments               Check   Banded P   PA   Banded P+PA   Mean, plastic     
                         --------Total number of ears/25 feet--------
With plastic             52.0      44.0    46.0      56.0        49.5Z
No plastic               34.5      37.0    42.3      41.3        38.8
Mean, + or - PA:          -PA      41.9    +PA       46.4Y
Mean, + or - Banded P:   -Banded P 43.7    +Banded P 44.6                   
ZMeans for plastic treatments significantly different at 99 percent 
 confidence level.
YMeans for PA treatments significantly different at 95 percent 
 confidence level.


Table 19. Effect of Plastic Mulch, PA, and Banded P on Average Weight of 
Grade 1 Ears of Sweet Corn                                                
Treatments              Check   Banded P   PA    BandedP+PA  Mean, plastic	
                        -Mean fresh wt. of Grade 1 ears (lb), incl. husks-
With plastic            0.69      0.69     0.77      0.67      0.71Z
No plastic              0.64      0.59     0.64      0.64      0.63
Mean, + or - PA:        -PA       0.65     +PA       0.68
Mean, + or - Banded P:  -Banded P 0.69     +Banded P 0.65                 
ZMeans for plastic treatments significantly different at 99 percent 
 confidence level.


Table 20. Effect of Plastic Mulch, PA, and Banded P on Silage 
Weight of Sweet Corn                                                     
Treatments             Check   Banded P   PA   BandedP+PA   Mean, plastic	
                       --------Silage fresht weight, tons/acre------
With plastic           25.2      22.7    23.3      24.6         24.0
No plastic             21.5      23.8    22.0      24.0         22.8
Mean, + or - PA:       -PA       23.3    +PA       23.5
Mean, + or - Banded P: -Banded P 23.0    +Banded P 23.8                  

Methods

Seeds were planted on April 13 in Jiffy Pots containing a mix of sandy loam:peatmoss:perlite (1:1:1) and placed in a heated greenhouse. Seedlings were fed 1/2 cup weekly of 10-30-20 (1 ounce/gallon) after appearance of the first true leaf. Just prior to first bloom, the plants were moved to the field and grown on 42 inch raised beds covered with black plastic mulch. Fertilizer consisted of 1,000 pounds/acre of 10-20-10 and 1,000 pounds/acre dolomite incorporated into the Willamette sandy shot loam before bed shaping. All plants received one cup of 1 ounce/gallon 10-30-20 at transplant. Viaflo tubing was used for irrigation. No pesticides were used.

Four replicates of three plants each were pruned to a single leader (vine) and tied to 6-foot stakes. An equal number of plants were neither pruned nor staked. Plant density in each case was one plant/square yard or about 4,800 plants/acre. Fruit was harvested weekly after August 1. In an attempt to induce blossom end rot (BER) and cracking, the beds were flooded on July 26 and then dried until plants were visibly wilted. The flooding was repeated on August 16 and the beds again allowed to dry. Water was given as needed after September 1. All fruit was picked at pink to red-ripe stage except that the last two harvests were at breaker stage.

Results

In 1978, with intentional induction of BER and cracking, the 1977 results were confirmed and, indeed, magnified. Fruit size was consid­erably larger (29 percent) for the more lightly cropped staked plants and earliness was again promoted, with 53 percent ripened by August 31 for staked plants vs. 35 percent for nonstaked plants (Table 21). Total yield was more than halved on staked plants while marketable yield was reduced by nearly half (Table 22). Incidence of BER was nearly 8-fold higher on staked plants and misshapen fruit and radial cracking were 3 to 4-fold greater on staked plants. Concentric cracking was not signifi­cantly different between the treatments. However, late blight affected over five times as many fruit on nonstaked as on staked plants.

The sugar/acid ratio or apparent ripeness of the fruit after three days at room temperature was not consistently affected by pruning method (Table 21). Three unblemished red-ripe fruit per replicate per harvest period were used for these measurements. Sugar was estimated by a refractometer reading of expressed juice while acid was estimated by titration against standard base assuming 100 percent citric acid. There was less seasonal variation in sugar/acid ratio in nonstaked fruit.

The lowered yields for staked plants are to be expected since sucker removal greatly reduces the number of flower clusters/plant. But since the trained plants require less space, a greater plant population is easily attainable and can correct the yield difference, although at a higher cost for seed, other materials, and transplanting. The increased fruit size and earlier ripening of the staked plants may be explained by reduced competition for photosynthate, minerals, etc.

