有机水稻品种产量、品质和氮素吸收利用的关系

Due to the relatively late start of organic rice (Oryza sativa L.) research in China, there is a still lack of systematic research on rice varieties, organic fertilizer management practices, and especially the mechanisms of nitrogen (N) uptake and utilization. Three rice varieties, Nanjing 5055, Nanjing 9108, and Nanjing 46, were grown at organic farming (OF) with three organic fertilizer levels (103.2, 160.8, and 218.4 kg N ha^-1) and conventional farming (CF) with regular chemical fertilizers. Rice grain yields, yield components, and quality, dry matter accumulation, and plant N were measured at different growth stages during the 2012 and 2013 growing seasons. Compared with CF, OF had a significantly reduced yield. Nanjing 9108 showed significant reductions in number of panicles per unit area and the percentage of filled grains, and had the lowest yield. The effects of fertilizer type and application rate on dry matter accumulation during the main growth periods were significant for all varieties. The N content and uptake of organically grown rice were lower compared with that of rice under CF. The N recovery efficiency and N agronomic efficiency were significantly lower, whereas N physiological efficiency and N partial factor productivity were greater under OF than under CF. Under OF, the processing quality showed a slight but insignificant decline, protein content and gel consistency increased, and amylose content decreased compared with those under CF. Correlation analysis showed that under OF, grain yield was significantly correlated with N uptake. The medium organic fertilizer level (160.8 kg N ha^-1) was found to be the optimum fertilizer treatment, and Nanjing 46 appeared to be the best variety for organic rice cultivation. To increase rice grain yields and reduce the potential risk of non-point source pollution in organic agriculture, further research is needed to improve the N use efficiency in organic rice cultivation.     

Diesel oil consumption,work duration,and crop production of corn and durum wheat under conventional and no-tillage in southeastern France

In no-tillage (NT) system, precedent crop residue retains on the soil surface to preserve soil water for crop growth. In response to the negative impact of soil degradation under conventional tillage (CT) system based on soil tillage, NT system without tillage practice and with protective cover of crop residue is being developed in many parts of the world. However, NT is a successful system especially in the South of America, but the impacts of this system on the Mediterranean climate especially in the southeast (SE) of France is less known; therefore, this study has been carried out within the scope of a European project. Durum wheat and corn were sown under CT and NT. Time requirement and fuel consumption in these two systems were measured. The results showed that durum wheat and corn yields were the same in both systems except of 2008, while work duration and energy requirement were 87% and 83% lower in NT system, respectively. Furthermore, NT could mitigate CO₂ emission up to 50% as compared with CT. These results show that NT can be considered as a relevant alternative for CT regarding economical and environmental advantages.     

我国主要麦区小麦籽粒锌含量对叶喷锌肥的响应

【目的】我国小麦籽粒锌含量普遍偏低,叶喷锌肥是提高小麦籽粒锌含量的重要措施,研究我国主要麦区小麦籽粒锌含量对叶喷锌肥的响应,对小麦科学施用锌肥、 调控小麦籽粒锌营养状况有重要意义。【方法】本研究在我国14个省(市)主要麦区布置了30个田间试验,在每个试验点设置不喷锌对照和叶面喷锌两个处理,以当地主栽小麦品种为供试作物,通过测定收获期小麦产量、 各器官锌含量,研究了叶喷锌肥提高小麦籽粒锌含量的效果、 区域差异及其与土壤主要理化性质、 小麦拔节前植株锌含量的关系。【结果】 30个试验点的结果显示,叶面喷锌对小麦籽粒产量、 生物量和收获指数均无明显影响,但籽粒锌含量显著提高,叶面喷锌的籽粒锌含量比对照平均提高5.2 mg/kg(17.5%), pH7.0的区域提高5.3 mg/kg(16.4%), pH 7.0的区域提高5.2 mg/kg(18.4%)。小麦地上部锌吸收与分配在两个区域间没有显著差异,叶面喷锌的小麦籽粒、 颖壳和茎叶平均锌吸收量分别为255.5、 26.0和117.5 g/hm2,比对照增加19.4%、 28.7% 和99.2%; 锌收获指数为64.1%,比对照降低12.2%。籽粒锌利用率和籽粒锌强化指数也不受区域的影响,平均值锌利用率为3.0%,锌强化指数为3.8 mg/kg。无论叶面喷锌与否,籽粒锌含量和土壤有效锌均呈显著正相关,土壤有效锌含量每升高1.0 mg/kg,籽粒锌含量平均提高约4.0 mg/kg; 籽粒锌含量和土壤pH呈显著负相关,土壤pH每升高1个单位,籽粒锌含量平均降低3.8 mg/kg; 籽粒锌含量与土壤有机质没有显著相关性。小麦籽粒锌含量与拔节前植株锌含量极显著正相关,拔节前植株锌含量每升高1.0 mg/kg,籽粒锌含量平均提高0.4 mg/kg。【结论】 除叶面喷施锌肥外,调节土壤酸碱性,提高土壤有效锌含量,促进小麦生长前期植株对锌的吸收对改善我国小麦锌营养均具有重要意义。     

