bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship Between Grain Growth and Postanthesis Leaf Area Duration in Dwarf, Semidwarf and Tall Isogenic Lines of Wheat
Authors: Mirallfs D. J. , Domingufz C. F. , Slafer G. A.
Published: April 2008

Experiments were carried out during 1992 and 1993 growing seasons using in the former year 2 (an early and late) sowing dates. Plants of three isogenic lines (standard height, semidwarf and dwarf) of wheat were grown under field conditions with no restrictions on water or nutrient availability with the objective of determining whether differences in rate of grain growth and in final grain weight were related To differences in leaf area duration postanthesis (LAD). A logistic and an optimization model were used to estimate the components of final grain weight and their performances were compared. The optimization model appeared more appropriate than the logistic to estimate final grain weight and their components (i.e. rate of grain growth and duration of grain filling).

The dwarf line presented the lowest average grain weight followed by the semidwarf and standard height lines, respectively. However, changes in grain weight due to the action of Rht alleles were independent of the I, AD, suggesting that reductions in grain weight due to delayed sowing date could be associated with a direct effect of temperature on grain development.

Changes in final grain weight were associated with changes in rate of grain growth, but nor with duration of the grain filling period, demonstrating that rate of grain growth was the main factor responsible for final grain weight.
Estimation of Nitrogen Fixation by the Natural 15N‐abundance Technique and Nitrogen Uptake by Pigeonpea Genotypes of Different Maturity Groups grown in an Inceptisol1
Authors: Kumar Rao J. V. D. K. , Johansen C. , Yoneyama T. , Tobita S. , Ito O.
Published: April 2008

The modulation, nitrogen fixation and nitrogen uptake of four pigeonpea genotypes belonging to extra short duration, short duration and long duration maturity groups grown on an Inceptisol were studied to examine why, despite the poor nodulation of pigeonpea in this soil, it still produces greater yields, than in Alfisols and Vertisols. The percentage nitrogen derived from the atmosphere (%Ndfa) was estimated by 15N natural abundance and N‐difference methods using a long duration sorghum as the non‐fixing reference crop. In general, nodulation of pigeonpea in the Inceptisol was much lower than that reported in Alfisols and Vertisols. The above‐ground dry matter ringed from 3.1 to 17.1 t ha−1 while the N uptake ranged from 62.3 to 215 kg ha−1 The fallen plant parrs of pigeonpea genotypes ranged from 1.4 to 4.9 t ha−1 and their N contents ranged from 25 to 84 kg ha−1. The estimates of percentage Ndfa obtained by the two methods were different. Those obtained by the 15N natural abundance appeared more appropriate as the δ15N of sorghum harvested along with short duration pigeonpea and later when it was mature did not change significantly. The extra short duration pigeonpea genotype ICPL 84023 contained very little N from atmospheric N2, while the short duration pigeonpea cv. ICPL 151 had 17% Ndfa and the long duration genotypes. ICPL 366 and T7 had up to 36 % Ndfa. It can be concluded that one of the causes of high yields of pigeonpea on Inceptisols compared to Alfisols and Vertisols despite poor nodulation could be the high N supplying capacity of these Inceptisols. Strategies have been suggested as to how pigeonpea genotypes grown in Inceptisols could improve their nodulation and nitrogen fixation and thus better contribute to a sustainable agriculture.
Ontogenic Changes in Growth and Assimilate Distribution as Influenced by N Supply in Rapeseed‐mustard
Authors: Patil B. N. , Lakkineni K. C. , Bhargava S. C.
Published: April 2008

Brassica juncea, cv. Pusa Bold, and Brassica campestris, cv. Pusa Kalyani, were raised under field conditions with varying levels of N fertilization, i.e. 0, 40, 80 and 120 kg N ha−1. Changes in dry matter accumulation in various plant parts as influenced by N supply were measured throughout the crop ontogeny. N supply up to 120 kg had an increasing effect on the growth of leaves, stem and pods during the entire period till maturity. Analysis on the assimilate distribution pattern revealed that 84–87% of the total was accumulated during the post‐flowering phase. Dry matter partitioning profile during the ontogeny indicated that about 72–83 % of the total DM was accumulated in the leaves, while 17–28 % in the stem, in the preflowering phase. This trend was found nearly opposite during the postflowering phase. At maturity, however, stem and pods accounted for nearly equal amounts of dry matter accumulation. Among the genotypes, Pusa Bold recorded significantly higher DM accumulation and seed yield over Pusa Kalyani which, on the other hand, exhibited a better assimilate‐partioning ability than the former. Nitrogen levels had a favourable effect on LAI, LAD and CGR in both genotypes. Highly significant correlations were obtained between seed yield vs. LAI, LAD and CGR. N fertilization up to 120 kg ha−1 was found beneficial in enhancing growth and yield of rapeseed‐mustard.
Cross‐linked, Water‐Storing Polymers as Aids to Drought Tolerance of Tomatoes in Growing Media
Authors: Johnson M. S. , Piper C. D.
Published: April 2008

