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1.
A 2-year field study evaluated the influence of subsoiling and nematicide application, alone and in combination, on the growth and yield of field corn in a sandy soil in north-central Florida. The field had a 25-30-cm-deep tillage pan (plowpan) and was infested with Belonolaimus longicaudatus, Hoplolaimus galeatus, Trichodorus christei, and Pratylenchus spp. Subsoiling increased corn yield both years, and the residual effect of subsoiling in the first year increased yields in the second year. Preplant application of DD injected in-row increased yields and reduced nematode populations. At-planting applications of DD injected in-row and carbofuran in-furrow or in a band were less effective than subsoiling in increasing yields and reducing nematode numbers. Interactions between subsoiling and nematicide treatments occurred in the second year.  相似文献   

2.
A field trial was conducted for 2 years in an Arredondo fine sand containing a tillage pan at 15-20 cm deep to determine the influence of subsoiling on the distribution of corn roots and plant-parasitic nematodes. Soil samples were taken at various depths and row positions at 30, 60, and 90 days after planting in field corn subsoiled under the row with two chisels and in non-subsoiled corn. At 30 and 60 days, in-row nematode population densities to 60 cm deep were not affected by subsoiling compared with population densities in nonsubsoiled plots. After 90 days, subsoiling had not affected total root length or root weight at the 20 depth-row position sampling combinations, but population densities of Meloidogyne incognita and Criconemella spp. had increased in subsoiled corn. Numbers of Pratylenchus zeae were not affected. Subsoiling generally resulted in a change in distribution of corn roots and nematodes in the soil profile but caused little total increase in either roots or numbers of nematodes. Corn yield was increased by subsoiling.  相似文献   

3.
Four methods of placement of DBCP (l,2-dibromo-3-chloropropane) and a single method of application of ethoprop (0-ethyl S,S-dipropyl phosphorodithioate) wexe compared in each of two areas for control of nematodes on soybeans. One area was a Marlboro sand infested with Hoplolaimus columbus. The other area was a Fuquay loamy sand infested with Meloidogne incognita. Soybean yields were increased and numbers of H. columbus in the row 0-20 cm deep were decreased similarly by all methods of DBCP application in Marlboro soil. All DBCP treatments increased the average soybean yields and decreased numbers of M. incognita larvae in the row 0-20 cm deep in the Fuquay soil. Average root-knot indices were reduced by all DBCP treatments except with placement 40 cm deep beneath the row. Similarly, placement of all or part of the DBCP 20 cm deep and 13 cm to either side of the row resulted in greater average yields than placement of the DBCP 40 cm deep. Apparently, control of M. incognita is more critical 0-20 cm deep than 20-40 cm deep for increasing soybean yields. DBCP did not control H. columbus as effectively as it did M. incognita. Control of H. columbus and M. incognita was not obtained at 0-20-cm and 20-40-cm depths 30 cm and 45 cm from the row regardless of the method used to apply DBCP. H. columbus and M. incognita were controlled more effectively and soybean yields were higher with DBCP at 13.6 kg a.i./ha than with ethoprop at 4.5 kg a.i./ha.  相似文献   

4.
Yields of four soybean, Glycine max, cultivars were increased with subsoiling under the row and application of the nematicide, DBCP i 1,2-dibromo-3-chloropropane) in Tiflon sandy loam heavily infested with the root-knot nematode Meloidogyne incognita. These cultivars represent four maturity groups: very early (V), "Essex'', early (VI), "Davis'': medium (VII), ''Ransom''; and late (VIII), '' Hutton ''. The average increase for the four cullivars was about the same for subsoiling or DBCP. When the treatmcnts were used together, the increase was greater than when either was used alone, but the effects were not additive. Increased yields were obtained with subsoiling and DBCP for the most nematode resistant cultivar, Hutton, as well as for the most susccptiblc, Davis. Subsoiling reduced root-knot galling in nonfumigated plots but did not affect it in fumigated plots. On 12 September, M. incognita larvae were most numerous at the 0- to 20 cm depth, intermediate at 20 to 33 cm depth and least numerous at 33 to 46 cm depth, Subsoiling did not affect larval populations at the three levels.  相似文献   

