This paper reports the development of the first SSR marker-based sugarcane (Saccharum spp.) molecular identity database in the world. Since 2005, 1,025 sugarcane clones were genotyped, including 811 Louisiana, 45 Flor...This paper reports the development of the first SSR marker-based sugarcane (Saccharum spp.) molecular identity database in the world. Since 2005, 1,025 sugarcane clones were genotyped, including 811 Louisiana, 45 Florida, 39 Texas, 130 foreign, and eight consultant/seed company clones. Genotyping was done on a fluorescence-capillary electrophoresis detection platform involving 21 highly polymorphic SSR markers that could potentially amplify 144 distinctive DNA fragments. Genotyping data were processed with the GeneMapper? software to reveal electrophoregrams that were manually checked against the 144 fragments. The presence (A) or absence (C) of these 144 fragments in any sugarcane clone was recorded in an affixed sequence order as a DNAMAN? file to represent its molecular identity being achieved into a local molecular identity database. The molecular identity database has been updated annually by continued genotyping of newly assigned sugarcane clones. The database provides molecular descriptions for new cultivar registration articles, enables sugarcane breeders to identify mis-labeled sugarcane clones in crossing programs and determine the paternity of cross progeny, and ensures the desired cultivars are grown in farmers’ fields.展开更多
The effect of different concentrations of 6-benzylaminopurine （BA） with or without 0.2 mg/L NAA on in vitro regeneration of sugarcane （Saccharum spp.） cultivars SP726180, B47419, M1176/77 and M2119/88 were evaluat...The effect of different concentrations of 6-benzylaminopurine （BA） with or without 0.2 mg/L NAA on in vitro regeneration of sugarcane （Saccharum spp.） cultivars SP726180, B47419, M1176/77 and M2119/88 were evaluated. Leaf base explants were cultured on Murashige and Skoog （MS） basal medium supplemented with 3.0 mg/L 2,4-dichlorophenoxyacetic acid （2,4-D） for 4 weeks. Thereafter, induction of somatic embryogenesis was observed following the transfer of resulting calli to 2,4-D-free medium for another 4 weeks. Regeneration was achieved by transfer of the embryogenic calli to regeneration media fortified with different concentrations of BA ＋ tt-naphthylacetic acid （NAA）. The number, length and vigor of shoots produced in all the genotypes were highest on media supplemented with 1.0 and 1.5 mg/L BA with and without 0.2 mg/L NAA. Among the genotypes tested, B47419 and M1176/77 recorded highest number of shoots, while maximum shoot length and crop vigor was obtained with M1176/77. Induction of callus with 3.0 mg/L 2,4-D and its subsequent incubation on 2,4-D-free media, followed by regeneration on media supplemented with 1.0 or 1.5 mg/L BA with 0.2 mg/L NAA was found to be efficient for in vitro regeneration of the sugarcane genotypes used in this study. This protocol could be applied for micropropagation of other elite genotypes.展开更多
Brix weight per stool (BW) of sugarcane is a complex trait, which is the final product of a combination of many components. Diallel cross experiments were conducted during a period of two years for BW and its five com...Brix weight per stool (BW) of sugarcane is a complex trait, which is the final product of a combination of many components. Diallel cross experiments were conducted during a period of two years for BW and its five component traits, in- cluding stalk diameter (SD), stalk length (SL), stalk number (SN), stalk weight (SW), and brix scale (BS) of sugarcane. Phenotypic data of all the six traits were analyzed by mixed linear model and their phenotype variances were portioned into additive (A), dominance (D), additive×environment interaction (AE) and dominance×environment interaction (DE) effects, and the correlations of A, D, AE and DE effects between BW and its components were estimated. Conditional analysis was employed to investigate the contribution of the components traits to the variances of A, D, AE and DE effects of BW. It was observed that the heritabilities of BW were significantly attributed to A, D and DE by 23.9%, 30.9% and 28.5%, respectively. The variance of A effect for BW was significantly affected by SL, SN and BS by 25.3%, 93.7% and 17.4%, respectively. The variances of D and DE effects for BW were also significantly influenced by all the five components by 5.1%～85.5%. These determinants might be helpful in sugarcane breeding and provide valuable information for multiple-trait improvement of BW.展开更多
