Simulation of faba bean (Vicia faba L.) root system development under Mediterranean conditions

Root growth of faba bean genotype ILB 1814 grown under both limited and sufficient moisture supply was studied in 1993–1994 and 1994–1995 at ICARDA's Tel Hadya research station. Crops were sown on two dates in both growing seasons. Root-length density (RLD) and root dry weight were measured at four depths in three locations relative to the crop row. In general, RLD decreased considerably with depth, and by the start of pod-filling, around 60% of the roots were found in the top 15 cm of soil. In the upper 30 cm soil profile, the RLDs of drought-stressed faba beans were significantly lower than those measured beneath well-watered crops. In the deeper soil layers, the RLDs were similar in both moisture supply treatments. An existing root model was employed for the simulation of faba bean root growth. The model estimates the depth of rooting and RLD in each soil layer based on dry matter allocation to the root system, soil layer water contents, genotype-specific rooting characteristics, and soil physical properties. A faba bean growth model provided daily allocation of dry matter to roots as well as soil layer water contents. Overall, with a few modifications, the root model was capable of predicting the RLD of faba bean grown both under limited and sufficient water supply realistically. Limitations of the model and some aspects that need further improvement are discussed.     

Competition,growth and yield of faba bean (Vicia faba L.)

This paper reviews current knowledge regarding the influence of plant density on the growth and yield of the faba bean crop (Vicia faba L.). An analysis is also made of sowing rate and other factors that may modify optimum plant density, including environmental conditions; in this sense, should be made a differentiation between faba crops grown in temperate conditions and those grown in Mediterranean and semi-arid conditions. The genotype also prompts variations in optimum plant density, depending on the botanical type (mayor, equina or minor) and the growth habit (determinate versus indeterminate) of the cultivar selected. Sowing date also influences optimum seeding rate, which is lower for autumn–winter sowing under temperate and Mediterranean conditions and increases as the sowing date is delayed. For the spring-sown crops typical of temperate conditions, optimum plant density will be higher due to the shorter growing season. With a longer growing season and under optimum environmental conditions, there is normally no additional response to densities over 20 plants m⁻², while in suboptimal conditions, optimum plant density may increase to over 60 plants m⁻². Although the faba bean crop displays considerable plasticity in response to variations in plant density, mainly with regard to number of pods per square meter, it is not wholly clear to which component of yield this should really be ascribed. Number of stems per plant appears to be the most influential factor, although further research is required to confirm this.     

Simulation of faba bean (Vicia faba L.) growth and development under Mediterranean conditions: Model adaptation and evaluation

This study reports the adaptation of a simple and mechanistic crop growth model for faba bean (FAGS) to growing conditions in the Mediterranean region. The FAGS model was originally developed for small-seeded cultivars grown in the temperate zone under non-limiting water and nutrient conditions. In order to account for the effect of drought stress on faba bean growth, a submodel for the simulation of soil water balance has been included in the FAGS model. The enhanced FAGS model was calibrated using data from field experiments with a large-seeded faba bean genotype (ILB 1814) conducted in 1993–1994 and 1994–1995 at ICARDA's Tel Hadya research station in northern Syria. In both seasons, crops were sown on two dates under different water supply levels. The model was capable of predicting the faba bean phenology, leaf area development, biomass production, and grain yield as well as the soil water extraction using daily climatic data, genotype-specific parameters, and soil physical properties. The calibrated faba bean model was tested against independent experimental data from the 1991–1992 and 1992–1993 growing seasons at Tel Hadya and was able to satisfactorily predict grain yield of crops grown under different drought intensities. Limitations of the model and aspects requiring better understanding to improve model predictions are discussed.     

