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1.
Intercropping is widely used by smallholder farmers in developing countries, and attracting attention in the context of ecological intensification of agriculture in developed countries. There is little experience with intercropping of food crops in Western Europe. Yields in intercrops depend on planting patterns of the mixed species in interaction with local growing conditions. Here we present data of two years field experimentation on yield and yield components of a wheat–maize intercrop system in different planting configurations in the Netherlands. Treatments included sole crops of wheat (SW) and maize (SM), a replacement intercrop consisting of strips of six wheat rows alternating with two maize rows (6:2WM), as well as subtractive or additive designs, based on skip-row (6:0WM, 0:2WM) and add-row (8:2WM, 6:3WM) configurations. The land equivalent ratio (LER) of intercrops varied from 1.18 to 1.30 in 2013 and from 0.97 to 1.08 in 2014. Wheat grown in the border rows of wheat strips had higher ear number per meter row, greater kernel number per ear, and greater yield per meter row than wheat in inner rows and sole wheat, indicating reduced competition. Wheat in the border rows in the intercrops had, however, reduced thousand kernel weight and harvest index, indicating that competition in border rows intensified over time. Intercropping negatively affected maize biomass and thousand kernel weight, especially in add-row treatments. This study indicates that there is a potential yield benefit for the wheat–maize intercropping system under Western European growing conditions. However, the LER was affected by yearly variation in weather conditions and significantly greater than one in only one of the two years of the study.  相似文献   

2.
Nuña beans (Phaseolus vulgaris L.), an ancient and pre-ceramic landrace native to Andean region, possess the property of popping and a high content of proteins and carbohydrates, which makes it an alternative nutritious snack. Knowledge on the genetic bases of popping ability is relevant for common bean improvement. Progenies derived from two nuña bean crosses were used in a generation mean based mating design to determine the inheritance and gene action for five popping related traits: length of popped seeds (PSL), popping dimension index (PDI), percentage of un-popped seeds (PUS), popping percentage average (PPA) and expansion coefficient (EC). Significant additive gene effects were found for all traits, and was the only source of the observed variation for PSL, while dominance and higher-order interactions among loci contributed to the genetic divergence for the other traits. The dominance of the cultivated over nuña alleles for PDI, PPA, EC and PUS, was confirmed by high mid-parent heterosis values and generation mean comparisons. The [d] and [dd] gene effects were in opposite direction for PPA and EC, indicating duplicate epistasis. Therefore, epistasis is likely to be an important explanation for the heterosis in both traits. For PDI and PUS, the opposite signs for [aa] and [dd] gene effects indicated that the genes for increasing popping are dispersed between the parents. Generation means and variances of BC1P2 indicated advantages of the backcross breeding procedure to improve the adaptation of the exotic germplasm and at the same time, transfer part of the desired donor genes to cultivated common bean. The backcross to the nuña parent could be an alternative to maintain/recover the favorable epistatic gene combinations found for PDI, PPA, EC and PUS traits.  相似文献   

3.
The objective of this investigation was to check if epistasis is present in Andean × Mesoamerican beans crosses using triple test cross (TTC) method. The parents of the segregating population were Carioca–MG (Mesoamerican) and BRS Radiante (Andean). In July 2005, F2 progenies (backcrossed with the parents and F1 generation) were evaluated at two locations for three characters: number of pods plant−1, number of grains plant−1 and grain weight plant−1. The presence of epistasis was detected for all yield components. In the partitioning of epistasis in additive x additive (i) and dominant x dominant (j) and dominant × additive (l) it was observed that, for the traits number of pods/plant and number of grains/plant, only epistasis of the type (j) + (l) were significant. For the trait grain mass/plant, all types of epistasis were significant.  相似文献   