Banana streak virus (BSV) and Sugarcane bacilliform virus (SCBV) are two badnaviruses commonly found in all banana growing areas of the world. It is a threat to the production and improvement of Musa germplasm. In Bur...Banana streak virus (BSV) and Sugarcane bacilliform virus (SCBV) are two badnaviruses commonly found in all banana growing areas of the world. It is a threat to the production and improvement of Musa germplasm. In Burkina Faso, the presence of badnaviruses was reported in banana producing regions. The objective of this study was to determine the prevalence of BSV and SCBV in banana production areas of Burkina Faso. A survey followed by a symptomatologic study was conducted in banana plantations in 27 localities of the nine main banana producing regions from July to October 2018 and September to December 2020. In all, 251 leaf samples were collected and analysed for BSV and SCBV infection by Indirect Antigen Coated Plate Assay-ELISA followed by amplification of the RT/RNase H region using Polymerase chain reaction with Badna FP/RP and SCBV F/R primers, respectively. A variety of symptoms were observed on almost all plant organs which were revealed due to BSV by symptomatologic study. The results of serological and molecular diagnosis revealed a high overall prevalence of BSV in 80.48% of the samples tested. BSV was distributed in seven survey regions out of nine with prevalence ranging from 10% to 100% in North, Centre, Centre West, Hauts Bassins, Cascades, Centre East and Boucle of Mouhoun regions. Very low prevalence was recorded for SCBV in Cascades and East Centre region with 4.35 and 12.5%, respectively. Species detection using specific primers to each species revealed three main species: Banana streak Obino l’ewaï virus (BSOLV), Goldfinger virus (BSGFV) and Imové virus (BSIMV) in the samples tested, respectively in the proportions of 23%, 8% and 0.8%. Co-infection between BSV species was also detected.展开更多
An important factor for the sustainability of soils highly susceptible to degradation is the use of monitoring tools that promptly and realistically reflect changes imposed on soil by different cropping systems. To se...An important factor for the sustainability of soils highly susceptible to degradation is the use of monitoring tools that promptly and realistically reflect changes imposed on soil by different cropping systems. To select soil quality indicator variables in sugarcane (Saccharum officinarum L.) production areas that fulfill the criteria of sensitivity to management practices and between-season consistency in the management discrimination, ten composite soil samples (0–10 cm) were collected in July 2005 (rainy season) and again in March 2006 (dry season) from areas under cultivation of organic sugarcane (OS), green sugarcane (GS), burned sugarcane (BS) and from an adjacent native forest (NF) area at Usina Triunfo, Boca da Mata, Alagoas, Brazil. Microbial biomass-C (MBC), total organic C (TOC), soil enzyme activity expressed as the rate of fluorescein diacetate (FDA) hydrolysis, mean weight diameter of water-stable soil aggregates (MWD), and percentage of water-stable macroaggregates (PWSA) were analyzed. Although MBC and TOC were higher in NF than in the cultivated areas, no differences were observed in these C pools between the three sugarcane systems. The response of FDA to the site management was dependent on the sampling time. In the rainy period, the activity followed the order: NF > OS > GS > BS, whereas in the dry season, only NF differed from the other treatments. Irrespective of the sampling time, MWD and PWSA decreased in the order NF > OS = GS > BS. The variables MWD and PWSA are quite sensitive for discriminating between site management histories regardless the sampling season.展开更多
