bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparisons of Methods of Estimating the Seed Filling Period in Soybeans*
Authors: Pfeiffer T. W. , Suryati D.
Published: April 2008

An experiment was conducted at Lexington, K.Y., USA (38° N latitude) utilizing 18 soybean (Glycine max [L.] Merr.) genotypes in three stem termination groups (determinate, indeterminate, and segregating) to compare eight methods of estimating seed filling period in terms of 1) ability to differentiate among genotypes, 2) lack of bias towards any stem termination type, 3) ease of measurement, and 4) consistency across environments. Growth stage estimates R1 to R8, R4 to R7, R5 to R7 and the reproductive period duration (estimate of the time period of the linear increase in harvest index) detected significant differences among the seed tilling periods of the genotypes. Significant stem termination group measurement method interactions were present, but because the indeterminate stem termination group had a shorter seed filling period than the other two groups for most methods, we were unable to evaluate bias towards stem termination type. The growth stage methods required 4x to 10x less time for data collection than the effective tilling period and reproductive period duration methods. Only the R4 to R7 and R5 to R7 growth stage estimates had significant rank correlation coefficients among genotypes across years. From this and previously published evidence we recommend using the R5 to R7 estimate of seed filling period following the separation of genotypes into stem termination classes for the selection of soybean genotypes based on seed filling period duration.
Soybean Genotypic Variation for Nitrogen Fixation
Authors: Reddy G. B. , Faza Alexandra
Published: April 2008

Eighteen soybean (Glycine max [L.] Merr) cultivars from maturity groups V and VI were screened with two Bradyrhizobium japonicum strains (USDA 110 and TAL 378) in the greenhouse to determine N2 fixation (C2H2: reduction) rates. Antibiotic resistant markers were used for observing nodule occupancy. Cultivars L.‐76‐0132, PI 159319, Hoberland, Lee, PI 22173 and Centennial showed high nitrogenase activity of 6.25, 5.54, 17.43, 4.73, 6.94, and 4.81 μM C2H4/Pl/hr, respectively. Cultivars PI417419, PI 230978, Ogden, and FC 31665 showed low nitrogenase activity of 1.51, 0.80, 0.62 and 0.94 μM C2H4/Pl/hr, respectively. The data from this screening experiment suggest that the N2 fixation varied among genotypes and all the nodules were occupied by the inoculated strains only. Rhizobial strain effect was observed among soybean cultivars (MGVI).
Chemical Composition and In Vitro Dry Matter and Organic Matter Digestibility of Triticale Forage
Authors: Fearon A. L. , Felix A. , Sapra V. T.
Published: April 2008

Triticale (X Triticosecale Wittmack) cultivars Council and Morrison were planted in mid‐September (early planting) and mid‐October (late planting) in 1984 at the Alabama A &: M University‐experiment station for studying organic matter digestibility. The plants were harvested at the tillering, milk and dough stages and samples were subjected to proximate analyses and in vitro digestibility tests. A 1,100 lb Hereford steer fitted with a permanent ruminal fistula was used as the rumen fluid donor. In vitro dry matter digestibility (IVDMD) and in vitro organic matter digestibility (IVOMD) were determined by Moore's modification of the two‐stage digestion technique of Tilly and Terry (1963). Triticale cultivar Council was comparable to Morrison for phosphorus (P), dry matter (DM), ceil wall content, IVDMD and IVOMD. Crude protein (CP) and ash content were significantly higher for Morrison than for Council, while gross energy (GE) was significantly higher for Council than for Morrison. Both early and late plantings showed similar levels of DM, GE, P and cell wall constituents. However, CP and ash content were higher for early planting than late planting. The tillering stage was consistently higher than the milk or dough stages for CP, ash, P, calcium (Ca), IVDMD and IVOMD. The results indicate that the milk stage was superior to the tillering or dough stages in DM and cell wall content. Results from this study showed no significant differences in digestibilities for two triticale cultivars and planting dates. Based on the higher DM content at the milk stage, it seems that milk stage in triticale would be more acceptable as a forage than the tillering or dough stage.
On the Variability of Harvest Indices
Authors: Hühn M.
Published: April 2008

The harvest index Z is defined, for example for cereals, as the ratio between grain yield X and biological yield Y: Z = X/Y. For many purposes the variance of Z is of major interest. In this paper several approximations for this variance are derived and their accuracy was investigated. These explicit formulae depend on some characteristics (means, variances or coefficients of variation, covariances or correlations) of the component variables grain yield X and biological yield Y. It is shown that for most practical applications the approximation v2z = v2x + v2y ‐ 2rvxvy provides a sufficient accuracy for numerical calculations (vx vy and vz are the coefficients of variation for grain yield X, biological yield Y and harvest index Z and r denotes the correlation coefficient between X and Y). Some conclusions on the relations between vx, vy and vz are derived.

