Pub Date : 2022-03-15DOI: 10.1080/02571862.2021.2009049
LS Tlomatsana, PF Loke, E. Kotzé, MP Aghoghovwia
Soil aggregate dynamics have received renewed interest due to their relevance in carbon (C) stabilisation. This study evaluated changes in aggregate-size distribution and intra-aggregate C following 41 years of wheat production in semi-arid central South Africa. Management practices that have been applied for 41 years include two straw management protocols (unburned and burned), three tillage systems (no-tillage, stubble mulch and mouldboard ploughing) and two weeding methods (chemical and mechanical). Soil cores were taken at 0–10 cm and 10–20 cm depths and fractionated to aggregates of different sizes using wet sieving. All the fractions including bulk soil were analysed for C. Unburned plots had more small macro-aggregates (35% and 33%, respectively) in the 0–10 cm and 10–20 cm depths, but 26% and 27% lower large macro-aggregate and bulk C, respectively were found in the 10–20 cm depth compared to the burned plots. No-tillage stimulated re-aggregation, especially large macro-aggregates, by 68% in the 0–10 cm depth compared to stubble mulch. Small macro-aggregates, large micro-aggregates and bulk soil under no-tillage had on average 25% higher C compared to those under mouldboard ploughing in the 0–10 cm soil layer. Although signs of aggregate equilibrium state were evident, future studies focusing specifically on this subject are needed.
{"title":"Aggregate dynamics and intra-aggregate carbon contents as influenced by long-term wheat production management in semi-arid South Africa","authors":"LS Tlomatsana, PF Loke, E. Kotzé, MP Aghoghovwia","doi":"10.1080/02571862.2021.2009049","DOIUrl":"https://doi.org/10.1080/02571862.2021.2009049","url":null,"abstract":"Soil aggregate dynamics have received renewed interest due to their relevance in carbon (C) stabilisation. This study evaluated changes in aggregate-size distribution and intra-aggregate C following 41 years of wheat production in semi-arid central South Africa. Management practices that have been applied for 41 years include two straw management protocols (unburned and burned), three tillage systems (no-tillage, stubble mulch and mouldboard ploughing) and two weeding methods (chemical and mechanical). Soil cores were taken at 0–10 cm and 10–20 cm depths and fractionated to aggregates of different sizes using wet sieving. All the fractions including bulk soil were analysed for C. Unburned plots had more small macro-aggregates (35% and 33%, respectively) in the 0–10 cm and 10–20 cm depths, but 26% and 27% lower large macro-aggregate and bulk C, respectively were found in the 10–20 cm depth compared to the burned plots. No-tillage stimulated re-aggregation, especially large macro-aggregates, by 68% in the 0–10 cm depth compared to stubble mulch. Small macro-aggregates, large micro-aggregates and bulk soil under no-tillage had on average 25% higher C compared to those under mouldboard ploughing in the 0–10 cm soil layer. Although signs of aggregate equilibrium state were evident, future studies focusing specifically on this subject are needed.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46315934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-15DOI: 10.1080/02571862.2022.2050316
Mekedes Lulu, Bekele Lemma, Legesse Hidoto, A. Melese
This study assessed the effect of the interactions of biochar (BC), farmyard manure (FYM) and lime on soil chemical properties, and on different wheat attributes in Southern Ethiopia. The experimental design was a randomised complete block in three replications. The site significantly (p ≤ 0.05) influenced soil and wheat attributes. Biochar showed a large significant effect (p ≤ 0.05) on soil organic carbon, cation exchange capacity, and exchangeable potassium (K) while lime showed a substantially significant (p ≤ 0.05) effect on exchangeable Calcium (Ca)and acidity. Farmyard manure (10 tonnes ha−1) had a significant effect on soil total nitrogen (TN). Biochar and lime showed a large significant effect on soil pH and available phosphorus (P) depending on the site. All amendments showed a significant (p ≤ 0.001) effect on most wheat attributes, but the highest effect was from BC. Biochar produced highly significant (p ≤ 0.001) effects on plant height, total number of tillers and productive tillers, number of seeds per spike, aboveground biomass, grain yield, and P and K content in wheat grain and straw. We accredited the greater effect of BC on wheat attributes to its influence on soil chemical properties. We recommend long-term studies on the impact of BC alone or in combination with FYM on acid soil types.