Three assays were developed from April 3, 1995 to October 10, 2005. The work with corn was conducted in a greenhouse, using velvet bean (Mucuna aterrima) and sunn hemp (Crotalaria juncea) as green manure with 15N labe...Three assays were developed from April 3, 1995 to October 10, 2005. The work with corn was conducted in a greenhouse, using velvet bean (Mucuna aterrima) and sunn hemp (Crotalaria juncea) as green manure with 15N labeling of either shoots or roots, in two soils with contrasting textural classes. The mineralization of N from legume plants incorporated into the two soils was investigated too. This work included two green manures: velvet bean and sunn hemp, and the common bean (Phaseolus vulgaris) residues. Nitrogen from the velvet bean accounted for a greater proportion of the soil inorganic N;shoots were responsible for most of N accumulated. Common bean residues caused immobilization of inorganic N. The leguminous species added were intensively and promptly mineralized, preserving the soil native nitrogen. One hundred days after emergence of the corn, velvet bean provided higher accumulation of nitrogen in the soil, higher absorption by corn plants and accumulation in the aerial part. The green manure decomposition was more intense in the medium textured soil. In this soil, highest nitrogen losses were also observed. The sugarcane (Saccharum spp.) was cultivated for five years in the field and was harvested three times;15N recovery was evaluated in the first two harvests. The combination of inorganic fertilizer and green manure resulted in higher sugarcane yields than either N source applied separately;however, in the second cutting the yields were higher where sunn hemp was used than in plots with ammonium sulfate. The recovery of N by the first two consecutive harvests accounted for 19% to 21% of the N applied as sunn hemp and 46% to 49% of the N applied as ammonium sulfate. Very little inorganic N was present in the 0-40 cm soil layer with both N sources.展开更多
New strategies are required in the sugarcane selection process to optimize the genetic gains in breeding programs. Conventional selection strategies have the disadvantage of requiring the weighing of all the plants in...New strategies are required in the sugarcane selection process to optimize the genetic gains in breeding programs. Conventional selection strategies have the disadvantage of requiring the weighing of all the plants in a plot or a sample of stalks and the counting of the number of stalks in all the experimental plots, which cannot always be performed because more than 200,000 genotypes routinely comprise the first test phase (T1) of most sugarcane breeding programs. One way to circumvent this problem is to use decision trees to rank the yield components (the stalk height, the stalk diameter and the number of stalks) and to subsequently use this categorization to select the best families for a specific trait. The objective of this study was to evaluate the categorization of yield components using the classification and regression tree (CART) algorithm as a family selection strategy by comparing the performance of CART with those of conventional methods that require the weighing of stalks, such as the best linear unbiased prediction (BLUP) with sequential (BLUPS) or individual simulated (BLUPIS) procedures. Data from five experiments performed in May 2007 in a randomized block design were analyzed. Each experiment consisted of five blocks, 22 families and two controls (commercial varieties). CART effectively defined the classes of the yield components and selected the best families with an accuracy of 74% compared to BLUPS and BLUPIS. Families with at least 11 stalks per linear meter of furrow resulted in productivities that were above the average productivity of the commercial varieties used in this study and are, therefore, recommended for selection.展开更多
The aim of this work was to evaluate the effects of the application of different sources and doses of nitrogen(N)in the growth and productivity of sugarcane in cane plant.Field experiments were conducted in the area o...The aim of this work was to evaluate the effects of the application of different sources and doses of nitrogen(N)in the growth and productivity of sugarcane in cane plant.Field experiments were conducted in the area of Rio Paraiso II farm,belonging to the Raízen factory,in the city of Jataí,GO.The soil was classified as dystrophic red latosol.The experimental design used was in randomized block,analysed in factorial scheme of 2×4×4,with three replications.The factors analysed were two sources of N(urea and ammonium nitrate),four doses of N(0,60,120 and 180 kg/ha)and four evaluation times(210,250,290 and 330 d after planting(DAP)).The parameters analysed were plant height(PH),diameter of stalks(DS),length of internodes(LI)and productivity of stalks(PS).Results observed significant difference in the sources and doses of N for the evaluated parameters in sugarcane plant.Urea in the average doses of 110 kg/ha and 100.87 kg/ha provided the greatest PH and LI of sugarcane,respectively.Ammonium nitrate at a dose of 180 kg/ha presented the largest DS of sugarcane(cane plant)at 330 DAP.The PS of sugarcane SP80-1816 at 60 kg/ha and 120 kg/ha ammonium nitrate has higher increments.For the PS,it is recommended the application of doses between 60 kg/ha and 120 kg/ha of N of the source ammonium nitrate in sugar cane(cane plant).展开更多