5.
Greenhouse and laboratory experiments were performed to determine if an interaction exists between Meloidogyne incognita and Hoplolaimus columbus on Davis soybean. Greenhouse tests were performed with three population levels of M. incognita and H. columbus (0, 1,500, 6,000/1.5-liter pot) separately and in all combinations. Dry root weight (DRT) declined nonlinearly and dry shoot weight (DST) declined linearly with respect to increasing initial populations of M. incognita and H. columbus. When the two nematode species were added to the soil together, the amount of DRT and DST suppression by one species was dependent on the initial level of the concomitant species. The final root population of M. incognita or H. columbus declined linearly with increasing initial population density of the concomitant species. H. columbus suppressed M. incognita populations in the soil nonlinearly, but M. incognita had no effect on H. columbus.  相似文献   

6.
Yields of ''McNair 800'' soybeans, Glycine max (L.) Merr., were significantly increased with ethylene dibromide + chloropicrin, DBCP, phenamiphos, and aldicarb applied at-planting and with phenamiphos, aldicarb, and DBCP applied postplant to soil infested with Meloidogyne incognita (Kofoid and White) Chitwood. Yields of ''GaSoy 17'' were significantly increased with ethylene dibromide + chloropicrin, DBCP, phenamiphos, and aldicarb applied, preplant and with DBCP, carbofuran, phenamiphos, aldicarb, and DBCP applied postplant to soil infested with Hoplolaimus columbus Sher. In several instances, preplant or at-planting treatments plus postplant treatments with the same or different chemicals were more effective than either treatment alone. Generally, the fumigants were more effective than the nonfumigants when they were applied at-planting to M. incognita-infested soil and preplant to H. columbus-infested soil. Phenamiphos, aldicarb, and DBCP were about equally effective when they were applied postplant in M. incognita-infested soil, but DBCP was more effective than carbofuran. Carbofuran, phenamiphos, aldicarb, and DBCP were about equally effective when applied postplant to H. columbus-infested soil.  相似文献   

7.
Cotton seedlings grown in a greenhouse and a growth chamber were inoculated with Scutellonema brachyurum, Hoplolaimus columbus, and Meloidogyne incognita, singly and in all possible combinations, at two initial population (Pi) levels (100 and 300/100 cm³). S. brachyurum alone was not pathogenic to cotton at these population levels. It fed primarily as an ectoparasite but matured and reproduced within the root when it penetrated. Populations of S. brachyurum increased in the presence of H. columbus but were suppressed by M. incognita. H. columbus suppressed dry shoot weights of cotton (P = 0.05) at a Pi of 300/100 cm³ soil. Simultaneous inoculation of H. columbus with either M. incognita or S. brachyurum increased H. columbus populations over treatments with H. columbus alone, both at 60 and 90 d after inoculation. M. incognita suppressed cotton shoot weights significantly (P = 0.05) at both Pi levels. Inoculation with S. brachyurum increased M. incognita populations 60 d after inoculation, while H. columbus suppressed populations of M. incognita. Most larvae of M. incognita did not develop to maturity in the presence of H. columbus. Giant cells aborted and were necrotic 20-25 d after inoculation. Since M. incognita and H. columbus feed on different tissues, the inhibition of M. incognita may have resulted from a physiological effect of H. columbus on the host.  相似文献   

8.
The effects of initial populations of Hoplolaimus columbus and Meloidogyne incognita on growth and yield of Davis soybean were determined for 1980 and 1981 in microplots and H. columbus in field tests in 1981. M. incognita suppressed yield in microplots both years and H. columbus in 1980. Maximum suppression of dry pod weight by M. incognita was 45% and by H. columbus 35%. The relationship of yield vs. nematode population at planting time was described by a declining exponential model. Maximum reproductive rates for M. incognita and H. columbus were 67.0 and 4.7, respectively, and were inversely proportional to initial population level. Nematode reproductive rates, survival ability, and feeding habits suggest species specific life strategies in the ecological community.  相似文献   