Finally, all the theoretical investigations and results are demonstrated and applied to a numerical example of winter‐rapeseed data.
Nitrogen Distribution and Dry Matter Accumulation in Oilseed Rape (Brassica napus L.) as Influenced by N Nutrition
Authors: Ogunlela V. B. , Kullmann A. , Geisler G.
Published: April 2008

A greenhouse experiment was conducted to study N distribution and dry matter accumulation in oilseed rape (Brassica napus L. cv. Callypso) in relation to N supply. Three levels of N supply (30, 100 or 170 ppm N) were tested as treatments. Stem and leaf dry weights increased at higher N fertility up to 170 ppm N but root dry weight did not respond to N. Dry matter yield during the vegetative phase was seriously depressed by N deficiency. Most of the plant dry matter was accumulated in the lower segments of the stem and roots. Dry weights of stem and axillary branches increased significantly as N supply increased up to 100 ppm N. Although hull dry weight increased with N supply up to 100 ppm N, seed dry weight did not respond to N. High root N concentration was maintained at 100 or 170 ppm N; but declined as plants advanced in age. N content of leaf and stem also declined with time. Leaf growth was particularly responsive to N fertility and N was mobilised from the older to the younger leaves over time. Nitrogen content of hulls and seeds increased significantly with N supply but N was translocated from the vegetative into the generative organs or from older into younger tissues during pod development. There is need for proper N fertility management in order to achieve successful rape production.
Cassava and Maize Intercropping Systems ‐ The Effects of Varieties and Plant Populations
Authors: Ezumah H. C. , Lawson T. L.
Published: April 2008

Maize dominated cassava irrespective of cassava or maize growth habit and the optimum maize population giving the highest production based on relative yield total or land equivalent ratio varied with maize variety in a tropical Alfisol at Ibadan, transition humid/subhumid zone in West Africa. The sparsely vegetative, early maize supported higher intercrop maize population (up to 80,000 ha−1) than the late maturing, highly vegetative TZSRW. Because there is a compensatory relationship in the yields of the two crop components, the choice of an appropriate crop type and maize population in cassava + maize intercrop system will depend on the relative economic importance of each crop component.
Photosynthetic Response of Wheat to Soil Water Deficits in the Tropics
Authors: Brar G. S. , Kar S. , Singh N. T.
Published: April 2008

The changes in photosynthetic rate and translocation of photosynthates in winter wheat (Triticum Aestivum L.) grown in lysimeters were studied, in response to periodic soil water deficit during late tillering and flowering stages. Soil water deficits were imposed to previously nonstressed plants during late tillering and flowering states. Timing of irrigation was scheduled according to the ratio between irrigation water applied and cumulative pan evaporation (IW/CPE) of 0.75 (low deficit), and 0.5 (moderate deficit), as well as by suspending irrigations after crown root initiation stage (severe deficit). To determine the rate of photosynthesis, a short radioactive pulse of 14CO2 with 300 ppm concentration was given to second leaf from the top at tillering, and to the flag leaf at flowering stages for 20 second exposure time. The translocation of photosynthates was estimated by scanning 14C activity in different plant parts. In late tillering the midday Photosynthetic rate (PR) was significantly 3 mg CO2 dm−2 h−1 lower under low water deficit (WD1) than under zero water deficit (WD0). Under higher stress conditions, soil water acted as a limiting factor to keep the rate from rising above 13.2 during stress at late tillering (WD2), 14.5 flowering (WD4), and 10.0 mg CO2 dm−2 h−1 for stress at both the growth stages (WD5), respectively. The difference in daily accumulated photosynthesis (8 h), between stressed and nonstressed were 15, 40, 42, and 77 mg CO2 dm−2 h−1 respectively at WD1 WD2, WD4, and WD5. The retention of 14C in flag leaf decreased considerably after 24 hours of exposure time when the labelled assimilates were translocated in bulk to the ear head. Under stressed condition a general trend was observed for upward translocation of assimilates towards the ear, even from the stem and root. The percent 14C activity observed in ear after 24 hours was greatest in severely stressed plants. The photosynthetic rate is reasonable predicted by midday LDR and surface moisture.
Ein Beitrag zur Stickstoffwirkung nach unterschiedlichen Verfahren stabilisierter Klärschlämme*
Authors: Schkrer H. W. , Steffens Do.
Published: April 2008

A distribution to the availability of the nitrogen in sewage sludges stabilized with different processes

In two pot experiments the availability of the nitrogen in sewage sludges stabilized with different processes was investigated. Further it was examined whether the Quantofix‐N‐Volumeter (method for rapid determination of ammonia in slurries) is able to determine the plant available nitrogen in sewage sludge.

The following results were obtained:

In the experiment where same amounts of total N were applied as sewage sludge a highly significant correlation existed between the amount of NH4‐N applied and the N uptake of the plants.

When equal amounts of NH4‐N were applied the N uptake was lowest with the sewage sludges with a high relative part of NH4‐N of the total N (thermophile‐aerob; mesophile‐anaerob). However the reason for this result was not only the lower application rate of total N with these sewage sludges but also the lower efficiency of the organically bound nitrogen.

A very highly significant correlation existed between the application rate of organically bound nitrogen and the N uptake.

The values of nitrogen in sewage sludges measured by the rapid method gave information about the plant available nitrogen in the year of application.