The area cultivated with sugarcane in Brazil is expanding, and increasingly using legumes cover crop in new deployed areas and in those which were reformed. Long-term trials were carried out in Piracicaba, Sao Paulo, ...The area cultivated with sugarcane in Brazil is expanding, and increasingly using legumes cover crop in new deployed areas and in those which were reformed. Long-term trials were carried out in Piracicaba, Sao Paulo, Brazil, to evaluate the effect of leguminous green manure on the natural infestation of Diatraea saccharalis (Fabr.) during five cropping cycles of sugarcane “IAC 87-3396”. This study was carried out from October 1999 to October 2005 in Piracicaba, Sao Paulo, Brazil, at coordinates 22°42''S and 47°38''W, 560 m above sea level, in soil classified as Typic Paleudult. Green manure crops were assigned to five treatments: peanuts (Arachis hypogaea L.) (cultivar “IAC-Tatu” and “IAC-Caiapó”), sunn hemp (Crotalaria juncea L.) (cultivar “IAC 1”) and velvet-bean [Mucuna aterrima (Piper & Tracy) Holland] (cultivar “common”). A treatment without any green manure or weed was used as the control. The previous sugarcane crop was destroyed and the soil was prepared in a conventional way (using plow and harrow) before the leguminous crops were sowed. Thirty days after the sowing, weeds were removed and, 120 days later, the crops were cut and its biomass was deposited on the soil surface without incorporation. Experimental plots comprised five rows of sugarcane, each one measuring 10 m long and spaced 1.40 m apart. The sugarcane was harvested 18 months after biomass deposit, on October 25th, 2001 and its stalks were collected at intervals of approximately 12 months in: 07/09/2002, 08/01/2003, 11/07/2004 and 10/06/2005. At harvest, the masses were determined from a sample of sugarcane, cut from three rows (2 m long) in the center of the plot. The losses caused by the sugarcane borer were estimated by the intensity of the infestation by randomly observing and collecting sugarcane stems from each plot. A great reduction in the number of stalks and in the yield was noted proportionally to the intensity of the infestation of the borer in the sugarcane crop grown after the velvet-bean. The sugarcane-velvet-bean rotation should be regarded considering the intensity of sugarcane borer infestation. No influence of the other green manure crops was observed on the intensity of the infestations. However, the harvest seasons of the sugarcane seemed to influence the borer infestation.展开更多
文摘This paper reports the development of the first SSR marker-based sugarcane (Saccharum spp.) molecular identity database in the world. Since 2005, 1,025 sugarcane clones were genotyped, including 811 Louisiana, 45 Florida, 39 Texas, 130 foreign, and eight consultant/seed company clones. Genotyping was done on a fluorescence-capillary electrophoresis detection platform involving 21 highly polymorphic SSR markers that could potentially amplify 144 distinctive DNA fragments. Genotyping data were processed with the GeneMapper? software to reveal electrophoregrams that were manually checked against the 144 fragments. The presence (A) or absence (C) of these 144 fragments in any sugarcane clone was recorded in an affixed sequence order as a DNAMAN? file to represent its molecular identity being achieved into a local molecular identity database. The molecular identity database has been updated annually by continued genotyping of newly assigned sugarcane clones. The database provides molecular descriptions for new cultivar registration articles, enables sugarcane breeders to identify mis-labeled sugarcane clones in crossing programs and determine the paternity of cross progeny, and ensures the desired cultivars are grown in farmers’ fields.
