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Osamu Ito - One of the best experts on this subject based on the ideXlab platform.
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Estimation of nitrogen fixation by the natural 15N-abundance technique and nitrogen uptake by pigeonpea genotypes of different Maturity Groups grown in an inceptisol
Journal of Agronomy and Crop Science, 1996Co-Authors: J. V. D. K. Kumar Rao, C. Johansen, T. Yoneyama, Satoshi Tobita, Osamu ItoAbstract:The modulation, nitrogen fixation and nitrogen uptake of four pigeonpea genotypes belonging to extra short duration, short duration and long duration Maturity Groups grown on an Inceptisol were studied to examine why, despite the poor nodulation of pigeonpea in this soil, it still produces greater yields, than in Alfisols and Vertisols. The percentage nitrogen derived from the atmosphere (%Ndfa) was estimated by 15N natural abundance and N-difference methods using a long duration sorghum as the non-fixing reference crop. In general, nodulation of pigeonpea in the Inceptisol was much lower than that reported in Alfisols and Vertisols. The above-ground dry matter ringed from 3.1 to 17.1 t ha−1 while the N uptake ranged from 62.3 to 215 kg ha−1 The fallen plant parrs of pigeonpea genotypes ranged from 1.4 to 4.9 t ha−1 and their N contents ranged from 25 to 84 kg ha−1. The estimates of percentage Ndfa obtained by the two methods were different. Those obtained by the 15N natural abundance appeared more appropriate as the δ15N of sorghum harvested along with short duration pigeonpea and later when it was mature did not change significantly. The extra short duration pigeonpea genotype ICPL 84023 contained very little N from atmospheric N2, while the short duration pigeonpea cv. ICPL 151 had 17% Ndfa and the long duration genotypes. ICPL 366 and T7 had up to 36 % Ndfa. It can be concluded that one of the causes of high yields of pigeonpea on Inceptisols compared to Alfisols and Vertisols despite poor nodulation could be the high N supplying capacity of these Inceptisols. Strategies have been suggested as to how pigeonpea genotypes grown in Inceptisols could improve their nodulation and nitrogen fixation and thus better contribute to a sustainable agriculture.
P L G Vlek - One of the best experts on this subject based on the ideXlab platform.
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remobilization of nitrogen from senescing leaves of pigeonpea cajanus cajan l millsp genotypic differences across Maturity Groups
Journal of Experimental Botany, 1998Co-Authors: C M Sanetra, O Ito, S M Virmani, P L G VlekAbstract:Remobilization of leaf nitrogen during the seed filling stage was investigated in relation to patterns of leaf abscission with three pigeonpea genotypes (Cajanus cajan) of different Maturity duration (extra-short (ESD), short (SD), and medium (MD)). Leaflet abscission (trifoliate leaf) started from the bottom of the plants. The life span of defined leaf layers in the canopy differed among the genotypes and tended to be longer toward the top of the plants. At harvest, the leaf layer close to the pod-bearing top of the plant had a survival rate of 75% and 31% in ESD and SD pigeonpea, respectively, indicating that a large number of leaves in ESD was not entirely exploited for nutrient redistribution to the seed. Net remobilization of nitrogen from leaves during the reproductive stage was obtained from an above-ground plant budget for N and amounted to 35, 47, and 37% of the pod''s requirement for N in ESD, SD, and MD, respectively. The amount of nitrogen in the defined leaf layers decreased exponentially with time, and the rate of N loss was calculated from the regressions in terms of half-life. For most of the layers half-life was longest in ESD pigeonpea indicating slower abscission and remobilization compared with both other genotypes. It is suggested that the efficiency to remobilize leaf nitrogen for seed development is related to the pattern of leaf abscission in pigeonpeas, and that SD pigeonpeas remobilize leaf N more efficiently than ESD and MD
Gustavo Zimmer - One of the best experts on this subject based on the ideXlab platform.