4.
This work reports a gene pyramiding approach assisted by DNA markers used to develop “carioca” seeded common bean (Phaseolus vulgaris L.) elite lines harboring three different rust resistance genes. Rust is among the most destructive diseases that attack P. vulgaris and cause serious damage worldwide. The rust resistance genes Ur-5 (from ‘Mexico 309’), Ur-11 (from ‘BelMiDak RR-3’), and Ur-14 (from ‘BRS Pioneiro’, a “carioca” seeded cultivar derived from the resistance source ‘Ouro Negro’) were combined in the “carioca” seeded bean cultivar ‘Rudá’. Firstly, two different backcross programs were conducted separately to produce progenies harboring individually the Ur-5 and Ur-11 genes. Molecular fingerprinting analysis was used to select plants genetically similar to ‘Rudá’ in the backcross cycles to accelerate the recurrent-background recovery. The obtained progenies were initially intercrossed and then crossed with ‘BRSMG Pioneiro’ (Ur-14). The final F1 plants derived from these crosses were screened with DNA markers linked to the three rust resistance genes: SI19 (Ur-5), SAE19 (Ur-11) and OPX11 (Ur-14). The plants selected as harboring all the alleles of interest were used to obtain the next generations. The selection based on DNA markers was conducted up to the F4:5 generation. We were able to select F4:7 progenies showing all the DNA markers associated to the genes of interest and resistant to all specific races of U. appendiculatus used for phenotypically detecting each one of the rust resistance genes. Yield evaluations show that these selected lines are as productive as the recurrent parent ‘Rudá’ and high-performing control cultivars grown in Brazil.  相似文献   

5.
Mark J. Bassett 《Euphytica》2005,141(1-2):139-145
The inheritance of the virgata pattern of partly colored seed coats found in common bean (Phaseolus vulgaris L.) Early Giant (EG) was studied by a series of test crosses with line 5-593 and genetic stocks developed by backcrossing selected genes into the recurrent parent 5-593, a Florida dry bean breeding line with a self-colored, black seed coat with genotype T Z Bip P [C r] J G B V Rk. Analysis of the F2 from the cross EG × 5-593 led to the hypothesis that the virgata pattern of EG has genotype t z bipvgt, where vgt stands for virgata. The test cross EG × t z virgarcus BC3 5-593 confirmed the hypothesis that EG carries t z from data recorded in F1, F2, and 27 F3 progenies from randomly selected F2 plants. The F3 segregation was also consistent with the hypothesis that a single recessive gene converts virgarcus into virgata. The test cross EG × t z bip bipunctata BC3 5-593 failed to show genetic complementation in F1 progeny, and the F2 segregated 3:1 for the parental phenotypes virgata and bipunctata, respectively. Including previously published data, all possible crosses were made among bipunctata, virgata, and virgarcus parents, supporting a multiple allelic series at Bip. We propose the gene symbol bipvgt for the new allele at Bip, where the allelic series has the order of gene dominance Bip > bipvgt > bip. Based on test crosses, the complete seed-coat color and pattern genotype of EG is tz bipvgt P [C r] J G B vlae rkd.  相似文献   

6.
Journal of Crop Science and Biotechnology - This study evaluated the growth characteristics, forage yield, and feed value of a maize–soybean intercropping system under different fertilizer...  相似文献   

7.
8.
Crop residue removal and subsoil compaction are limiting to yield improvement in the North China Plain (NCP). We conducted a field study composed of six consecutive crop growing seasons from 2010 to 2013 in Henan province, China, to determine responses of soil properties, crop root distribution and crop yield to tillage and residue management in a wheat–maize cropping system under irrigated conditions. Tillage practices comprised mouldboard ploughing (MP) to a depth of 15-cm, deep mouldboard ploughing (DMP) to a depth of 30-cm, and chisel ploughing (CP) to a depth of 30-cm. Crop residue management included crop residue retained (CRRet) and crop residue removed (CRRem). The results indicated that yields in DMP and CP increased by 6.0% and 7.3% for wheat and by 8.7% and 9.0% for maize, respectively, relative to MP. The CRRet treatment also increased wheat yield by 6.7% and maize yield by 5.0%. The yield increases under DMP and CP were related to reduced bulk density and soil penetration resistance, increased soil water content, improved total N distribution and improved root density (0–60-cm). Compared with MP, the root mass density under DMP and CP were increased by 43.4% and 42.0% for wheat and by 40.6% and 39.4% for maize, respectively. The yield increases under CRRet were also related to increased soil water content, reduced penetration resistance and increased N status (0–40-cm). Overall, for DMP + CRRet and CP + CRRet, a more favorable soil environment alongside greater root mass density and suitable spatial distribution resulted in higher grain yields of wheat and maize. Thus, compared with conventional shallow tillage practice, DMP or CP with residue application could improve soil quality and agricultural productivity under irrigated areas with loam soil in the NCP.  相似文献   