9.
探讨蔗地机械化耕作深度对耕层土壤物理性状及甘蔗产量构成因子的影响,阐明深松作业的针对性土壤区位和障碍因子,可为甘蔗良好耕层的构建和土壤改良策略的制定提供科学依据.本研究设置3种深松作业深度(35、40和45 cm),以不深松为对照,对蔗地土壤物理性状(紧实度、容重、含水率、孔隙度、三相容积率)和甘蔗产量构成因素及蔗茎产量等指标进行研究.结果表明: 耕作作业深度与蔗地土壤结构特性及甘蔗产量的改善提升效应呈显著正相关.深松能够打破犁底层,显著降低土壤紧实度和容重,减小机械作业相应的贯入阻力和抗剪强度,尤其对20~30 cm土层的上述因子具有显著改善效应,对甘蔗高产意义重大.深松显著提高了30 cm以内土层的液相容积率,增大了土壤水分库容,使10~30 cm土层的水分指标显著改善.10~30 cm土层是深松对耕层土壤固相容积率改善效应最显著的区位.耕作深度的增加对甘蔗有效茎数、株高、蔗茎产量及蔗糖含量具有显著的促进效应.鉴于蔗区当前较普遍的机具装备水平,我国适宜蔗区实施机械化深松的作业深度标准应不小于40 cm.  相似文献   

10.
Quantitative techniques were used to analyze and determine optimal potential profitability of 3-year rotations of cotton, Gossypium hirsutum cv. Coker 315, and soybean, Glycine max cv. Centennial, with increasing population densities of Hoplolaimus columbus. Data collected from naturally infested on-farm research plots were combined with economic information to construct a microcomputer spreadsheet analysis of the cropping system. Nonlinear mathematical functions were fitted to field data to represent damage functions and population dynamic curves. Maximum yield losses due to H. columbus were estimated to be 20% on cotton and 42% on soybean. Maximum at-harvest population densities were calculated to be 182/100 cm³ soil for cotton and 149/100 cm³ soil for soybean. Projected net incomes ranged from a $17.74/ha net loss for the soybean-cotton-soybean sequence to a net profit of $46.80/ha for the cotton-soybean-cotton sequence. The relative profitability of various rotations changed as nematode densities increased, indicating economic thresholds for recommending alternative crop sequences. The utility and power of quantitative optimization was demonstrated for comparisons of rotations under different economic assumptions and with other management alternatives.  相似文献   

11.
《植物生态学报》2014,38(7):767
Aims The purpose of this study was to determine a suitable combination of tillage method and nitrogen rate to improve wheat (Triticum aestivum) yield and protein content in lime concretion black soil.
Methods Under the field experimental conditions, three tillage methods (subsoiling and rotary tillage, rotary tillage, and conventional tillage) were used as the main treatments, and four nitrogen application rates (0, 120, 225 and 330 kg·hm–2) were used as sub-treatments. Nitrogen assimilation after jointing stage, grain yield, and protein content were determined in wheat plants to study the effects of different tillage methods and nitrogen application rate on these variables.
Important findings Results showed that the glutamine synthetase (GS) activity, free amino acid content, and soluble protein content in wheat plants initially increased and then decreased during growth. The peaks of GS activity, free amino acid content, and soluble protein content occurred 10 days after flowering in the subsoiling treatment with 225 or 330 kg·hm–2 nitrogen application rate, and at the flowering stage for other treatment combinations. Compared with the conventional tillage and rotary tillage, the bulk density of 10 to 40 cm soil in the subsoiling treatment was significantly reduced, and the soil total porosity and root dry weight were significantly increased. Tillage method and nitrogen application rate had a significant impact on grain yield and protein content in wheat plants. Grain yield and protein content were highest in the subsoiling treatment. Regardless of the tillage method, the grain yield and protein content both increased with increasing nitrogen application rate. The grain yield in the subsoiling treatment was highest with nitrogen application rate at 330 kg·hm–2, whereas the outputs of conventional tillage and rotary tillage were peaked at nitrogen application rate of 225 kg·hm–2. The grain proteincontent was highest at nitrogen application rate of 225 kg·hm–2 under the three tillage methods. Thus, subsoiling with optimum nitrogen rate should be promoted in lime concretion black soil. Subsoiling increased grain yield and protein quality by improving soil conditions and the absorption of root systems for soil nitrogen.  相似文献   