Resistance against broomrapes (Orobanche and Phelipanche spp.) in faba bean (Vicia faba) based in low induction of broomrape seed germination

Broomrapes are weedy root parasitic plants that severely constraint faba bean production. After long and extensive breeding efforts made in several countries only moderately resistant cultivars are available to farmers, being their resistance based on a combination of avoidance and resistance mechanisms. In this work we characterize the resistance mechanism of two faba bean breeding lines selected for resistance to Orobanche crenata. Mini-rhizotron experiments showed that low induction of seed germination is a major component of resistance in these lines against O. crenata, O. foetida and P. aegyptiaca. This is confirmed by in vitro experiments with root exudates. The fact that low induction of germination is similarly operative against O. crenata, O. foetida and P. aegyptiaca reinforce the value of this resistance.     

沙芥生长发育及种子产量形成与播种期关系的研究

在1998-2002年预备试验的基础上,于2003-2004年期间研究了不同播期对沙芥生长发育及种子产量的影响。试验采用直播法,每隔15 d播种1次,共12个播种期。结果表明:沙芥从播种至出苗需7~18 d,种子发芽出土的活动起始温度为12.56℃,有效积温为69.07℃;各播种期株高、总叶片数、株展、茎粗、一级分枝数、返青率、种子产量均随播种期推后而降低,且播种过晚,翌年才出苗;一年生植株安全越冬且翌年能抽薹开花的日历苗龄为59 d以上,植株形态指标为株高9.6 cm,株展为15.5 cm,平均叶片数为5.8片,茎粗为0.8 cm以上;二年生植株生长势、种子产量与一年生苗生长势呈正相关,返青后二年生植株的生育进程基本相同,其全生育期分为营养生长期、休眠期、生殖生长期。沙芥在内蒙古呼和浩特地区的栽培或采种的春季适宜播期是5月中旬,寄子栽培可以在10月上旬播种。研究确定了人工栽培条件的适宜播种期,掌握了越冬的最小苗龄,为沙芥人工栽培及繁育技术的研究奠定了基础。     

Effects of previous cropping on seed yield and yield components of oil-seed rape (Brassica napus L.)

Information about the effect of the preceding crop or crop combination on the seed yield of oil-seed rape is extremely scarce. Experiments were carried out in northwest Germany to investigate the effect of different preceding crops on the growth, seed yield and yield components of oil-seed rape. The two directly preceding crops, wheat and oil-seed rape, had only a negligible and non-significant effect on the seed yield of the following oil-seed rape crop. Oil-seed rape grown after wheat had more pods per plant, due to an increase in the number of pods on the higher category branches. In contrast, the seed yield and yield components were more affected by the cropping sequence, i.e. the crops 2 years before. Averaged over two experimental years, the greatest yields were observed in oil-seed rape following the sequence peas-wheat (694 g m⁻²), whereas the smallest seed yield occurred after 2 years of oil-seed rape cropping (371 g m⁻²). The differences in the seed yield were again associated with more pods per plant, which compensated for the lower number of plants m⁻², whereas the number of seeds per pod and the mean seed weight were almost unaffected by the previous cropping. It was not possible to relate the described differences to the crop development, since differences in the biomass caused by the previous cropping were only significant at maturity. Oil-seed rape grown after 2 years of oil-seed rape had the highest ratings of stem canker (Leptosphaeria maculans) as well as verticillium wilt (Verticillium dahliae). But the general level of the diseases was low, and therefore other causes for the effects described must be considered.     

Factors affecting root and seed yield in ahipa (Pachyrhizus ahipa (Wedd.) Parodi), a multipurpose legume crop

Ahipa (Pachyrhizus ahipa) is a legume crop, which produces carbohydrate-rich tuberous roots and seeds rich in protein and oil. In the present work, we studied the effect of different agronomic practices and climatic conditions on root and seed yield in order to make a preliminary assessment of the yield potential under different managements for the ahipa crop in south-western Europe. Sowing date affected productivity when delayed, because of growth season shortening. Reproductive pruning greatly increased root yield. Increasing planting density affected root and fruit growth per plant but increased yield to a certain extent. Seed inoculation with effective rhizobia greatly increased root and seed production. Low temperature is a main factor to be considered as it reduced productivity in areas of cool nights. Ahipa has a low environmental impact and low input requirement (fertilizer, pesticides), providing an attractive alternative to traditional sources of carbohydrates for conserving non-renewable resources and maintaining farmer profitability. Competitive yields for the simultaneous production of starch, feed protein and industrial oil may be obtained with low investment using available landraces.     