文摘The effect of different concentrations of 6-benzylaminopurine （BA） with or without 0.2 mg/L NAA on in vitro regeneration of sugarcane （Saccharum spp.） cultivars SP726180, B47419, M1176/77 and M2119/88 were evaluated. Leaf base explants were cultured on Murashige and Skoog （MS） basal medium supplemented with 3.0 mg/L 2,4-dichlorophenoxyacetic acid （2,4-D） for 4 weeks. Thereafter, induction of somatic embryogenesis was observed following the transfer of resulting calli to 2,4-D-free medium for another 4 weeks. Regeneration was achieved by transfer of the embryogenic calli to regeneration media fortified with different concentrations of BA ＋ tt-naphthylacetic acid （NAA）. The number, length and vigor of shoots produced in all the genotypes were highest on media supplemented with 1.0 and 1.5 mg/L BA with and without 0.2 mg/L NAA. Among the genotypes tested, B47419 and M1176/77 recorded highest number of shoots, while maximum shoot length and crop vigor was obtained with M1176/77. Induction of callus with 3.0 mg/L 2,4-D and its subsequent incubation on 2,4-D-free media, followed by regeneration on media supplemented with 1.0 or 1.5 mg/L BA with 0.2 mg/L NAA was found to be efficient for in vitro regeneration of the sugarcane genotypes used in this study. This protocol could be applied for micropropagation of other elite genotypes.
基金Project supported partly by the National Science and TechnologySupport Program (No. 2006BAD10A09-08), Chinathe Great Science Research Program of Guangdong Province (No. A20602),China
文摘Brix weight per stool (BW) of sugarcane is a complex trait, which is the final product of a combination of many components. Diallel cross experiments were conducted during a period of two years for BW and its five component traits, in- cluding stalk diameter (SD), stalk length (SL), stalk number (SN), stalk weight (SW), and brix scale (BS) of sugarcane. Phenotypic data of all the six traits were analyzed by mixed linear model and their phenotype variances were portioned into additive (A), dominance (D), additive×environment interaction (AE) and dominance×environment interaction (DE) effects, and the correlations of A, D, AE and DE effects between BW and its components were estimated. Conditional analysis was employed to investigate the contribution of the components traits to the variances of A, D, AE and DE effects of BW. It was observed that the heritabilities of BW were significantly attributed to A, D and DE by 23.9%, 30.9% and 28.5%, respectively. The variance of A effect for BW was significantly affected by SL, SN and BS by 25.3%, 93.7% and 17.4%, respectively. The variances of D and DE effects for BW were also significantly influenced by all the five components by 5.1%～85.5%. These determinants might be helpful in sugarcane breeding and provide valuable information for multiple-trait improvement of BW.
文摘Banana streak virus (BSV) and Sugarcane bacilliform virus (SCBV) are two badnaviruses commonly found in all banana growing areas of the world. It is a threat to the production and improvement of Musa germplasm. In Burkina Faso, the presence of badnaviruses was reported in banana producing regions. The objective of this study was to determine the prevalence of BSV and SCBV in banana production areas of Burkina Faso. A survey followed by a symptomatologic study was conducted in banana plantations in 27 localities of the nine main banana producing regions from July to October 2018 and September to December 2020. In all, 251 leaf samples were collected and analysed for BSV and SCBV infection by Indirect Antigen Coated Plate Assay-ELISA followed by amplification of the RT/RNase H region using Polymerase chain reaction with Badna FP/RP and SCBV F/R primers, respectively. A variety of symptoms were observed on almost all plant organs which were revealed due to BSV by symptomatologic study. The results of serological and molecular diagnosis revealed a high overall prevalence of BSV in 80.48% of the samples tested. BSV was distributed in seven survey regions out of nine with prevalence ranging from 10% to 100% in North, Centre, Centre West, Hauts Bassins, Cascades, Centre East and Boucle of Mouhoun regions. Very low prevalence was recorded for SCBV in Cascades and East Centre region with 4.35 and 12.5%, respectively. Species detection using specific primers to each species revealed three main species: Banana streak Obino l’ewaï virus (BSOLV), Goldfinger virus (BSGFV) and Imové virus (BSIMV) in the samples tested, respectively in the proportions of 23%, 8% and 0.8%. Co-infection between BSV species was also detected.