A close quantitative agreement existed between the available nitrogen determined with the rapid method and the values calculated with the formula of Furrer and Bolliger (1978).
Radio Tracer Studies on P Use Efficiency in a Rice Based Cropping System
Authors: Sreekantan Lekha , Palaniappan SP.
Published: April 2008

Tracer studies using 32P labelled superphosphate and rock phosphate were conducted in microplots in a field experiment on rice‐rice‐greengram cropping system. The trial revealed that in all the rice crops studied, P uptake and P use efficiency were higher in superphosphate treated plots than in rock phosphate applied ones. P uptake was improved with organic manuring through application of green manure or crop residues like long rice stubbles. While superphosphate performed well either with or without organic manuring, rock phosphate performed fairly well only with organic manuring. Fairly good P use efficiency could be obtained in the system when green manuring and rock phosphate application in the first crop was followed by superphosphate and long stubble incorporation in the second crop. Apparent recovery values also showed nearly the same results. But tracer studies were found to be definitely superior in the evaluation of fertilizers.
Zum Einfluß von Saatzeiten, Saatstärken und Sorten auf agronomische Merkmale von Winterweizen in einem System mit geringer Betriebsmittelzufuhr von außen
Authors: Stöppler H. , Kölsch E. , Vogtmann H.
Published: April 2008

The influence of sowing date, seed rate, and variety on agricultural characteristics of winter wheat in a low external input system

Growth conditions of winter wheat in agricultural low external input systems, e.g. ecological agriculture, are very different compared to conventional agriculture (mineral nutrition, impact of diseases, competition of weeds). In 1986, 1987, and 1988 the influence of sowing date and seed rate on crop development and grain production was studied with two varieties of winter wheat in field experiments in Northern Hessia.

Drilling after the first decade of October decreases grain yield of both varieties significantly. The decrease was due to poor emergence, low plant densities, and low grain weights. Tillering could not compensate low plant densities, presumably because of low mineralization of nutrients in cold soils during respective growth stages.

Variation of seed rate (350, 500, and 650 viable seeds/m2) had little influence on grain yield. Low plant densities and low numbers of ears per nr after sowing in the end of October could not be improved satisfactorily by increased seed rates.

The ability of varieties of winter wheat to compensate unfavourable growth conditions due to “late” sowing varies considerably. Cultivars which are able to develop a high plant density seem to be more suitable for delayed sowing dates, as compared to varieties which own a high grain weight.

Further investigations concerning wheat production are needed to optimize agricultural low external input systems. Especially sandy soils with quick response to increased ambient temperature, and sites with favourable growth conditions in late autumn and early spring should be considered.
Soybean‐Rhizobium Combination for Tolerance to Low P‐High Aluminum
Authors: Taylor R. W. , Sistani K. R. , Patel S.
Published: April 2008

Two greenhouse experiments were conducted to evaluate the performance of selected soybean‐Bradyrhizobium combinations in a soil having low P‐high aluminum stresses under controlled conditions. Growth parameters such as plant height, nodule numbers, dry weight, nitrogenase activity and seed yield were used as an index. Three selected acid (low P‐high Al) tolerant (Essex, Tracy and Bedford) and three sensitive (Peking, Hill and McNair 600) soybean (Glycine max) varieties were sown in each pot. Three of the most tolerant strains of Bradyrhizobium (USDA 6, 110, 122), a mixture of these strains, and a commercial inoculant (Nitragin) were used to inoculate the Hartselle sandy loam soil. The results indicated that soil acidity significantly affected the soybean Bradyrhizobium symbiosis. The combination of variety Tracy plus Nitragin (mixed‐strain) produced the highest and variety Peking plus mix‐strain Nitragin the lowest plant height at all pH levels. Plants inoculated with Nitragin had higher shoot dry weight and seed yields. Variety Essex in combination with Nitragin produced the highest seed yields at all pH levels. Plants inoculated with Nitragin developed significantly more nodules than the other strains except for variety Peking. There was no significant difference in total nodule numbers between tolerant and sensitive soybean varieties at all soil pH levels except for Nitragin. Shoot total N did not increase by increasing the pH level or by using different variety‐strain combinations.
Fatty Acid Composition of Oil from Erucic Acid‐Free Summer Rape Seed (Brassica napus L.) in Relation to Nitrogen Nutrition and Raceme Position
Authors: Ogunlela V. B. , Kullmann A. , Geisler G.
Published: April 2008

A greenhouse study was conducted to determine the effect of nitrogen supply (30, 100 or 170 ppm N) and raceme position on the fatty acid composition of oil extracted from erucic acid‐free summer rape seed (Brassica napus cv. Callypso). The seven fatty acids analyzed for include palmitic, palmitolcic, stearic, oleic, linoleic, linolemc, and eicosenoic acids; of which oleic (59.54–64.84 %) and palmitoleic (0.36–0.4 %) acids were the highest and lowest levels respectively. Generally, N nutrition influenced fatty acid pattern only to a little extent. Palmitic, palmitoleic and stearic acid levels were increased by 170 ppm N, depending on raceme position, but oleic and linolenic acids were unaffected. Similarly, 170 ppm N produced the highest fatty acid levels in seeds on the lower portions of racemes, with the exception of oleic acid. This was also true in the case of the upper portions of racemes, except that 30 ppm N produced the highest levels of oleic and linoleic acids in rape seeds. Under the optimum N supply level (i.e. 100 ppm N), position of raceme on the rape plant did not greatly influence the levels of different fatty acids in lipids.
Sustainable Agricultural Systems: Concepts and Definitions
Authors: Geng S. , Hess C. E. , Auburn J.
Published: April 2008