Synthetic polymers with high water‐absorbing abilities and most of their stored moisture available to plants have been shown to benefit growth and production of tomato in drought‐stressed, organic‐based growing media and also coarse, sandy soils. Additions of polymers to organic and sand growing media had beneficial effects on shoot dry weight and fruit production. The quality of tomato yield was also improved by the application of polymer to the growing medium due to the reduced impact of water stress during the growing cycle. Cost‐effective use of gel‐forming polymers could be made within certain tomato production systems.
Exogenous Glycinebetaine Enhances Grain Yield of Maize, Sorghum and Wheat Grown Under Two Supplementary Watering Regimes
Authors: Agboma P. C. , Jones M. G. K. , Peltonen‐Sainio P. , Rita H. , Pehu E.
Published: April 2008

Drought occurring at critical growth and developmental stages in cereals affects productivity by reducing biomass accumulation, grain set, and grain yield and quality. Maize (cv. SR‐73), sorghum (cv. Trump), and wheat (cv. Spear) were established in drought‐prone field conditions in Perth, Western Australia, in l994. The plants were then subjected to optimal and suboptimal supplementary watering regimes at growth stages that were sensitive to water availability. Glycinebetaine in aqueous solution was applied to leaves at three rates (2, 4 and 6 kg ha−1 and a control) to establish whether its application could ameliorate the effects of drought on the yield of the crops. Above‐ground biomass production was measured at the beginning and at termination of the watering regimes. Leaf tissue glycinebetaine concentrations were determined 1 and 3 weeks after application. At physiological maturity, grains from the crops were harvested and grain yield, number of grains m−2 and single grain weight were recorded. Drought significantly reduced above‐ground biomass production in maize (P = 0.047), but not in sorghum and wheat. Grain yield of maize, number of grains m−2 of maize and sorghum, and single grain weight of sorghum were significantly depressed by drought. Foliar application of aqueous glycinebetaine marginally enhanced biomass production in the three crops and significantly increased grain yield of maize (P = 0.001) and sorghum (P = 0.003). It also resulted in more grains m−2 of maize, sorghum and wheat (P = 0.001, 0.001 and 0.003, respectively), with interactions between water and glycinebetaine treatments for sorghum and wheat (P = 0.001 and 0.001. respectively). Residual tissue glycinebetaine levels remained high 3 weeks after application to the crops. The positive effects of glycinebetaine treatment appear to be linked to its physiological role as a plant osmoticum that improves drought tolerance. The results of these studies suggest that foliar application of glycinebetaine may be used to improve drought tolerance and economic yield of maize and sorghum, but not of wheat. Increased grain yield was associated with more grains m−2 rather than greater single grain weight.
Effects of Sugar Beet as a Preceding Crop on Cotton
Authors: Kalburtji K. L. , Gagianas A.
Published: April 2008

Cotton (Gossypium hirsutum L.) is one of the most profitable cash crops in Greece. It is usually grown as a monoculture but it is also found in rotation systems with other plant species including sugar beet (Beta vulgaris L.). Poor cotton performance following sugar beet was persistently reported by farmers. Glasshouse and field experiments were conducted to determine whether: 1) sugar beet as a preceding crop affected seed germination, seedling growth and yield of cotton; and 2) N fertilization can minimize the effects of sugar beet. Seedling growth was diminished by sugar beet extracts; emergence, seed‐cotton, stalks and biomass of cotton in pots were affected by the soil incorporation of sugar beet residues; and emergence, flowers, bolls and seed‐cotton production in the field were also affected by the soil incorporation of sugar beet residues. These harmful effects were eliminated by N fertilization.
Seed Invigoration by Hydration–Dehydration for Improvement of Seed Quality in Safflower (Carthamus tinctorius L.)
Authors: Ramamoorthy K. , Natarajan N.
Published: April 2008

Three midstorage hydration‐dehydration treatments viz., soaking, moisture equilibration and moist‐sand conditioning followed by drying, each at varying durations for preservation of vigour and viability during storage in safflower var. K.1, were evaluated for their efficacy. Soaking seeds for 3 h followed by dehydration proved to be the best. Maintenance of membrane integrity and counteraction of lipid peroxidation may be the possible reasons for such advantage as evidenced by lower electrical conductance and peroxide values in the best treatment.
The Influence of Irradiance on Rate of Development and Components of Yield In Barley
Authors: Kernich G. C. , Halloran G. M.
Published: April 2008