The effect of different production systems on the content of micronutrients and trace elements in potato tubers

The aim of this study was to determine the effect of different production systems (conventional, integrated and organic) on the content of micronutrients and trace elements in the tubers of very early, early and medium-early maturing potato cultivars. Five Polish potato cultivars were grown in three production systems under field conditions. In plant material selected microelements (chemical elements essential for living organisms) were analysed: boron (B), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn) as well as some trace elements (not regarded as essential element for living organisms): chromium (Cr), nickel, (Ni) and lead (Pb). The content of micronutrients and trace elements in potato tubers was modified by production system, genotype and weather conditions during the growing season. Organically grown potatoes had a higher content of B (8.6–8.9?mg kg^?1) and Cu (2.8–3.1?mg?kg^?1), and a lower content of Fe (47.0–47.1?mg?kg^?1), Mn (6.0–6.4?mg?kg^?1) and Zn (11.9–12.2?mg?kg^?1), than potatoes grown in conventional and integrated systems. Potatoes grown in the conventional system had the highest Pb content. Organic cultivation can assure better alimentation of potato tubers with B and Cu, which are important microelements often deficient in the soils. On the contrary, when cultivating potato in conventional system, one should supply this element with fertilisers.     

Arbuscular mycorrhizae in a long-term field trial comparing low-input (organic, biological) and high-input (conventional) farming systems in a crop rotation

 Arbuscular mycorrhizal (AM) root colonization was studied in a long-term field trial in which four farming systems currently in use in Switzerland were continuously applied to a randomized set of plots at a single field site from 1978 till 1993. There were two low-input farming systems (organic and bio-dynamic) and two high-input (conventional) farming systems (according to Swiss guidelines of integrated plant production with and without farmyard manure). The systems had an identical 7-year crop rotation and tillage scheme and differed essentially only in the amount and type of fertilizer supplied and in plant protection management. The percentage of root colonization by AM fungi was determined in field samples 2–3 times over the growing season in crops in the rotation, namely in winter wheat (Triticum aestivum L. cv. Sardona), vetch-rye and grass-clover. We found the percentage of root length colonized by AM fungi to be 30–60% higher (P≤0.05) in the plants grown in soils from the low-input farming systems than in those grown in conventionally farmed soils. Approximately 50% of the variation of AM root colonization was explained by chemical properties of the soils (pH, soluble P and K, exchangeable Mg), the effect of soluble soil P being most pronounced. The potential of the field soils from the differently managed plots to cause symbiosis with AM fungi was tested in a glasshouse experiment, using wheat as a host plant. Soils from the low-input farming systems had a greatly enhanced capacity to initiate AM symbiosis. The relative differences in this capacity remained similar when propagules of the AM fungus Glomus mosseae were experimentally added to the soils, although overall root colonization by AM fungi was 2.8 times higher. Received: 27 August 1999     

不同蔬菜生产模式对日光温室土壤质量的影响

有机农业作为常规农业的一种替代模式,其对土壤及作物的影响研究逐渐受到学术界的关注。该文通过对日光温室有机、无公害和常规生产模式的比较试验,分析有机生产模式对土壤养分、土壤微生物碳氮以及土壤酶活性的影响。结果表明,经过6年的试验,有机生产模式可显著提高土壤全碳、全氮含量以及土壤微生物量碳、氮含量,并提高土壤主要酶的活性,各项指标均表现为有机模式优于无公害模式优于常规模式。有机生产模式能够显著提高土壤质量,有利于土壤的可持续利用。3种生产模式下夏茬番茄产量有机模式高于无公害模式高于常规模式,且随着种植年限的增加有机模式秋茬作物产量呈增加趋势。     