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genetic control and allele variation among soybean Maturity Groups 000 through ix
The Plant Genome, 2021Co-Authors: Gustavo Zimmer, Mark J Miller, Clinton J Steketee, Scott A Jackson, Lilian Vanussa Madruga De TunesAbstract:Soybean [Glycinemax (L.) Merr.] Maturity determines the growing region of a given soybean variety and is a primary factor in yield and other agronomic traits. The objectives of this research were to identify the quantitative trait loci (QTL) associated with Maturity Groups (MGs) and determine the genetic control of soybean Maturity in each MG. Using data from 16,879 soybean accessions, genome-wide association (GWA) analyses were conducted for each paired MG and across MGs 000 through IX. Genome-wide association analyses were also performed using 184 genotypes (MGs V-IX) with days to flowering (DTF) and Maturity (DTM) collected in the field. A total of 58 QTL were identified to be significantly associated with MGs in individual GWAs, which included 12 reported Maturity loci and two stem termination genes. Genome-wide associations across MGs 000-IX detected a total of 103 QTL and confirmed 54 QTL identified in the individual GWAs. Of significant loci identified, qMG-5.2 had effects on the highest number (9) of MGs, followed by E2, E3, Dt2, qMG-15.5, E1, qMG-13.1, qMG-7.1, and qMG-16.1, which affected five to seven MGs. A high number of genetic loci (8-25) that affected MGs 0-V were observed. Stem termination genes Dt1 and Dt2 mainly had significant allele variation in MGs II-V. Genome-wide associations for DTF, DTM, and reproductive period (RP) in the diversity panel confirmed 15 QTL, of which seven were observed in MGs V-IX. The results generated can help soybean breeders manipulate the Maturity loci for genetic improvement of soybean yield.
J. V. D. K. Kumar Rao - One of the best experts on this subject based on the ideXlab platform.
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Estimation of nitrogen fixation by the natural 15N-abundance technique and nitrogen uptake by pigeonpea genotypes of different Maturity Groups grown in an inceptisol
Journal of Agronomy and Crop Science, 1996Co-Authors: J. V. D. K. Kumar Rao, C. Johansen, T. Yoneyama, Satoshi Tobita, Osamu ItoAbstract:The modulation, nitrogen fixation and nitrogen uptake of four pigeonpea genotypes belonging to extra short duration, short duration and long duration Maturity Groups grown on an Inceptisol were studied to examine why, despite the poor nodulation of pigeonpea in this soil, it still produces greater yields, than in Alfisols and Vertisols. The percentage nitrogen derived from the atmosphere (%Ndfa) was estimated by 15N natural abundance and N-difference methods using a long duration sorghum as the non-fixing reference crop. In general, nodulation of pigeonpea in the Inceptisol was much lower than that reported in Alfisols and Vertisols. The above-ground dry matter ringed from 3.1 to 17.1 t ha−1 while the N uptake ranged from 62.3 to 215 kg ha−1 The fallen plant parrs of pigeonpea genotypes ranged from 1.4 to 4.9 t ha−1 and their N contents ranged from 25 to 84 kg ha−1. The estimates of percentage Ndfa obtained by the two methods were different. Those obtained by the 15N natural abundance appeared more appropriate as the δ15N of sorghum harvested along with short duration pigeonpea and later when it was mature did not change significantly. The extra short duration pigeonpea genotype ICPL 84023 contained very little N from atmospheric N2, while the short duration pigeonpea cv. ICPL 151 had 17% Ndfa and the long duration genotypes. ICPL 366 and T7 had up to 36 % Ndfa. It can be concluded that one of the causes of high yields of pigeonpea on Inceptisols compared to Alfisols and Vertisols despite poor nodulation could be the high N supplying capacity of these Inceptisols. Strategies have been suggested as to how pigeonpea genotypes grown in Inceptisols could improve their nodulation and nitrogen fixation and thus better contribute to a sustainable agriculture.
Darija Lemic - One of the best experts on this subject based on the ideXlab platform.
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european corn borer and its parasites overwintering abundance and damages on different corn fao Maturity Groups
Journal of Central European Agriculture, 2019Co-Authors: Darija Lemic, Jakov Mandic, Maja Cacija, Zrinka Drmic, Martina Mrganic, Snjezana Cavlovicak, Renata Bazok, Helena Viric GasparicAbstract:European corn borer (ECB) is one of the most significant maize pests in the world and also in Croatia. ECB causes yield reduction from 2 to 25%, even more in years favorable for its development. According to estimations, these losses are around 7%. About 90% of the hybrids had some resistance to whorl-leaf feeding (first-generation ECB) and 75% had some resistance to sheath and sheath-collar feeding (second-generation ECB). Along with resistance, modern maize hybrids possess certain level of tolerance. The main aim of this paper was to determine moth eclosion of the overwintering generation and presence of the parasites of ECB larvae during the overwintering as well as to estimate population density of ECB on maize growing area in Croatia. Also, we aimed to establish the differences among different maize FAO Maturity Groups in damage caused by ECB larvae. Estimated overwintering population was over 8,000 moths/ha i.e. more than 4 million larvae of first generation. During the overwintering four different parasites attacked the larvae. Two species belong to the order Hymenoptera (Cotesia marginiventris Cresson and Eriborus terebrans Gravenhorst) and two species belong to the order Diptera (Ramonda spathulata Fallen and Lydella thompsoni Herting). One caterpillar predator species Paragymnomerus spiricornis Spinola (Hymenopetra) overwinters in maize stalks as well. The highest attack of the first ECB generation was recorded on FAO Maturity group 500. The damage from second ECB generation was the highest on FAO Groups 400 and 500. The maize of the higher FAO Groups has high and robust stems with large number of big leaves. That intensive vegetative growth is a biological characteristic that attracts first generation of ECB to intensifying egg lying. High population level of the first generation also leads to high level of second ECB generation which ultimately caused yield reduced on the hybrids of longer vegetation period (medium-late FAO Maturity Groups).
