SUNScholar - Browsing by Author "Fourie, J. C."

Browsing by Author "Fourie, J. C."

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Control potential of brassicaceae cover crops as green manure and their host status for meloidogyne javanica and criconemoides xenoplax
(South African Society for Enology and Viticulture, 2015-12) Kruger, D. H. M.; Fourie, J. C.; Malan, Antoinette P.
Laboratory bioassays were undertaken to determine the potential of Avena sativa cv. Pallinup (Pallinup oats), Sinapis alba cv. Braco (white mustard), Brassica napus cv. AV Jade (canola), Brassica juncea cv. Caliente 199 (Caliente) and Eruca sativa cv. Nemat (Nemat) to suppress Meloidogyne javanica (root-knot nematode) and Criconemoides xenoplax (ring nematode) when applied as green manure. The host status of the crops also was determined during glasshouse trials. Plant material of the different cover crops was macerated and mixed with nematode-inoculated soil. After a period of 14 and 28 days respectively, susceptible tomato plants were planted in the soil, where they were left to grow in a glasshouse, prior to the performance of a root gall index. The same procedure was followed for C. xenoplax, except that, in this case, the nematodes were extracted from the soil after 14 and 28 days to determine the impact of the plant biomass on nematode numbers. To determine the host status of the cover crops concerned, potted plants were inoculated with the two nematode species. Results from the bioassays showed significant suppression of M. javanica by white mustard, Caliente 199 and Nemat. However, no significant differences were found in the C. xenoplax bioassays. In the M. javanica glasshouse host trials, Nemat was classified as a poor host. In the C. xenoplax host trials, canola was found to have a suppressing effect on C. xenoplax. The results are the first to show the effect of biofumigation on C. xenoplax nematode.
Cover crop management in a chardonnay/99 Richter Vineyard in the Coastal Region, South Africa. 2. effect of different cover crops and cover crop management practices on grapevine performance
(South African Society for Enology and Viticulture, 2006) Fourie, J. C.; Louw, P. J. E.; Agenbag, G. A.
The trial was conducted over a period of 10 years (1993/94 to 2002/03) on a medium textured soil in a Chardonnay/99 Richter vineyard near Stellenbosch (33°55’S, 18°52’E), situated in the Coastal Wine Grape Region of the Western Cape. Sixteen treatments, consisting of three grain species and five legumes, managed according to two cover crop management practices, were included. The one cover crop management practice consisted of cover crops being sown annually and full surface post-emergence chemical control being applied before bud break and when the berries reached pea size (BB). The other management practice consisted of cover crops being sown biennially and postemergence chemical control applied to the vine row before bud break and full surface when the berries reached pea size (AB). From 1999/2000 to 2002/03 the cover crops were sown annually, while the full surface post-emergence chemical control applied at the end of November was advanced to mid-October. These treatments were compared to a control, in which no cover crop was sown and the weeds were controlled mechanically in the work row and chemically in the vine row from bud break to harvest (approximately the first week of February). A treatment in which no cover crop was sown and full surface post-emergence chemical weed control was applied from before bud break to harvest (weedchem) was also included. During the 1994/95 season, the shoot mass of the two-year-old grapevines in the BB treatments was significantly higher than that of the control and the AB treatments. In the following season, the shoot mass and grape yield of the BB treatments was, with the exception of Vicia faba L. v. Fiord (faba bean) and Avena sativa L. v. Overberg, significantly higher than that of the control and weedchem. The grape yield of the control and AB treatments was significantly less than that of weedchem. Although significant differences in shoot mass (2000/01 and 2002/03) and grape yield (2002/03) were detected between treatments, no significant differences could be detected between the BB and AB treatments, with the exception of the shoot mass of Medicago scuttelata v. Kelson (‘Kelson’ medic). The mean petiole NO3-N concentration for the period 1994/95 to 1998/99 tended to be lower in the AB treatment of a cover crop species compared to that of the BB treatment of the same species. In the case of ‘Kelson’ medic (BB) the petiole NO3-N and juice N concentrations were significantly higher than that of the control and weedchem. The juice N concentration of the control and weedchem was significantly less than that of the faba bean treatments during 2000/01 and 2001/02, the Vicia dasycarpa Ten (grazing vetch) and ‘Kelson’ medic treatments during 2000/01, as well as that of Medicago truncatula Gaertn. (BB) and Trifolium subterraneum L. v. Woogenellup (BB) during the 2001/02 season. Wine quality did not differ between treatments.