{"title":"Effect of biochar, farmyard manure, and lime on soil properties, and on growth and nutrient uptake of wheat on acidic soils in Southern Ethiopia","authors":"Mekedes Lulu, Bekele Lemma, Legesse Hidoto, A. Melese","doi":"10.1080/02571862.2022.2050316","DOIUrl":"https://doi.org/10.1080/02571862.2022.2050316","url":null,"abstract":"This study assessed the effect of the interactions of biochar (BC), farmyard manure (FYM) and lime on soil chemical properties, and on different wheat attributes in Southern Ethiopia. The experimental design was a randomised complete block in three replications. The site significantly (p ≤ 0.05) influenced soil and wheat attributes. Biochar showed a large significant effect (p ≤ 0.05) on soil organic carbon, cation exchange capacity, and exchangeable potassium (K) while lime showed a substantially significant (p ≤ 0.05) effect on exchangeable Calcium (Ca)and acidity. Farmyard manure (10 tonnes ha−1) had a significant effect on soil total nitrogen (TN). Biochar and lime showed a large significant effect on soil pH and available phosphorus (P) depending on the site. All amendments showed a significant (p ≤ 0.001) effect on most wheat attributes, but the highest effect was from BC. Biochar produced highly significant (p ≤ 0.001) effects on plant height, total number of tillers and productive tillers, number of seeds per spike, aboveground biomass, grain yield, and P and K content in wheat grain and straw. We accredited the greater effect of BC on wheat attributes to its influence on soil chemical properties. We recommend long-term studies on the impact of BC alone or in combination with FYM on acid soil types.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43132025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-15DOI: 10.1080/02571862.2022.2038711
S. Mthimkhulu, D. Elephant, N. Miles, L. Titshall
This study investigated the effects of surface-application of lime and gypsum on soil properties and yields of ratoon sugarcane crops. Treatments involved once-off surface application of dolomitic lime (L), gypsum (G) and dolomitic lime plus gypsum (LG) in factorial combination, with four replications. Soil chemical properties were measured on samples collected at intervals of 20 between depths of 0 and 80 cm in the first and fifth years after treatment application. Yield parameters were measured annually. In the first year, treatment effects were mainly restricted to a depth of 0–20 cm. The LG increased pH(CaCl2) from 3.9 to 4.5, and calcium from 123 to 350 mg L−1. Little treatment effect was observed on yield parameters in the first year. In the fifth year, L and LG generally showed similar impacts on soil properties. The L treatment led to markedly increased pH(CaCl2) and calcium and somewhat decreased magnesium levels in the topsoil. The sucrose and cane yields in LG were significantly higher than in other treatments, which all had similar results. It was, therefore, concluded that LG may be a viable option for the correction of soil acidity through surface application in the sugarcane ratoon crops grown in the sandy soils of KwaZulu-Natal.