12.
The potential of Pasteuria penetrans for suppressing Meloidogyne arenaria race 1 on peanut (Arachis hypogaea) was tested over a 2-year period in a field microplot experiment. Endospores of P. penetrans were mass-produced on M. arenaria race 1 infecting tomato plants. Endospores were inoculated in the first year only at rates of 0, 1,000, 3,000, 10,000, and 100,000 endospores/g of soil, respectively, into the top 20 cm of microplots that were previously infested with M. arenaria race 1. One peanut seedling was planted in each microplot. In the first year, root gall indices and pod galls per microplot were significantly reduced by 60% and 95% for 100,000 endospores/g of soil, and 20% and 65% for 10,000 endospores/g of soil, respectively. Final densities of second-stage juveniles (J2) in soil were not significantly different among the treatments. The number of endospores attached to J2 and percentage of J2 with attached endospores significantly increased with increasing endospore inoculation levels. Pasteuria penetrans significantly reduced the densities of J2 that overwintered. In the second year, root and pod gall indices, respectively, were significantly reduced by 81% and 90% for 100,000 endospores/g of soil, and by 61% and 82% of 10,000 endospores/g of soil. Pod yields were significantly increased by 94% for 100,000 and by 57% for 10,000 endospores/g of soil, respectively. The effect of P. penetrans on final densities of J2 in soil was not significant. Regression analyses verified the role of P. penetrans in the suppression of M. arenaria. The minimum number of endospores required for significantly suppressing M. arenaria race 1 on peanut was 10,000 endospores/g of soil.  相似文献   

13.
From the fall of 1968 through the summer of 1973, a Georgia cotton field with a lengthy history of the Cotton Stunt Disease Complex was sampled for the presence of plant parasitic nematodes. Although Meloidogyne incognita was recovered on all sampling dates, concomitant populations of Hoplolaimus columbus were not recovered until the spring of 1970. During the succeeding four growing seasons, the population density and horizontal distribution of H. columbus increased, and H. columbus replaced M. incognita as the predominant phytopathogenie species. A second Georgia cotton field containing concomitant populations of H. columbus and M. incognita was observed from the fall of 1971 through the summer of 1973. In this case the horizontal distribution of both species remained relatively constant and the population density of H. columbus increased steadily. In both locations, the presence of either H. columbus or M. incognita significantly inhibited the presence of the concomitant species. In general, however, the initial spring or final fall population densities of H. columbus or M. incognita had no significant influence on the population density of the concomitant species, The data are also discussed in relation to the biological significance of H. columbus in the southeastern coastal plain.  相似文献   

14.
Sting nematode (Belonolaimus longicaudatus) is recognized as a pathogen of cotton (Gossypium hirsutum), but the expected damage from a given population density of this nematode has not been determined. The objective of this study was to quantify the effects of increasing initial population densities (Pi) of B. longicaudatus on cotton yield and root mass. In a field plot study, nematicide application and cropping history were used to obtain a wide range of Pi values. Cotton yields were regressed on Pi density of B. longicaudatus to quantify yield losses in the field. In controlled environmental chambers, cotton was grown in soil infested with increasing Pi''s of B. longicaudatus. After 40 days, root systems were collected, scanned on a desktop scanner, and root lengths were measured. Root lengths were regressed on inoculation density of B. longicaudatus to quantify reductions in the root systems. In the field, high Pi''s (>100 nematodes/130 cm³ of soil) reduced yields to near zero. In controlled environmental chamber studies, as few as 10 B. longicaudatus/130 cm³ of soil caused a 39% reduction in fine cotton roots, and 60 B. longicaudatus/130 cm³ of soil caused a 70% reduction. These results suggest that B. longicaudatus can cause significant damage to cotton at low population densities, whereas at higher densities crop failure can result.  相似文献   