Rate and inheritance of cross-fertilization in faba bean (Vicia faba L.)

Summary To assess the feasibility for synthetic varieties of Vicia faba L., 108 faba bean genotypes were screened for cross-fertilization rate in five field experiments carried out in 1989 and 1990 at Wageningen.Significant genotypic differences were observed for outcrossing rate, which ranged from 1 to 55%. These percentages, however, are thought to be not high enough for a commercially feasible production of synthetic varieties.The inheritance of cross-fertilization rate, determined by testing the F₄ generation of a cross between two inbreds, both with high outcrossing rates, appeared to be of a polygenic nature, as was indicated by the wide variation in, and the continous distribution of, the cross-fertilization rates. Among the F₄ lines tested some had a significantly higher cross-fertilization rate than the parents. However, this difference was not found when these lines were retested, indicating that possibilities for successful selection for higher outcrossing rates might be limited.     

Adaptation and yielding ability of castor plant (Ricinus communis L.) genotypes in a Mediterranean climate

Successful castor (Ricinus communis L.) cropping in Greece depends on the yielding ability and yield stability of the cultivars (hybrids or inbreds) as well as the reliability of production systems. The adaptation and yielding ability of 19 modern castor oil genotypes were studied for 3 years in two sites of Northern Greece. Genotypes combining high seed and oil yield and desirable morphological characteristics were tested for 2 or 3 years, whereas the rest were tested for 1 year only. The growing period in both locations was long enough for ripening the first raceme and a number of secondary racemes depending on the genotypes. The plant height was dependent mainly on the genotypes but also was affected by the site and the year of the experimentation and ranged from 79 to 278 cm. The seed yield varied between 2.5 and 5.0 Mg ha⁻¹, values that are among the highest reported in the literature. The seed yield was higher in the site where plants produced and ripened more secondary racemes. The seed oil content was dependent mainly on the genotype and ranged from 44.5 to 54.2%. The oil yield followed the changes in seed yield. The variation in seed yield between years was low and in most genotypes less than 20%. Results indicate that the castor oil crop was satisfactorily adapted in the area.     

The Interaction of Sowing Date and Water Availability in Determining Plant Architecture, Fruiting Pattern and Yield Components of Soybean (Glycine max L. Merr.)

A 2-year trial has been carried out in northern Italy on soybean (cv. Hodgson) grown in lysimeters, comparing three soil water regimes (well-watered conditions and water stress during vegetative and reproductive stages) at two sowing dates. Plant evapotranspiration and water uptake depth were calculated from volumes of water independently supplied to eight lysimeter layers; at harvest, plant architecture, yield components and fruit distribution along the main stem and lateral branches were evaluated.
Although water stress intensity was not severe, crop evapotranspiration and water uptake depth were severely restricted by water shortage. Both low water-availability and late sowing significantly modified the architecture of plants, decreasing total height, number and length of internodes and lateral branches. Seed allocation along the stem was shifted downwards both by delaying the sowing date and by reducing the water supply; the component most responsible for yield decrease was the number of pods per plant, while unit seed weight was only slightly affected by water stress. Grain yield reduction was higher when water availability was inadequate during the reproductive phase in the early-sown crop and during the vegetative stage in the late-sown crop. This suggests that the intensity of the water shortage, plant phenological stage of stress application, as well as the date of stress application within the growing season determine the yield response of soybean.     

Effect of preceding crop combination and N fertilization on yield of six oil-seed rape cultivars (Brassica napus L.)