{"title":"The short-term effects of surface-applied dolomitic lime and gypsum on soil chemical properties and yields of sugarcane ratoon crops in KwaZulu-Natal, South Africa","authors":"S. Mthimkhulu, D. Elephant, N. Miles, L. Titshall","doi":"10.1080/02571862.2022.2038711","DOIUrl":"https://doi.org/10.1080/02571862.2022.2038711","url":null,"abstract":"This study investigated the effects of surface-application of lime and gypsum on soil properties and yields of ratoon sugarcane crops. Treatments involved once-off surface application of dolomitic lime (L), gypsum (G) and dolomitic lime plus gypsum (LG) in factorial combination, with four replications. Soil chemical properties were measured on samples collected at intervals of 20 between depths of 0 and 80 cm in the first and fifth years after treatment application. Yield parameters were measured annually. In the first year, treatment effects were mainly restricted to a depth of 0–20 cm. The LG increased pH(CaCl2) from 3.9 to 4.5, and calcium from 123 to 350 mg L−1. Little treatment effect was observed on yield parameters in the first year. In the fifth year, L and LG generally showed similar impacts on soil properties. The L treatment led to markedly increased pH(CaCl2) and calcium and somewhat decreased magnesium levels in the topsoil. The sucrose and cane yields in LG were significantly higher than in other treatments, which all had similar results. It was, therefore, concluded that LG may be a viable option for the correction of soil acidity through surface application in the sugarcane ratoon crops grown in the sandy soils of KwaZulu-Natal.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47426682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-15DOI: 10.1080/02571862.2021.2000051
G. Ceronio, J. V. Van Tonder, C. du Preez
Commercial humates manufactured from oxidised lignites are often recommended to improve soil condition and crop growth. The benefits ascribed to these products are questioned, since they differ from humates that exist naturally in soils. Growth chamber, glasshouse and field experiments were conducted at facilities of the University of the Free State to quantify the influence of three potassium (K)-humate products on irrigated wheat growth and development, in loamy sand, sandy clay loam and clay loam soils. The humate products were applied to the soils at rates prescribed by their promoters. Results showed that the K humates were not beneficial for wheat growth and development as indicated by above-ground and subsoil plant parameters at tillering, stem elongation and maturity. However, the application of the K-humates caused higher bacteria and fungi counts in soil, which differed between the products applied. Despite the higher counts of bacteria and fungi in soil, grain yields were not affected, probably because no improvement in soil chemical properties were observed. Therefore, the application of K-humate products is not necessarily economically viable since they are relatively expensive. However, foliar applications of K humates may have stimulatory effects on wheat growth and development, resulting in better grain yields that could justify the higher production cost. An investigation into this aspect is suggested.
{"title":"Is application of commercial potassium humates beneficial to soil and wheat?","authors":"G. Ceronio, J. V. Van Tonder, C. du Preez","doi":"10.1080/02571862.2021.2000051","DOIUrl":"https://doi.org/10.1080/02571862.2021.2000051","url":null,"abstract":"Commercial humates manufactured from oxidised lignites are often recommended to improve soil condition and crop growth. The benefits ascribed to these products are questioned, since they differ from humates that exist naturally in soils. Growth chamber, glasshouse and field experiments were conducted at facilities of the University of the Free State to quantify the influence of three potassium (K)-humate products on irrigated wheat growth and development, in loamy sand, sandy clay loam and clay loam soils. The humate products were applied to the soils at rates prescribed by their promoters. Results showed that the K humates were not beneficial for wheat growth and development as indicated by above-ground and subsoil plant parameters at tillering, stem elongation and maturity. However, the application of the K-humates caused higher bacteria and fungi counts in soil, which differed between the products applied. Despite the higher counts of bacteria and fungi in soil, grain yields were not affected, probably because no improvement in soil chemical properties were observed. Therefore, the application of K-humate products is not necessarily economically viable since they are relatively expensive. However, foliar applications of K humates may have stimulatory effects on wheat growth and development, resulting in better grain yields that could justify the higher production cost. An investigation into this aspect is suggested.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41420775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-15DOI: 10.1080/02571862.2021.2001598
J. Strauss, K. Truter, P. Swanepoel
A seed-drill should facilitate seed placement in an environment conducive to uniform seedling emergence. In semi-arid rain-fed production regions, low rainfall intensity and erratic rainfall events can result in non-uniform emergence. Evaluation of seed-drills is necessary to supply small grain producers with potential solutions to combat non-uniform seedling emergence. The aim of this study was to investigate the influence of three seed-drills on seeding depth, crop emergence, biomass production and yield over the duration of two growing seasons. Barley, canola and wheat were established with three seed-drills, each equipped with a different opener. Seed-drills contained either double disc openers, tine openers, or a combination of both tines and single discs. Crops responded variably to seeding equipment under different climatic conditions. For example, accuracy of seeding depth varied between the three seed-drills utilised. Seed-drills, together with their associated seed placement characteristics, influenced crop emergence. Biomass production was variable over the course of the growing season. Biomass production of crops established with the double disc seed-drill tended to be higher than that of crops established with tine seed-drills. Additional research about adaptations of agronomic practices and seed-drill openers may increase resilience to adverse climatic conditions in semi-arid small grain production regions. Various factors, including soil physical conditions, environmental conditions, economic feasibility and practical applications must be taken into consideration when selecting a seed-drill.
