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Rosario P. Mauro - One of the best experts on this subject based on the ideXlab platform.
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Selection of shade-adapted subterranean Clover species for cover cropping in orchards
Agronomy for Sustainable Development, 2010Co-Authors: Giovanni Mauromicale, Angelo Occhipinti, Rosario P. MauroAbstract:The environmental side effects of intensive agriculture have underlined the need to develop sustainable farming systems. In particular, the use of cover cropping in orchards is a means of improving cash crop yield and of reducing the quantity of applied fertilisers. In the Mediterranean environment, subterranean Clover species could be the best choice for cover cropping, but they are only poorly adapted to the heavily shaded conditions characteristic of modern high-density orchards. The plant traits needed to improve adaptation of subterranean Clover are not well understood. Therefore, in a two-year experiment we studied the effects of four shading levels, of 0%, 40%, 60% and 90% reduction of photosynthetic active radiation, on phenology, growth and development of two subterranean Clover species: Trifolium brachycalycinum cv. 'Clare' and T. subterraneum ecotype 'Ragalna'. Our results show that shading progressively delayed seedling emergence by up to 21 days, the initiation of flowering by up to 27 days, and the end of flowering by up to 25 days. Shading also lengthened the life cycle from 237 to 267 days. Shading reduced both soil cover by up to 38.2% and cover crop density by up to 39.7%. Shading lowered both the quantity of above-ground dry biomass by up to 820 g m−2 and photosynthetically active surface area by up to 213 cm2 plant−1. Trifolium brachycalycinum 'Clare' was more productive in terms of above-ground dry biomass yield, but T. subterraneum 'Ragalna' was better adapted to shading in terms of rapid emergence, earliness and the time taken to achieve soil cover. These species differences suggest that the breeding targets for improving the adaptation of subterranean Clover to heavy shading are the ability to maintain earliness and the capacity to quickly break down hard-seededness under conditions of partial shade. A rapid initial increase in photosynthetically active surface area is particularly needed for maximising light harvesting during the early growth period.
Sara Elfstrand - One of the best experts on this subject based on the ideXlab platform.
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Clover cover crops under sown in winter wheat increase yield of subsequent spring barley effect of n dose and companion grass
Field Crops Research, 2011Co-Authors: Goran Bergkvist, Maria Stenberg, Johanna Wetterlind, Birgitta Bath, Sara ElfstrandAbstract:Abstract Four two-year field trials, arranged in randomised split-plots, were carried out in southern Sweden with the aim of determining whether reduced N fertiliser dose in winter wheat production with spring under-sown Clover cover crops, with or without perennial ryegrass in the seed mixture, would increase the Clover biomass and hence the benefits of the cover crops in terms of the effect on the wheat crop, on a subsequent barley crop and on the risk of N leaching. Four doses of nitrogen (0, 60, 120 or 180 kg N ha −1 ) constituted the main plots and six cover crop treatments the sub-plots. The cover crop treatments were red Clover ( Trifolium pratense L.), white Clover ( Trifolium repens L.) and perennial ryegrass ( Lolium perenne L.) in pure stands and in mixtures. The winter wheat ( Triticum aestivum L.) was harvested in August and the cover crops were ploughed under in November. The risk of N leaching was assessed in November by measuring the content of mineral N in the soil profile (0–30, 30–90 cm). In the following year, the residual effects of the cover crops were investigated in spring barley ( Hordeum distichon L.) without additional N. Under-sowing of cover crops did not influence wheat yield, while reduced N fertiliser dose decreased yield and increased the Clover content of the cover crops. When N was applied, the mixed cover crops were as effective in depleting soil mineral nitrogen as a pure ryegrass cover crop, while pure Clover was less efficient. The Clover content at wheat harvest as well as the amount of N incorporated with the cover crops had a positive correlation with barley yield. Spring barley in the unfertilised treatments yielded, on average, 1.9–2.4 Mg DM ha −1 more in treatments with Clover cover crops than in the treatment without cover crops. However, this positive effect decreased as the N dose to the preceding wheat crop increased, particularly when the Clover was mixed with grass.
