bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contribution of Leaf Photosynthesis towards Seed Yield in Brassica species
Authors: Ramana S. , Ghildiyal M. C. 
Published: April 2008

AbstractThe effect of defoliation after flowering, when a considerable number of pods were already formed on yield components, was examined in four Brassica species. In B. campestris and B. juncea, a decrease in seed yield by defoliation was associated with a decrease in the number of pods per plant as seed number per pod and thousand‐seed weight were not significantly affected by this treatment. In B. nigra, apart from decreasing the pod number per plant, defoliation also significantly decreased the thousand‐seed weight, Defoliation significantly decreased both seed number per pod and thousand‐seed weight apart from decreasing the number of pods per plant in B. carinata. The study indicated that in B. campestris and B. juncea, the role of leaf photosynthesis seemed to be restricted mainly to the formation of pods. On the other hand, in B. nigra and B. carinata it appeared that leaf photosynthesis also contributed towards seed development.
Effect of Low Light on Photosynthetic Pigments, Photochemical Efficiency and Hill Reaction in Rice (Oryza sativa L.)
Authors: Viji M. M. , Thangaraj M. , Jayapragasam M. 
Published: April 2008

AbstractPhotosynthesis and related functions in low light tolerant (CO 43 and Swarnaprabha) and low light susceptible (IR 20) rice varieties were measured under shaded conditions and in normal sunlight. The increase in the contents of chlorophyll (chi) a, chi b, total chlorophyll and caro‐tenoids under low hght treatment was more prominent i n Swarnaprabha and CO 43 than that of IR 20. But a decreasing trend was observed in chi ah ratio in all the three cultivars due to predominant increase of chi h fraction. The decrease in ratio was less in Swarnaprabha and CO 43 than that of IR 20, Higher photochemical efficiency and photosynthetic rate over IR 20 were maintained by Swarnaprabha and CO 43 grown under shaded condition. Shading up to flowering stage enhanced the Hill reaction and during harvest stage induced a reduction in Hill reactivity in all the three varieties.
Site Specific Weed Control in Winter Wheat
Authors: Gerhards R. , Sökefeld M. , Schulze‐Lohne K. , Mortensen D. A. , Kühbauch W. 
Published: April 2008

AbstractField experiments were conducted in two winter wheat fields to assess weed control and quantify the amount of herbicide applied with a GIS map‐based patch sprayer. Site specific weed management decisions were based on previously acquired weed distribution maps and an economic weed threshold model. A weed treatment map (on‐off) was generated and georeferenced to control the sprayer. A global positioning system was used to locate the sprayer in the field. In both fields, Alopecurus myos‐uroides was observed at low infestation levels, Galium aparine at medium infestation levels and the mean density for other broadleaf species exceeded 40 weed seedlings va‐ in both fields. Herbicide application was recommended for 58.3% of the first field and 54.6% of the second field. With the patch sprayer used for this study, 21% less herbicides were sprayed compared to an uniform broadcast application. Additional assessments of weed density in the first field 3 and 6 weeks after site specific weed control showed that almost the entire field was weed free. The results of this study demonstrated that site specific weed control was technically feasible but further investigations are needed to verify and evaluate site specific weed control methods.
Screening for Drought Resistance in Spring Chickpea in the Mediterranean Region*
Authors: Singh K. B. , Omar M. , Saxena M. C. , Johansen C. 
Published: April 2008

