Mount Vernon Northwestern Washington Research and Extension Center

Vegetable Research and Extension

Photo collage of watermelon tasting, tractor, dry beans

Baby Corn Production 1997

By: Carol A. Miles, Ph.D., and Leslie Zenz
Washington State University Extension,
360 NW North St., Chehalis, WA 98532

Introduction

Baby corn, popular in many Asian cuisines, has become a staple in salad bars across the United States. Most of the baby corn sold in the US and in Europe is imported from Thailand, Taiwan and Indonesia. Baby corn is an extremely easy crop to produce, and for a corn growing nation like the United States, it is surprising that baby corn is an imported crop. The reason baby corn is not produced locally is that hand labor is required for harvesting and processing, which economically prevents large-scale production. However, locally produced fresh baby corn can have an advantage over imported baby corn. Imported baby corn is almost exclusively processed and canned and there is virtually no fresh baby corn, which is superior in both taste and texture, imported into the United States. Also, in countries like the United States and Japan, there has been a large increase in demand for organic foods, and none of the imported baby corn is organically grown. Locally grown fresh and organic baby corn may now have a place on the small farm. This may be the time for growers to test the market demand in their area for small-scale production of baby corn for home canning, the organic market, and the high-end market such as restaurants.

Producing Baby Corn

Baby corn is produced from regular corn plants which are harvested early while the ears are very immature, resulting in small ears or "baby corn" (Figure 1).

photo of baby corn at harvest size

Figure 1. Baby Corn is harvested 1–3 days after the silks appear, when the ear is very immature.

Regular sweet corn (referred to as Su), sugary enhanced sweet corn (Se), and super sweet corn (sh2) varieties are all suitable for fresh baby corn production. Field corn varieties (Su) can also be used for fresh baby corn production, and there are a few baby corn varieties (Su) such as Baby Corn which are grown solely for baby corn. Growers should be aware that if field corn or baby corn varieties (both are Su) are grown close to sweet corn varieties (Su, Se, and sh2) which are being grown for mature ears, they will cross pollinate and the sugariness will be lost from the sweet corn. Detassling the field corn or baby corn will prevent undesirable cross pollination and will have no effect on baby corn production. There is no taste advantage in using sweet corn instead of field corn as the immature ears are harvested before pollination occurs and before any sugars have accumulated in the kernels. Baby corn varieties look just like a regular corn plant – they are the same height and are not, as might be assumed, dwarf plants (Figure 2). The baby corn varieties are field corn types and if the ear is allowed to mature it will look like a typical medium-sized ear of field corn.

photo of Master Gardener harvesting baby corn

Figure 2. WSU master gardener volunteer helping to harvest baby corn trial at Shaffner Farms in Montesano, Grays Harbor County; corn plants for baby corn production are "normal" in height and average 6–7 feet tall.

Baby corn can be produced in two ways. In the first method, a regular sweet corn or field corn planting can be used for baby corn production. In this system the corn is planted following the guidelines for sweet corn, corn silage or corn grain production. The second ear down from the top of the plant (the secondary ear) is harvested for baby corn while the ear closest to the top of the plant (the primary ear) is harvested for sweet corn, corn silage or corn grain. If the corn plant is prolific – sets more than 2 ears per plant – all of the lower ears can be used for baby corn without affecting overall crop production. This method of producing baby corn is recommended in areas where the market or demand for baby corn is unsure. This method allows growers to take advantage of the secondary ear which otherwise may not mature for sweet corn production nor contribute greatly to the silage or grain harvest.

If baby corn ears are the primary objective for a corn planting then another production system is used. In this second method, the corn is planted 2–4 inches apart in the row and the rows are spaced 36–42 inches apart (a typical between-row spacing for corn is used). Both sweet corn varieties and field corn varieties are suitable for this system. Nitrogen fertilization must be adequate in this system as low nitrogen fertility will prevent the plant from developing ears. However, high nitrogen rates are not essential as the corn is harvested well before ear maturation begins and the ear maturation stage of corn growth is a high nitrogen use time. Every ear is harvested as it reaches the correct maturity stage, which is generally 1 to 3 days after silking. Early corn harvest prevents many pests such as corn ear worm and cucumber beetle from affecting ear quality, thus insecticide usage can be greatly reduced. The crop is harvested while the corn plant is still lush and green, and the plant can be green chopped for animal fodder or incorporated into the soil as green manure.