Information about the effect of the cropping history on the seed yield of oil-seed rape is extremely scarce. In 1992/93 and 1994/95, the effects of different preceding crop combinations (winter barley and winter wheat as preceding crops, oil-seed rape and wheat as pre-preceding crops) on the yield of six double low oil-seed rape cultivars were examined in a field trial at Hohenschulen Experimental Farm, north-west Germany. In addition, eight nitrogen treatments (different amounts and distribution patterns) were tested for their potential to reduce negative effects of the preceding crops. Following the cropping sequence of oil-seed rape then wheat, oil-seed rape yielded only 3.12 t ha⁻¹; after oil-seed rape then barley, the yield was 3.43 t ha⁻¹ compared with 3.77 t ha⁻¹ following wheat then barley and 3.71 t ha⁻¹ following wheat then wheat. The number of seeds per m² showed a similar pattern, whereas the thousand-seed weight partly compensated for the reduced seed number. It was highest if oil-seed rape was grown 2 years previously. The cultivars differed significantly in their yield potential. Express (3.79 t ha⁻¹) yielded 0.6 t ha⁻¹ more than Falcon (3.18 t ha⁻¹). Increasing amounts of fertilizer-N (80–200 kg N ha⁻¹) increased the seed yield from 3.21 t ha⁻¹ to 3.84 t ha⁻¹. Changes in the distribution pattern within one fertilizer amount had no effect on seed yield. In addition, no interactions between preceding crop combination and the different cultivars or N treatments occurred. It is concluded that crop management cannot totally eliminate the negative effects of an unfavourable cropping history on the seed yield of oil-seed rape.     

Effects of harvest management on growth dynamics, forage and seed yield in berseem clover

Berseem clover (Trifolium alexandrinum L.) is an annual forage crop widely grown in Mediterranean environments. However, there is little information available on the patterns of accumulation and partitioning of assimilate in berseem and how this varies with harvest management, plant ontogeny or is influenced by genotype. Field experiments were conducted in Foggia (Italy) during three growing seasons (1991–92, 1992–93 and 1993–94), with the aim of evaluating the effects of different harvest managements on growth dynamics, forage yield and seed yield of one population of Egyptian (cv. ‘Giza 10’) as well as Italian (cv. ‘Sacromonte’) origin. Cutting treatments were applied at three different plant ages: sixth internode elongation (A), early flowering (B), and uncut control (C). The growth and development of the shoot and root systems were followed by destructive harvests made at about 5-day intervals during 9 weeks in spring in all treatments. Seasonal growth pattern, determined as dry matter accumulation, forage yield and seed production were greatly influenced by harvest management. The maximum value (20.5 g per plant on average) of dry weight was reached at about 250 days after sowing for treatment C. Defoliation induced a decrease of crown and root dry matter, however, as shown by the allometric relationships, the growth of roots and shoots was closely correlated and in most cases, shoot growth was higher than root growth and stem relative growth rate (RGR) was higher than leaf RGR. Berseem clover is a defoliation-tolerant species because after cutting, regrowth was accompanied by higher values of leaf-stem ratio (LSR), RGR and stem elongation rate (SER) than in control plants. The highest value for total forage yield (1.6 Kg m⁻²) and seed yield (60.5 g m⁻²) were obtained in treatment B and A, respectively. Plants cut at the sixth internode elongation showed a good seed yield and a small decrease (15%) in total forage yield as regards treatment B. Therefore, treatment A appeared the most favourable for obtaining double utilization (forage and seed yield) in a berseem crop. Berseem plants were greatly influenced by harvest treatments applied, but the response did not vary according to the genetic characteristics of the two cultivars examined.     

Environmental effects on linseed (Linum usitatissimum L.) yield and growth of flax at different stand densities

The effect of environmental factors and stand density on linseed (Linum usitatissimum L.) yield was investigated by examining yield components and development rates from 4 years of field experiments carried out at Viterbo, Central Italy, in which different seed rates were tested. Spring sowings were carried out using the linseed cultivar ‘Mikael’. Growth analysis using the functional approach and modelling using the SUCROS model for potential production parameterized for linseed were used to carry out a more detailed analysis of environmental effects.

Linseed yields varied greatly in response to weather and soil type but showed very little effect of plant density. The crop was able to compensate for reduced stand densities mainly by increasing the number of capsules per plant. All yield components were significantly influenced by weather as represented by the year of sowing. Growth analysis showed that the unit leaf rate had higher values at lower stand densities, suggesting that self-shading at higher densities decreased the efficiency of the foliage. The environmental factors most likely to affect yields were high temperature, due to its effect on development rate, and the consequent shortening of the growing cycle and perhaps water shortage. The foliage duration was more important than the maximum leaf area index.     