AbstractEven though chickpea (Cicer arietinum L.) is well adapted to growing on stored soil moisture in drought‐prone environments, drought is a major yield reducer in most chickpea‐growing regions. Little progress has been made in breeding for improved performance under drought stress for want of a reliable and repeatable method of screening for drought resistance. Therefore, a study was initiated in 1990 to develop a screening technique and a rating scale to evaluate germplasm for drought resistance. A spring date‐of‐planting experiment was conducted during spring from 1990 to 1992 at Tel Hayda (northern Syria) to see if the expression of genotypic differences in drought resistance should be accentuated. Simultaneously, a rating scale was developed. Using the screening technique and rating scale, over 4000 germplasm lines were evaluated from 1992 to 1995. The resulting screening technique involves delayed sowing by 3 weeks during spring at a relatively dry site (long‐term average annual rainfall of 328 mm), preliminary evaluation of materials on a rating scale of 1–9 to discard susceptible lines, and final evaluation of promising lines under stress (drought) and non‐stress (supplemental irrigation) conditions, selecting drought‐resistant lines which perform well under both conditions. In the 1–9 rating scale that was developed: 1 = no yield reduction as compared to a non‐stress control and 9 = all plants dry without producing any seed. Using this technique, 19 lines out of 4165 lines screened were identified as drought resistant, producing over 1 t ha−1 seed yield under drought conditions while being able to yield over 2t h−1 under non‐stress conditions. Resistant lines are being used by national programs in the Mediterranean region and by ICARDA for developing drought‐ and disease‐resistant. high‐yielding cultivars.
Availability and Utilization of Assimilates in Relation to Grain Growth Within the Ear of Wheat
Authors: Kumari Sunita , Ghildiyal M. C. 
Published: April 2008

AbstractThe development of grains of different positions in the apical, middle and basal spikelets of wheat var. Kaly‐ansona showed that beyond first two basal grains, the more distal a grain in a spikelet the lower its weight. The distal grains received less assimilates than the proximal grains as revealed from sugar concentration in the grains. The eflficiency of distal grains of kalyansona to synthesize reserves was, however, not inferior than the proximal grains in a spikelet. The depression in grain weight lowards extreme spikelet was lower compared to the depression in weight of individual grams towards a distal position in a spikelet. The study seems to suggest that in order to ensure better grain uniformity while maintaining a higher grain number per ear, the spikelet number per ear should be increased instead of increasing the grain number per spikelet.
Effect of Sodium Chloride on Germination and Seedling Characters of Different Types of Rice (Oryza sativa L.)
Authors: Khan M. S. A. , Hamid A. , Karim M. A. 
Published: April 2008

AbstractThe rice eultivars grown in the tropies and sub‐tropics can be broadly categorized as aromatic small grain, local coarse grain and modern high yielding varieties (HYV). The first two categories are traditional rice, and are generally palatable. The aromatic rice has better market value than HYV rice, yet farmers are unwilling to expand its cultivation because of the low yield potential. One possibility to expand the cultivation of traditional rice is o t find stress tolerant cultivars for growing in marginal land. The salinity tolerance of nine rice cultivars representing three from each type of aromatic small grains, local coarse grains and HYV types, was analysed at germination and early seedling stage. Seeds were placed for germination and the seedlings were allowed to grow for nine days at NaCl concentrations of 0, 50, 100, 150 and 200 mM. NaCl decreased the germination index (GI), speed of germination, seedling height and seedling dry matter weight. Seedling characteristics were decreased more than GI. In general aromatic small grain type showed more salt sensitivity than the other two types. Among the nine cultivars Shakkorkhora (aromatic type) showed the least salt tolerance in relation to germination and seedling characters while the other two cultivars of the same group showed tolerance as high as the tolerant cultivars in other types. Generalization of group salt tolerance of rice, therefore, has little value from the agronomic point of view at least at early growth stage. As the number of cultivars employed in this study was only three from each type it is suggested that more cultivars be considered for the purpose of salt tolerant improvement programme of various types of rice.
The Effect of Nitrogen Fertilization and Population Density of the Field Bean (Vicia faba L. minor) of Indeterminate and Determinate Growth Habit on the Symbiosis with Root Nodule Bacteria and on the Seed Yield
Authors: Filek W. , Kościelniak J. , Grzesiak S. 
Published: April 2008

AbstractField beans of indeterminate (cv. Nadwiślański) and determinate (cv. Tibo) growth habits were grown on field plots with a density of 20, 40 and 80 plants m−2 at two levels of nitrogen fertilization: low (20 kg N ha−1) and very high (150 kg N ha−1). At the phase of intense pod growth the number and the dry matter weight of root nodules as well as their nitrogenase activity and some features of the plants growth were determined, and in the period of ripeness the components of seed yield were established.It was found that increased density of sowing as well as the high level of nitrogen fertilization inhibited the growth and development of root nodules and limited their nitrogenase activity in both cultivars. Plants of both varieties were characterized by a similar potential of forming the root nodules, however, in plants of the cv. Tibo the nitrogenase activity of nodules was much lower than in the cv. Nadwiślański.Increased population density of the plants has in both varieties given increased seed yield when calculated per m2 of the soil, compensating in excess the depression of the seed yield from one plant. Such compensation did not occur in the case of the depression of nitrogen fixation under intense nitrogen fertilization.
Influence of Repeated Application of Herbicides on Weed Succession and Yield of Rice Based Cropping System in India
Authors: Kandasamy O. S. 
Published: April 2008