15.
通过在甘肃引黄灌区灰钙土2015—2017年的田间试验,研究深松35 cm秸秆还田、深松35 cm秸秆不还田与传统旋耕秸秆不还田对土壤紧实度、容重、入渗率和0~100 cm土层土壤水分、玉米产量、养分吸收量的影响.结果表明: 与深松35 cm秸秆不还田及旋耕秸秆不还田相比,深松35 cm秸秆还田使0~40 cm土层土壤紧实度和容重降低最明显,2017年收获后紧实度与容重较2015年试验前分别下降42.6%、7.0%,且2016和2017年播种前与收获后0~40 cm土层紧实度和容重的变幅最小,紧实度变异系数平均为6.1%,容重为3.2%,土壤入渗率较旋耕秸秆不还田提高33.6%;深松35 cm秸秆还田可显著提高春秋两季0~100 cm土层剖面含水量,降低剖面水分变异,0~100 cm土层土壤贮水量较旋耕秸秆不还田春季增加15.5%,秋季增加5.6%,水分利用效率提高32.4%;此外,深松35 cm秸秆还田能促进玉米生产,较旋耕秸秆不还田的经济产量两年平均分别增产25.6%,生物产量提升33.3%,玉米氮、磷、钾养分吸收量分别提高49.6%、51.5%和37.6%.综上,深松35 cm秸秆还田能改善物理土壤特性,稳定耕层物理性状,提高0~100 cm土层剖面水分含量及春秋两季土壤平均贮水量,降低水分变异,是促进玉米水肥高效利用,实现高产的最优措施,为甘肃引黄灌区耕层构建技术的深入研究提供理论依据.  相似文献   

16.
Hoplolaimus columbus suppressed growth and pod yield of soybean in greenhouse tests. Although populations of H. columbus decreased in short-term experiments, increases occurred in long-term studies. The nematode caused extensive damage to the cortical parenchyma and occasionally to the endodermal-vascular region of both cotton and soybean roots. The nematode frequently entered secondary root primordia. Roots of soybean parasitized by H. columbus at high inoculum levels were severely damaged. The relationship of populations of H. columbus and stunting of soybean and cotton is discussed.  相似文献   

17.
Movement and persistence of 1,2-dibrotno-3-chloropropane (DBCP) in a Coastal Plain soil containing a sandy plow-pan were enhanced in each of 2 years by subsoiling, increased depth of application, and increased rate of application. DBCP was extracted from the soil with hexane and analyzed by gas chromatography. Subsoiling at a 35-cm depth gave the greatest increase in lateral movement and downward penetration of DBCP in 1975 (a wet year), but bad less effect in 1976 (a dry year). An increased application rate (10 kg/ha vs. 13.5) improved coverage moderately in 1975 by increasing lateral movement, but had little effect in 1976. Increased application depth (18 vs. 35 cm) improved coverage in both years though more in 1976. Deep placement extended DBCP retention time. Rainfall in 1975 probably decreased the number and size of air-filled pores, slowing loss of DBCP to the atmosphere. Because of reduced porosity, the plow-pan was impervious to the passage of DBCP unless disrupted by subsoiling.  相似文献   

18.
为探究耕作覆盖对土壤水热及旱作马铃薯产量的影响,连续2年在宁南旱区不同耕作深度结合覆盖模式下开展了研究工作。结果表明: 耕作深度、覆盖材料对马铃薯播种期0~100 cm土层土壤贮水量有极显著影响,而二者交互作用无显著影响;2019年土壤贮水量以深松30 cm覆盖地膜处理最高,2020年以深松40 cm覆盖秸秆处理较高,分别较翻耕15 cm不覆盖处理(对照)显著提高16.9%和33.4%;耕作深度、覆盖材料可显著影响马铃薯关键生育期土壤贮水量;同一耕作深度下土壤贮水量以秸秆、地膜覆盖处理效果较好,同一覆盖材料下以深松30~40 cm处理最佳。覆盖材料、耕作深度与覆盖材料二者交互作用对播种-现蕾期0~25 cm土层土壤有效积温影响显著;同一耕作深度下覆盖地膜处理土壤有效积温平均较不覆盖处理显著增加9.3%,而覆盖秸秆处理较不覆盖处理显著降低18.7%;2019和2020年各处理全生育期土壤有效积温分别以深松30 cm和深松40 cm覆盖地膜处理最高。2019年马铃薯总产量和经济效益以深松30 cm覆盖秸秆处理较高,分别较对照显著提高84.6%和107.9%;2020年以深松40 cm覆盖秸秆处理最佳,分别较对照显著提高81.7%和105.7%。耕作深度、覆盖材料对作物水热利用效率均有显著影响,水分利用效率以深松30~40 cm覆盖秸秆处理较高,而积温利用效率不同耕作深度结合秸秆覆盖各处理均较翻对照显著提高。相关分析表明,块茎形成期的土壤水分和有效积温对马铃薯总产量的形成至关重要,而全生育期土壤水分对总产量的影响高于土壤有效积温。可见,深松30~40 cm覆盖秸秆处理可改善土壤水热状况,实现马铃薯增产增收和水热资源的高效利用,在宁南半干旱区马铃薯生产中有一定的应用推广价值。  相似文献   