Inheritance of seedling colour in faba bean (Vicia faba L.)

Summary The inheritance of purple seedling colour was studied, in relation to the genetic control of flower colour. It was found that purple seedling colour is likely to be controlled by a single gene and that the trait is dominant over green seedling colour. White flowering prohibited the expression of the purple seedling colour, and is therefore thought to be epistatic.This character can be used to estimate rate of outcrossing in breeding programmes, as well as contribute to our knowledge of the biosynthesis of plant pigments and secondary metabolites such as tannins.     

Effect of depth of fertilizer banded-placement on growth,nutrient uptake and yield of oilseed rape (Brassica napus L.)

A better understanding of crop growth and nutrient uptake responses to the depth of fertilizer banded-placement in the soil is needed if growth and nutrient uptake responses are to be maximized. A two-year field study covering two rape seasons (2010–2011 and 2011–2012) was conducted to examine the effect of banded-placement of N–P–K fertilizer at various depths on growth, nutrient uptake and yield of oilseed rape (Brassica napus L.). The results showed that fertilization at 10 cm and 15 cm soil depth produced greater taproot length and dry weight than fertilization at 0 cm and 5 cm. 0 cm and 5 cm deep fertilization significantly increased the lateral root distribution at 0–5 cm soil depth, while 10 cm and 15 cm deep fertilization induced more lateral root proliferation at 5–15 cm soil depth. At 36 days after sowing (DAS), 5 cm deep fertilization produced better aboveground growth and nutrient uptake than 10 cm and 15 cm deep fertilization. However, reversed results were observed after 36 DAS. 10 cm and 15 cm deep fertilization produced more rapeseed than 0 cm and 5 cm deep fertilization, moreover, the yield difference was more significant in drought season (2010–2011) than in relatively normal season (2011–2012). In summary, these results preliminarily suggest that both 10 cm and 15 cm are relatively proper fertilizer placement depth when the practice of banding fertilizer is used in oilseed rape production. But from the viewpoint of diminishing the production cost, 10 cm deep fertilization should be recommended in actual farming. Because 15 cm deep fertilization may require higher mechanical power input, and thus resulting in higher cost of production.     

Effects of water deficit and plant interaction on morphological growth parameters and yield of white clover (Trifolium repens L.) and ryegrass (Lolium perenne L.) mixtures

The effects of soil water deficit and interspecific plant interaction were studied on the dry matter (DM) yield of white clover and ryegrass and on the morphogenesis of white clover. Plants were grown either: (1) individually (no interaction); or in a mixture of equal plant numbers with either (2) just shoot interaction, or (3) both shoot+root interaction. Plants were subjected to soil water deficits corresponding to no (0 MPa), moderate (−0.5 MPa) or severe (−1.0 MPa) water deficit. Ryegrass had higher above- and below-ground DM yields than white clover. The above- and below-ground DM yield for ryegrass, and the above-ground DM yield, stolon growth and relative growth rate (RGR), and leaf appearance rate (LAR) for white clover decreased as soil water deficit increased. In shoot+root interaction at no and moderate soil water deficit levels, white clover had the highest proportion of above-ground growth in the leaf form (69%) and had, respectively, 11% and 32% more above-ground DM yield than when grown in just shoot interaction; ryegrass had, respectively, 20% and 25% more above-ground DM yield than ryegrass grown in just shoot interaction. In shoot+root interaction at severe soil water deficit, ryegrass had twice as much above-ground DM yield as white clover (3.50 g per plant versus 1.59 g per plant, respectively) and white clover had 60% less above-ground DM yield than when grown in just shoot interaction. In a soil column of restricted depth (30 cm) at no and moderate soil water deficit levels, remarkable increases in shoot biomass yield were observed for both white clover and ryegrass grown in shoot+root interaction. The increased shoot biomass yield of ryegrass can be attributed to benefits from white clover's N fixing ability, whereas the causes for increased white clover biomass yield need to be studied further. However, at severe soil water deficit, ryegrass had a competitive advantage over white clover when grown in shoot+root interaction. This was due to the larger root system of ryegrass and its ability to control transpirational losses more efficiently, thus prolonging its growth period compared with white clover.     