AbstractField experiments were conducted to determine the effect of continuous application of herbicide on weed growth and yield of rice‐rice‐pulse cropping sequence over nine cropping seasons. The dominant weed species were Marselia quadrifolia, Echinochloa crus‐galli, Cyperus difformis and Monochoria vaginalis. In hand weeded plots M. quadrifolia and the annual grass E. crus‐galli were dominant in the early crops; E. crus‐galli dominated in the later crops, with a shift to M. vaginalis in dicots. Annual application of herbicides caused a population shift from dicots to monocots, particularly grasses. Among grasses, Leptochloa chinensis, a difficult weed to control replaced dicots and reduced E. crus‐galli. Combined chemical treatment and manual weeding as well as manual weeding controlled the weed growth and maintained the yield of rice throughout the period of study.
Characterization of CO2 Responsiveness in a Brassica oxycamp Interspecific Hybrid
Authors: Uprety D. C. , Dwivedi Neeta , Mohan Rajat 
Published: April 2008

AbstractA study of the characterization of CO2 responsiveness in Brassica oxycamp and its parents Brassica oxyrrhina and Brassica campestris was done using open top chamber technology. The response of the X. B. oxycamp (hybrid) to elevated CO2 was significantly positive in respect of photosynthesis and growth and similar to that of its parent B. campestris. X B. oxycamp and B. campestris with greater sink potential responded significantly, whereas B. oxyrrhina with a poor sink, did not respond to CO2 enrichment. Photosynthetic changes at elevated CO3 levels in the hybrid and parents are partially attributed to the CO2 effects on stomatal conductance and chlorophyll fluorescence.
Intercropping Studies in Lemongrass (Cymbopogon flexuosus) (Steud. Wats.)
Authors: Singh M. , Shivaraj B. 
Published: April 2008

AbstractLemongrass (Cymbopogon flexuosus (Steud.) Wats) is a perennial, multicut aromatic grass, which yields an essential oil used in perfumery and pharmaceutical industries and Vitamin A, has a long initial lag phase. To utilize the crop growth resources more efficiently during this phase, studies were made to explore the possibility of intercropping food legumes with lemongrass. An experiment conducted during 1992–93 revealed that the food legumes like blackgram (Vigna mungo (L) Hepper), cowpea (Vigna unguiculata (L) Walp) or soybean (Glycine max (L) Merr.) could be intercropped in the initial stages of lemongrass to get extra yields over and above that of lemongrass, without affecting the yield of lemongrass.
Root Yield and Quality of Sugar Beet (Beta vulgaris L.) in Relation to Plant Population
Authors: Çakmakçi R. , Oral E. , Kantar F. 
Published: April 2008

AbstractIntroduction of genetic monogerm seed and the advancement of agricultural techniques raised the possibility of eliminating costly thinning operations in sugar beet farming. However, this requires high and uniform seedling emergence to provide prerequisite plant populations in the field. This work investigated the minimum levels of seedling emergence for non‐thinned sugar beet farming. The experiment was carried out in a loamy soil to investigate the effects of three levels of emergence (60, 50 and 35%) and two intra‐row spacings (8 and 15cm) with or without thinning using seed source of graded viability of cv Eva in 1992 and 1993 under field conditions in Eastern Anatolia. Plant population throughout the growing period was monitored and data were taken of yield and quality parameters. On average, 60, 50 and 35% emergence levels were achieved using seed source of 90, 72 and 54% viability range, which resulted in different levels of plant stands depending on intra‐row spacing and thinning. Plant density at harvest ranged between 49 500 and 124 500 ha−1 on average depending on initial establishment, intra‐row spacing and thinning. Root yield and sugar yield were the highest at plant stands between 90 000 and 100 000 ha−1, below or above of which declined. Impurity contents (e.g. Na, K and a‐amino N contents) and extractable sugar content decreased but sugar content and clear juice purity enhanced as plant stands at harvest increased.
Effects of Bean Population and Row Arrangement on the Productivity of Chilli/Dwarf Bean (Capsicum annuum/Phaseolus vulgaris L.) Intercropping in Sri Lanka
Authors: De Costa W. A. J. M. , Perera M. K. K. W. 
Published: April 2008