Early Girl is an early, rather small-fruited variety and increased fruit size might improve marketability when competing against later, larger-fruited varieties. The increased BER and cracking with alternate flooding and drying suggests that fruit on staked plants are more susceptible to changes in water or nutrient availability. However, control of both water and nutrient status should normally be no problem with plastic mulch and drip irrigation. Staking appears to offer some disease protection, possibly because of better air movement, remoteness from soil-borne pathogens and greater spatial separa­tion between clusters.

In summary, severe pruning and staking of the popular hybrid tomato cultivar Early Girl will produce earlier ripening, increased fruit size, and possibly some disease protection at the cost of decreased yield/plant, possible BER or cracking problems when moisture and nutrients are inade­quately controlled, and increased expenditures for materials and labor.

Table 21. Effect of Pruning Method on Earliness, Fruit Size, and 
Sugar/Acid Ratios of Early Girl Tomato at Various Harvest Periods        
                  Pruning           Harvest period                Season
                  method     7/31-  8/09-  9/01-  9/21-  10/12-   average
                             8/08   8/31   9/20  10/11   10/24           
Percent ripened   Staked      13     40     12     19     16        -
during period     Nonstaked    3     32     45     14      6        -
---------­----------------------------------------------------------------
Fruit size        Staked     137a   159a   176a  117a    106a      l4laY
(grams)           Nonstaked   94b   124b   113b   85b     60b      109b         
-------------------------------------------------------------------------­
Sugar/acidZ       Staked     5.7a   6.3a   5.9a  4.9a     -        5.8a
ratio             Nonstaked  5.2a   5.3b   5.9a  5.5a     -        5.5a  
ZSugar/acid ratio is the percent by weight soluble solids/percent by 
 weight titratable acidity.
YMeans in same column followed by different letters are significantly 
 different at 95 percent confidence level.


Table 22. Effect of Pruning Method on Yield, Incidence of Blossom-end Rot,
Concentric Circular Cracking, Radial Cracking, Rough Fruit, and Susceptibility 
to Late Blight of Early Girl Tomato                                           
Pruning     Total    Market-  BER   Conc.      Radial     Rough,      Late
method      yield    ableZ          cracking   cracking   misshapen   blight
            ton/     yield
            acre     ton/acre   %      %           %        %            %    
Staked       24a     15a      19.0a   15a        18a      14a           7a
Nonstaked    55b     29b       2.4b   lla         5b       4b          40b    
ZMarketable yield is the total yield less any fruit which were severely 
 cracked, split, blighted, severely misshapen, or blossom-end rotted. 
 Many individual fruits had a combination of two or more defects.

The purpose of this study was to investigate the effect of several combinations of soil pH and nitrogen fertilizer rates on yield and mineral uptake of bush beans, carrots, and crisphead lettuce. Of particular concern are the nutrient elements potassium, calcium, phosphorus, magnesium, zinc, and copper, and heavy metals such as manganese which may be toxic to plants if present in sufficient quantity. Optimal soil pH levels are not well known for many vegetable crops and probably vary with soil type, cation exchange capacity, amount of organic matter etc. As in 1977, this study was designed to determine pH optima for the three crops listed above. The design is essentially a repeat of the 1977 plan except that the number of nitrogen rate variables was decreased to two, 50, and 150 pound/acre.

Methods

Cultivars used were Spartan Arrow bean, Ithaca lettuce, and Chantenay carrot. Two hundred pounds/acre each of 0-0-52.5 and 0-45-0 were broadcast and incorporated. All plots were seeded on May 25. Nitrogen rates were applied on May 28 as 150 and 450 pounds/acre of 34-0-0. Soil pH varied from 4.9 to 6.7. Seeding and herbicide applications took place during very wet weather with resulting problems of herbicide run and soil compac­tion. Row spacing for all crops was 30 inches. Acceptable stands were achieved for all crops. Weed control was adequate for protection through the seedling stage, but cultivation of all crops was necessary by July. Harvest dates were August 3 for beans and lettuce, and August 22 for carrots.

