Weather conditions greatly affect the growth and yield of vegetable crops. Wet, cool weather often leads to disease problems. Unfavorable weather can also cause physiological disorders or problems.
Below are common non-infectious, weather-related problems that occur in the vegetable garden and how to manage them.
Blossom Drop
Plants fail to set fruit.
Affected Crops
Tomato, pepper, snap beans.
Cause
Extremes in temperature and dry conditions may result in poor pollination and cause the flowers to drop from the plant without setting fruit. For example, blossom drop on tomatoes may occur when night temperatures are below 55 F or above 75 F.
Control
Water the plants deeply once a week. Fruit set should increase when temperatures moderate.
Poorly Filled Ears
Ears of corn are poorly filled.
Affected Crops
Sweet corn, popcorn.
Cause
Poorly filled ears result from inadequate pollination. Hot, dry winds and dry soil conditions during pollination may result in poorly filled ears. Improper planting may also affect pollination.
Control
Corn is wind pollinated, plant sweet corn and popcorn in blocks of 4 or more short rows to insure pollination. Water the plants during pollination if the soil is dry.
Bitter Fruit
Fruit have a bitter taste.
Affected Crops
Cucumbers.
Cause
Bitterness develops when plants are subjected to stressful growing conditions. Stressful conditions include high temperatures, drought, and disease problems.
Control
Much of the bitterness may be removed by cutting off the stem end of the cucumber and peeling the remaining portion of the fruit. Bitterness can be reduced by watering plants during dry periods and practicing good disease control. Cucumber varieties differ in their tendency to produce bitter fruit. 'Straight Eight' often produces bitter fruit. 'Sweet Slice' and 'Burpless Hybrid' have fewer problems.
Blossom-End Rot
A brown or black spot develops on the blossom end of the fruit. Secondary organisms invade the affected tissue and cause the fruit to rot.
Affected Crops
Tomato, pepper, summer squash.
Cause
Blossom-end rot is a physiological disorder caused by a lack of calcium in the developing fruit. Wide fluctuations in soil moisture levels impair calcium uptake by the root system. Excessive nitrogen fertilization may also contribute to blossom-end rot.
Control
To reduce blossom-end rot, mulch and water plants during dry weather to maintain uniform soil moisture levels. Avoid over- fertilizing with nitrogen.
Sunscald
Initial symptoms are shiny white or yellow areas on the sides of the fruit exposed to the sun. Later, the affected tissue dries out and collapses, forming slightly sunken, wrinkled areas. Secondary organisms invade the affected areas causing the fruit to rot.
Affected Crops
Tomato, pepper
Cause
Sunscald occurs on fruit exposed to the sun during periods of extreme heat.
Control
Grow tomatoes in wire cages. Plants grown in cages provide good foliage protection. Also, control foliar diseases of tomatoes and peppers which may defoliate the plants and expose the fruit to direct sunlight.
Split Cabbage Head
Cabbage head splits when mature.
Affected Crops
Cabbage
Cause
The splitting results from a build-up of water pressure.
Control
Splitting may be prevented by pulling the mature plant upward and gently twisting the plant to break some of the roots, thereby reducing water uptake. Plant only the number of cabbage you can use over a 2- to 3-week period when the crop is mature. Another alternative would be to plant early, mid-season, and late maturing cabbage varieties to prolong the harvest season.
Fruit Cracks
Radial and concentric cracks at the stem end of the fruit.
Affected Crop
Tomato
Cause
Heavy rainfall or irrigation following a long, dry period promotes rapid growth during ripening. This growth results in cracking. Exposure of tomatoes to high temperatures (above 90 F) and direct sunlight also contribute to cracking. Large-fruited varieties, such as 'Beefsteak,' are more susceptible to cracking.
Control
Cracking can be reduced by providing uniform supplies of moisture to the plants. Mulch and water the plants during dry weather. Also, plant crack-resistant varieties, such as 'Jetstar.'
Photo credits: 1: Mila Makhova/AdobeStock