9.
Different tillage systems (conventional, minimum, raised bed and no tillage) and four mulch levels (control, polythene, straw and soil) were compared in maize (Zea mays) and wheat (Triticum aestivum) production for three years on an experimental field (sandy loam) located at Dry Land Research Sub Station, Dhiansar, Jammu. Each treatment was replicated four times in split plot design. The aim of the research was to determine the influence of tillage and mulch practices on economics, energy requirement, soil physical properties and performance of maize and wheat. Tillage methods significantly affected the soil physical properties as change in soil moisture contents and infiltration rate of soil was recorded. The soil moisture contents in minimum tillage (MT) were maximum (12.4%, 16.6%) in surface soil as compared to conventional tillage (CT) in maize and wheat crops, respectively. Comparing to the CT infiltration rate was (1.16times, 1.21times and 1.11times) higher in minimum tillage (MT), no tillage (NT) and raised bed (RB), respectively in kharif season. Similar results were also found in rabi season. The greatest maize yield of 1865 kg ha?1 was achieved with CT system while not significantly lower yield was achieved with MT system (1837 kg ha?1). However, wheat yield was recorded higher in MT as compare to the CT system. Comparing to the energy requirement of different operations, MT required 34.3% less, NT 31.1% less and RB 46.0% less than the CT system. MT system saved 2.5 times energy in tillage operation compared to the CT system. The economic analysis also revealed that the maximum benefits could be obtained from MT (EUR 202.4 ha?1) followed by RB (EUR 164.2 ha?1) and NT (EUR 158.3 ha?1) and lowest in CT (EUR 149.5 ha?1). Benefit-cost ratio was highest in MT (0.71) and lowest in CT (0.44). Results revealed that mulch significantly affected the soil physical properties and growth of maize. The maximum soil moisture content, infiltration rate and grain yield of maize and wheat recorded higher in mulching practices over no mulch treatment. Polythene mulch and straw mulch were almost equally valuable in maize and wheat sequence. Tillage (minimum) and mulch (polythene and straw) have pronounced effect on soil physical properties (improved infiltration rate and conserve soil water), energy requirement, economics and growth of maize and wheat.  相似文献   

10.
Agroforesry is a common traditional practice in China, especially in the saline-alkaline regions, like the lower North China Plain (LNCP) characterized by lower yields of food crops. Adding trees to the agricultural land creates additional fruitsets or woody biomass besides food crops, enabling farmers to diversify the provision of farm commodities. However, the productivity of many agroforestry systems has been lower than expected in recent years, highlighting the need for a mechanistic understanding of below- or above-ground interactions. The study combined investigation and experimental data together to evaluate the effects of long-term intercropping agroforestry system [jujube tree (Zizyphus jujuba Mill. var. inermis (Bunge) Rehd.)/winter wheat–summer maize] on soil fertility balance, crop production and system economic efficiency over the past 22 years in LNCP, with a view to developing an effective fertilization management for the moderately alkaline soils. Except remain higher pH, the soils are basically free of sodic and soil salinity is not the major restriction factor for intercrops, even through there are some fluctuation with season and distance from jujube tree. The intercropping system significantly reduced soil nutrient contents, like soil organic C (SOC), total N (TN), available P (avail. P) and K (avail. K) in most parts of the ecotone of the system, but increased those nutrients in the belt of underneath the edge of tree canopy, The growth of intercrops at the belt of 3.5 m from tree was severely negative stressed by jujube tree in term of lower soil moisture, nitrate, avail. P and K although receiving more photosynthetically active radiation (PAR), whereas the winter wheat growing at the 2.5 m row had more water and nutrients supplied and thus produced more grain yield. Uneven fertilization to the ecotone (about 1–2.5 m of the intercrop field boundary) could partly offset the consumption and competition for nutrients between the tree and the intercrops, and improved the grain yields by 12.1% and 14.5% in the ecotone regions (distance from jujube trees) of 1.5 m for winter wheat and 2.5 m for summer maize by increasing respective yield components. Although the mean grain yield of intercropped winter wheat and summer maize was reduced by 35.6 and 35.2%, respectively, compared to sole cropping system, the intercropping system proved to be a profitable land use type based on net income and economic returns, in addition to the wood and ecological benefits of the jujube tree in the moderate desalinate- alkaline regions.  相似文献   

