| Autor: |
Felts, S. G., Bateman, N. R., Lorenz, G. M., Thrash, B. C., Taillon, N. M., Plummer, W. A., Plummer, W. J., McPherson, J. K., Clayton, T. L., Floyd, C. A., Rice, C. |
| Předmět: |
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| Zdroj: |
B.R. Wells Rice Research Studies - Arkansas Agricultural Experiment Station, University of Arkansas System; Aug2020, Issue 667, p105-108, 4p |
| Abstrakt: |
Armyworms are commonly found in rice fields in the mid-southern U.S. and have the potential to cause severe defoliation to the rice crop. The two main armyworm species observed in rice in this region are true armyworms and fall armyworm. It is common to see infestations at all growth stages of rice. The current threshold for armyworms in rice is based on the number of larvae per square foot. A defoliation-based threshold would provide growers and consultants with a simple way to make economically sound decisions for controlling armyworms in rice. Rice plants in large field plots were mechanically defoliated at 0%, 33%, 66%, and 100% with a weed eater at 2-3 leaf, early tiller, late tiller, and green ring growth stages across three planting dates. Large amounts of yield loss were observed when plants were defoliated either 66% or 100% at the green ring growth stage. A delay in heading was also observed when plants were defoliated at 66% or 100% during any growth stage, with delays ranging from 2 days for defoliation occurring at the 2-3 leaf growth stage to 28 days for defoliation occurring at the green ring growth stage. Yield loss and delays in heading were greater for the June planting date compared to the April or May planting date. This data will help form a defoliation-based threshold in rice to help keep rice growers profitable. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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