When to Harvest Baby Corn

It is generally recommended to harvest baby corn ears 1 to 3 days after the silks become visible. Field corn varieties which produce larger ears (greater than 8 inches when mature) may need to be harvested before the silks emerge in order to meet the size requirements for baby corn. Baby corn ears are generally harvested when they are 2–4 inches long and 1/3–2/3 inch in diameter. At this early stage of ear development, the ear can grow very quickly and in a day or two can easily grow larger than is acceptable. To best determine the appropriate time of harvest for a given variety in your area, a test harvest is recommended. As soon as the ears appear on the stalk, harvest a few each day to see when they reach the right size. Harvest the ears at the optimum size and place them immediately in refrigerated storage with the husks intact to conserve ear moisture and preserve quality.

WSU Baby Corn Variety Trial

In 1997, Washington State University Extension in collaboration with Owen Shaffner of Shaffner Farms, Montesano, conducted a baby corn variety trial in Grays Harbor County. We planted ten varieties of corn and tested their ear quality characteristics for baby corn production (Table 1).

Planting date was May 26, 1997; plant spacing was 2 inches in the row and 40 inches between the row; and 15-15-15 fertilizer was banded at planting at the rate of 150 pounds actual N-P-K per acre. After seeding, the plots were covered with floating row cover to protect the planting from crows which completely destroyed the trial in 1996. The row cover was removed on June 10 (2 weeks later) and plant growth was enhanced due to the higher temperatures under the row cover, resulting in an advanced harvest of 2 weeks.

Table 1. Ten corn varieties grown for baby corn in Montesano, Grays Harbor County in 1997.

Variety Type Company Comments
Tom Thumb popcorn (Su) Johnny's  recommended for baby corn production
M212 popcorn (Su) Johnny's suggested for baby corn production
Baby Corn field corn (Su) Nichols  a specialty baby corn variety
Jubilee sweet corn (Su)  Nichols common sweet corn variety
Tainan # 5 field corn (Su) from Taiwan  a major variety for baby corn production
NK 1699  field corn (Su) Northrup King  commonly grown in SW Washington
NK 0565 field corn (Su)  Northrup King commonly grown in SW Washington
Cargill 1877 field corn (Su) Cargill new to western Washington
Cargill 1037 field corn (Su)  Cargill new to western Washington
Cargill 1077 field corn (Su) Cargill new to western Washington

Harvestingbaby corn is labor intensive as it requires hand labor, and the height of the ear on the plant affects ease of picking and how much time it takes to pick a variety. In our evaluation of ten varieties for baby corn production we measured plant height and the height on the plant of the lowest and the top ears as indicators of ease of picking (Table 2). Tom Thumb is a dwarf popcorn variety which averaged 2 1/2 feet tall in our trial and the ear height ranged from 1/4–1 foot, making it extremely difficult to harvest – we were picking on our knees or bent over to the ground. Cargill 1077 is a dwarf grain corn which was also quite short, 4 1/4 feet, and ear height ranged from 1/3–2 feet, making it somewhat difficult to harvest. Tainan # 5 was quite tall, greater than 7 feet, and ear height ranged from 2/3–4 1/2 feet; the top ear was sometimes difficult to see due to leaf coverage. In this trial, all other varieties were on average 6–7 feet tall and ear height ranged from 1/2–3 1/2 feet and were generally easy to pick.

Table 2. Mean plant height (ft), height (ft) of the bottom ear, and height (ft) of the top ear at harvest of ten corn varieties grown for baby corn in Montesano, Grays Harbor County in 1997.

Variety Plant Height
(ft)
Height (ft) of
Bottom Ear
Height (ft) of
Top Ear
Johnny's M212 (popcorn)
6.4
0.53
3.47
Johnny's Tom Thumb (popcorn)
2.52
0.21
1.08
Nichols Baby Corn(Su)
5.64
0.47
3.51
Jubilee (Su)
5.94
0.49
2.61
Tainan # 5 (Taiwan)(Su)
7.65
0.64
4.41
NK 1699 (Su)
6.05
0.5
2.96
NK 0565 (Su)
6.26
0.52
3.22
Cargill 1877 (Su)
6.72
0.56
3.56
Cargill 1037(Su)
6.56
0.55
3.33
Cargill 1077(Su)
4.21
0.35
1.92

Market criteria for baby corn include ear length of 2–inches and ear diameter of 1/3–2/3 inch. We measured ear length and ear diameter of the ten varieties, however, in our trial we soon found that our first harvest was too late – we harvested 3–5 days after silking – and the ears tended to be too large for baby corn. The mean ear length of all varieties harvested from 1–3 days after silking in this trial ranged from 2–3 inches and the ear diameters ranged from 1/3–1/2 inch. We found it was critical to harvest each variety within one or two days of optimum harvest time as the ears of some varieties grew quite rapidly and were soon too large to market as baby corn.

photo of canned bby corn

Figure 3. Canned baby corn from the WSU baby corn trial at Shaffner Farms in Montesano, Grays Harbor County; jar on left contains ears which are too large and jar on right contains ears which are the right size and appearance for the baby corn market.

