Back to top

Chapter 27: Tomatoes (Field)

27.1 Recommended Varieties

Most commercial tomato hybrids are determinate, having a restricted branching and fruiting pattern and branches terminating in a flower cluster. These varieties are preferred for commercial production because the harvest period is more concentrated and the plants are more compact and bushlike, making optimal spacing more predictable and facilitating cultivation. Many home garden varieties, some commercial staking varieties, and some cherry tomato varieties are indeterminate, continuing to produce new branches and flowers throughout the growing season.

Type
Ground culture High Tunnel Determinate
Sunstart (64)1 Mountain Fresh (75)
Spitfire (68) Primo Red (70)2
Sunrise (69) BHN 589 (75)
Mountain Spring (71) High Tunnel - Indeterminate
Sunbrite (73) Geronimo (80)2
Mountain Delight (73) Trust (78)
Sunbeam (74) Cobra (72)
Mountain Fresh (75) Plum
Mountain Pride (79) BHN 410 (76)
Trellis/stake LaRossa (78
Mountain Spring (71) Cherry
Sunbrite (73) Sun Gold (orange) (60)
Mountain Delight (73) Sweet 100 (62)
Sunbeam (74) Mountain Belle (68)
Mountain Fresh (75)  
Mountain Pride (79)  
1: Days to maturity.
2: Resistant to Brown Leaf Mold

Tables of Disease Resistant Varieties

27.2 Planting Methods

Because tomatoes are sensitive to frost, transplants are seldom put in the field before May 10 in upstate New York. The latest plantings for fall harvest are at the end of June. Transplants are grown in greenhouses at 70° to 75°F day and 60° to 65°F night temperatures. Bottom heat (75°F) improves emergence. For early market, a two to three inch cell for each plant in the flat is recommended. Plants are usually six to seven weeks old and just showing buds when taken to the field.

Before transplanting to the field, tomato seedlings should be hardened by withholding water and nitrogen, not by exposure to cold temperatures. Transplants exposed to cold (60° to 65°F day and 50° to 60°F night) for one week or longer are more prone to catfacing, a serious physiological disorder that can reduce marketable yield substantially.

For high tunnels, tomatoes are transplanted approximately 4 weeks prior to traditional field transplant dates.  Within New York this could vary between April 1 and May 15.  Black plastic mulch and drip irrigation are common within high tunnels.  Research has shown that on calm, cold nights high tunnel temperatures may drop below outside air temperature.  Thus back-up emergency heat with propane heaters, in addition to spun-bond floating row covers, is important to prevent losses to frost.

Table 27.2.1 Recommended spacing

Type Row (feet) In-row (inch)
Ground Culture    
Determinate 4-5 15-24
Indeterminate 5-6 24-36
Trellis 5 18-24

Staking and pruning can hasten early fruit production by a week or more, protect fruit quality, and facilitate harvest. The cost-effectiveness of this system depends, in part, on the prices paid for early and high quality fruit. Wooden stakes, four to five feet long and one inch square, are generally used; they are driven one foot into the ground between every other plant in the row. Weather-resistant twine is tied to an end stake, passed along one side of the plants, and looped around each stake until the end of the row. The process is repeated on the other side of the plants. A short length of metal conduit or PVC pipe is often used as an extension of the stringer’s arm, with the twine fed through the tube. The first stringing is at an eight to ten inch height when the plants are 12 to 16 inches tall. The next stringing is six to eight inches higher and applied before the plants start to fall over. It may be necessary to string three or four times.

Pruning will result in a lower total yield, but the fruits produced will tend to be larger, and the first set may mature a few days early. Pruning involves removing all suckers (when they are two to four inches long) up to the one immediately below the first flower cluster. More severe pruning is not recommended because it will cause leaf curl and plant stunting. Some growers prune only one or two suckers or none at all, particularly if the variety does not have a vigorous growth habit. Plants should be pruned before the first stringing and not when they are wet because this could spread disease.

27.3 Fertility

Maintain a pH of 6.0 to 6.5. Zinc may be needed if the organic matter is low and the pH is greater than 7. If these conditions exist, apply zinc sulfate in the transplant water. For transplants, add 1/2 pound zinc sulfate in 100 gallons of transplant water for a 0.2 percent solution. See Table 27.3.1 and Table 27.3.2, below, for the recommended rates of nitrogen, phosphorus, and potassium.

Table 27.3.1 Recommended nutrients based on soil tests for transplants in bare ground

N pounds/acre P2O5 pounds/acre   K2O pounds/acre Comments
  Soil Phosphorus Level   Soil Potassium Level  
  low med. high   low med. high  
100 150 100 50   180 120 60 Total recommended.
50 150 100 50   180 120 60 Broadcast and disk-in.1
50 0 0 0   0 0 0 Apply when first clusters set fruit.2
1: If equipment is available, apply half of the phosphorus and potassium in bands 4" deep and 4" from the row at planting.
2: Nitrogen can be applied as a split application. Apply half at fruit set and the rest when fruit are 1" in diameter.