P. D. Penning - One of the best experts on this subject based on the ideXlab platform.
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Managing grass/Clover swards to produce differing Clover proportions
Grass and Forage Science, 1994Co-Authors: N. H. Yarrow, P. D. PenningAbstract:Management treatments were applied to an established ryegrass/white Clover sward with the aim of producing differences in Clover content. The treatments were: mowing (M) with no fertilizer N (intended to give high Clover), grazing by cattle (C) with no fertilizer N (medium Clover) and grazing by sheep (S) with 300 kg N ha−1 applied (low Clover). Following treatments significant differences (P < 0.001) were observed, with M, C and S containing respectively. 237, 81 and 3 kg DM ha−1 of live Clover. Treatment M swards had fewer ryegrass tillers but greater numbers of Clover growing points than did treatment S, with values being intermediate on treatment C. Following overwintering most of the differences in the Clover component between treatments C and M were lost, but those on treatment S still persisted. Management can be used to manipulate the botanical composition of ryegrass/white Clover swards, but these changes may be only transient.
Giovanni Mauromicale - One of the best experts on this subject based on the ideXlab platform.
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Selection of shade-adapted subterranean Clover species for cover cropping in orchards
Agronomy for Sustainable Development, 2010Co-Authors: Giovanni Mauromicale, Angelo Occhipinti, Rosario P. MauroAbstract:The environmental side effects of intensive agriculture have underlined the need to develop sustainable farming systems. In particular, the use of cover cropping in orchards is a means of improving cash crop yield and of reducing the quantity of applied fertilisers. In the Mediterranean environment, subterranean Clover species could be the best choice for cover cropping, but they are only poorly adapted to the heavily shaded conditions characteristic of modern high-density orchards. The plant traits needed to improve adaptation of subterranean Clover are not well understood. Therefore, in a two-year experiment we studied the effects of four shading levels, of 0%, 40%, 60% and 90% reduction of photosynthetic active radiation, on phenology, growth and development of two subterranean Clover species: Trifolium brachycalycinum cv. 'Clare' and T. subterraneum ecotype 'Ragalna'. Our results show that shading progressively delayed seedling emergence by up to 21 days, the initiation of flowering by up to 27 days, and the end of flowering by up to 25 days. Shading also lengthened the life cycle from 237 to 267 days. Shading reduced both soil cover by up to 38.2% and cover crop density by up to 39.7%. Shading lowered both the quantity of above-ground dry biomass by up to 820 g m−2 and photosynthetically active surface area by up to 213 cm2 plant−1. Trifolium brachycalycinum 'Clare' was more productive in terms of above-ground dry biomass yield, but T. subterraneum 'Ragalna' was better adapted to shading in terms of rapid emergence, earliness and the time taken to achieve soil cover. These species differences suggest that the breeding targets for improving the adaptation of subterranean Clover to heavy shading are the ability to maintain earliness and the capacity to quickly break down hard-seededness under conditions of partial shade. A rapid initial increase in photosynthetically active surface area is particularly needed for maximising light harvesting during the early growth period.
J R Crush - One of the best experts on this subject based on the ideXlab platform.
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Effects of Clover root weevil and moisture stress on subterranean, balansa, Persian, arrowleaf and white Clovers
Proceedings of the New Zealand Grassland Association, 2008Co-Authors: J R Crush, P.j. Gerard, L. Ouyang, D.j. WilsonAbstract:The effect on plant growth of Clover root weevil (CRW) larval feeding on nodules and roots was examined for the annual Clovers, subterranean cv. Leura, balansa cv. Bolta, arrowleaf cv. Arrowtas and Persian cv. Mihi, and white Clover cv. Tribute. Mini-swards of each Clover species were used in a glasshouse experiment, with half of these exposed to CRW larval feeding. A moisture stress treatment was imposed as a sub-treatment on half the swards with and without CRW. CRW larval feeding had no effect on shoot growth, but reduced root weights significantly with most effect on white Clover. More CRW larvae were recovered from core samples taken from white Clover than from the annual Clovers. Effects of CRW were generally more severe in the well-watered swards. It is concluded that the relative tolerance to CRW shown by the annuals combined with the negative effects of summer drought on CRW populations should mean that CRW does not pose a major threat to dryland pastures based on annual legumes.