The interaction of stem strength with plant density and nitrogen application in wheat progeny from parents with varying stem strength

Abstract

Lodging is largely influenced by the strength of the stem, which is determined by the length of the internodes, the thickness of the stem and stem cortex and the solidity of the stem. The aim of this study was to study the effect of different N treatments and plant densities on stem strength of selected cultivars and their hybrids. Four combinations of plant density and N fertilizer were evaluated. Plant height, length and diameter of each internode, stem cortex and pith thickness, breaking weight and stem strength were measured. When plant density and N fertilizer increased, stem strength decreased, but the combined effect of these two factors was higher than when applied separately. The cultivar which performed the best in all treatments was a double haploid which expressed the solid stem trait for all internodes. Cultivars and hybrids with normal stems performed the poorest. Breaking weight was positively correlated with stem strength for all four treatments. Shorter internodes caused stronger stems. Stem cortex thickness was also positively correlated with stem strength for all the treatments. This shows that the thicker the stem cortex and the thicker the pith, the stronger the stem of the plant.     

Nitrate leaching from organic arable crop rotations: effects of location, manure and catch crop

Abstract. Nitrate leaching from crop rotations supporting organic grain production was investigated from 1997 to 2000 in a field experiment at three locations in Denmark on different soil types. Three experimental factors were included in the experiment in a factorial design: (1) proportion of N₂-fixing crops in the rotation (crop rotation), (2) catch crop (with and without), and (3) manure (with and without). Three, four-course rotations were compared, two at each location. The nitrate leaching was measured using ceramic suction cells. Leaching losses from the crop rotation with grass–clover green manure and without catch crops were 104, 54 and 35 kg N ha⁻¹ yr⁻¹ on the coarse sand, the loamy sand, and the sandy loam, respectively. There was no effect of manure application or time of ploughing-in the grass–clover green manure crop on the accumulated nitrate leaching from the entire rotation. Catch crops reduced nitrate leaching significantly, by 30–38%, on the sandy soils. At all locations catch crops reduced the annual averaged nitrate concentration to meet drinking water quality standards in the crop rotation with green manure. On the coarse sand there was a time lag between the onset of drainage and the start of N-uptake by the catch crop.     

Effects of various cover crops after peas on nitrate leaching and nitrogen supply to succeeding winter wheat or potato crops

In organic farming systems, it has been demonstrated that grain pulses such as peas often do not enhance soil N supply to the following crops. This may be due to large N removals via harvested grains as well as N‐leaching losses during winter. In two field‐trial series, the effects of legume (common vetch, hairy vetch, peas) and nonlegume (oil radish) cover crops (CC), and mixtures of both, sown after peas, on soil nitrate content, N uptake, and yield of following potatoes or winter wheat were studied. The overall objective of these experiments was to obtain detailed information on how to influence N availability after main‐crop peas by adapting cover‐cropping strategies. Cover crops accumulated 56 to 108 kg N ha^–1 in aboveground biomass, and legume CC fixed 30–70 kg N ha^–1 by N₂ fixation, depending on the soil N supply and the length of the growing period of the CC. Nitrogen concentration in the aboveground biomass of legume CC was much higher and the C : N ratio much lower than in the nonlegume oil radish CC. At the time of CC incorporation (wheat series) as well as at the end of the growing season (potato series), soil nitrate content did not differ between the nonlegume CC species and mixtures, whereas pure stands of legume CC showed slightly increased soil nitrate content. When the CC were incorporated in autumn (beginning of October) nitrate leaching increased, especially from leguminous CC. However, most of the N leached only into soil layers down to 1.50 m and was recovered more or less by the following winter wheat. When CC were incorporated in late winter (February) no increase in nitrate leaching was observed. In spring, N availability for winter wheat or potatoes was much greater after legumes and, after mixtures containing legumes, resulting in significantly higher N uptake and yields in both crops. In conclusion, autumn‐incorporated CC mixtures of legumes and nonlegumes accomplished both: reduced nitrate leaching and larger N availability to the succeeding crop. When the CC were incorporated in winter and a spring‐sown main crop followed even pure stands of legume CC were able to achieve both goals.     