11.
Diseases are major production constraints of pinto bean despite 75 years of breeding. The objectives were to (1) assess progress made and (2) discuss future breeding strategies. Bean common mosaic virus (BCMV), anthracnose, rust, white mold, common blight, and halo blight and growth habit, seed weight, and seed coat darkening were evaluated for 52 cultivars released between 1944 and 2001. Sixteen cultivars were resistant to BCMV, 12 to race 53 of rust, five to race 73 of anthracnose, two to halo blight, and none to common blight and white mold. Four were resistant to two and none to three or more diseases. Four had Type I, ten Type II, and others Type III growth habit. Bill Z, Grand Mesa, Montrose, Olathe, Othello, Ouray and Pindak darkened slower in storage. Pintoba had the largest and Cahone smallest seed. An integrated breeding strategy is suggested for simultaneous improvement of resistance to multiple-diseases.  相似文献   

12.
The use of resistant cultivars is one of the best methods for nematode control and reduction of economic losses caused by these pathogens. Studies of inheritance of nematode resistance in common bean (Phaseolus vulgaris L.) are nonetheless scarce. The present paper reports on the estimation of genetic parameters associated with resistance to the root nematode Meloidogyne incognita race 1 in common beans. Two contrasting bean lines, ‘Aporé’ (P1 = nematode resistant) e ‘Macarr?o Rasteiro Conquista’ (P2 = susceptible), and the generations F1 (P1 × P2), F2 (P1 × P2), BC1(P1) = (F1 × P1) and BC1(P2) = (F1 × P2), were assessed 45 days after nematode inoculation, through a scale related to the number of eggs per gram of root tissue. Dominant genetic effects were inferior in magnitude to additive effects, indicating incomplete dominance of nematode resistance. Dominance was in the direction of increased nematode resistance (i.e., lower number of eggs per g root). Resistance to Meloidogyne incognita race 1 in common bean is under control of a single gene locus, with incomplete dominance of the resistance allele present in ‘Aporé’, but modifier genes affecting its expression appear to be present in the susceptible parent ‘Macarr?o Rasteiro Conquista’.  相似文献   

13.
The advantages and disadvantages of varying mixture proportion of crimson clover (Trifolium incarnatum L.) and Italian ryegrass (Lolium multiflorum Lam.), used as winter cover crops, and cover crop biomass management before maize sowing (Zea mays L.) were studied in a series of field experiments in Eastern Slovenia. Pure stands and mixtures of cover crops on the main plots were split into different cover crop biomass management subplots: whole cover crop biomass ploughed down before maize sowing, aboveground cover crop biomass removed before ploughing and sowing, or aboveground cover crop biomass removed before sowing directly into chemically killed residues.Cover crop and cover crop biomass management affected the N content of the whole aboveground and of grain maize yields, and the differences between actual and critical N concentrations in the whole aboveground maize yield. The whole aboveground and grain maize dry matter yields, and the apparent remaining N in the soil after maize harvesting, showed significant interaction responses to cover crop × management, indicating positive and negative effects. Crimson clover in pure stand provided high, and pure Italian ryegrass provided low maize dry matter yields and N content in the yields in all the observed methods of biomass management. However, within individual management, mixtures containing high proportions of crimson clover sustained maize yields and N contents similar to those produced by pure crimson clover. Considering the expected ecological advantages of the mixtures, the results thereby support their use.  相似文献   

