Early growth and development of wild radish (Raphanus raphanistrum L.) in relation to wheat

2001 ◽  
Vol 52 (7) ◽  
pp. 755 ◽  
Author(s):  
R. D. Cousens ◽  
J. W. Warringa ◽  
J. E. Cameron ◽  
V. Hoy

Raphanus raphanistrum was grown in monoculture and as a range of cohorts of emergence in mixture with wheat. Growth and development were recorded at frequent intervals up to anthesis of the wheat.R. raphanistrum remained shorter than wheat, only over-topping the crop prior to anthesis for 2 of 7 sowing dates. When expressed in terms of photothermal time, growth in monocultures was similar for all sowing dates except those for wheat in mid-summer. Even a short delay in R. raphanistrumemergence in mixture decreased its growth considerably; R. raphanistrum emerging more than 4 weeks after the crop had no detectable effect on the wheat. However, even R. raphanistrum plants emerging 10 weeks after the crop produced some seeds. In mixture, R. raphanistrum had a higher specific leaf area (SLA), reduced leaf partitioning, and taller stems than in monoculture. A physiological growth model based on parameters from monocultures was unable to predict growth in mixtures; inclusion of changes in SLA and height in mixture improved predictions in some cases. It is concluded that competition models based on monoculture parameters, although previously successful for species with similar height and phasic development, are unlikely to work for species that differ in these attributes. Further work is required on the physiology of plants within mixtures.

2021 ◽  
pp. 1-23
Author(s):  
Michael J. Walsh ◽  
Peter Newman ◽  
Paul Chatfield

Abstract Wild radish is the most problematic broadleaf weed of Australian grain production. The propensity of wild radish to evolve resistance to herbicides has led to high frequencies of multiple herbicide resistant populations present in these grain production regions. The objective of this study was to evaluate the potential of mesotrione to selectively control wild radish in wheat. The initial dose response pot trials determined that at the highest mesotrione rate of 50 g ha−1, PRE application was 30% more effective than POST on wild radish. This same rate of mesotrione POST resulted in a 30% reduction in wheat biomass compared to 0% for the PRE application. Subsequent, mesotrione PRE dose response trials identified a wheat selective rate range of >100 and < 300 g ai ha−1 that provided greater than 85% wild radish control with less than 15% reduction in wheat growth. Field evaluations confirmed the efficacy of mesotrione at 100 to 150 g ai ha−1 in reducing wild radish populations by greater than 85% following PRE application and incorporation by wheat planting. Additionally, these field trials demonstrated the opportunity for season-long control of wild radish when mesotrione PRE was followed by bromoxynil POST. The sequential application of mesotrione, an HPPD-inhibiting herbicide, PRE followed by bromoxynil, a PS II-inhibiting herbicide POST has the potential to provide 100% wild radish control with no effect on wheat growth.


2010 ◽  
Vol 34 (4) ◽  
pp. 521-530 ◽  
Author(s):  
Xi-wu YAN ◽  
Qi WANG ◽  
Yue-huan ZHANG ◽  
Zhong-ming HUO ◽  
Yue ZHAO ◽  
...  

2018 ◽  
Vol 66 (51) ◽  
pp. 13378-13385 ◽  
Author(s):  
Danica E. Goggin ◽  
Gareth L. Nealon ◽  
Gregory R. Cawthray ◽  
Adrian Scaffidi ◽  
Mark J. Howard ◽  
...  

2018 ◽  
Vol 66 (2) ◽  
pp. 161 ◽  
Author(s):  
Elaine Cotrim Costa ◽  
Renê Gonçalves da Silva Carneiro ◽  
Juliana Santos Silva ◽  
Rosy Mary dos Santos Isaias

Analyses of gall biology and development allow determination of morphogenesis events in host-plant organs that are altered by galling insects. Currently, we assume that there is a correlation between Lopesia sp. instars and the alterations in gall tissues on Mimosa gemmulata that generate the gall shape. The development of Lopesia sp. (three larval instars, pupae and adult) correlates positively with gall growth, especially on the anticlinal axis. First-instar larvae are found in galls at the stage of induction, Instar 2 in galls at early growth and development, Instar 3 in galls at late growth and development, pupae in galls at maturation, and the adult emerges from senescent galls. At induction, the larva stimulates cell differentiation in pinnula and pinna-rachis tissues on M. gemmulata. At early growth and development stages, cell division and expansion are increased, and non-glandular trichomes assist gall closing. Homogenous parenchyma and neoformed vascular bundles characterise late growth and development. At maturation, tissues are compartmentalised and cells achieve major expansion through elongation. At senescence, galls open by the falling of trichomes, and mechanical and nutritive cells have thickened walls. The neoformed nutritive tissue nurtures the developing Lopesia sp., whose feeding behaviour influences the direction of cell elongation, predominantly periclinal, determinant for gall bivalve shape.


Author(s):  
Stephen J. Simpson ◽  
David Raubenheimer

This chapter studies intake and growth targets. For clarity, earlier chapters have treated intake and growth targets as static points integrated across a particular period in the life of an animal. In reality they are, of course, not static but rather trajectories that move in time. In the short term, the requirements of the animal change as environmental circumstances impose differing demands for nutrients and energy. At a somewhat longer timescale, targets move as the animal passes through the various stages of its life, from early growth and development to maturity, reproduction, and senescence. On an even longer timescale, nutritional traits are subject to natural selection and move as species evolve to exploit new or changing nutritional environments and to adopt differing life-history strategies. Presaging such evolutionary change in gene frequencies within populations are epigenetic effects, whereby the nutritional experiences of parents influence the behavior and metabolism of their offspring without requiring changes in gene frequencies.


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