A field study was conducted to investigate the effects of variation in levels of daily irradiance on the level of spike‐let abortion and the rate of development using two cultivars of spring barky (Hordeum vulgare L.), Schooner and Weeah. Three different irradiance treatments were imposed from the cessation of spikelet primordia initiation until anthesis: a reduced irradiance treatment (high competition treatment, HCT); an untreated control for medium competition treatment; MCT); and an increased amount of irradiance (low competition treatment. LCT). Variation, in natural daily irradiance (MCT) was imposed by either shading plants with shadecloth (HCT) or by exposing plants to relatively low inter‐row irradiance competition effects by obstructing adjoining plant rows with plastic mesh (LCT). The duration of the spikelet growth phase was longer by 5 days (Schooner) and 9 days (Weeah) for HCT when compared to MCT, but there was no difference in its duration between LCT and MCT. Spikelet abortion occurred at 8–16 days before anthesis, but this was dependent on treatment. LCT For both cultivars showed a trend towards higher spikelet numbers per spike, although the increase was not significant over MCT, and HCT was significantly lower in both cultivars. Grain yield and biomass were lower (P < 0.05) for HCT compared to both LCT and MCT.
Tolerance of Drought and Temperature Stress in Relation to Increased Antioxidant Enzyme Activity in Wheat
Authors: Sairam R. K. , Deshmukh P. S. , Shukla D. S.
Published: April 2008

An experiment was conducted with three wheat genotypes differing in their sensitivity to moisture and/or temperature stress to study the relationship of the chloroplast antioxidant system to stress tolerance. Both moisture stress and temperature stress increased glutathione reductase and peroxidase and decreased membrane stab‐iltty, chlorophyll content and chlorophyll stability index in all genotypes. Under moisture stress. DL 153–2 showed the highest membrane stabihty index, chlorophyll content, chlorophyll stability index, glutathione reductase activity and peroxidase activity. However, under elevated temperature conditions, HD 2285, and to a lesser extent DL 153–2, showed higher membrane stability, chlorophyll content and chlorophyll stability index and activities of glutathione reductase and peroxi‐dase. Raj 3077, which is sensitive to both drought and temperature stress, showed the lowest membrane stability, chlorophyll content and chlorophyll stability index and glutathione reductase and perosidase activity under elevated temperature as well as drought conditions. Thus, it can be concluded that tolerance of the genotype to moisture and/or temperature stress is closely associated with its antioxidant enzyme system.
Contribution of Leaf Photosynthesis towards Seed Yield in Brassica species
Authors: Ramana S. , Ghildiyal M. C.
Published: April 2008

The 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

Photosynthesis 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

Field 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

Even 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

The 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

The 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

Field 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

Field 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

A 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

Lemongrass (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

Introduction 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

Intercropping 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

Following 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

Following 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

A 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

Planting 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

Water 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

The 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.
Differential Response of Two Wheat Genotypes to Nitrogen Supply. I. Ontogenic Changes in Laminae Growth and Photosynthesis
Authors: Sivasankar A. , Lakkineni K. C. , Jain Vanita , Kumar P. A. , Abrol Y. P.
Published: April 2008

Two wheat genotypes viz. Uniculm ‘gigas’ (VI) and Kalyansona (V2) were raised till maturity with low (N1) and adequate (N2) nitrogen levels supplied at 30 and 120kg ha−1, respectively. Laminae, numbering 1–8 on the main shoot, were examined for various parameters at weekly intervals from emergence through senescence. N1 resulted in gradual reduction in laminae growth from 5th leaf onwards with maximum effect on flag and penultimate laminae of both the genotypes. Chlorophyll concentration, soluble protein, rubisco concentration and rubisco activity in response to low N supply was reduced in the top two laminae in V2. Pn rate varied little with leaf position in wheat at adequate N supply. In V2, low N supply resulted in the reduction of laminae N content by about 25% with corresponding reduction in Pn rates in the penultimate and flag laminae. VI, in contrast, exhibited no significant change in leaf N concentration and hence maintained similar Pn rates at both levels of N supply throughout the ontogeny.