Table 27.3.2 Recommended nutrients based on soil tests for transplants in plastic mulch

(If plastic mulch is used without fertigation, broadcast and incorporate all fertilizer before laying plastic mulch).

N pounds/acre P2O5 pounds/acre   K2O pounds/acre Comments
  Soil Phosphorus Level   Soil Potassium Level  
  low med. high   low med. high  
100 150 100 60   180 120 60 Total recommended.
40 90 40 0   120 60 0 Broadcast and disk-in.1
20 20 20 20   20 20 20 Apply 1 week after transplanting.
20 20 20 20   20 20 20 Apply when first fruit are 1" in diameter.
20 20 20 20   20 20 20 Apply when first fruit turn color.
1: If equipment is available, apply half of the phosphorus and potassium in bands 4" deep and 4" from the row at planting.

Table 27.4.1 Nonpathogenic disorders

Disorder Guideline
Blossom End Rot (BER) Characterized by a large, leathery brown or black spot on the bottom of the fruit caused by a calcium deficiency. Test the soil to make sure calcium levels are adequate, and maintain uniform moisture. Varieties vary in susceptibility.
Catface Severe scarring on the blossom end of the fruit, usually most severe on the earliest fruit of large, fruited varieties. Temperatures during fruit set of 60° to 65°F during the day and 50° to 55°F at night aggravate the problem. Do not harden transplants by lowering the temperature.
Fruit cracking Due to rapid uptake of water by the fruit, as a result of heavy rain or watering. Choose crack resistant varieties, and maintain uniform soil moisture by mulching and steady watering.
Yellow or green shoulders Tops of fruit never ripen completely. This is a genetic problem that can be eliminated by growing plants with the uniform ripening gene. See Recommended Varieties above.
Blossom drop Due to daytime temperatures in excess of 90°F and night time temperatures over 80°F. Varieties vary in susceptibility.
Sunscald Symptoms appear as a yellow to white water-soaked area on the side of the fruit exposed to the sun. Ensure plants are adequately fertilized, so healthy foliage shades fruit. Do not prune plants after fruit has formed.
Internal browning/ blotchy ripening/gray wall Fruit ripens slowly and unevenly. Exact cause is unknown but may be related to tomato mosaic virus (TMV); cloudy, moist, cool weather; soil compaction; or low potassium levels.

27.4 Harvesting

Fresh-market tomatoes, especially those that will be shipped, may be dumped from field or transport containers into large tanks of water to prevent bruising immediately after harvest. Water temperature in dump tanks should be slightly higher (5° to 10°F) than fruit temperature to prevent the movement of bacteria into the stem end of the fruit. Fruit are usually washed with a water spray immediately after the dumping operation regardless of whether a wet or dry dumping method is used. Only chlorinated water should be used. See Section 10.1 in the Postharvest Handling chapter.

Tomatoes should be stored between 55° and 70°F and 90 to 95 percent relative humidity. Chilling injury can develop if temperatures are below 50°F for more than 24 hours. Tomatoes ripen more quickly as temperatures increase; although they ripen faster at 75°F than at 70°F, they will have a better color to firmness ratio at 70°F. Temperatures above 80°F will inhibit red color development. Tomatoes harvested at mature green can be held for up to two weeks at 55°F. Ripening of mature green fruit can be initiated by a 24 to 48 hour exposure to 100 to 150 parts per million of ethylene at 70°F and 85 to 90 percent relative humidity.

27.5 Disease Management

27.5.1 Bacterial Canker, Bacterial Speck, and Bacterial Spot
27.5.2 Bacterial Soft Rot
27.5.3 Damping-off
27.5.4 Early Blight
27.5.5 Anthracnose
27.5.6 Septoria Leaf Spot
27.5.7 Buckeye Fruit Rot
27.5.8 Botrytis Gray Mold, Gray Leaf Mold, and White Mold or Timber Rot
27.5.9 Late Blight
27.5.10 Cucumber Mosaic Virus
27.5.11 Double Virus Streak
27.5.12 Tomato (Tobacco) Mosaic Virus
27.5.13 Tomato Spotted Wilt Virus

27.5.14 Powdery Mildew

 

27.6: Insect Management

27.6.1 Colorado Potato Beetle
27.6.2 Flea Beetle
27.6.3 Brown Marmorated Stink Bug, Green Stink Bug, and Brown Stink Bug
27.6.4 Tarnished Plant Bug
27.6.5 Potato Aphid
27.6.6 Tomato Fruitworm, Yellowstriped Armyworm, and Hornworm
27.6.7 Cutworms
27.6.8 Two-spotted Spider Mite

27.6.9 Western Flower Thrips

 

27.7 Weed Management

 

Websites

Maintained by Abby Seaman, New York State IPM Program. Last modified 2019.