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European corn borer and its parasites overwintering abundance and damages on different corn FAO Maturity Groups
University of Zagreb Faculty of Agriculture, 2019Co-Authors: Darija Lemic, Jakov Mandic, Maja Cacija, Zrinka Drmic, Martina Mrganic, Snjezana Cavlovicak, Renata Bazok, Helena Viric GasparicAbstract:European corn borer (ECB) is one of the most significant maize pests in the world and also in Croatia. ECB causes yield reduction from 2 to 25%, even more in years favorable for its development. According to estimations, these losses are around 7%. About 90% of the hybrids had some resistance to whorl-leaf feeding (first-generation ECB) and 75% had some resistance to sheath and sheath-collar feeding (second-generation ECB). Along with resistance, modern maize hybrids possess certain level of tolerance. The main aim of this paper was to determine moth eclosion of the overwintering generation and presence of the parasites of ECB larvae during the overwintering as well as to estimate population density of ECB on maize growing area in Croatia. Also, we aimed to establish the differences among different maize FAO Maturity Groups in damage caused by ECB larvae. Estimated overwintering population was over 8,000 moths/ha i.e. more than 4 million larvae of first generation. During the overwintering four different parasites attacked the larvae. Two species belong to the order Hymenoptera (Cotesia marginiventris Cresson and Eriborus terebrans Gravenhorst) and two species belong to the order Diptera (Ramonda spathulata Fallén and Lydella thompsoni Herting). One caterpillar predator species Paragymnomerus spiricornis Spinola (Hymenopetra) overwinters in maize stalks as well. The highest attack of the first ECB generation was recorded on FAO Maturity group 500. The damage from second ECB generation was the highest on FAO Groups 400 and 500. The maize of the higher FAO Groups has high and robust stems with large number of big leaves. That intensive vegetative growth is a biological characteristic that attracts first generation of ECB to intensifying egg lying. High population level of the first generation also leads to high level of second ECB generation which ultimately caused yield reduced on the hybrids of longer vegetation period (medium-late FAO Maturity Groups)
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european corn borrer damage on different fao maize Maturity Groups on location sasinovecki lug in 2017
62. seminar biljne zaštite, 2018Co-Authors: Jakov Mandic, Darija LemicAbstract:Kukuruzni moljac (Ostrinia nubilalis Hubner) jedan je od najznacajnijih stetnika kukuruza u svijetu i kod nas. Kukuruzni moljac uzrokuje sniženje prinosa od 2 do 25 %, a u godinama povoljnim za njegov razvoj i vise. Otprilike 90 % hibrida kukuruza pokazuje određen stupanj otpornosti na kukuruznog moljca u vegetativnim stadijima razvoja. Uz otpornost, moderni hibridi kukuruza posjeduju visoku razinu tolerancije na stete. Cilj ovoga rada bio je utvrditi pojavu i visinu populacije kukuruznog moljca te utvrditi razlike između hibrida kukuruza razlicitih FAO grupa u visini napada prve generacije i ostecenja na klipovima od druge generacije. Ostecenja od prve generacije kukuruznog moljca na stabljikama 32 hibrida su podjednaka. FAO grupa 500 pokazuje nesto vecu visinu ostecenja. Pregledom klipova utvrđena su najveca ostecenja od druge generacije moljca na hibridima FAO grupa 400 i 500. Kukuruzi visih FAO grupa imaju visoke i robusne stabljike s velikim brojem krupnijih listova te je upravo taj intenzivan vegetativni rast biolosko svojstvo koje privlaci leptire prve generacije na intenzivnije odlaganje jaja. Veca brojnost prve generacije uvjetuje i veca ostecenja na klipovima od druge generacije kukuruznog moljca. Veca ostecenja klipova u konacnici utjecala su na smanjene prinose hibrida visih FAO grupa (500).