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Development of Clovers that are tolerant to Clover root weevil
Proceedings of the New Zealand Grassland Association, 2005Co-Authors: J R Crush, B.m. Cooper, D.r. Woodfield, P.j. GerardAbstract:Clover root weevil (CRW) has become a major pest of white Clover in pastures in much of the North Island. In contemporary, intensively stocked pastures, high volumes of nitrogen (N) cycling through the soil/plant/ animal system stimulate grass growth and reduce the Clover content of pastures. Clover root weevil imposes further stresses on Clovers. A range of white and red Clover germplasm was evaluated f or CRW tolerance from 2002-2005 on Waikato dairy and sheep/beef farms. Results confirmed the importance of good agronomic adaptation if Clovers are to survive the additional stress of CRW. Two recently released white Clover cultivars (Grasslands Kopu II and Tribute) were amongst the top performing lines under dairy farm grazing. Under sheep/ beef grazing, spreading type red Clovers also performed well. A white c lover breeding line selected for tolerance of plant-feeding nematodes was in the top group of Clovers at both sites. Reducing stresses on Clovers from other pasture pests will contribute to improved tolerance to CRW. A glasshouse experiment showed that CRW larval feeding can severely damage white Clover nodules and reduce N fixation. The plants have considerable capacity to grow new nodules but this diverts energy away from other growth processes. Our conclusions are that welladapted, vigorous white Clover cultivars are better able to cope with the additional stress imposed by the root weevil. Good pasture management and attention to fertiliser requirements can improve Clover survival under root weevil herbivory. New generation red Clovers show considerable potential for weevil infested areas. Coselection for tolerance/resistance to other major Clover pests e.g. Clover flea and root nematodes will improve plant performance under CRW stress. Keywords: Clover root weevil, nitrogen fixation, plant breeding, red Clover, white Clover
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FEEDING HABITUATION TO RED Clover BY Clover ROOT WEEVIL ADULTS
New Zealand Plant Protection, 2003Co-Authors: P.j. Gerard, J R CrushAbstract:Red Clover (Trifolium pratense) has been observed to persist longer than white Clover (T repens) during field screening of legumes for tolerance of Clover root weevil (Sitona lepidus) It has been suggested that this is linked to adult feeding preferences A laboratory trial was undertaken to confirm the feeding preference for white Clover over red and to determine whether adults became habituated to red Clover over time Groups of Clover root weevil adults were caged on either white Clover cv Grasslands Huia or 3 lines of Grasslands Pawera red Clover At weeks 2 4 6 and 8 subsamples of adults were removed from the cages and were subjected to a 24 h choice test It was found that although adults showed a strong preference for white Clover those that had been continuously fed red Clover were more likely to feed on red Clover in the choice test than those that had previously been fed white Clover
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Red Clover - a legume showing tolerance to Clover root weevil
Proceedings of the New Zealand Grassland Association, 2003Co-Authors: B.m. Cooper, J R Crush, D.r. Woodfield, B.e. Willoughby, K.a. PanckhurstAbstract:Clover root weevil (CRW) has now spread through the northern North Island, and south into Taranaki and Hawke's Bay r egions. Sever e infestations can decimate white Clover in pasture. In 1998, 2000 and 2002, trials were estab lished on a Warkworth Northland dairy farm to test a range of legume species for resistance or tolerance to CRW damage. Trial lines were regularly assessed for relative vigour and levels of CRW damage. No plant resistance w as identified among white Clover, red Clover, lucerne, Lotus corniculatus, Lotus pedunculatus or Caucasian Clover seed lines. A few lines were adapted to the site and showed tolerance to CRW. Red Clover suf fered the least damage and tolerant selections were made from a creeping red Clover and nine white Clover lines. Two further trials confirmed that red Clover showed the least damage. Further cycles of selection are required to develop the potential tolerance shown in field tests. Red Clover or a well-adapted white Clover offers potential to cope with the CRW stress. Keywords: Clover root weevil, Clover selections, legume tolerance, Sitona lepidus
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INTERACTION BETWEEN Clover ROOT WEEVIL AND Clover ROOT TYPE
New Zealand Plant Protection, 2000Co-Authors: D. A. Care, J R Crush, S. Hardwick, S. N. Nichols, L. OuyangAbstract:A slant board experiment investigated the effect of four white Clover (Trifolium repens L.) root types on tolerance of root feeding by larvae of Clover root weevil (Sitona lepidus Gyllenhal). Root damage was determined by image analysis and larval weight gains were measured. Differences in root type did not have a major impact on initial damage by Clover root weevil. However different root types were affected differently by the Clover root weevil. A Clover genotype with long fine roots had more functional root length after larval feeding than genotypes with different root types.