Cover crop management in a chardonnay/99 Richter Vineyard in the Coastal Region, South Africa. 3. effect of different cover crops and cover crop management practices on organic matter and macro-nutrient content of a medium-textured soil
(South African Society for Enology and Viticulture, 2007) Fourie, J. C.; Agenbag, G. A.; Louw, P. J. E.
The trial was conducted over a period of 10 years (1993/94 to 2002/03) on a medium-textured soil in a Chardonnay/99 Richter vineyard near Stellenbosch (33°55’S, 18°52’E), which is situated in the Coastal wine grape region of the Western Cape, South Africa. Sixteen treatments, consisting of three cereals and five legumes, managed according to two cover crop management practices, were included. These treatments were compared to a control, in which no cover crop was sown and the weeds were controlled mechanically in the work row and chemically in the vine row from bud break to harvest (approximately the first week of February). A treatment in which no cover crop was sown and full-surface post-emergence chemical weed control was applied from before bud break to harvest (BB) (weedchem) was also included. After five seasons, the soil organic matter (SOM) content in the 0 to 300 mm soil layer increased in all the cover crop management treatments. In weedchem and in the control, SOM remained unchanged and decreased by 16% respectively. The SOM content in the 0 to 150 mm soil layer of the cover crop treatments was, with the exception of Vicia dasycarpa Ten. (grazing vetch), significantly higher than that of the mechanically-cultivated control after a period of 10 years. The SOM content in the 0 to 300 mm soil layer of Secale cereale L. v. Henog and the treatments in which the N-fixing cover crops were sown (with the exception of grazing vetch) was significantly higher than that of weedchem. The total inorganic N (TIN) concentration of the 0 to 150 mm soil layer in the BB treatments of the two Medicago species and Trifolium subterraneum L. v. Woogenellup, as measured for the 1996/97 season during full bloom of the grapevines, was significantly higher than that of the control, weedchem, and the treatments in which full-surface chemical control was applied after bud break (AB). The TIN concentration of the 0 to 600 mm soil layer in the AB treatment of a species, measured after harvest in 2002/03, tended to be higher than that of the BB treatment of that species. The applied treatments had no significant effect on the exchangeable K, Ca and Mg.
Cover crop management in a chardonnay/99 Richter Vineyard in the Coastal Wine Grape Region, South Africa. 1. effect of two management practices on selected grass and broadleaf species
(South African Society for Enology and Viticulture, 2006) Fourie, J. C.; Louw, P. J. E.; Agenbag, G. A.
The trial was conducted over a period of 10 years (1993/94 to 2002/03) on a medium textured soil in a Chardonnay/99 Richter vineyard near Stellenbosch (33°55’S, 18°52’E), situated in the Coastal Wine Grape Region of the Western Cape. Sixteen treatments, consisting of three grain species and five N-fixing broadleaf species managed according to two cover crop management practices, were included. These treatments were compared to a control treatment, in which no cover crop was sown and the weeds were controlled mechanically in the work row and chemically in the vine row from the first week of September to the end of March (grapevine growing season). A treatment in which no cover crop was sown and full surface post-emergence chemical control was applied during the grapevine growing season was also included. The different weed control actions were carried out during the first week of September and/or at the end of November, as well as mid October (1999/00 to 2002/03). Secale cereale L. v. Henog (rye), Avena sativa L. v. Overberg (‘Overberg’ oats), Avena strigosa L. v. Saia (‘Saia’ oats) and Vicia faba L. v. Fiord [only if sown annually and controlled chemically before bud break (BB)], showed the ability to produce, on average, significantly more dry matter during winter than the weeds in the region. The dry matter production of all the cover crops increased from the end of August to the end of November if left to complete their life cycles, with the exception of rye and ‘Overberg’ oats sown in early April. None of the cover crop species were able to reestablish successfully. Continuous effective suppression of winter growing weeds (less than 20% of the weed stand in the control) was achieved with ‘Overberg’ oats (BB) and ‘Saia’ oats (BB), while total suppression was achieved for six and five of the 10 years, respectively. Effective, long-term control of the summer growing weeds was obtained with rye (BB), ‘Overberg’ oats (BB) and ‘Saia’ oats (BB).