14.
15.
Fusarium head blight (FHB) is a destructive disease of wheat worldwide. Sources of resistance to FHB are limited in wheat. Search for novel sources of effective resistance to this disease has been an urgent need in wheat breeding. Fusarium head blight resistance has been identified in relatives of wheat. Alien chromatin carrying FHB resistance genes has been incorporated into wheat through chromosome addition, substitution, and translocation. Relatives of wheat demonstrate a great potential to enhance resistance of wheat to FHB.  相似文献   

16.
Cotton (Gossypium hirsutum L.) is the leading cash crop being grown across the globe including Pakistan. By the inclusion of insect resistant transgenic cotton (BT cotton), the cotton production has mounted many folds in Pakistan. BT cotton is mostly grown in Southern Punjab in cottonwheat cropping system of Pakistan; however there exists a time conflict among wheat harvest and BT cotton sowing in this system. Wheat is harvested during late April but the ideal sowing time of BT cotton is early-mid March indicating a time conflict of 46 weeks which is becoming the main concern leading to wheat exclusion from this system. Intercropping of BT cotton in standing wheat is one of the possible options to manage this overlapping period. This two year field study was, therefore, conducted at two locations (Multan, Vehari) to evaluate the economic feasibility of relay intercropping of BT cotton through different sowing methods in BT cottonwheat cropping system. BT cottonwheat cropping systems included in the study were: conventionally tilled cotton (CTC) on fallow land during early and late March, CTC during late April after harvest of flat sown wheat (FSW), bed sown wheat (BSW) + intercropped cotton during early and late March, and ridge sown wheat (RSW) + intercropped cotton during early and late March. Planting cotton in fallow land with conventional tillage during early March had more seed cotton yield; whereas planting in the same way during April after wheat harvest had minimum seed cotton yield. Likewise, FSW had more yield than ridge and bed sown wheat with intercropped BT cotton during early or late March. However, the system productivity in terms of net income, benefit: cost ratio and marginal rate of return of BSW + intercropped BT cotton during early March was the highest during both years at both locations. However, the system with sole crop of BT cotton sown on fallow land during late or early March was the least economical even than the system with CTC during late April after harvest of FSW. In conclusion, BSW + intercropped cotton during early March may be opted to manage the time conflict and improve the economic productivity of BT cottonwheat cropping system without wheat exclusion from the system.  相似文献   

17.
Numerous bacterial, fungal, and viral diseases cause severe damage on roots, foliage, stem, pods, and seeds, resulting in yield and quality losses in common bean (Phaseolus vulgaris L.) worldwide. Cultivars with resistance to multiple diseases are needed to reduce these losses and dependence on pesticides for disease control. Our objective was to determine the effectiveness of simultaneous selection in the F1 and F2 for resistance to five diseases, namely angular leaf spot (ALS), anthracnose (ANT), bean common mosaic (BCM), common bacterial blight (CBB), and common bean rust (CBR) in three Andean x Middle American inter-gene pool double-cross populations, namely ST?=???Chocho??/??Catrachita??//G 5686/VAX 3, CN?=???DIACOL Calima??/VAX 6//A 193/G 5686, and CB?=?A 483/??Talash??//Wilkinson 2/G 5686. One hundred seventy-five F1 plants of ST, 177 of CN, and 195 of CB and their parents were evaluated in the greenhouse using sequential inoculations with pathogens causing BCM, CBR, ALS, CBB, and ANT, in that order. Progenies of surviving F1 plants were again evaluated in the F2, using similar sequential inoculations. The F4-derived F5 breeding lines were developed using single-seed descent method. No selection was practiced for any trait in the F3 and F4. In the F5, five breeding lines from ST, two from CN, and one from CB exhibited intermediate to high levels of resistance to the five diseases when compared with the parents. Thus, selection in the F1 and F2 was effective for simultaneous introgression of resistance to the five diseases in all three Andean?×?Middle American inter-gene pool common bean populations.  相似文献   