不同有机肥和氮磷组合对旱地小麦的增产机理研究

【目的】 有机无机肥配施可为作物提供更全面的养分,改善光合性能而提高产量。为进一步挖掘旱地小麦的增产潜力,2012~2014年,在山西省临汾市丘陵旱地开展了有机肥与氮磷配施对小麦增产效果与机理的研究。【方法】 通过田间裂区设计,有机肥为主区,设施羊粪22.5 t/hm2（M_S）、猪粪22.5 t/hm2（M_P）、精制有机肥2.25 t/hm2（M_O）;氮磷配施量为副区,设不施氮、磷肥（N₀P₀）,N 105 kg/hm2、P₂O₅ 75 kg/hm2（N₁₀₅P₇₅）、N 150 kg/hm2、P₂O₅ 105 kg/hm2（N₁₅₀P₁₀₅）。供试小麦品种'晋麦92号',生育期测定旗叶SPAD相对值、籽粒灌浆参数、干物质积累和收获期籽粒产量。【结果】 有机肥与氮磷配施均使小麦灌浆后期SPAD相对值下降缓慢。单施有机肥时,猪粪使小麦灌浆中期SPAD相对值和平均灌浆速率最高,精制有机肥使灌浆后期SPAD相对值最高,灌浆持续期延长最多,茎叶转移量和穗部积累量最高。有机肥与氮磷配施时,M_SN₁₅₀P₁₀₅、M_PN₁₀₅P₇₅、M_ON₁₀₅P₇₅有利于提高旗叶后期SPAD相对值,延长灌浆持续期,使干物质积累量增加。有机肥与氮磷配施较单施有机肥成穗数和千粒重提高,产量增加,以M_SN₁₅₀P₁₀₅产量最高,其次是M_PN₁₀₅P₇₅,二者间差异不显著。【结论】 山西南部丘陵旱地小麦有机肥与适量化肥配施,使成穗数增加,并可以改善光合特性,延长灌浆持续期,增加千粒重实现增产。本研究中,施羊粪22.5 t/hm2时,配施纯N 150 kg/hm2、P₂O₅ 105 kg/hm2的增产效果最好,施猪粪22.5 t/hm2时,配施纯N 105 kg/hm2、P₂O₅ 75 kg/hm2可实现减施高产。     

Effect of wheat,legume and legume enriched wheat residue and nitrogen application on soil fertility under rice-wheat cropping system

The field experiments were conducted for two crop years of 1997?–?98 and 1998?–?99 at the Indian Agricultural Research Institute, New Delhi to study the effect of wheat, legume and legume enriched wheat residue (WR) on soil fertility under the rice-wheat cropping system. A rice-wheat cropping system without incorporation of residue depleted organic C over initial level by 0.061%, kjeldahl-N by 0.012%, available P by 0.7?kg ha^???1 and available K by 36?kg ha^???1, whereas incorporation of Sesbania green manure (SGM), mungbean residue (MBR), SGM?+?WR and MBR?+?WR increased organic C over the initial level by 0.071, 0.100, 0.163 and 0.133%, respectively, kjeldahl-N by 0.001, 0.004, 0.001 and 0.005% respectively, available P by 2.7, 5.0, 8.5 and 3.2?kg ha^???1, respectively and available K by 35, 5, 92 and 12?kg ha^???1, respectively in 2 years. As compared with no residue control, incorporation of WR increased organic C by 0.036?–?0.102%, kjeldahl-N by 0.002?–?0.007% and available K by 23?–?45?kg ha^?1, whereas incorporation of SGM and MBR increased organic C by 0.082?–?0.132 and 0.103?–?0.161%, respectively, kjeldahl-N by 0.009?–?0.023 and 0.005?–?0.013%, respectively and available K by 5?–?71 and 4?–?45?kg ha^???1, respectively. Incorporation of WR with SGM and MBR was more effective and increased organic C by 0.121?–?0.224 and 0.125?–?0.194%, respectively, kjeldahl-N by 0.005?–?0.029 and 0.010?–?0.021%, respectively and available K content by 23?–?128 and 11?–?116?kg ha^???1. Nitrogen application to rice also increased organic C, kjeldahl-N, available P and available K content in soil and also increased effects of crop residues. Crop residues had no significant effect on available P content in soil. Incorporation of WR with SGM and MBR with adequate fertilizer-N is, thus, recommended for building up organic C, kjeldahl-N and available K content in soil.     