{"title":"The influence of seed-drill choice on crop performance in a semi-arid production region of South Africa","authors":"J. Strauss, K. Truter, P. Swanepoel","doi":"10.1080/02571862.2021.2001598","DOIUrl":"https://doi.org/10.1080/02571862.2021.2001598","url":null,"abstract":"A seed-drill should facilitate seed placement in an environment conducive to uniform seedling emergence. In semi-arid rain-fed production regions, low rainfall intensity and erratic rainfall events can result in non-uniform emergence. Evaluation of seed-drills is necessary to supply small grain producers with potential solutions to combat non-uniform seedling emergence. The aim of this study was to investigate the influence of three seed-drills on seeding depth, crop emergence, biomass production and yield over the duration of two growing seasons. Barley, canola and wheat were established with three seed-drills, each equipped with a different opener. Seed-drills contained either double disc openers, tine openers, or a combination of both tines and single discs. Crops responded variably to seeding equipment under different climatic conditions. For example, accuracy of seeding depth varied between the three seed-drills utilised. Seed-drills, together with their associated seed placement characteristics, influenced crop emergence. Biomass production was variable over the course of the growing season. Biomass production of crops established with the double disc seed-drill tended to be higher than that of crops established with tine seed-drills. Additional research about adaptations of agronomic practices and seed-drill openers may increase resilience to adverse climatic conditions in semi-arid small grain production regions. Various factors, including soil physical conditions, environmental conditions, economic feasibility and practical applications must be taken into consideration when selecting a seed-drill.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42283925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-03-15DOI: 10.1080/02571862.2022.2039792
L. D. Lyimo, Jackline A Bakengesa, Janeth D Mbuma
The abundance and distribution of plant-parasitic nematodes (PPN) on tomato plants grown in nine villages in the semi-arid zones of Singida and Dodoma in Tanzania were assessed in December 2020. Samples from soil and plant roots were evaluated for abundance, genera and distribution of PPN. Nematodes were extracted, counted and identified based on morphological descriptors. Ten genera of PPN were identified in both root and soil samples, with root-knot nematodes (RKN) being the most common PPN in all nine villages surveyed. The results showed that the abundance of RKN was significantly higher (p = 0.002) in soil than in tomato roots. Tutu and Chamkoroma villages had a significantly (p = 0.001) higher population density of RKN compared to other villages. In addition, RKN was associated with Penicillium and Aspergillus fungi, while the nematode genera Helicotylenchus, Aphelenchus, Scutellonema and Pratylenchus exhibited relationships with Alternaria and Fusarium fungi. The results also indicated that the abundance of RKN was significantly higher (p = 0.001) in sandy soil as compared to other types of soils. Inappropriate agronomical practices (e.g., no fallow, rotation of tomato plant with related crops) and poor phytosanitary measures were the major factors associated with high levels of abundance and distribution of RKN in soil.
{"title":"Abundance and distribution of plant-parasitic nematodes in tomatoes grown in a semi-arid agro-ecological zone in Tanzania","authors":"L. D. Lyimo, Jackline A Bakengesa, Janeth D Mbuma","doi":"10.1080/02571862.2022.2039792","DOIUrl":"https://doi.org/10.1080/02571862.2022.2039792","url":null,"abstract":"The abundance and distribution of plant-parasitic nematodes (PPN) on tomato plants grown in nine villages in the semi-arid zones of Singida and Dodoma in Tanzania were assessed in December 2020. Samples from soil and plant roots were evaluated for abundance, genera and distribution of PPN. Nematodes were extracted, counted and identified based on morphological descriptors. Ten genera of PPN were identified in both root and soil samples, with root-knot nematodes (RKN) being the most common PPN in all nine villages surveyed. The results showed that the abundance of RKN was significantly higher (p = 0.002) in soil than in tomato roots. Tutu and Chamkoroma villages had a significantly (p = 0.001) higher population density of RKN compared to other villages. In addition, RKN was associated with Penicillium and Aspergillus fungi, while the nematode genera Helicotylenchus, Aphelenchus, Scutellonema and Pratylenchus exhibited relationships with Alternaria and Fusarium fungi. The results also indicated that the abundance of RKN was significantly higher (p = 0.001) in sandy soil as compared to other types of soils. Inappropriate agronomical practices (e.g., no fallow, rotation of tomato plant with related crops) and poor phytosanitary measures were the major factors associated with high levels of abundance and distribution of RKN in soil.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41984856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1080/02571862.2021.1994046