Cover crop management in a Sauvignon blanc/Ramsey vineyard in the semiarid Olifants River Valley, South Africa. 1. effect of management practices on selected grass and broadleaf species
(South African Society for Enology and Viticulture, 2005) Fourie, J. C.; Louw, P. J. E.; Agenbag, G. A.
This trial was conducted over a period of ten years on a sandy soil in a Sauvignon blanc/Ramsey vineyard in Lutzville (31°35’S, 18°52’E), situated in the semi-arid Olifants River Valley of the Western Cape. Twenty-three treatments were applied. Eight cover crop species that received the same amount of fertilizer were controlled chemically at the end of August or at the end of November. Two treatments were also applied in which Avena sativa L. v. Saia (‘Saia’ oats) and Vicia dasycarpa Ten. (grazing vetch) were controlled mechanically during bud break. In addition to these eighteen treatments, two fertiliser application rates were applied to ‘Saia’ oats and grazing vetch. A mechanically cultivated control in which no cover crop was sown was included in the trial. Secale cereale L v. Henog and Ornithopus sativus L. v. Emena produced, on average, the highest amount of dry matter at the end of August (3.29 t/ha and 3.06 t/ha, respectively) after receiving on average 278 mm of water, of which 172 mm was supplied by means of a micro-sprinkler irrigation system. The average dry matter produced by Medicago truncatula Gaertn. v. Paraggio and ‘Saia’ oats at the end of August was not significantly lower than that of the firstmentioned two species. Under conditions of this experiment, it seemed that P and K at a concentration of 10 mg/kg and 78 mg/kg, respectively, in the top 300 mm soil layer supplied the needs of grazing vetch. Saia oats performed poorly unless 30 kg P, 30 kg K and 42 kg N were applied during establishment and the early growing phase. All the species, except M. truncatula Gaertn v. Parabinga, produced additional fibre from September to the end of November following a dry winter (rain and irrigation totaling 201 mm), while none produced additional fibre if the water supply was luxurious up to the end of August (rain and irrigation totaling 364 mm). The cover crops did not produce enough seeds to re-establish successfully over a period of five years. It will, however, be possible to reduce the seeding density of grazing vetch (40% after two seasons) and the two M. truncatula varieties (20% after five seasons) if the species were left to ripen their seeds.
Cover crop management in vineyards of the Lower Orange River region, South Africa. 2, Effect on plant parasitic nematodes
(SASEV, 2008-10) Addison, Pia; Fourie, J. C.
This study was conducted as part of a larger investigation into the effect of management practices on selected sown cover crops and the effects thereof on grapevine performance. The aim of this study was to determine the effect of these cover crops on plant parasitic nematode populations under natural field conditions. The trial site was in an own-rooted Sultanina vineyard situated in the Lower Orange River of the Northern Cape Province. Three management practices were applied selectively to ten cover crop species, with two control treatments consisting of weeds. Nematodes were monitored for a period of four years. 'Saia' oats were indicated as being poor hosts to both root-knot and root-lesion nematodes, while 'Overberg' oats showed poor host status against ring nematodes. 'Midmar' ryegrass and 'Paraggio' medic were also poor hosts for root-knot nematodes, while grazing vetch appeared to be a good host for root-knot nematodes. The most notable result from this study was the relatively high numbers of all three nematodes on the vine row, as opposed to the inter-row where cover crops were established. This indicates that vines were much better hosts for these nematodes than the cover crops. It is recommended that if more definite trends are to be observed, Brassica species, which have direct toxic/repellant effects on nematodes, should be tested.