基金Project supported by the Brazilian Corporation for Agricultural Research (No.02.03.01.01.04) the Usina Triunfo(Alagoas State), Brazil.
文摘An important factor for the sustainability of soils highly susceptible to degradation is the use of monitoring tools that promptly and realistically reflect changes imposed on soil by different cropping systems. To select soil quality indicator variables in sugarcane (Saccharum officinarum L.) production areas that fulfill the criteria of sensitivity to management practices and between-season consistency in the management discrimination, ten composite soil samples (0–10 cm) were collected in July 2005 (rainy season) and again in March 2006 (dry season) from areas under cultivation of organic sugarcane (OS), green sugarcane (GS), burned sugarcane (BS) and from an adjacent native forest (NF) area at Usina Triunfo, Boca da Mata, Alagoas, Brazil. Microbial biomass-C (MBC), total organic C (TOC), soil enzyme activity expressed as the rate of fluorescein diacetate (FDA) hydrolysis, mean weight diameter of water-stable soil aggregates (MWD), and percentage of water-stable macroaggregates (PWSA) were analyzed. Although MBC and TOC were higher in NF than in the cultivated areas, no differences were observed in these C pools between the three sugarcane systems. The response of FDA to the site management was dependent on the sampling time. In the rainy period, the activity followed the order: NF > OS > GS > BS, whereas in the dry season, only NF differed from the other treatments. Irrespective of the sampling time, MWD and PWSA decreased in the order NF > OS = GS > BS. The variables MWD and PWSA are quite sensitive for discriminating between site management histories regardless the sampling season.
基金To the technical research support of Gilberto Farias,Benedito Mota,and Maria Aparecida C.de GodoyTo FAPESP and CNPq for the grants.Piraíseeds for green manure and cover crops and Fundag for the support.
文摘Three assays were developed from April 3, 1995 to October 10, 2005. The work with corn was conducted in a greenhouse, using velvet bean (Mucuna aterrima) and sunn hemp (Crotalaria juncea) as green manure with 15N labeling of either shoots or roots, in two soils with contrasting textural classes. The mineralization of N from legume plants incorporated into the two soils was investigated too. This work included two green manures: velvet bean and sunn hemp, and the common bean (Phaseolus vulgaris) residues. Nitrogen from the velvet bean accounted for a greater proportion of the soil inorganic N;shoots were responsible for most of N accumulated. Common bean residues caused immobilization of inorganic N. The leguminous species added were intensively and promptly mineralized, preserving the soil native nitrogen. One hundred days after emergence of the corn, velvet bean provided higher accumulation of nitrogen in the soil, higher absorption by corn plants and accumulation in the aerial part. The green manure decomposition was more intense in the medium textured soil. In this soil, highest nitrogen losses were also observed. The sugarcane (Saccharum spp.) was cultivated for five years in the field and was harvested three times;15N recovery was evaluated in the first two harvests. The combination of inorganic fertilizer and green manure resulted in higher sugarcane yields than either N source applied separately;however, in the second cutting the yields were higher where sunn hemp was used than in plots with ammonium sulfate. The recovery of N by the first two consecutive harvests accounted for 19% to 21% of the N applied as sunn hemp and 46% to 49% of the N applied as ammonium sulfate. Very little inorganic N was present in the 0-40 cm soil layer with both N sources.
文摘New strategies are required in the sugarcane selection process to optimize the genetic gains in breeding programs. Conventional selection strategies have the disadvantage of requiring the weighing of all the plants in a plot or a sample of stalks and the counting of the number of stalks in all the experimental plots, which cannot always be performed because more than 200,000 genotypes routinely comprise the first test phase (T1) of most sugarcane breeding programs. One way to circumvent this problem is to use decision trees to rank the yield components (the stalk height, the stalk diameter and the number of stalks) and to subsequently use this categorization to select the best families for a specific trait. The objective of this study was to evaluate the categorization of yield components using the classification and regression tree (CART) algorithm as a family selection strategy by comparing the performance of CART with those of conventional methods that require the weighing of stalks, such as the best linear unbiased prediction (BLUP) with sequential (BLUPS) or individual simulated (BLUPIS) procedures. Data from five experiments performed in May 2007 in a randomized block design were analyzed. Each experiment consisted of five blocks, 22 families and two controls (commercial varieties). CART effectively defined the classes of the yield components and selected the best families with an accuracy of 74% compared to BLUPS and BLUPIS. Families with at least 11 stalks per linear meter of furrow resulted in productivities that were above the average productivity of the commercial varieties used in this study and are, therefore, recommended for selection.