AbstractIntercropping of chilli (Capsicum annuum) and dwarf bean (Phaseolus vulgaris) is a recently adopted practice by farmers in Sri Lanka. As chilli fetches a higher market price, the bean population which could be incorporated into a 100% population of chilli has to be found. In the present experiment, effects of three bean populations (100, 75 and 50% of sole crop population 250 000 pl ha−1) and four row arrangements (1:1, 1:2, 2:1 and 2:2) were tested at Kundasale, Sri Lanka. The land equivalent ratio (LER) of all intercrops were significantly greater than one, indicating a greater productivity per unit land area in intercropping than sole cropping. At 100% and 75% bean populations, LER and intercrop yields of bean were significantly greater than at 50%. Row arrangement did not have a significant effect on either LER or bean yield in intercrops. Intercrop bean yields were lower than sole bean yields indicating significant competition from chilli. Chilli yields were not affected by either bean population or row arrangement. Intercrop chilli yields were greater than the sole chilli yield indicating significant positive effects from bean. Greater radiation interception and lower weed growth and the absence of overlap between yield formation periods of the two component crops were probably responsible for the greater productivity (LER) of intercrops.
Phenological Growth Stages of the Peanut Plant (Arachis hypogaea L.): Codification and Description according to the BBCH Scale1
Authors: Munger P. , Bleiholder H. , Hack H. , Heß M. , Stauss R. , van den Boom T. , Weber E. 
Published: April 2008

AbstractFollowing the introduction of the general BBCH scale, the specific BBCH scale for the peanut plant is presented providing crop‐specific descriptions and detailed assessment instructions.The phenological development process of the peanut plant is described by periods (principal growth stages) and steps (secondary growth stages). A 2‐digit decimal code suitable for data processing in crop production experiments is assigned to each developmental step.
Phenological Growth Stages of the Cotton Plant (Gossypium hirsutum L.): Codification and Description according to the BBCH Scale1
Authors: Munger P. , Bleiholder H. , Hack H. , Hess M. , Stauß R. , van den Boom T. , Weber E. 
Published: April 2008

AbstractFollowing the introduction of the general BBCH scale, the specific BBCH scale for the upland cotton plant is presented which provides crop‐specific descriptions and detailed assessment instructions.The development process of the plant is described by periods (principal growth stages) and steps (secondary growth stages).A 2‐digit decimal code suitable for data processing in crop production experiments is assigned to each step of development.
Water Stress and N Fertilization Effects on Yield and Smut Disease Incidence in Corn (Zea mays L.)
Authors: Kostandi S. F. , Soliman M. F. 
Published: April 2008

AbstractA 2‐year field experiment was conducted in sandy clay loam soil to quantify the single and combined effects of N fertilization and water stress (WS) treatments on yield and smut incidence in corn. The plants were supplied with two different N rates (225 and 300 kg ha−1) and subjected to 2 weeks' water stress, imposed at vegetative (Vg), tasselling (Ta), silking (Si) and grain‐filling (Gf) growth stages. In addition, a control treatment (Cr) was also included to allow the plants to grow under unstressed conditions. The plants were artificially infected two times with Ustilago maydis spores and smut severity was recorded. At harvest, grain yield (GY), total biomass (Tbm) and harvest index (HI) were determined in smut‐free (0) and smutted plants (S). Results have shown that GY0 and GYs were markedly reduced when the plants were subjected to WS. The depressing effects of WS were, comparatively, high at Gf. intermediate at Ta and Si. and low at Vg growth stages. Smut index (SI) data revealed that severity was higher on plants stressed at Gf than those exposed to WS at Vg, Ta or Si stages. Considerable variations were detected on Tbm and HI of smut‐free and smutted plants, indicating the detrimental effect of plant water deficit at Gf stage. The combined effect of WS and N on Tbms showed mixed results, ranging from positive response for stressed plants at Si and Gf to little response at Cr, Vg or Ta stages at higher N rate. Although the effect of WS exposure on RYL data was dominant at Gf, the rate of yield depression was relatively higher at Ta and Si than the other growth stages, because of water deficit effects. The results proved that N fertilization did not conclusively alleviate the depressing effect of WS on grain yield losses.
Planting Time and Seed Density Effects on Potato in Subtropical China
Authors: He W. , Struik P. C. , He Q. , Zhang X. 
Published: April 2008