Cover crops with biofumigation properties for the suppression of plant-parasitic nematodes : a review
(South African Society for Enology and Viticulture, 2013-08) Kruger, D. H. M.; Fourie, J. C.; Malan, Antoinette P.
Plant-parasitic nematodes are a problem in vineyards worldwide, with some species acting as vectors of grapevine soil-transmitted viruses. Global pressure on the use of soil-applied chemical nematicides has led to a search for new control options, or for alternative methods to suppress plant-parasitic nematodes as part of integrated pest management. This paper gives valuable background information on the use of cover crops with biofumigation properties for the suppression of plant-parasitic nematodes in vineyards.
The effect of cover crops and their management on plant-parasitic nematodes in vineyards
(South African Society for Enology and Viticulture, 2015) Kruger, D. H. M.; Fourie, J. C.; Malan, Antoinette P.
In South Africa the use of annual cover crops is an established soil cultivation practice in vineyards that is environmentally friendly and financially sustainable in the long term. Species from the Brassicaceae family are well known for their biofumigation potential. In this study, Sinapis alba (white mustard), Brassica napus cv. AV Jade (canola), Brassica juncea cv. Caliente 199 (Caliente), Eruca sativa cv. Nemat and Avena sativa cv. Pallinup were established as cover crops in a vineyard for three growing seasons and evaluated for their biofumigation impact, as well as crop host impact on the suppression of economically important plant-parasitic nematodes. Mechanical and chemical cover crop management practices on Criconemoides xenoplax (ring nematode) and Meloidogyne javanica (root-knot nematode) numbers were determined. Canola and Caliente showed a consistent reduction of C. xenoplax present in the vine row 60 days after the management practices applied at the end of the third growing season. This trend was found during the three-year trial period for all different sampling periods (0, 15, 30 and 60 days). Lowered numbers for the total plant-parasitic nematodes were also found for the three-year trial period measured at 60 days after the management practice sampling period. The results can be attributed mainly to the crop host status of the two cover crop species towards C. xenoplax. White mustard showed a constant increase in C. xenoplax numbers in the vine row over the three-year period compared to the treatments in which no cover crop was sown.
Effect of management practices applied to cover crops with biofumigation properties on cover crop performance and weed control in a vineyard
(South African Society for Enology and Viticulture, 2015) Fourie, J. C.; Kruger, D. H. M.; Malan, Antoinette P.
This five-year trial (2009 to 2013) was carried out in a full-bearing seven-year-old Shiraz/101-14 vineyard established on a sandy to sandy clay loam soil at Blaauwklippen farm (33°58’S, 18°50’E) near Stellenbosch, South Africa. Fourteen treatments were applied, consisting of two management practices applied to five cover crop species, winter-growing weeds (no cover crop), and winter-growing weeds (no cover crop) combined with a nematicide application in the vine row. The dry matter production (DMP) increased between 0.55 and 2.62 t/ha from 2009 to 2010 for the small-seeded Sinapis alba cv. Braco (white mustard), Brassica napus cv. AVJade (canola), Brassica juncea cv. Caliente 199 (Caliente) and Eruca sativa cv. Nemat (Nemat). This was attributed to the finer seedbed that could be created. All cover crops suppressed the winter-growing weeds throughout the study. Although the stand of summer-growing weeds differed significantly between treatments in 2010, 2011 and 2012, the cover crop treatments did not suppress these weeds significantly. However, for the duration of the study, the weed stand in the canola controlled chemically full surface (CC) during grapevine bud break tended to be lower than that of the canola controlled mechanically (MC) during grapevine bud break. The same trend occurred between CC and MC for Avena sativa cv. Pallinup (Pallinup oats) and the treatments in which no cover crops were sown, with the exception of in 2009 and 2010 respectively.

Browsing by Author "Fourie, J. C."

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