Functional Traits, Morphology, and Herbage Production of Vernalised and Non-Vernalised Chicory cv. Choice (Cichorium intybus L.) in Response to Defoliation Frequency and Height
Functional Traits, Morphology, and Herbage Production of Vernalised and Non-Vernalised Chicory cv. Choice (Cichorium intybus L.) in Response to Defoliation Frequency and Height
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DOI：
10.3390/plants9050611
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发表时间：
2020-05
期刊：
影响因子：
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通讯作者：
M. Mangwe;R. Bryant;Cristian A Moreno García;T. Maxwell;P. Gregorini
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文献类型：
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作者：
M. Mangwe;R. Bryant;Cristian A Moreno García;T. Maxwell;P. Gregorini
菊苣（chichorium intybus L.）用于放牧系统中，具有饲料物种所需的属性，可减少动物尿氮对土壤的负荷，增加牛奶产量，并提高牛奶脂肪酸含量，以改善畜牧农场系统，以满足日益增长的全球乳制品需求和畜牧业系统的环境标准。更多地采用菊苣需要对管理决策有信心，这些决策可以控制农业生产的风险，即春化后的抽苔或菊苣枝持久性的下降，这些都减缓了菊苣在畜牧系统中的采用。因此，我们测量了新西兰坎特伯雷春化前后灌溉条件下菊苣的功能性状、形态和牧草产量。试验场地采用完全随机区组设计，设4个重复，采用2个再生间隔和2个落叶高度。再生间隔期对功能性状和牧草产量的影响强于落叶高度，春化后影响更为显著。再生间隔较短的植株根系较窄，糖浓度较低，可能影响其寿命。此外，较短间隔期管理的植株大部分仍是营养植物，叶片较重、较长，但光合能力低于较长间隔期管理的植株。较长间隔期处理植株的茎伸长起始热时间为~274生长度d，平均茎伸长率以1.4±0.08 mm/生长度d呈线性增加。本研究的主要结果量化了春化后菊苣茎伸长的生长日数，为菊苣脱叶时间的选择提供了管理指导，以保证放牧牲畜的饲料质量。交替频繁和不频繁的落叶制度可用于优化营养生长、根系储备和牧草持久性。
Chicory (Cichorium intybus L.) used in pastoral systems has the attributes required of a forage species to reduce animal urinary nitrogen loading to soil, increase milk production, and enhance milk fatty acid profile to improve pastoral farm systems for matching increasing global demand for dairy products and environmental standards of livestock systems. Greater adoption of chicory requires confidence in management decisions that can control risks to farm production, namely bolting after vernalisation or a decline in persistence of chicory swards, which have slowed its adoption in pastoral systems. We, therefore, measured functional traits, morphology and herbage production of chicory under irrigated field conditions before and after vernalisation in Canterbury, New Zealand. The experimental site was laid out in a complete randomized block design with four replications where two regrowth intervals and two defoliation heights were applied. Regrowth interval had a stronger influence over functional traits and herbage production than defoliation height, with more pronounced effects after vernalisation. Plants managed under shorter regrowth intervals had narrower roots with lower concentration of sugars than plants under longer intervals, which might compromise their longevity. In addition, plants managed under shorter intervals remained mostly vegetative with heavier and longer leaves, though with reduced photosynthetic capacity than those managed under longer intervals. The thermal time to initiate stem elongation in plants managed under longer intervals was ~274 growing degree-days, with a mean stem elongation rate increasing linearly at 1.4 ± 0.08 mm/growing degree-days. The key outcomes of this research quantify the growing degree-days to initiate stem elongation post vernalisation, which provides management directive for timing of defoliation of chicory in order to maintain feed quality for grazing livestock. Alternating frequent and infrequent defoliation regimes might be used to optimise vegetative growth, root reserves, and pasture persistence.