Results and Discussion

I. Beans
Bean yields in general were much lower than in 1977, caused in part by lower density planting and earlier harvest, but also by poorer plant performance. Plant vegetative growth and pod yield were inhibited severely in certain parts of the field, and apparently in a pattern not related to treatment. Soil compaction or herbicide injury may have been a problem. Bean plant vegetative yield was not significantly affected by treatment. Maximum bean pod yield of 4.1 tons/acre occurred at pH 6.4 and 50 pounds nitrogen. Leaf tissue concentrations of phosphorus, potassium, and magnesium were unaffected by nitrogen or pH while calcium levels increased with increasing pH up to pH 6.4. Zinc levels decreased with increasing pH and some values for individual plots were in the deficient range of less than 20 parts per million (ppm) at pH 6.4 and above. The foliage also showed possible zinc deficiency symptoms. The most striking effect of pH was the inverse relationship between soil pt and leaf manganese levels. Manganese concentration of 200 ppm was obtained at pH 5.0, but only 103 ppm at pH 6.6. In contrast, in 1977, leaf manganese varied from about 65 ppm at pH 5.0 to 30 ppm at pH 6.6.

II. Carrots
Total carrot yield responded significantly to both pH and nitrogen rate. At pH 5.6, carrots yielded 60 percent more than at pH 5.0 but liming to higher pH did not result in any further yield increase. Application of 150 pounds/acre of nitrogen reduced yield at each pH level below that obtained with 50 pounds/acre of nitrogen. This was due at least in part to inhibition of stand establishment by the high nitrogen rate. The cause of this nitrogen effect might be ammonium toxicity, salt injury, or a pH lowering effect.

Yield of Grade 1 plus Grade 2 (all but culls) carrots responded in the same fashion as total yield. Thus, neither pH nor nitrogen rate significantly affected carrot cull rate (percentage of over-or undersized, broken, split, forked etc.).

Carrot leaf tissue levels of phosphorus, magnesium, and potassium were unaffected by soil pH. The higher nitrogen rate tended to depress potassium levels. Calcium levels increased with both pH and nitrogen rate. Zinc and manganese levels decreased with increasing pH, with zinc levels being possibly deficient at pH 6.4 and above. Manganese levels at pH 5.0, while double those at 6.4 - 6.6, were not in the toxic range.

III. Lettuce
Lettuce head size increased dramatically with increasing pH to a maximum of 1.4 pounds at pH 6.4 and 150 pounds/acre of nitrogen. There was a trend for the high nitrogen rate to suppress head size at low pH and increase it at high pH.

Leaf tissue levels of magnesium, potassium, and calcium were unaffected by pH and nitrogen. Phosphorus levels increased with increasing pH while manganese and zinc levels decreased with increasing pH. Leaf tissue manganese decreased from nearly 200 ppm at pH 5.0 to less than 40 ppm at pH 6.4. The 200 ppm level may well be in the toxic range. Lettuce stands were suppressed by both low pH and high nitrogen rate.

In summary, bean yields were not greatly affected by pH or nitrogen rate because of great variability between and within plots. Carrot yields increased with increasing pH but were depressed by the high nitrogen rate. Lettuce yields responded dramatically to increasing pH and manganese toxi­city may be a factor in poor lettuce growth at low pH. Stands of lettuce and carrots were improved at higher pH but suppressed by high nitrogen. Data from these experiments will be published in the 1979 Proceedings of the Western Washington Horticultural Association.

Methods

Crops and varieties for 1978 were Nantes carrot, Blue Lake 274 bush bean, Early Girl tomato, Victory cucumber, and Russet Burbank potato. All crops but tomato were exposed to single run-off sprays of 2,4-D dimethyla­mine at rates of 0, 5, and 50 ppm. Rates for tomato were 0, 1, and 10 ppm. Treatments were replicated three times in a randomized block design. Tomatoes, cucumbers, and potatoes were sprayed at first bloom, beans after expansion of the second trifoliate, and carrots after formation of the fleshy taproot. All leaf samples were taken 24 hours after spray application. Plants were observed daily following treatment and weighed and graded at harvest. No chemical pest control was used in the plots and fertilizer was applied according to standard practice for each crop.

Results

The tomato crop was severely infected with curly top shortly before bloom and yield data were not obtained. Carrot gross yields were increased nearly 25 percent over control by application of 5 ppm 2,4-D. However, 5 ppm reduced net fresh market yield nearly to zero since the roots were rough, scaley, misshapen and covered with prominent root primordia. Foliar symptoms were nearly indiscernible at this rate. Gross yields were reduced to about 65 percent of controls by 50 ppm 2,4-D and marketable yield was zero. Pronounced and lasting foliar symptoms were present at this rate.

