Causes of poor pollination, no fruit , deformed fruit, or small fruit

Wanted to bring up the correlation of boron and fruit. Fruit problems are frequently overlooked and seldom does anyone discuss poor pollination if they get fruit. This is an interesting short article Poor Pollination | NC State Extension Publications

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Poor Pollination Strawberry Abiotic Disorders

Problem

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Poor pollination, misshaped fruit.

Two strawberries shown with a poorly shaped one on the right.

Normal fruit and mishaped fruit due to poor pollination.

Rocco D Schiavone

strawberry fruit with shrunken dark tip and undeveloped seeds.

Poor pollination due to cold injury.

Rocco D Schiavone

Symptoms

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Small misshaped fruit, malformed fruit, flowers that do not develop into fruit, small seeds and normal seeds on same fruit.

Similar Problems

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Micro nutrient deficiencies such as boron, damage to flowers from insects (thrips, mites, tarnish plant bug, etc.) and botrytis may cause misshaped fruit.

Additional Information

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Usually occurs very early in spring during frost/freeze conditions as well as cold wet weather or when row covers are used for an extended period of time.

Diagnostic Tips

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Micro nutrient deficiencies such as boron, damage to flowers from insects (thrips, mites, tarnish plant bug, etc.) and pathogens (botrytis) may also cause pollination problems. Examine plants closely for insects and pathogens also use tissue testing to check nutrient status to rule these out.

Corrective Measures

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When using row covers remove as soon as possible and uncover during warm days when used for extended time periods to allow wind and insect pollination.

Management

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Protect flowers/fruit from freeze and frost with overhead irrigation or row covers. Introduce bees in the field at 10% bloom. Avoid using row covers during the day when plants are blooming. Avoid pesticide sprays when crop is blooming. Spray pesticides early in the morning or late in the evening to avoid bee activity.

Useful Resources

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North Carolina Agricultural Chemicals Manual

Southern Region Small Fruit Consortium

NCCE Strawberry Growers portal

Funding Sources

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Funding was provided in part by the National Sustainable Agriculture Program: Sustainable Strawberry Initiative and the following sources.

University of Arkansas Division of Ag logo

Walmart logo

Author

Rocco Schiavone

Research Specialist
Horticultural Science

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2 Likes

You’re over looking the main cause of poor pollination or no pollination, which has plagued me this year is the weather. During bloom time, there was never any consistently warm and dry weather for the pollinators to do their thing. So they never came out and all of the blooms died unpollinated. The little amount of fruit that did get pollinated died with consistently bad weather.

3 Likes

@rayrose

Yes your right it’s nearly always weather related. In my area I saw a complete lack of pollinators in the daytime. Never saw anything like this year. Lucky for me one type of moth showed up one night. Wind was really bad as well. Lost a colony of bees last year and my suscipicion is some of the new people in the area are spraying when flowers are in bloom.