It is concluded that the two genotypes responded differently to N supply in relation to laminae growth and photosynthesis. Uniculm ‘Gigas’ (VI) responded to low N with large reduction in laminae size, adequately maintaining the metabolic constituents such as chlorophyll, soluble protein, rubisco and laminae N concentration and Kalyansona (V2), in contrast, responded with small changes in laminae size and greater reduction in synthesis and maintenance of the metabolic constituents.
Effect of Water Stress on Biochemical and Physiological Characteristics of Oat Genotypes
Authors: Chandra A. , Bhatt R. K. , Misra L. P.
Published: April 2008

Activities of enzymes catalase, peroxidase, and level of total soluble proteins were studied in two genotypes (JHO 884, JHO 888) of oat (Avena sativa L.) subjected to water stress for 1, 3, and 4 days by withholding water in a pot culture experiment. No change was observed in the level of total soluble proteins at early stage but it increased significantly at higher magnitude of water stress. Increase in catalase activity was noticed in JHO 884 whereas reverse trend was observed in JHO 888 at highest level of stress. The JHO 884 genotype showed increase in peroxidase activity from the first day of water stress. Results suggest that the efficiency level of antioxidant system is found different in these two genotypes.
Nitrogen Mineralization Rates and Kinetics in Soils Freshly Amended with Green Manures
Authors: Dinesh R. , Dubey R. P.
Published: April 2008

Long term incubation studies to determine the nitrogen (N) mineralization rates and kinetics in soils freshly amended with some commonly used green manures such asSesbania rostrata. Gliricidia maculata. Leucaena leucocephalaandAzolla pinnataare scarce. A long term aerobic study was, therefore, conducted by incubating soils freshly amended with the above‐mentioned green manures in PVC columns at 35 ± 1 C and with 0.01 Mpa moisture content. The soils were then leached at periodic intervals for up to 36 weeks.

The N‐mineralization rates were greatest during the first week and decreased with time in all soils. The green manure amended soils leached 247 mg kg−1more NO3+ NO2– N than the unamended control. In general, the total N mineralized (mean 61%) was almost twice that of net N mineralized (mean 30%) in the amended soils. The percent N mineralized (total and net), however, varied with the nature of green manure incorporated into the soil. It was greatest in the soil amended with sesbania and lowest in the soil amended with azolla. The kinetic parameters derived using the double exponential model indicated that green manure amended soils possessed significantly higher N‐mineralization potentials and rate constants compared to the unamended control. The kinetic parameters also varied with the nature of green manure incorporated into the soil. Among the various parameters lignin content, lignin to N ratio and lignin + polyphenol to N ratio of the green manures were the key factors governing the rate of decomposition and subsequent N mineralization from the amended soils.
A Rapid Method for Measuring Freezing Resistance in Crop Plants
Authors: Herzog H. , Olszewski A.
Published: April 2008

The objective of this study was to develop a technique based on chlorophyll fluorescence to assess freezing injury and resistance of leaves. Optimization was done with faba bean leaves and applicability to other crops was examined at winter and spring with types of barley, oats, rape and faba beans. Selected leaves from young hardened beans were subjected to standardized freezing tests with different minimum temperatures (Tmin) and fluorescence was monitored. After a dark period basic fluorescence (FO was induced by 0.2 μmol m−2 s−1 pulsed red light and maximum fluorescence (Fm) was assayed at different light intensities. 1500 μmol m−2 s−1 rendered to give the maximum possible output of Fm and best differentiation of differently damaged leaves by Fn=Fm ‐ FO. Leaf temperature during measurement and during a short storage (± 2 h) should be kept at about 0°C to avoid biases between differently damaged leaves. The measuring spot on the leaf must be standardized since fluorescence response differed at the tip and base of a leaflet, but not between the two leaflets of a faba bean leaf. The applicability of Frr (ratio of Fr of stressed to unstressed leaves) as a measure of resistance was demonstrated by comparison of winter hardiness of cultivars with freezing resistance calculated from the relationship of Fvr and the Tmin used in freezing tests.
Factors Affecting Growth and Harvest Index in Pea (Pisum sativum L.) Varieties Differing in Time of Flowering and Maturity
Authors: Chandra R. , Polisetty R.
Published: April 2008

Three varieties of Pea (Pimm sativum L.) viz. EC33866 (early), P‐116 (medium) and T‐163 (late), differing in their flowering and maturity times, were taken for this study. The early variety recorded lower dry matter, CO2 exchange rate and lower yield. The harvest index (HI) was the highest (44 %) in this variety. Though medium and late varieties did not differ significantly in dry matter accumulation and pod yield, they differed in their HI. The HI in the medium variety is 42 % but in the late variety it is only 36%.