Tillage and mulch effects on soil physical environment, root growth, nutrient uptake and yield of maize and wheat on an Alfisol in north-west India

Field experiments were conducted for 6 years on a silty clay loam to study the effect of soil management on soil physical properties, root growth, nutrient uptake and yield of rainfed maize (Zea mays L.) and wheat (Triticum aestivum L.) grown in a sequence. Treatments were: no-tillage (NT), NT+pine needle mulch at a rate of 10 t ha⁻¹ (NT+M), conventional tillage (CT), CT+pine needle mulch at a rate of 10 t ha⁻¹ (CT+M) and deep tillage (DT). The soil is classified as a Typic Hapludalf and has compact sub-surface layers. The NT treatment increased the bulk density of the surface layer but this problem was not observed in the no-tilled treatment having mulch at the surface (NT+M). The CT+M and NT+M treatments favourably moderated the hydro-theregime resulting in greater root growth, nutrient uptake and grain yields of maize and wheat. The DT treatment, imposed only once, at the beginning of the study, also enhanced root growth and grain yields. The yields were similar to the mulched treatments for maize and somewhat less than the mulched treatments for wheat. Mulched treatments generally showed significantly greater total uptake of N, P and K than corresponding unmulched ones. Since NT+M was comparable to CT for maize and superior for wheat, the latter is preferable since it does not require ellaborate tillage.     

Long-term conservation agriculture and intensified cropping systems: Effects on growth, yield, water, and energy-use efficiency of maize in northwestern India

Conservation agriculture(CA)-based best-bet crop management practices may increase crop and water productivity, while conserving and sustaining natural resources. We evaluated the performance of rainy season maize during 2014 under an ongoing long-term trial(established in 2008) with three tillage practices, i.e., permanent bed(PB), zero tillage(ZT), and conventional tillage(CT) as main plots, and four intensified maize-based cropping systems, i.e., maize-wheat-mungbean, maize-chickpea-Sesbania(MCS), maizemustard-mungbean, and maize-maize-Sesbania) as subplot treatments. In the seventh rainy season of the experiment, maize growth parameters, yield attributes, yield, and water-and energy-use efficiency were highest at fixed plots under ZT. Maize growth parameters were significantly(P 0.05) superior under ZT and PB compared with CT. Maize yield attributes, including cobs per m~2(7.8), cob length(0.183 m), grain rows per cob(13.8), and grains per row(35.6), were significantly higher under ZT than CT; however, no significant effect of cropping systems was found on maize growth and yield attributes. Zero tillage exhibited the highest maize productivity(4 589 kg ha~(-1)). However, among the cropping systems, MCS exhibited the highest maize productivity(4 582 kg ha~(-1)). In maize, water use was reduced by 80.2–120.9 mm ha-1under ZT and PB compared with CT, which ultimately enhanced the economic water-use efficiency by 42.0% and 36.6%, respectively. The ZT and PB showed a 3.5%–31.8% increase in soil organic carbon(SOC) at different soil depths(0–0.45 m), and a 32.3%–39.9% increase in energy productivity compared with CT. Overall, our results showed that CA-based ZT and PB practices coupled with diversified maize-based cropping systems effectively enhanced maize yield and SOC,as well as water-and energy-use efficiency, in northwestern India.     

Nitrate leaching from an organic dairy crop rotation: the effects of manure type, nitrogen input and improved crop rotation

Abstract. Four management systems combining high and low livestock densities (0.7 and 1.4 livestock units ha⁻¹) and different types of organic manure (slurry and straw based FYM) were applied to an organic dairy crop rotation (undersown barley – grass–clover – grass–clover – barley/pea – oats – fodder beet) between 1998 and 2001. The effects of the management systems on crop yields and nitrate leaching were measured. In all four years, nitrate leaching, as determined using ceramic suction cups, was higher in the three crops following ploughing of grass–clover than under the barley or grass–clover. Overall, no significant differences in nitrate leaching were observed between the management systems. However, the replacement of the winter wheat crop used in the earlier experimental period (1994–97) by spring oats with catch crops in both the preceding and succeeding winters reduced nitrate leaching compared with the earlier rotation. Increasing the livestock density, which increased manure application by c. 60 kg total N ha⁻¹, increased crop yields by 7 and 9% on average for FYM and slurry, respectively. Yields were 3–5% lower where FYM was used instead of slurry. The experiment confirmed the overriding importance of grassland N management, particularly the cultivation of the ley, in organic dairy crop rotations.     