19.
为明确砂姜黑土区小麦(Triticum aestivum)产量和品质形成的耕作方式及施氮量最优组合, 在大田试验条件下, 以深松、旋耕和常规耕作3种耕作方式为主区, 0、120、225、330 kg·hm-2 4个施氮量为副区, 研究了不同耕作方式及施氮量组合对小麦拔节后氮代谢、籽粒产量和蛋白质含量的影响。结果表明, 随着生育期的推进, 叶片谷氨酰胺合成酶活性、游离氨基酸含量和可溶性蛋白含量均呈先升后降的趋势, 深松方式配合中高氮处理的峰值在花后10天, 而常规耕作和旋耕的4个施氮处理以及深松的低氮处理峰值多在开花期。与常规耕作和旋耕相比, 深松耕作显著降低了10-40 cm的土壤容重, 提高了土壤总空隙度和根干质量, 有利于中后期根系氮素吸收。耕作方式和施氮量对籽粒产量和蛋白质含量影响显著, 均以深松方式最高。3种耕作方式下小麦产量和蛋白质含量均随施氮量增加而增加, 籽粒产量以深松方式配合330 kg·hm-2施氮量最高, 而常规耕作和旋耕方式的产量在施氮量为225 kg·hm-2时达到最大。3种耕作方式下籽粒蛋白质含量均以施氮225 kg·hm-2最高。因此, 在砂姜黑土区宜采用深松耕作方式配合适宜的施氮量, 以改善土壤条件, 促进根系氮素吸收, 延长叶片功能期, 达到产量与蛋白品质提升之目的。  相似文献   

20.
BackgroundLong-term tillage has been shown to induce water stress episode during crop growth period due to low water retention capacity. It is unclear whether integrated water conservation tillage systems, such asspringdeepinter-row subsoiling with annual or biennial repetitions, can be developed to alleviate this issue while improve crop productivity.MethodsExperimentswere carried out in a spring maize cropping system on Calcaric-fluvicCambisolsatJiaozuoexperimentstation, northern China, in 2009 to 2014. Effects of threesubsoiling depths (i.e., 30 cm, 40 cm, and 50 cm) in combination with annual and biennial repetitionswasdetermined in two single-years (i.e., 2012 and 2014)againstthe conventional tillage. The objectives were to investigateyield response to subsoiling depths and soil water deficit(SWD), and to identify the most effective subsoiling treatment using a systematic assessment.ResultsAnnualsubsoiling to 50 cm (AS-50) increased soil water storage (SWS, mm) by an average of8% in 0–20 cm soil depth, 19% in 20–80 cm depth, and 10% in 80–120 cm depth, followed by AS-40 and BS-50, whereas AS-30 and BS-30 showed much less effects in increasing SWS across the 0–120 cm soil profile, compared to the CK. AS-50 significantly reduced soil water deficit (SWD, mm) by an average of123% during sowing to jointing, 318% during jointing to filling, and 221% during filling to maturity, compared to the CK, followed by AS-40 and BS-50. An integrated effect on increasing SWS and reducing SWD helped AS-50 boost grain yield by an average of 31% and biomass yield by 30%, compared to the CK. A power function for subsoiling depth and a negative linear function for SWD were used to fit the measured yields, showing the deepest subsoiling depth (50 cm) with the lowest SWD contributed to the highest yield. Systematic assessment showed that AS-50 received the highest evaluation index (0.69 out of 1.0) among all treatments.ConclusionDeepinter-row subsoilingwith annual repetition significantly boosts yield by alleviating SWD in critical growth period and increasing SWS in 20–80 cm soil depth. The results allow us to conclude that AS-50 can be adopted as an effective approach to increase crop productivity, alleviate water stress, and improve soil water availability for spring maize in northern China.  相似文献   

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