18.
Integrated crop–livestock systems can help achieve greater environmental quality from disparate crop and livestock systems by recycling nutrients and taking advantage of synergies between systems. We investigated crop and animal production responses in integrated crop–livestock systems with two types of winter cover cropping (legume-derived N and inorganic fertilizer N), two types of tillage [conventional disk (CT) and no tillage (NT)], and whether cover crops were grazed by cow/calf pairs or not. The 13-ha field study was a modification of a previous factorial experiment with four replications on Ultisols in Georgia, USA. Recurring summer drought severely limited corn and soybean production during all three years. Type of cover crop had little influence and grazing of cover crops had minor influence on crop production characteristics. Cattle gain from grazing of winter cover crops added a stable component to production. No-tillage management had large positive effects on corn grain (95 vs. 252 g m−2 under CT and NT, respectively) and stover (305 vs. 385 g m−2) production, as well as on soybean grain (147 vs. 219 g m−2) and stover (253 vs. 375 g m−2) production, but little overall effect on winter wheat grain (292 g m−2) and stover (401 g m−2) production. Our results suggest that robust, diversified crop–livestock systems can be developed for impoverished soils of the southeastern USA, especially when managed under no tillage to control environmental quality and improve resistance of crops to drought.  相似文献   

19.
One of the substantial differences between conventional and organic growing systems is the degree to which the farmer can control biotic and abiotic stresses; for organic growing systems varieties are needed with a broad adaptation to annually varying factors, while at the same time a good specific adaptation is necessary with respect to more constant climate and soil conditions. This combination of requirements implies that varieties for organic farming need to be better characterised with respect to genotype × environment interactions than varieties for conventional farming. Such interactions, which often are found for quantitatively expressed traits, are in general difficult to deal with in phenotypic selection. New approaches for QTL analyses (e.g. using physiological models) facilitate estimation of effects of genes on a trait (the phenotype) as a response to environmental influences. From such analyses, markers can be identified which may help to predict the trait expression of a plant genotype in relation to defined environmental factors. The application of markers to select for loci with specific interactions with the environment could, therefore, be especially important for plant breeders targeting organic farming systems.  相似文献   

20.
We evaluated the re-establishment of an Italian ryegrass pasture by self-seeding on a no-till integrated crop–livestock systems (ICLS) in the southern region of Brazil. This work is part of a long-term experimental protocol initiated in 2003. We tested the effects of various management practices, such as summer crop systems (soybean vs. maize–soybean rotation), stocking methods (continuous vs. rotational) and grazing intensities (low vs. moderate), on Italian ryegrass pasture establishment. In addition, we tested resilience of the system by testing pasture's ability to re-establish following a year without seed head production. The experiment consisted in the rotation, on the same area, of Italian ryegrass pasture grazed by sheep during the winter and up to the end of the grass production cycle, and soybean or soybean–maize grain crops rotation cultivated during the summer. The pasture established itself by self-seeding since 2005. Data were collected in 2011 and 2012 stocking season. The soybean summer crop, continuous stocking and low grazing intensity, all positively affected the production of reproductive tillers in 2011. Grazing intensity in 2011 strongly influenced early vegetative tiller densities (before crop harvest) in 2012. However, none of the grazing intensity or the stocking method treatments affected herbage mass at the end of pasture establishment in 2011 or 2012. On the other hand, the soybean summer crop positively affected pasture establishment, both in term of tiller densities and herbage mass at the end of pasture establishment. The removal of all seed heads in 2011 (preventing seed production) resulted in the total failure of pasture establishment in 2012. Overall, Italian ryegrass establishment by self-seeding relies on the annual replacement of the soil seed bank. This experiment demonstrated that under various stocking methods, moderate grazing intensity and maize or soybean summer crop, Italian ryegrass pasture establishment by self-seeding remains successful even when the stocking periods extended up to the end of the grass production cycle. Self-seeding with moderate grazing intensity ensures successful pasture establishment, reduces labour and costs and allows to increase the stocking period and so animal live weight gain over the grazing season.  相似文献   

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