文摘The aim of this work was to evaluate the effects of the application of different sources and doses of nitrogen(N)in the growth and productivity of sugarcane in cane plant.Field experiments were conducted in the area of Rio Paraiso II farm,belonging to the Raízen factory,in the city of Jataí,GO.The soil was classified as dystrophic red latosol.The experimental design used was in randomized block,analysed in factorial scheme of 2×4×4,with three replications.The factors analysed were two sources of N(urea and ammonium nitrate),four doses of N(0,60,120 and 180 kg/ha)and four evaluation times(210,250,290 and 330 d after planting(DAP)).The parameters analysed were plant height(PH),diameter of stalks(DS),length of internodes(LI)and productivity of stalks(PS).Results observed significant difference in the sources and doses of N for the evaluated parameters in sugarcane plant.Urea in the average doses of 110 kg/ha and 100.87 kg/ha provided the greatest PH and LI of sugarcane,respectively.Ammonium nitrate at a dose of 180 kg/ha presented the largest DS of sugarcane(cane plant)at 330 DAP.The PS of sugarcane SP80-1816 at 60 kg/ha and 120 kg/ha ammonium nitrate has higher increments.For the PS,it is recommended the application of doses between 60 kg/ha and 120 kg/ha of N of the source ammonium nitrate in sugar cane(cane plant).
文摘The area cultivated with sugarcane in Brazil is expanding, and increasingly using legumes cover crop in new deployed areas and in those which were reformed. Long-term trials were carried out in Piracicaba, Sao Paulo, Brazil, to evaluate the effect of leguminous green manure on the natural infestation of Diatraea saccharalis (Fabr.) during five cropping cycles of sugarcane “IAC 87-3396”. This study was carried out from October 1999 to October 2005 in Piracicaba, Sao Paulo, Brazil, at coordinates 22°42''S and 47°38''W, 560 m above sea level, in soil classified as Typic Paleudult. Green manure crops were assigned to five treatments: peanuts (Arachis hypogaea L.) (cultivar “IAC-Tatu” and “IAC-Caiapó”), sunn hemp (Crotalaria juncea L.) (cultivar “IAC 1”) and velvet-bean [Mucuna aterrima (Piper & Tracy) Holland] (cultivar “common”). A treatment without any green manure or weed was used as the control. The previous sugarcane crop was destroyed and the soil was prepared in a conventional way (using plow and harrow) before the leguminous crops were sowed. Thirty days after the sowing, weeds were removed and, 120 days later, the crops were cut and its biomass was deposited on the soil surface without incorporation. Experimental plots comprised five rows of sugarcane, each one measuring 10 m long and spaced 1.40 m apart. The sugarcane was harvested 18 months after biomass deposit, on October 25th, 2001 and its stalks were collected at intervals of approximately 12 months in: 07/09/2002, 08/01/2003, 11/07/2004 and 10/06/2005. At harvest, the masses were determined from a sample of sugarcane, cut from three rows (2 m long) in the center of the plot. The losses caused by the sugarcane borer were estimated by the intensity of the infestation by randomly observing and collecting sugarcane stems from each plot. A great reduction in the number of stalks and in the yield was noted proportionally to the intensity of the infestation of the borer in the sugarcane crop grown after the velvet-bean. The sugarcane-velvet-bean rotation should be regarded considering the intensity of sugarcane borer infestation. No influence of the other green manure crops was observed on the intensity of the infestations. However, the harvest seasons of the sugarcane seemed to influence the borer infestation.
