Decreasing Defoliation Frequency Enhances <i>Bromus valdivianus</i> Phil. Growth under Low Soil Water Levels and Interspecific Competition
<i>Bromus valdivianus</i> Phil. (Bv) is a water stress-tolerant species, but its competitiveness in a diverse pasture may depend on defoliation management and soil moisture levels. This glasshouse study examined the effect of three defoliation frequencies, based on accumulated growing de...
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| Format: | Article |
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MDPI AG
2021-06-01
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| Series: | Agronomy |
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| Online Access: | https://www.mdpi.com/2073-4395/11/7/1333 |
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| author | Javier García-Favre Yongmei Zhang Ignacio F. López Daniel J. Donaghy Lydia M. Cranston Peter D. Kemp |
| author_facet | Javier García-Favre Yongmei Zhang Ignacio F. López Daniel J. Donaghy Lydia M. Cranston Peter D. Kemp |
| author_sort | Javier García-Favre |
| collection | DOAJ |
| description | <i>Bromus valdivianus</i> Phil. (Bv) is a water stress-tolerant species, but its competitiveness in a diverse pasture may depend on defoliation management and soil moisture levels. This glasshouse study examined the effect of three defoliation frequencies, based on accumulated growing degree days (AGDD) (250, 500, and 1000 AGDD), and two soil water levels (80–85% of field capacity (FC) and 20–25% FC) on Bv growth as monoculture and as a mixture with <i>Lolium perenne</i> L. (Lp). The treatments were applied in a completely randomised block design with four blocks. The above-ground biomass of Bv was lower in the mixture than in the monoculture (<i>p</i> ≤ 0.001). The Bv plants in the mixture defoliated more infrequently (1000 AGDD) showed an increase in root biomass under 20–25% FC compared to 80–85% FC, with no differences measured between soil water levels in the monoculture. Total root length was highest in the mixture with the combination of infrequent defoliation and 20–25% FC. Conversely, frequent defoliation treatments resulted in reduced water-soluble carbohydrate reserves in the tiller bases of plants (<i>p</i> ≤ 0.001), as they allocated assimilates mainly to foliage growth. These results provide evidence that <i>B. valdivianus</i> can increase its competitiveness relative to Lp through the enhancement of the root growth and the energy reserve in the tiller base under drought conditions and infrequent defoliation in a mixture. |
| first_indexed | 2024-03-10T09:55:40Z |
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| issn | 2073-4395 |
| language | English |
| last_indexed | 2024-03-10T09:55:40Z |
| publishDate | 2021-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Agronomy |
| spelling | doaj.art-5a1a57df749b423c80fe96e324c83fc12023-11-22T02:19:55ZengMDPI AGAgronomy2073-43952021-06-01117133310.3390/agronomy11071333Decreasing Defoliation Frequency Enhances <i>Bromus valdivianus</i> Phil. Growth under Low Soil Water Levels and Interspecific CompetitionJavier García-Favre0Yongmei Zhang1Ignacio F. López2Daniel J. Donaghy3Lydia M. Cranston4Peter D. Kemp5School of Agriculture and Environment, Massey University, Private Bag 11-2221, 4440 Palmerston North, New ZealandGansu Provincial Key Laboratory of Aridland Crop Science, Gansu Agricultural University, Lanzhou 730070, ChinaSchool of Agriculture and Environment, Massey University, Private Bag 11-2221, 4440 Palmerston North, New ZealandSchool of Agriculture and Environment, Massey University, Private Bag 11-2221, 4440 Palmerston North, New ZealandSchool of Agriculture and Environment, Massey University, Private Bag 11-2221, 4440 Palmerston North, New ZealandSchool of Agriculture and Environment, Massey University, Private Bag 11-2221, 4440 Palmerston North, New Zealand<i>Bromus valdivianus</i> Phil. (Bv) is a water stress-tolerant species, but its competitiveness in a diverse pasture may depend on defoliation management and soil moisture levels. This glasshouse study examined the effect of three defoliation frequencies, based on accumulated growing degree days (AGDD) (250, 500, and 1000 AGDD), and two soil water levels (80–85% of field capacity (FC) and 20–25% FC) on Bv growth as monoculture and as a mixture with <i>Lolium perenne</i> L. (Lp). The treatments were applied in a completely randomised block design with four blocks. The above-ground biomass of Bv was lower in the mixture than in the monoculture (<i>p</i> ≤ 0.001). The Bv plants in the mixture defoliated more infrequently (1000 AGDD) showed an increase in root biomass under 20–25% FC compared to 80–85% FC, with no differences measured between soil water levels in the monoculture. Total root length was highest in the mixture with the combination of infrequent defoliation and 20–25% FC. Conversely, frequent defoliation treatments resulted in reduced water-soluble carbohydrate reserves in the tiller bases of plants (<i>p</i> ≤ 0.001), as they allocated assimilates mainly to foliage growth. These results provide evidence that <i>B. valdivianus</i> can increase its competitiveness relative to Lp through the enhancement of the root growth and the energy reserve in the tiller base under drought conditions and infrequent defoliation in a mixture.https://www.mdpi.com/2073-4395/11/7/1333defoliation managementplant traitsdroughtdiversity |
| spellingShingle | Javier García-Favre Yongmei Zhang Ignacio F. López Daniel J. Donaghy Lydia M. Cranston Peter D. Kemp Decreasing Defoliation Frequency Enhances <i>Bromus valdivianus</i> Phil. Growth under Low Soil Water Levels and Interspecific Competition Agronomy defoliation management plant traits drought diversity |
| title | Decreasing Defoliation Frequency Enhances <i>Bromus valdivianus</i> Phil. Growth under Low Soil Water Levels and Interspecific Competition |
| title_full | Decreasing Defoliation Frequency Enhances <i>Bromus valdivianus</i> Phil. Growth under Low Soil Water Levels and Interspecific Competition |
| title_fullStr | Decreasing Defoliation Frequency Enhances <i>Bromus valdivianus</i> Phil. Growth under Low Soil Water Levels and Interspecific Competition |
| title_full_unstemmed | Decreasing Defoliation Frequency Enhances <i>Bromus valdivianus</i> Phil. Growth under Low Soil Water Levels and Interspecific Competition |
| title_short | Decreasing Defoliation Frequency Enhances <i>Bromus valdivianus</i> Phil. Growth under Low Soil Water Levels and Interspecific Competition |
| title_sort | decreasing defoliation frequency enhances i bromus valdivianus i phil growth under low soil water levels and interspecific competition |
| topic | defoliation management plant traits drought diversity |
| url | https://www.mdpi.com/2073-4395/11/7/1333 |
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