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ARS Home » Southeast Area » Miami, Florida » Subtropical Horticulture Research » Research » Publications at this Location » Publication #144143
Title: HOW CAN YOU REDUCE FLOODING DAMAGE TO VEGETABLE CROPS?

Author
item LI, YUNCONG - UNIVERSITY OF FLORIDA
item RAO, RENUKA - UNIVERSITY OF FLORIDA
item Reed, Stewart

Submitted to: University of Florida Handout
Publication Type: Other
Publication Acceptance Date: 1/30/2003
Publication Date: 8/1/2003
Citation: Li, Y., Rao, R., Reed, S.T. 2003. HOW CAN YOU REDUCE FLOODING DAMAGE TO VEGETABLE CROPS?. University of Florida Handout. EDIS.ifas.ufl.edu/SS425. 2003.

Interpretive Summary: Flooding causes a significant decrease in N content and rate of N accumulation in plants because of reduced root activity. Plant available soil N is also very low because of leaching or runoff. Thus, a strategic use of N fertilizer after flooding may alleviate N deficiency and enhance crop recovery from flooding. Growers should apply fertilizers as soon as soils dry enough for tractor operation. Foliar application of liquid fertilizers is more effective than broadcasting dry fertilizer because of root damage due to flooding. Recently we tested several fertilizers and found: potassium nitrate sp > urea sp> calcium nitrate. A regular granular dry fertilizer such as 10N-10P2O5-10K2O also can be used for flooded crops, but it is not as effective as foliar and liquid fertilizers. Spraying shoots with a synthetic cytokinin (6-benzylaminopurine [BAP]) has been reported to reduce flooding damage by improvements in leaf extension and retarded premature loss of chlorophyll in older leaves. However, our recent study with six growth regulators showed no effects on sweet corn and cowpea recovery from flooding. Some growth regulators even inhibited crop recovery by affecting photosynthesis and evapotranspiration. Flooding reduces the ability of the root systems to obtain mineral nutrients or perform other functions essential to the shoot. Application of fungicides probably reduces the incidence of disease in waterlogged plants and thereby increases plant tolerance to flooding. However, we tested two fungicides (Ridomil and Bravo 720) and found both chemicals had no significant effect on plant growth.

Technical Abstract: Flooding causes a significant decrease in N content and rate of N accumulation in plants because of reduced root activity. Plant available soil N is also very low because of leaching or runoff. Thus, a strategic use of N fertilizer after flooding may alleviate N deficiency and enhance crop recovery from flooding. Growers should apply fertilizers as soon as soils dry enough for tractor operation. Foliar application of liquid fertilizers is more effective than broadcasting dry fertilizer because of root damage due to flooding. Recently we tested several fertilizers and found: potassium nitrate sp > urea sp> calcium nitrate. A regular granular dry fertilizer such as 10N-10P2O5-10K2O also can be used for flooded crops, but it is not as effective as foliar and liquid fertilizers. Spraying shoots with a synthetic cytokinin (6-benzylaminopurine [BAP]) has been reported to reduce flooding damage by improvements in leaf extension and retarded premature loss of chlorophyll in older leaves. However, our recent study with six growth regulators showed no effects on sweet corn and cowpea recovery from flooding. Some growth regulators even inhibited crop recovery by affecting photosynthesis and evapotranspiration. Flooding reduces the ability of the root systems to obtain mineral nutrients or perform other functions essential to the shoot. Application of fungicides probably reduces the incidence of disease in waterlogged plants and thereby increases plant tolerance to flooding. However, we tested two fungicides (Ridomil and Bravo 720) and found both chemicals had no significant effect on plant growth.