The evolution of concepts and definitions of agricultural systems over time is presented. Inputs of an agricultural system are classified as components and activities. A component is either a resource or a technology. The activities are the management of resources and the application of technology in the production process. The outputs of a production process will include both the targeted product and the environmental impact. When these terms are used to describe an agricultural system graphically, the dynamic aspects of the system can easily be illustrated and problems associated with the system can be properly identified. Sustainable agriculture is recognized as conveying certain objectives or delineating certain requirements of an agricultural system, in terms of both the input and output of the system. These objectives are: (1) producing necessary quantity of high quality food and fiber; (2) profitable to the grower; (3) conserving nonrenewable resources; and (4) harmonious with biological, physical and social environments. These objectives have long‐term implications and attempt to secure the future viability of agriculture. Therefore they embrace the concept of sustainability. The difficulty of constructing such a system is that not all the objectives are compatible; compromise or trade‐offs among the objectives are often necessary in developing a workable sustainable system. Progress and improvement can always be made through research, but no perfect system can realistically be constructed. General research issues in sustainable agriculture are discussed. Priorities in developing appropriate technology based on sound biological principles and laws of physics and mechanics for pest and weed control are suggested.
Effect of Pre‐ and Post‐Kinetin Treatments on Salt Tolerance of Different Potato Cultivars Growing on Saline Soils
Authors: Abdullah Zaibunnisa , Ahmad Rafiq
Published: April 2008

Different potato cultivars were subjected to 10 −6M kinetin treatment prior to the transplantation in saline soils (pre‐kinetin treatment) and to the plants already growing on the saline soils (post‐kinetin treatment). The kinetine when applied before the exposure of plants to saline soils showed promotory effects on growth, tuberization and some biochemical parameters of potato at 0.5 % salinity. The degree of inhibition in number of tubers and yield was reduced at 1 % salinity due to pre‐kinetin treatment. The level of proline, reducing sugars and sodium was increased in different plant parts to maintain the osmoregulation. However, kinetin did not play any specific role in reducing down the increase in proline content resulted due to salinity. The level of K+ was found to be higher at low salinity in all the cultivars of potato. Higher concentrations of proteins and enhanced activity of starch synthetase at low level of salinity suggest the salutary effect of Na+ in metabolic functions of plant cells. The nitrate reductase (NR) activity was appeared to be more sensitive than starch synthetase. This could possibly be due to the localization of the enzyme and the cellular concentration of toxic substances increased under stress. Total Glyoalkaloids (TGA) content was reduced at both the salinity levels irrespective of kinetin treatments. On the contrary Na+ content was increased in all the treatments of kinetin at both levels of salinity. During this study cvs. Red Lasoda, Patrones and Atom alue approved to be more tolerant as compare to rest of the cultivars tested. This could be a combined effect of genetic setup, amendments in saline soils and pre‐kinetin treatments of plants exposed to various regimes of salinity. Furthermore it is argued that salt tolerance limit can be extended upto certain level of salinity by pre‐kinetin treatment in potato plants.
Dry Matter Production and Distribution of 14C‐Assimilates of Spelt (Triticum spelta L.) and Wheat (Triticum aestivum L.) as Influenced by Different Temperatures Before and During Grain Filling
Authors: Rüegger A. , Winzeler H. , Nösberger J.
Published: April 2008

Morphological characters, dry matter production and the distribution of 14C‐assimilates of the flag leaf were investigated on two spelt varieties (Ostro and Rouquin) and two wheat varieties (Arina and Probus) under controlled conditions. Single plants were grown at three different temperature regimes (18/13 °C continuously = T1; 18/13 °C until anthesis and 13/8 °C after anthesis = T2; 13/8 °C until anthesis and 18/13 °C after anthesis = T3).

Spelt produced up to 10 tillers more per plant than wheat. However, tiller reduction was also higher for spelt so that both species finally had a similar number of ears per plant.

Under favourable conditions (T1) the large single grain weight of spelt, did not fully compensate for its lower kernel number. As a result, the grain yield per ear was 12 % higher in wheat than in spelt. Under low temperatures during grain filling (T2), wheat did not fill it's kernels completely; thus, under these conditions grain yield of spelt was 12 % higher. It seems that the kernel growth of spelt is less limited as compared to wheat (maximum single grain weight reported at T2: Ostro 67 mg; Rouquin 63 mg; Arina 53 mg; Probus 47 mg [SE 1.8]).

The distribution of the l4C from the flag leaf was similar for both spelt and wheat. At anthesis the highest amount of 14C was found in the last two internodes. Three weeks after anthesis, the ear of the main culm was the most important sink (exception T2). Between 48 h after the labelling with 14CO2 and maturity, different amounts of assimilates were translocated from the stem into the ear of the main shoot and partially also into the tillers.

