Peppers - 2010 Ohio Vegetable Production Guide
Peppers are a warm-season crop, being sensitive to cold weather. Transplants normally are set in the field after the danger of frost. The sweet bell pepper is the most popular type; if allowed to ripen, the fruit turns red, orange, cream yellow or purple depending on cultivar, and remains sweet. In certain areas, red peppers are sought in the marketplace. Hot peppers are always pungent and vary in shape, color and degree of pungency. Pepper seeds germinate best at 85-90°F. Seedlings develop best at 75°F during the day and 65°F at night. To avoid transplant shock, harden the plants by only slightly reducing water and temperature, and increase the air movement to get them used to field conditions. Overhardened plants are slow to take off and can result in reduced yields. When setting transplants, be sure to use a starter fertilizer that is high in phosphorus. To reduce the loss of fruit set: (1) select varieties reported to set under unfavorable conditions, (2) keep growth progressing uniformly, (3) do not field set too early and (4) meter the fertilizer. Some fresh-market growers have significantly increased yields by planting double rows on black plastic mulch, with trickle irrigation laid under the plastic. This provides uniform moisture and fertility during the growing season. Also, extra magnesium and calcium nitrate can be added through the drip tubes. Poor fruit set occurs when night temperatures are below 60°F or above 75°F. Daytime temperatures much higher than 90°F also cause pollen sterility.