AbstractPlanting times of potato in subtropical China vary and are often not optimal; their effects were studied in association with those of plant density. The research programme included 10 trials at three elevations (500, 750, 1200 m asl) in the spring and autumn seasons of 2 years with several contrasting varieties and different seed origins. Earlier planting in spring increased yield at 500 m asl. This effect was associated with better light use efficiency, higher rates of photosynthesis and more tubers per plant. At 750 m asl the effects of planting time in spring were the opposite: later planting increased yield. At 1200 m asl effects on yield were absent. Effects of planting time in autumn on yield were generally absent at all elevations, although plant stands at early planting were consistently and often severely reduced. Denser planting produced yields that were higher per unit area because of larger accumulated canopy cover but were lower per plant. Higher density consistently reduced plant stand. Density did not interact with planting time, not even in those experiments in which planting time also affected plant stands.Optimal planting time depended on the amount of rainfall prior to planting especially in the autumn season, but also on cultivar and dormancy of the seed tubers used. The earlier variety yielded more than the later variety at low elevation, whereas the later variety yielded more at higher elevation. It is necessary to use cultivars that tuberize early to make better use of the limited growing period at lower elevation. The large variation of dormancy that affects plant growth and yield is caused primarily by differences in accumulated temperature sum (as affected by planting time, elevation of growth and storage, and season), genetics (variety), and their interaction with cultivation techniques.
Water Stress, Water Use Efficiency, Carbon Isotope Discrimination and Leaf Gas Exchange Relationships of the Bush Bean
Authors: Raeini‐Sarjaz M. , Barthakur N. N. , Arnold N. P. , Jones P. J. H. 
Published: April 2008

AbstractWater use efficiencies for the whole plant (WUE1) and single leaves (WUE1) were studied in a greenhouse as a function of soil moisture during four phenological stages of bush bean growth. WUE1 increased significantly with soil moisture stress and attained its maximum value before the flowering stage. WUE1 and WUE1 were linearly related (r= 0.92), and WUE1 was correlated with the transpiration rate (r= ‐0.87), stomatal conductance (r= ‐0.80) and photosynthetic rate (r= 0.81). Carbon isotope discrimination.), decreased as soil moisture decreased, and) was negatively correlated with both WUE1 (r= ‐0.92) and WUE1 (r= ‐0.88). There were significant differences in leaf N among water regimes.
Physiological Effects of Winter Rape (Brassica napus var. oleifera) Prehardening to Frost. I. Frost Resistance and Photosynthesis during Cold Acclimation
Authors: Rapacz M. , Janowiak F. 
Published: April 2008

AbstractThe objective of the research was to define the changes in photosynthetic activity induced by prehardening and to determine their involvement in frost tolerance of winter rape.Prehardening of winter rape, consisting of keeping the plants at + 12°C during the light periods from sprouting until the beginning of the 1st stage of cold hardening, contributed to increasing its effectiveness. After 42 days of hardening at + 2°C the resistance of the prehardened plants equalled that attained by winter rape in the most favourable seasons of vegetation in the field. Prehardening stimulated the efficiency of photosynthesis at chill temperatures (+ 2–5°C). Differences in photosynthetic efficiency, like those in frost resistance, increase with successive weeks of hardening. They also concern the leaves already developed at the hardening temperature. A prehardened photosynthetic apparatus is less susceptible to the progress of photoinactivation taking place when the seedlings are kept at + 2°C. It also demonstrated greater activity even during the first hour of hardening or in the newly expanding leaves, and also at higher temperatures, most probably because of the more efficient progress of the dark, processes. The described changes in the functioning of the photosynthetic apparatus induced by prehardening were thus qualitatively very similar to those observed during long‐term growth at + 5°C. already described in the literature.