生土条件下冬小麦对氮、磷、钾的原始响应

配方施肥是提高作物肥料利用率和产量品质的重要措施。但氮、磷、钾营养元素之间的相互关系仍然存在一些不确定性,不同土壤肥力及不同的研究方法是造成这一结果的原因。本研究采用肥力极低的生土为基质,探讨了氮、磷、钾、有机肥及不同组合、配比对冬小麦产量和品质性状的影响。结果表明,只有磷素存在才能使小麦正常生长发育,单施氮、钾以及氮钾配施都不能保证小麦生长的基础代谢,不能形成正常产量。磷对氮的效应远大于氮对磷的效应。在土壤营养极度匮乏的非耕作土壤条件下,磷素是产量与品质形成的第一限制因素,可能作为土壤肥力形成的原始起动因素。     

耕作方式对豫南雨养区土壤微环境及冬小麦产量的影响

针对豫南雨养农业区降水基本满足作物生长需求但年内和年际间分配不均、土壤耕性差的生态实际,为解决小麦播种期和冬春干旱以及改善耕层水、肥、气、热等因子提供理论依据。于2007—2015年,在豫南雨养农业区进行了连续9a的大田定位试验,研究了不同耕作模式对小麦生长季土壤水分、容重、温度及冬小麦产量的影响。试验共设置6个处理:T1(传统翻耕)、T2(不覆盖/不深松+覆盖/免耕)、T3(覆盖/不深松+不覆盖/免耕)、T4(不覆盖/深松+不覆盖/免耕)、T5(覆盖/深松+覆盖/免耕)以及T6(不覆盖/不深松+还田/旋耕)。结果表明,(覆盖/深松+覆盖/免耕)T5可以有效提高小麦播种期0~40cm土层的含水量,为麦播提供较好的水分基础,不同耕作方式处理对冬小麦越冬期和返青期土壤日平均温度影响较小,不足以对冬小麦发育进程产生影响。(覆盖/深松+覆盖/免耕)T5能够有效降低耕层0~20cm和0~40cm的土壤容重。覆盖/深松+覆盖/免耕处理的前3a,冬小麦产量较对照有所降低,从第4年开始较对照增产,2011—2015年增产幅度分别为2.02%、2.83%、10.93%、5.88%、1.97%。以上结果表明,通过T5(覆盖/深松+覆盖/免耕)的简耕覆盖技术可以有效利用降水资源、培肥地力,提高产量,具有节本增效的作用。     

Urease activity and its relation to soil organic matter, microbial biomass nitrogen and urea-nitrogen assimilation by maize in a Brazilian Oxisol under no-tillage and tillage systems

 We studied the relationship between urease activity (UA) and soil organic matter (SOM), microbial biomass N (N_biom) content, and urea-N fertilizer assimilation by maize in a Dark Red Latosol (Typic Haplustox) cultivated for 9 years under no-tillage (NT), tillage with a disc plough (DP), and tillage with a moldboard plough (MP). Two soil depths were sampled (0–7.5 cm and 7.5–15 cm) at 4 different times during the crop cycle. Urea was applied at four different rates, ranging from 0 to 240 kg N ha^–1. The levels of fertilizer N did not affect the UA, SOM content, and N_biom content. No significant difference between the treatments (NT, DP, and MP) was observed for SOM during the experiment, probably because the major part of the SOM was in recalcitrant pools, since the area was previously cultivated (conventional tillage) for 20 years. The N_biom content explained 97% and 69% of the variation in UA in the upper and deeper soil layer, respectively. UA and biomass N were significantly higher in the NT system compared to the DP and MP systems. The highest maize productivity and urea-N recovery was also observed for the NT system. We observed that the increase in urea-N losses under NT, possibly as a consequence of a higher UA, was compensated for by the increase in N immobilized in the biomass. Received: 2 July 1999     

Revealing the donors of the systems of adaptability, attraction and micro-distribution in winter wheat varieties

A group of physiologists, geneticists and breeders investigated genetic and physiological systems of adaptability, attraction and micro-distribution in winter wheat varieties in eight geographical points, the levels of mineral feeding in every point being different (1992, 1993). This investigation is based on the new method of the genetic analysis of quantitative characters, Dragavtsev (1993). The following two-dimensional systems of the character coordinates were examined: the 'mass of the ear' (breeding character – BCh) and the 'mass of straw' (foil character – FCh); the 'mass of grains in the ear' (BCh) and the 'mass of chaff in the ear' (FCh). They were investigated on the main stem, on individual plants, on plants per square meter, which made it possible to characterize the varieties by frequency occurrence of strong positive drifts in every system and to specify the universal and regional donors in the systems under consideration.