In conclusion significant differences were found between spelt and wheat in tiller formation, grain number per ear, single grain weight and grain yield. Especially under low temperature during grain filling kernel growth of spelt was less limited than that of wheat.
Modification of Leaf Photosynthesis by Foliar Application of Aliphatic Alcohols
Authors: Malik C. P. , Singh Parmil , Kaur Sukhvinder , Malik Sonali , Parmar Usha , Grewal Manjit , Bhatia D. S.
Published: April 2008

A decrease in net photosynthesis (Pn) in leaves of main shoot with age (7‐28 days after opening) at two stages of peanut (Arachis hypogaea L. var. M‐13) reproductive growth (70 and 90 DAS) is reported. Pn rate decreased with advance in age of leaves, the decline was rapid during peak period of pod filling (90 DAS). Foliar application with aliphatic alcohols, maintained the chlorophyll content and enhanced PEP carboxylase activity. The present studies suggest that aliphatic alcohols enhance functional capabilities of leaf for a larger duration and hence maintain the supply of photoassimilates to the developing kernels of peanut leading to increased yield.
Transport of 14C‐Sucrose and 14C‐Benzyl Adenine in Winter Wheat (Triticum aestivum L.) in the Pre‐Anthesis Period
Authors: Borkovec V. , Procházka S. , Ibrahim M. El.‐D.
Published: April 2008

The transport and distribution of 14C‐sucrose and 14C‐BA were studied in internode segments with ear of two winter wheat cultivars with a different mass of kernels in the period prior to anthesis. Both labelled substances were transported intensively into all the developing parts of the car, namely the rachis became the main site of 14C‐BA accumulation. While the difference in the transport of l4C‐sucrose among the cultivars was not unambiguous, a more intensive transport of 14C‐BA was observed in the cultivar with a simultaneously higher mass of 1000 kernels. The higher level of zeatin and zeatin riboside in kernels detected in this cultivar suggested that in the period before anthesis it could accumulate (due to intensive transport, probably from the roots) an important part of cytokinins, available for the early stages of kernel development.
Abscisic Acid and Proline Levels in Cold Hardened Winter Wheat Leaves in Relation to Variety‐Specific Differences in Freezing Resistance
Authors: Dörffling K. , Schulenburg S. , Lesselich G. , Dörffling H.
Published: April 2008

Changes in dry weight, osmotic potential, abscisic acid and free proline contents were measured during cold hardening of nine winter wheat varieties differing in freezing resistance. During the first weeks of cold hardening dry weight and proline levels increased and the osmotic potential decreased parallel to the development of freezing resistance. Dry weight reached a broad maximum between the seventh and tenth week of hardening. ABA levels had a sharp maximum around the seventh week of hardening, when the dry weight increase began to cease. Maximal levels of proline were observed seven to ten weeks after the start of cold hardening. The mean and final dry weights, the mean, maximal and final proline contents, as well as the maximal ABA contents of the nine varieties correlated significantly with freezing resistance measured at the end of the hardening period.

The possible use of proline and of ABA as biochemical markers for freezing resistance in winter wheat breeding is discussed.
Genetic Variability for Net Photosynthesis in Finger Millet (Eleusine coracana Gaertn) Genotypes An Approach to Identify High CER Types
Authors: Shankar A. G. , Udaya Kumar M. , Prasad T. G.
Published: April 2008

Germplasm lines of finger millet (400 lines) with diverse genetic background were screened to identify high CER and CGR genotypes. Considerable variation was noticed in LA, biomass and all the growth and yield attributes but range in stomatal frequency was relatively less. The difference in plant stomatal number was more due to variation in LA but not the frequency. Since high TDM is a primary criteria for achieving higher grain yield, from amongst the high biomass types, genotypes differing in LA/DM ratios but with similar DM and HI were selected. In six genotypes each from low and high LA/DM group which showed stability across the environment, gas exchange characteristics were studied. The CER in low LA/DM types was 45 per cent higher. A significant negative relationship (r = ‐0.87) exists between CER and LA/DM ratios. Higher net assimilation rate in these genotypes therefore could be attributed mainly due to CER rather than the dark respiration.

An approach to identify high CER types with high CGR and low plant conductances from the germplasm lines has been proposed. These conceptual types will have high CGR but with low functional LA, thus low transpiration leaf surface. These conceptual types will have specific advantage under rainfed water limited conditions.
Influence of Oil Seed Rape and Faba Bean as Green Manure on Nitrogen Utilization in a Spring Cereal Rotation
Authors: Jung J. , Dressel J. , Kuchenbuch R.
Published: April 2008

A lysimeter study was conducted to investigate how nitrogen uptake of spring wheat and oats and N leaching losses are differing when either oilseed rape or faba bean are grown as green manure. The experiment was conducted during 1982–1988, and fertilizer applied to the cereals was either farmyard manure, FYM, (6 and 12 g N/m2/year) or mineral fertilizer, MiF, at a rate of 6 g N/m2. On average of the 7 year period faba bean increased N uptake of the cereals fertilized with FYM at harvest by 3–4 g/m2. Differences between the two application rates were negligible. N‐leaching losses increased twofold when faba bean was grown instead of oilseed rape. Growing faba bean after cereals supplied with MiF, too, increased N uptake of the cereals and significantly increased leaching losses.
Influence of a Triazole Plant Growth Regulator on Root and Shoot Development and Nitrogen Utilisation of Oilseed Rape (Brassica napus L.)
Authors: Bruns Gundula , Kuchenbuch R. , Jung J.
Published: April 2008

A factorial experiment with 3 nitrogen (N) levels and 4 application rates of the triazole type plant growth regulator (PGR), BAS 111 W = l‐phenoxy‐3‐(1H‐1,2,4‐triazol‐1‐yl)‐4‐hydroxy‐5,5‐dimethylhexane, was conducted in hydroponics to study the influence on N uptake and morphological changes of oilseed rape. The following results were obtained:

–Increased N level of the nutrient solution increased plant height and root and shoot weight. Enhanced N uptake caused a higher N concentration of root and shoot.