MH Visser, A. Barnard, C. du Preez
Conservation agriculture (CA) is advocated to promote sustainable cropping. Little is known about the impact of preceding crop sequences on the growth and development of dryland wheat under CA in the eastern Free State Province of South Africa. In a criss-cross experimental design, the response of wheat planted after 25 summer and 25 winter crop sequences was evaluated. Biomass yield was a more reliable indicator than grain yield as a consequence of water and nitrogen stress in the reproductive phase as indicated by harvest index, precipitation use efficiency and nitrogen agronomic efficiency. The five best sequences that favoured wheat biomass yields were, in decreasing order: grain sorghum × maize, sunflower × dry bean, sunflower × maize, soybean × soybean, and maize × maize for summer crops (7.1–7.8 t ha−1); and fallow × vetch, fallow × wheat, fallow × fallow, vetch × fodder oat, and wheat × oat for winter crops (6.5–7.4 t ha−1). Of the grading parameters, only protein content was influenced significantly by the winter crop sequences. A single 3-year cycle comprising wheat after two seasons with preceding crop sequences was insufficient to test abiotic stress factors thoroughly to establish with certainty the best crop sequences for dryland wheat production.
保护性农业(CA)提倡促进可持续种植。在南非东部自由邦省，以前的作物序列对CA下旱地小麦生长发育的影响知之甚少。采用交叉试验设计，评价了小麦在25个夏季作物和25个冬季作物种植序列后的反应。收获指数、降水利用效率和氮素农艺效率表明，生物量产量比籽粒产量更可靠，是生殖期水分和氮胁迫的结果。最有利于小麦生物量产量的5个最佳序列依次为:高粱×玉米、向日葵×干豆、向日葵×玉米、大豆×大豆和玉米×玉米(7.1 ~ 7.8 tha−1);休耕×野豌豆，休耕×小麦，休耕×休耕，野豌豆×饲料燕麦，小麦×燕麦用于冬季作物(6.5-7.4 t / h)。在分级参数中，只有蛋白质含量受冬作物序列的显著影响。一个3年的周期，包括两个季节后的小麦和之前的作物序列，不足以彻底测试非生物胁迫因素，以确定旱地小麦生产的最佳作物序列。
{"title":"Impact of preceding crop sequences on wheat growth and development under conservation agriculture in the eastern Free State, South Africa","authors":"MH Visser, A. Barnard, C. du Preez","doi":"10.1080/02571862.2021.1994046","DOIUrl":"https://doi.org/10.1080/02571862.2021.1994046","url":null,"abstract":"Conservation agriculture (CA) is advocated to promote sustainable cropping. Little is known about the impact of preceding crop sequences on the growth and development of dryland wheat under CA in the eastern Free State Province of South Africa. In a criss-cross experimental design, the response of wheat planted after 25 summer and 25 winter crop sequences was evaluated. Biomass yield was a more reliable indicator than grain yield as a consequence of water and nitrogen stress in the reproductive phase as indicated by harvest index, precipitation use efficiency and nitrogen agronomic efficiency. The five best sequences that favoured wheat biomass yields were, in decreasing order: grain sorghum × maize, sunflower × dry bean, sunflower × maize, soybean × soybean, and maize × maize for summer crops (7.1–7.8 t ha−1); and fallow × vetch, fallow × wheat, fallow × fallow, vetch × fodder oat, and wheat × oat for winter crops (6.5–7.4 t ha−1). Of the grading parameters, only protein content was influenced significantly by the winter crop sequences. A single 3-year cycle comprising wheat after two seasons with preceding crop sequences was insufficient to test abiotic stress factors thoroughly to establish with certainty the best crop sequences for dryland wheat production.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48527040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1080/02571862.2021.1987536
Abera Daba, Mekuria Tadesse, Selamawit Negassa Chawaka, G. Berecha
A weed population survey was carried out to assess the variability in weed species composition and abundance in the main coffee production systems and regions of Ethiopia. A total of 168 coffee fields were assessed using a quadrat count in a systematic sampling technique. Weed species composition was evaluated using frequency, abundance and dominance of species at each site. We found a total of 98 weed taxa belonging to 35 families, of which Asteraceae and Poaceae were the most abundant. The most frequent weed species were Oplismenus hirtellus (L.) P.Beauv., Galinsoga parviflora Cav., Achyranthes bidentata Blume, Impatiens balfourii Hook. F., Bidens pilosa L. and Commelina benghalensis L., with a frequency of over 40%. The density of weed species varied and the highest abundance value was recorded by O. hirtellus. Similarity indices of the 16 districts assessed ranged from 8.33% to 72.73%, while the similarity indices of the coffee production systems and altitudinal range ranged from 7.14% to 49.49% and 41.76% to 68.75%, respectively. Coffee production systems and soil properties were the main explanatory variables influencing weed species distribution and composition in the study areas. In conclusion, coffee producers should take into account these variables while designing the appropriate management strategies to curtail weeds in coffee farms.