Modelling potential growth and yield of olive (Olea europaea L.) canopies

The wide variability and complexity of olive orchards makes it difficult to provide solutions to the numerous management questions using a pure experimental approach. In this paper we calibrate and validate a simple model of olive orchard productivity based on the Radiation-Use Efficiency (RUE) concept of Monteith. A calibration experiment was performed in Cordoba from 1998 to 2001 with drip-irrigated olive trees cv. ‘Arbequina’. Destructive samples of 18 trees and non-destructive measurements on 80 trees were used to determine RUE and dry matter partitioning coefficients. Validation experiments were performed in 18 drip-irrigated orchards of seven locations in Southern Spain, including two cultivars (‘Arbequina’ and ‘Picual’). Average RUE was 0.86 g dry matter (MJ PAR)⁻¹ which is equivalent to 1.56 g glucose (MJ PAR)⁻¹. Aboveground accumulated biomass was allocated equally to fruits and vegetative growth, which in turn was partitioned into 30% for leaves and 70% for stems, branches and trunk. The fraction of oil in fruits was 0.38 which implies that the average ratio oil yield/intercepted PAR, which is an equivalent RUE for oil production (_o), is 0.17 g oil (MJ PAR)⁻¹. The prediction of oil yield as the product of 0.17 and total intercepted PAR was tested successfully in the validation experiments (relative RMSE = 0.26). Errors of this simple model were partly due to alternate bearing and partly to a decrease in _o as canopy size increases, which deserves further research. The concept of _o may be also useful for the evaluation of alternate bearing in olive trees.

Estimated potential carbon sequestration by intensive irrigated olive orchards in Southern Spain was 7 t CO₂ ha⁻¹ year⁻¹ which is much higher than that of other agricultural systems in Europe.

The simple model of growth and yield presented herein is the core of a complete model of olive growth and yield and may be useful not only for evaluating productivity at different scales but also for solving different management problems (nutrient requirements, plant protection, etc.)     

The identification of faba bean (Vicia faba L.) trisomics by translocation tester set

Summary Five subtelocentric primary trisomics of Vicia faba L. were isolated from crosses between asynaptic mutants and normal plants or translocation tester stocks. The extra chromosome of each trisomic was identified cytologically by critical multivalent association at metaphase I of meiosis.     

采种季节和设施对矮生菜豆种子产量和质量的影响

以SG259和Provider两个矮生菜豆品种为材料，分春秋两季在不同设施下进行了采种试验。结果表明，采种季节、采种设施以及品种对矮生菜豆的生育期、单株分技数、单株结荚数、种子产量、种子千粒重以及发芽势和发芽率均有明显的影响。在杭州的气候条件下，Provider的种子产量和质量明显优于SG259；秋季采种时的种子质量优于春季采种。春季采种时，无论是种子产量或是种子质量均以温室采种较为理想；秋季采种时温室的优势不是非常明显。根据本试验结果，从种子产量、质量以及生产成本考虑，杭州地区矮生菜豆原种的繁殖宜在秋季露地进行。     

Pattern analysis and genotypic x environment interactions in faba bean (Vicia faba L.) populations

Summary Twenty-nine populations of faba bean (Vicia faba L. subsp. major, equina and minor) of mediterranean origin were evaluated for the genetic variability of 12 biomorphological characters at four locations in Apulia and Basîli cata regions (Italy) in 1983–84.A pattern analysis appoach, based on classification and ordination procedures is presented for to characterize differences among population in mean performance and response across environments. Informations about G × E interaction were obtained.Research work supported by CNR, Italy. Special grant I.P.R.A. Sub-project 1. Paper N. 1099.