–Increasing PGR application rates reduced plant height and shoot biomass production; this reaction was stronger at higher doses of N.

–Root weight, root length, root diameter and root surface area were increased by N application. None of these parameters was significantly altered by the PGR. This resulted in increased root‐shoot‐ratios at higher PGR rates.

–As a consequence of reduced shoot production PGR application resulted in increased concentrations of N. The root reacted similarly but to a lesser degree.
Thermal Infrared Radiation for Assessing Crop Water Stress in Wheat
Authors: Kumar Alok , Tripathi R. P.
Published: April 2008

Field studies on differentially irrigated wheat (Triticum aestivum L.) crops were conducted at Pantnagar for two years to evaluate the use of thermal infrared radiation to detect crop water stress. Data show that the stress‐degree‐day index (mid day canopy‐air temperature difference) is influenced by environmental variability other than soil moisture. Improvement in the stress‐degree‐day (SDD) index was achieved by including the measurements of vapor pressure deficit and approach was termed as plant water stress index (PWSI). Observations indicated that daily variation in SDD values due to meteorological changes was removed through PWSI. Better correlation was found between soil‐induced leaf water potential and plant water stress index than between total leaf water potential and plant water stress index. It is concluded that remote sensing of thermal infrared radiation offers a promising technique which can be incorporated into irrigation management programme.
Effects of Stocking Rate and Overseeding with Red Clover on Productivity of Native Pasture Continuously Grazed by Yearling Steers
Authors: Bryan W. B. , Prigge E. C.
Published: April 2008

Overseeding with red clover (Trifolium pratense L.) and stocking rate are factors that can affect composition and production of hill land pasture. A grazing experiment utilizing yearling beef steers (Bos taurus) was conducted using 3, 4, and 5 yearling steers ha−1 (285 kg), on native pasture (predominantly Poa pratensis L.) overseeded with red clover and non overseeded. Paddocks of 1 ha were continuously set stocked from mid May to the end of Sept. Herbage mass, herbage consumed and the percentage of legumes, grasses, dead material, and non‐leguminous broadleaf plants were recorded. Animals were weighed at the initiation and end of each grazing season and at 4 week intervals. Overseeding increased legume content 4‐fold the seeding year but much of this increase was lost the following year. Herbage mass was greater on overseeded pasture the year following seeding but no effect on animal productivity was found. Stocking rate did not affect percentage legume but the proportions of other broadleaf plants increased at high stocking rates. Average daily gain as well as total gain ha−1 was greatest at 4 steers ha−1.
Cassava and Maize Intercropping Systems — The Effects of Varieties and Plant Populations
Authors: Ezumah H. C. , Lawson T. L.
Published: April 2008

Maize dominated cassava irrespective of cassava or maize growth habit and the optimum maize population giving the highest production based on relative yield total or land equivalent ratio varied with maize variety in a tropical Alfisol at Ibadan, transition humid/subhumid zone in West Africa. The sparsely vegetative, early maize supported higher intercrop maize population (up to 80,000 ha‐1) than the late maturing, highly vegetative TZSRW. Because there is a compensatory relationship in the yields of the two crop components, the choice of an appropriate crop type and maize population in cassava + maize intercrop system will depend on the relative economic importance of each crop component.

Cassava und Mais Intercropping‐Systeme — die Bedeutung von Sorten und Bestandes‐dichten

Auf der Grundlage einer zweijährigen Unter‐suchung auf einem tropischen Alfisol zu Iba‐dan, Südwestnigeria, der charakteristisch für die humide/subhumide Übergangszone West‐afrikas ist, konnte gezeigt werden, daß Mais im Vergleich zu Cassava überlegen war, unabhan‐gig vom Cassava‐ oder Maiswachstumsverhal‐ten. Die optimale Maisbestandesdichte ergab in Abhängigkeit von der Maissorte die höchste Produktion in bezug auf relativen Gesamter‐trag bzw., land equivalent ratio“. Der schwach vegetativ entwickelte frühe Mais er‐laubte eine höhere Intercrop‐Bestandesdichte (bis zu 80 000/ha) als die späten Maissorten mit einer starken vegetativen TZSRW. Im Hin‐blick auf die kompensatorische Beziehung in den Erträgen der zwei Fruchtarten wird die Wahl eines geeigneten Fruchtartentyps und einer geeigneten Maisbestandesdichte in dem Cassava + Mais Intercrop‐System abhängig sein von der relativen Bedeutung der beiden Kulturpflanzenarten in der Mischung für den Farmer.
Effect of Growth Regulators on the Productivity of Some Major Oilseed Crops
Authors: Ghosh R. K. , Mandal Bikash Kumar , Chatterjee B. N.
Published: April 2008