The late variety maintained high leaf area, leaf dry weight, high shoot/root, shoot/nodule and root/nodule ratios, increased nodule dry weight and maximum glycolate oxidase activity. But acetylene reduction activity was low, and the harvest index was lowest. On the other hand, in the early variety the dry matter accumulation was lowest but HI was highest. The major reasons for high HI in this variety were translocation of photosynthates to reproductive organs and lower photorespiration as indicated by low glycolate oxidase activity.
Soil Microbial Biomass and Enzyme Activities as Influenced by Organic Manure Incorporation into Soils of a Rice‐Rice System
Authors: Dinesh R. , Dubey R. P. , Prasad G. Shyam
Published: April 2008

A fertilizer management study involving incorporation of poultry manure, farm yard manure, sesbania and gliricidia into soils of a rice‐rice system was initiated in May 1993. In order to determine the effects of organic manure incorporation on soil microbial biomass and enzyme activity, soils were collected from the respective plots at the end of the second rice crop in February 1996. and were incubated with and without the respective organic manure at the rate of 15 Mg ha−1at 25°C, under submergence. The total viable microbial counts, bacteria, actinomycetes, N flush, biomass C and activities of urease, amidase, acid and alkaline phosphatase, dehydrogenase and L‐glutaminase were determined after 60 days of incubation.

Soils freshly amended and soils previously amended with organic manures registered significantly greater microbial biomass and enzyme activity than the unamended control. The microbial biomass and enzyme activity, however, varied with the type of organic manure incorporated into the soil. Except for acid phosphatase, which showed slight inhibition, all the other enzymes were activated to different degrees by organic manure incorporation. A significant and positive relationship of enzyme activity with organic C and total N suggested that the addition of organic manure to soils increased C turnover, N availability and microbial activity which in turn led to greater enzyme synthesis and accumulation in the soil matrix.
Interactive Effect of Nitrogen and Sulphur on Growth and Yield of Rape‐seed‐Mustard (Brassica juncea L. Czern. and Coss. and Brassica campestris L.) Genotypes
Authors: Ahmad A. , Abraham G. , Gandotra N. , Abrol Y. P. , Abdin M. Z.
Published: April 2008

A simple randomized field experiment was conducted to assess the growth and yield of rape‐seed‐mustard in relation to sulphur and nitrogen interaction. Three levels of sulphur (0, 40 and 60 kg ha−1) in combination with three levels of nitrogen (60, 100 and 150 kg ha−1) were tested as treatments, T1, T2, T3, T4, and T5. Results indicated significant favourable effects of sulphur and nitrogen, when applied together, on yield components, seed and oil yield. Maximum response was observed with treatment T3 (having S and N of 40 and 100 kg ha1, respectively). Percentage oil content of seed was maximal at T4 (having S and N of 60 and 100 kg ha1) in both cultivars. The increase in N dose from 100 to 150 kg ha−1 without any change in applied S, i.e. 60 kg ha1 (T5), decreased the percentage oil content. The seed and oil yield, however, were similar to T3. Favourable responses of S and N interaction on leaf area index, rate of photosynthesis and biomass production were also observed.
Response of Wheat and Barley during Germination to Seed Osmopriming at Different Water Potential
Authors: Al‐Karaki Ghazi N.
Published: April 2008

Pre‐sowing osmotic seed treatments were evaluated as a means of improving water uptake and germination performance of wheat (Triticum durum L. cv. Hourani‐27) and barley (Hordeum vulgare L. cv. ACSAD 176) under four levels of water potential (0, –0.4, –0.8 and –1.2 MPa) created by using polyethylene glycol 8000. Seeds were osmoprimed in aerated solutions of 0.0, 0.2, 0.4 or 0.6 M KCl at 24 ± 2°C overnight and then rinsed and dried. Rate of water uptake by seeds was higher in osmoprimed than untreated seeds of both crops regardless of the water potential level. Decreasing water potential (more stress) adversely affected rate of water uptake in seeds of both crops. Seeds osmopriming increased germination percentage and decreased time to 50% germination at high water potentials (low stress), whereas the germination at low water potentials (more stress) was not affected by osmopriming treatments. The effect of osmopriming on rate of water uptake, germination percentage, and time to 50% germination was more pronounced in wheat than in barley. Reduction in the lag time of imbibition may be accounted for in part by some germination rate enhancement in the osmopriming treatments. Fresh weight and length of shoots (plumules) and roots (radicles) were enhanced in osmoprimed seeds in comparison to untreated seeds, in both crops at high water potentials (0 and – 0.4 MPa). As water potential in the medium decreased, these traits were inversely affected regardless of osmopriming treatment. Longer roots in wheat compared to barley were noted in the positive osmopriming treatments at high water potentials (0 and – 0.4). These results might indicate that wheat is more responsive than barley at relatively high water potentials to osmopriming through rapid penetrating root system.