{"title":"Weed species composition and abundance in the main coffee production systems and regions of Ethiopia","authors":"Abera Daba, Mekuria Tadesse, Selamawit Negassa Chawaka, G. Berecha","doi":"10.1080/02571862.2021.1987536","DOIUrl":"https://doi.org/10.1080/02571862.2021.1987536","url":null,"abstract":"A weed population survey was carried out to assess the variability in weed species composition and abundance in the main coffee production systems and regions of Ethiopia. A total of 168 coffee fields were assessed using a quadrat count in a systematic sampling technique. Weed species composition was evaluated using frequency, abundance and dominance of species at each site. We found a total of 98 weed taxa belonging to 35 families, of which Asteraceae and Poaceae were the most abundant. The most frequent weed species were Oplismenus hirtellus (L.) P.Beauv., Galinsoga parviflora Cav., Achyranthes bidentata Blume, Impatiens balfourii Hook. F., Bidens pilosa L. and Commelina benghalensis L., with a frequency of over 40%. The density of weed species varied and the highest abundance value was recorded by O. hirtellus. Similarity indices of the 16 districts assessed ranged from 8.33% to 72.73%, while the similarity indices of the coffee production systems and altitudinal range ranged from 7.14% to 49.49% and 41.76% to 68.75%, respectively. Coffee production systems and soil properties were the main explanatory variables influencing weed species distribution and composition in the study areas. In conclusion, coffee producers should take into account these variables while designing the appropriate management strategies to curtail weeds in coffee farms.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41876088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1080/02571862.2021.1969692
M. Zhou
Smut, Sporisorium scitamineum (Syd.) (formerly Ustilago scitamineum), is a major disease of sugarcane causing cane yield losses of 0.25 to 0.75% for every 1% of infected stools. Breeding resistant cultivars is part of integrated smut management. The objective of this study was to determine the effects of locations and seasons on smut infection genotype in irrigated sugarcane breeding trials. Data for smut-infected stools and smut whips collected from early and late season trials at Pongola (NPG) and Mpumalanga research stations (MP) were analysed using linear mixed models. There were significant (p < 0.001) location, season, location by season, genotype, genotype by location, genotype by season and genotype by location by season interaction effects for infected stools and whips. Broad sense heritability in late season trials averaged 0.89 compared to 0.61 in early season, while that for MP (0.79) was higher than for NPG (0.69) indicating higher selection efficiency for smut resistance in late season MP trials. Genotypes had significantly (p < 0.001) higher infected stools and whips at MP than at NPG and in late than early season trials. Smut-screening using MP late season trials will increase efficiency of breeding for smut resistance in South Africa.