A number of field experiments were conducted at the Viswavidyalaya Research Farm during 1984–85 to 1986–87 to study the effects of five growth regulators viz. Miraculan (a triacontanol based growth stimulant), Nutron (1‐triacontanol growth stimulant), Planofix (α‐napthylacetic acid), Paras or Mixtalol (Higher alcoholic carbon compounds) and N‐triacontanol on productivity of five different major oilseed crops viz. rapeseed (Brassica campestris L. var. yellow sarson), mustard (Brassica juncea L. Czern and Coss), sesame (Sesamum indicum L.), linseed (Linum usitatissimum L.) and safflower (Carthemus tinctorius L.). Results showed the positive influence of growth regulators on the productivity of crops (10–40 % increase in yield); however the influence was not consistent over the years. N‐triacontanol when tried on mustard only improved the grain yield significantly, more so when applied with paras or planofix, sesame was most influenced by spraying planofix and paras. Nutron favourably influenced safflower and linseed. The test weight of grains followed by the number of pods/plant were influenced most by the application of growth regulators. Inconsistency in results over the years, however, need further investigations on the timing of spraying.
Heat Unit Requirement and Prediction of Developmental Stages in Soybean
Authors: Ramesh P. , Gopalaswamy N.
Published: April 2008

Field experiments were conducted at Coimbatore, India with four dates of sowings in each of three seasons to determine the duration of phenological phases, heat unit requirements and evaluation of heat units to predict the developmental phases of Soybean (Glycine max [L.] Merr.). The variations in development of different phenological phases and maturity of Soybean due to season and sowing dates was manifested by varied accumulation of heat units calculated. There was a linear relationship between the number of days to flower initiation and cumulative day length. Growing degree days (GDD) were better predictors for development of phenological phases whereas maturity was controlled by Calender days and was closely followed by GDD. Photothermal units were the next best predictors for soybean developmental phases.
Yield Stability of Winter Oil‐Seed Rape (Brassica napus L.) as Affected by Stand Establishment and Nitrogen Fertilization
Authors: Boelcke B. , Léon J. , Schulz R. R. , Schröder G. , Diepenbrock W.
Published: April 2008

The effects of stand establishment and nitrogen fertilizer on yield and yield stability of winter oil‐seed rape (Brassica napus L.) were investigated in two field experiments in north eastern Germany (Mecklenburg‐Vorpommern). During six years of testing from 1984/85 to 1989/90 three sowing dates (10 Aug, 20 Aug, 5 Sept) as combined with three plant densities (60, 100, 140 plants/m2 in autumn) were compared. Although seed yield did not respond to the main effects of these treatments, the two‐way classification resulted in significant differences from the average yield. August sowing combined with lower plant densities caused comparably high yields, while delayed sowing was somewhat effective only with higher plant density. Highest yield stability was achieved at early sowing when combined with lower plant densities. From 1986/87 to 1988/89 nitrogen top‐dressings were applied during early March, at start of stem extension and shortly before start of flowering at five locations. 200 kg N/ha in one dose resulted in lowest yield performance and enhanced instability. Contrastingly, the 240 kg N/ha treatment advanced yield stability regardless of split regimes. Nevertheless, split application to 100 kg N/ha + 50 kg N/ha + 50 kg N/ha also guaranteed that high yield performance and optimum yield stability were reached simultaneously and, that the total nitrogen input could be limited to 200 kg N/ha.
Soybean Nodule Development and Nitrogenase Activity During the Reproductive Phase: Statistical Modeling Approach
Authors: Bona S. , Voltan R. , Mosca G.
Published: April 2008

Nitrogenase activity during the reproductive phase of the Hodgson 78 soybean variety was tested in a growth chamber experiment to evaluate its relationships with number, weight and specific nitrogenase activity of the nodules. A multiple regression model is proposed.

The number of nodules did not change, while the total nodule dry weight increased with the increase of the average dry weight.

The regression model adopted showed that the main factors affecting the total nitrogenase activity were the specific activity and the nodule mass, but the former induces the wider variations.

Unlike other crops the counting of the nodules cannot be considered as an indirect predictor for nitrogen fixation.
Behaviour of the Root Nodules in Soybean in the Presence of Nitrogen: The Use of a Statistical Simulation Model
Authors: Bona S. , Maculan A. , Mosca G.
Published: April 2008

Two varieties of soybean were grown in large pots out of doors. At the R2 stage, a state of temporary root anoxia appeared caused by a heavy rainfall and in R3, nitrogen was applied. The nitrogenase activity of the nodules was measured at weekly intervals (ARA test).

During the vegetative stage, the number of nodules and their weight increased rapidly, although the anoxia caused a slowing down followed by a recovery in the successive stages (R3–5). The same effect was apparent in consequence of a late nitrogen fertilization; both varieties attaining values close to those of the control 15 days after the treatment. Nitrogenase activity also showed an inhibition caused by the anoxia but it appeared earlier. During the latest stages of the cycle (R6–7), the nitrogen treatment increased the rate of nitrogen fixation in Hodgson 78 only. The use of a multiple regression model allowed a verification that the parameters controlling nitrogen fixation acted in a similar way in both varieties. In the field, the weight of the nodules, both single and total, appeared to be particularly important in determining the total nitrogen fixation rate.
Gas Exchange and Water Relations in Water and Salinity Stressed Wheat Lines
Authors: Zerbi G. , Morgan J. A. , Lecain D. R.
Published: April 2008

Differences in gas exchange parameters i.e. carbon exchange rate (CER), transpiration (Tr), water vapor conductance (g) were investigated, under a controlled environment, in a semi‐dwarf (SD) Triticum aestivum line, its tall (TL) near isoline and the Payne (PA) variety characterized by small leaves. The plants were maintained in: (a) optimal substrate moisture condition (CTR); (b) salinized by watering with a 0.12 m NaCl solution (SLT); (c) water stressed by withholding waterings during a period of six days (STR); (d) stressed and salinized during the same period and with the same saline solution (S + S). CER and Tr were negatively affected by the stresses; SLT and S + S treatments had a higher WUE compared to their respective controls CTR and STR.