Good ear appearance is also extremely important to baby corn quality and includes ear characters such as row alignment where straighter rows are preferred, kernel size where petite is preferred, and ear tip shape where tapered is preferred (Figure 3).

We rated each variety for overall appearance based on these three ear characters (Table 3). In this trial, Tom Thumb was rated very poor as rows were not straight, kernels were very large, and the ear tip was blunt. These characteristics combined with the extremely low ear height made it an unsuitable variety in our trial for baby corn production. The other popcorn variety, M212, and the field corn variety, Cargill 1037, both had large kernel size and were unacceptable. All other field corn varieties had good ear characters and were suitable for baby corn production. Jubilee and Baby Corn both had the highest quality ears and the best appearance.

In this trial we did not measure yield as we felt yield was secondary to ear quality when choosing a variety for baby corn production. Also, we wanted this first trial to be a simple test of some corn varieties commonly grown in western Washington to see if they would meet the quality criteria for baby corn production. We did, however, record harvest dates and the number of harvests for each variety. Baby corn harvest began for most varieties in mid-August (Table 3). Tom Thumb, the dwarf popcorn variety, was first harvested August 4 and the second (and last) harvest was August 13. We chose not to continue harvesting Tom Thumb as we felt it was not acceptable for the baby corn market. For all other varieties, harvest continued until mid-September and each was harvested 5 or 6 times. It is important to recognize that each plant was not harvested 5 or 6 times, rather the "planting" was harvested 5 or 6 times. All the varieties in this trial produced on average 2–3 ears per plant, however, because plant spacing was so close, 2 inches apart in the row, plant development was not uniform. Some plants of a given variety were just beginning to produce ears while a neighbor plant of the same variety had already produced 2 or 3 ears.

In 1998, we will repeat this baby corn variety trial and will continue to test sweet corn, field corn and baby corn varieties for baby corn production in Grays Harbor County. Ear quality criteria such as ear length and diameter, row alignment, kernel size, and ear tip shape, will remain our primary measures of suitability, while yield will remain a secondary but still an important measurement.

Table 3. Harvest dates, number of harvests and the overall appearance of ten varieties of corn grown for baby corn production in Montesano, Grays Harbor County, in 1997.

Variety Harvest Dates No. of
Harvests
Overall Appearance
Johnny's M212 (popcorn, Su)
Aug 23 - Sept 19
6
Poor
Johnny's Tom Thumb (popcorn, Su)
Aug 4 - Aug 13
2
Very poor
Nichols Baby Corn (Su)
Aug 21 - Sept 19
7
Very good
Jubilee (Su)
Aug 16 - Sept 7
6
Very good
Tainan # 5 (Taiwan)(Su)
Aug 26 - Sept 19
5
Good
NK 1699 (Su)
Aug 14 - Sept 3
6
Good
NK 0565 (Su)
Aug 13 - Sept 10
5
Good
Cargill 1877 (Su)
Aug 18 - Sept 14
6
Good
Cargill 1037(Su)
Aug 13 - Sept 5
6
Poor
Cargill 1077(Su)
Aug 11 - Aug 31
5
Good

Seed Sources

Johnny's Selected Seeds Nichols Garden Nursery

1 Foss Hill Road
RR 1 Box 2580
Albion Maine 04910-9731
Tel. 207-437-4301
–or–
1190 North Pacific Highway NE
Albany, Oregon 97321-4580
Tel. 541-928-9280
 

Pickled Baby Corn

Blanch baby corn ears for 30–45 seconds in boiling water or steam.
Cool at room temperature. Pack into pint or half-pint jars. Add 1/2 teaspoon salt per pint.
Cover with mixture of 1 part water and 1 part vinegar, leaving 1/4 inch headspace.
Add spices, if desired. Process in simmering hot (180° - 190° F) water bath for 15 minutes.

Source: WSU Food Safety Advisor Program
 

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