{"title":"Location and seasonal effects on sugarcane smut and implications for resistance breeding in South Africa","authors":"M. Zhou","doi":"10.1080/02571862.2021.1969692","DOIUrl":"https://doi.org/10.1080/02571862.2021.1969692","url":null,"abstract":"Smut, Sporisorium scitamineum (Syd.) (formerly Ustilago scitamineum), is a major disease of sugarcane causing cane yield losses of 0.25 to 0.75% for every 1% of infected stools. Breeding resistant cultivars is part of integrated smut management. The objective of this study was to determine the effects of locations and seasons on smut infection genotype in irrigated sugarcane breeding trials. Data for smut-infected stools and smut whips collected from early and late season trials at Pongola (NPG) and Mpumalanga research stations (MP) were analysed using linear mixed models. There were significant (p < 0.001) location, season, location by season, genotype, genotype by location, genotype by season and genotype by location by season interaction effects for infected stools and whips. Broad sense heritability in late season trials averaged 0.89 compared to 0.61 in early season, while that for MP (0.79) was higher than for NPG (0.69) indicating higher selection efficiency for smut resistance in late season MP trials. Genotypes had significantly (p < 0.001) higher infected stools and whips at MP than at NPG and in late than early season trials. Smut-screening using MP late season trials will increase efficiency of breeding for smut resistance in South Africa.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43973469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1080/02571862.2021.1994047
Sphiwokuhle Shandu, E. Gasura, K. Mashingaidze, J. Derera
Increases in genetic gains are crucial to maize breeding programmes. The objectives of this study were to identify higher-yielding and stable maize hybrids across stress and non-stress environments, to identify representative test environments for testing and selection of superior maize genotypes, and to determine the contribution of temperate maize germplasm in the performance of new tropical hybrids. Respectively 42 and 72 newly developed single-cross hybrids together with check hybrids were evaluated separately for grain yield performance across stress and non-stress environments, at four locations (Potchefstroom, Cedara, Vaalharts/Taung and Makhathini) in South Africa, in the 2014/15 and 2015/16 growing seasons (seasons 1 and 2, respectively). Additive main effects and multiplicative interaction (AMMI) and genotype + genotype × environment interaction (GGE) biplots were employed. In season 1, the hybrids MO17HtHtN × CML444 and I-39 × CML444 were the most stable and high-yielding genotypes after the ideal commercial check. In season 2, the hybrids FO215W × CML444, I-42 × CML444 and U71Y × CML444 were stable and high-yielding, with FO215W × CML444 being the most ideal. These stable hybrids would be the best suited for wide adaptation across non-stress and stress environments. Hybrids containing tropical CIMMYT testers were more stable than those derived from temperate Corn Belt material. The locations Potchefstroom and Vaalharts were the most suitable environments for evaluating the performance of these genotypes across the diverse environments.
{"title":"Contribution of temperate germplasm to the performance of maize hybrids under stress and non-stress environments in South Africa","authors":"Sphiwokuhle Shandu, E. Gasura, K. Mashingaidze, J. Derera","doi":"10.1080/02571862.2021.1994047","DOIUrl":"https://doi.org/10.1080/02571862.2021.1994047","url":null,"abstract":"Increases in genetic gains are crucial to maize breeding programmes. The objectives of this study were to identify higher-yielding and stable maize hybrids across stress and non-stress environments, to identify representative test environments for testing and selection of superior maize genotypes, and to determine the contribution of temperate maize germplasm in the performance of new tropical hybrids. Respectively 42 and 72 newly developed single-cross hybrids together with check hybrids were evaluated separately for grain yield performance across stress and non-stress environments, at four locations (Potchefstroom, Cedara, Vaalharts/Taung and Makhathini) in South Africa, in the 2014/15 and 2015/16 growing seasons (seasons 1 and 2, respectively). Additive main effects and multiplicative interaction (AMMI) and genotype + genotype × environment interaction (GGE) biplots were employed. In season 1, the hybrids MO17HtHtN × CML444 and I-39 × CML444 were the most stable and high-yielding genotypes after the ideal commercial check. In season 2, the hybrids FO215W × CML444, I-42 × CML444 and U71Y × CML444 were stable and high-yielding, with FO215W × CML444 being the most ideal. These stable hybrids would be the best suited for wide adaptation across non-stress and stress environments. Hybrids containing tropical CIMMYT testers were more stable than those derived from temperate Corn Belt material. The locations Potchefstroom and Vaalharts were the most suitable environments for evaluating the performance of these genotypes across the diverse environments.","PeriodicalId":21920,"journal":{"name":"South African Journal of Plant and Soil","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48589150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：