SD line had a better performance in terms of CER and WUE, particularly when water and salt stresses interacted. Leaf anatomy and assimilation/internal CO2 concentration curves contributed to explaining the SD performance.
Wurzelsystem, Biomasseproduktion, Bestockung und Ertragsbildung von vier Winterweizensorten in einem System mit geringer Betriebsmittelzufuhr von außen
Authors: Stöppler H. , Kölsch E. , Vogtmann H.
Published: April 2008

Rooting patterns, biomass production, tillering, and yield formation of four winter wheat cultivars in a low external input system

Growth conditions of winter wheat in agricultural low external input systems, e.g. ecological agriculture differ from those in conventional agriculture with regard to nutrient flow, impact of diseases, and weed competition. Knowledge of the dynamics of yield formation of winter wheat cultivars is very important for further development of such systems. During two growing seasons root growth, above ground biomass production, tillering, and yield formation were studied with four winter wheat cultivars of different periods of release at two ecologically managed farms in Northern Hessia. The results can be summarized as follows:

– In general, plant breeding did not lead to a reduced development of root systems or above ground biomass production in winter wheat (Stöppler et al. 1989 a). Modern wheat varieties develop an extensive root system in greater depth, which means better drought resistance.

– Not only root length densities, total root length, characteristics of tillering, and yield formation showed clear genotypic differences between the winter wheat cultivars, but also the development of root systems and above ground biomass production.

– Winter wheat cultivars with a high plant density seem to have a retarded root growth after tillering due to intra‐plant‐competition and late root growth during grain filling, whereas cultivars with a high ear weight develop an extensive root system before the grain filling period. At the beginning of this period, a great root length per culm seems to be most important to achieve a high ear weight. The results indicate that those cultivars with poor to medium tillering and high ear weight are very well adapted to the reduced nutrient flow in low external input systems of farming.

–In low external input systems, a satisfactory wheat crop need be established before tillering.
Effect of CCC on the Growth and Yield of Mung Bean (Vigna radiata [L.] Wilczek var. Guj‐2)
Authors: Shah T. , Prathapasenan G.
Published: April 2008

Pot experiments were conducted on mung bean by spraying 500, 1000 and 1500 ppm CCC, 14 days after the emergence of seedlings. Results showed that:

CCC application at 1000 and 1500 ppm led to stem shortening.

Dry weight of shoot system, leaf area, leaf thickness and total chlorophyll content were significantly increased by 1000 ppm CCC.

CCC at 1000 ppm increased amylase and invertase activity in the leaf tissue.

CCC at 1000 ppm increased the pod number/plant, seed number/pod, leading to increased seed yield/plant.

CCC had no effect on the 1000 seed weight.
Nitrogen Economy, Seed Production Efficiency and Seed Vigour of Panicum maximum by Intercropping of Pasture Legumes
Authors: Dwivedi G. K. , Sinha N. C. , Tomer P. S. , Dixit O. P.
Published: April 2008

A field experiment was conducted to evaluate the performance of pasture legumes (Desmanthus virgatus, Sesbania aegyptica, Macroptelmm autropurpureum, Desmodium tortuosum, Stylosanthes hamata used as in intercropped element) in terms of nitrogen economy, seed production efficiency and seed vigour potential of Panicum maximum– a grass based management maintained for 1986–88 at Research Farm, Indian Grassland and Fodder Research Institute, Jhansi under rainfed condition. Nitrogen economy under these intercropped pasture legumes was estimated on equating its value against nitrogen treatment i.e. 0, 10, 20, 30 and 40 kg N/ha. Among five intercropped legumes, Stylosanthes hamata and Macroptelium autropurpureum intercropping doubled the seed yield; S. aegyptica and M. autropurpureum brought out 46–55 per cent increase in biomass production over control value of 41.7 kg seed and 223.4 q biomass/ha respectively. These treatment showed 20–40 kg N/ha nitrogen equivalent value. Further more increased seed yield of Panicum maximum under intercropping was attributed to its better ear production, spike length and potential sink strength. Germination potential of harvested Panicum seeds under different treatments did not show variation among themselves. Potential seed production performance of Panicum maximum in the first year as compared to subsequent years might be due to its general transcript of plants and have some interaction with rainfall.
Some Comments on Gerechte Designs
Authors: Bailey R. A. , Kunert J. , Martin R. J.
Published: April 2008

In a companion paper we derived the correct analysis for gerechte designs with uncorrected errors. Here we show that this correct analysis cannot be justified by the usual randomization argument. However, when the regions are rectangular there is a randomization procedure which validates an analysis with three separate error terms. We also outline other developments in design and analysis that may be more satisfactory.