Potato yields and tuber shape were not affected by 5 or 50 ppm 2,4-D although foliar symptoms of vein-clearing, and leaf margin distortion were evident at 50 ppm. Cucumber yields were unaffected at 5 ppm but reduced by 25 percent at 50 ppm. Foliar symptoms and fruit shape distortions were evident at both rates of 2,4-D. Bean yields appeared to be depressed slightly by both rates of 2,4-D but the differences were not statistically significant. Foliar symptoms were readily apparent at 50 ppm.

These results agree nicely with results from the 1977 trials. Crop damage can occur at low exposures and root crops are particularly sensitive. The ability to predict yield reductions after accidental exposure of non-target crops will depend upon correlation of residues with known amounts of 2,4-D applied.

The first project in this category was initiated in 1975 and sought to investigate the use of anaerobically digested sewage sludges and poultry manure as fertilizers for sweet corn, winter cereals, and grass or pasture crops. This project was supported by the cities of Portland and Salem, and the Unified Sewerage Agency of Washington County, as well as Agricultural Experiment Station funds. The primary purposes were to determine how much of the nitrogen normally applied to each crop could be replaced with sludge or manure nitrogen, the degree of availability to the crops of the organic nitrogen in the waste materials, and the degree of accumulation of sludge­originated phytotoxic heavy metals in the crops. Three years’ yield and tissue analysis data have now been obtained for each crop. The next few growing seasons will be devoted to refinement of data for grain crops and further vegetable research will not be undertaken until the 1981 or 1982 growing season.

Another related project, supported by the U. S. Environmental Protection Agency, originated in 1978 and seeks to demonstrate the efficacy of chrome tannery waste as a fertilizer for vegetables and grass crops. As with sewage sludge, this material contains significant quantities of nitrogen but the use may be limited by the 0.8 to 3 percent chromium content.

Methods

In both the sludge and tannery waste experiments, commercial nitrogen fertilizers, usually ammonium nitrate or ammonium sulfate, were applied at rates from 0 to 300 pounds/acre to provide a comparison for the organic fertilizers. Sludge or waste applications were made about two weeks prior to planting at rates of up to 700 pounds of total nitrogen per acre, plowed under, and the seedbeds prepared. Jubilee sweet corn was the only vegetable crop in the sludge-poultry waste experiments; Jubilee corn and Spartan Arrow bush beans were used in the tannery waste experiments. Thirty-inch row spacing was used for corn and beans, and pesticide, cultivation, and irriga­tion practices were similar to those commonly used in the Willamette Valley. For both crops, harvest was near time of optimum maturity for the earliest maturity treatments. Especially for corn, this may have accentuated yield differences among treatments because of earlier maturity of certain treat­ments, e.g. where phosphorus was banded at planting.

Results

In 1978, for the first time in three years, sewage sludge additions greater than 150 pounds per acre of total nitrogen resulted in a significant increase in corn yields. In previous years, commercial nitrogen applications increased yields up to a rate of 200 pounds/acre, but 300 to 400-pound applications of sludge nitrogen yielded no more than 150 to 200-pound applica­tions. In 1978, low rates of sludge were equally as efficient as equivalent rates of commercial nitrogen but higher rates were only about 80 percent as efficient. Maximum sludge-fertilized yield was about 10 tons/acre compared to 12 tons/acre for commercial nitrogen. Unfertilized check plots yielded 4 to 5 tons/acre. Plant tissue analysis data for the 1978 crop are not yet available, but in 1976 and 1977, heavy metal accumulation did not appear to be a problem. In 1976, sweet corn grown on plots fertilized with Portland sludge had higher leaf tissue levels of cadmium and other metals than did corn from plots grown on U.S.A. or Salem sludge, but levels were not in a range considered to be dangerous. In 1977, after two consecutive sludge applications, cadmium levels were generally lower in plants from sludge amended plots than from commercial nitrogen plots. Poultry manure has been considerably less effective as a sweet corn fertilizer than either the sewage sludge or commercial nitrogen.

In the first year of the tannery experiment, the waste was only about 50 percent as effective as commercial nitrogen as a sweet corn fertilizer when expressed on the basis of equal weights of total nitrogen (180 pounds/ acre) applied. Both low and very high (720 pounds/acre of N) rates of tannery waste appeared to suppress corn yields. In the bean experiments, yields from check plots, commercial N plots, and low rates of tannery waste did not differ significantly. But the highest rate of tannery waste depressed yields well below those of unfertilized check plots. At least one more year will be devoted to refining data from these field plots. Results of plant tissue analyses are not yet available.