Spike Grain Research Articles

NITROGEN NUTRITION ON LEAF CHLOROPHYLL, CANOPY REFLECTANCE, GRAIN PROTEIN AND GRAIN YIELD OF WHEAT VARIETIES WITH CONTRASTING GRAIN PROTEIN CONCENTRATION

Wheat cultivars (‘AC Barrie’, ‘Brook Field’, ‘Hoffman’, and ‘Norwell’) with different protein concentrations were compared under four nitrogen (N) levels (0, 50, 100 and 150 kg ha−1) in an environment-controlled greenhouse, and the same experiment with an additional N level (200 kg N ha−1) was repeated in the field in 2007. In the greenhouse experiment, application of 100 kg N ha−1 resulted in significantly greater grain yield due mainly to higher number of grains per spike and heavier mean grain weight; in the field study, the 150 kg N ha−1 treatment produced the greatest yield (P<0.01) primarily due to more number of grains per spike. Crude grain protein percentage was increased significantly with each increment of N up to the highest level; however, protein yield (kg ha−1) increased significantly with fertilizer up to 150 kg N ha−1. Leaf chlorophyll contents were increased linearly with increment of N levels up to 150 kg ha−1 both in the greenhouse and field trials while leaf area indices continued to increase up to the highest application rate (200 kg N ha−1). Canopy reflectance, expressed as normalized difference vegetation index (NDVI), attained maximum value with 150 kg N ha−1 in the field experiment. Among the varieties tested, “Hoffman” out-yielded other three varieties due to heavier grain weight. Although highest grain and/or plant crude protein content were recorded in ‘AC Barrie’, it was the variety ‘Hoffman’ that produced the highest total protein (kg ha−1) with largest NDVI and leaf area index (LAI) values.

Multtvariate diversity of Polish winter triticale cultivars for spike and other traits

Multtvariate diversity of Polish winter triticale cultivars for spike and other traitsThe objective of the present study was to determine the extent and pattern of genotypic diversity for six spike quantitative characters and two other traits in 36 winter triticale cultivars released in Poland, to classify the cultivars into similarity groups (clusters) and to identify those traits, among the studied ones, which mostly discriminated distinguished groups of cultivars. The 36 cultivars, released in the period from 1982 to 1999, were evaluated across three years 2002-2004 at the Experimental Field Station in Czesławice near Nałęczów, Poland. The experiments were carried out on the brown soil with loess subsoil. In each year the one-replicated experimental design was used with 2 m2plots, rows 20 cm apart, and dense sowing using about 2 cm spacing of seeds. Analyses of variance for each trait data according to the random model (both cultivars and years were assumed to be random factors) were done. To classify and characterize genotypic diversity of the cultivars for the eight traits, the pattern analysis was used. It involved both cluster analysis using Ward's procedure with a measure of the multivariate similarity among cultivars being Squared Euclidean Distance and canonical variate analysis (CVA) on the basis of cultivarBLUPs for the original traits. Quite different groups of cultivars for the studied traits were found, specially one group was substantially distanced to the others. As it was shown by CVA, spike length and number of spikelets per spike as negatively correlated with number of grains per spikelet in the studied set of the cultivars relatively largest contributed to overall differentiation of the distinguished eight groups and then, these traits best discriminated among the eight cultivar groups in the term of Mahalanobis distance for the considered traits. The 1000 grain weight and grain protein content much less contributed to overall discrimination of the cultivar groups than the previous four traits. The most important agronomic traits characterizing productivity of the spike grain weight and its two components, e.g. number of grains per spikelet and number of grains per spike had least discriminating power for the groups of cultivars. Grain yield per unit area of cereals is a result of spike grain yield and the number of spikes per unit area. In these studies of winter triticale cultivar diversity only grain spike yield and its components were included. Thus, the presented study are a primary evaluating of phenotypic diversity in the cultivars. The further study on the cultivar diversity evaluation for grain yield per unit area and its components is necessary.

Spring wheat response to timing of water deficit through sink and grain filling capacity

Water and nitrogen (N) availability are the main factors influencing crop growth globally. Poorly distributed or insufficient water for crop growth requirements decreases yields in drought-prone areas such as those with a Mediterranean type environment. Cereal grain yield is a complex trait of interrelated components: plants per unit land area, spikes per plant, spikelets per spike, grains per spikelet, and single grain weight (SGW). The effect of water limitation and timing on development of yield components was studied in detail at the spike level in spring wheat ( Triticum aestivum L.) cultivar Amaretto. An experiment with three watering treatments (control watering, CONT; drought prior to pollination, DR1 and terminal drought, DR2) was arranged in a large greenhouse (20 m × 30 m), with the use of standard field-trial machinery. Automated blackout curtains were used to control day length, which was set to correspond to that at 40°N. With watering treatments, two N application rates (60 and 120 kg N ha −1) were used to investigate the N effect and potential watering × N interaction on yield formation and realisation. The water deficit effect exceeded the effect of N on fertile floret and grain number and SGW. DR1 strongly reduced the number of fertile florets and grains, whereas terminal drought reduced the number of grains per spike. Resuming the watering at pollination markedly enhanced photosynthesis, and hence grain filling capacity, resulting in the highest SGW in DR1. Enhancement in availability of key resources was associated with reduced rate of fertile floret and grain abortion, which resulted in higher grain to fertile floret ratio in DR1. Spikelets in the mid-section of the spike dominated yield formation in all treatments. In DR1 this was especially emphasised as 53% of the grain yield was produced in spikelets 4–6, whereas in DR2 and CONT this was 45 and 41%, respectively. Grains in proximal position in the spikelets produced about 80% of the spike grain yield, the proportion being slightly higher in stressed plants and plants receiving 60 kg N. No marked N × water deficit treatment interaction occurred for any of the measured parameters.

Effect of boric acid and some calcium and magnesium salts in the chemical and mineral composition of barley grain

The study was conducted in the wiry house in order to study the effect of treated soil with (Boric acid, Magnesium sulphat, calcium chloride) with concentrations (0.1%, 0.2%, 0.3%)Kg soil each one treated separately.on yield, carbohydrate, protein and metal composition of barley cultivar (402). Results showed that treated soil in (calcium chloride) especially in concentration (0.2%) led to improve the yield by increasing the number of the spike grains, weight of crop /plant, biological yield spike length and weight. Also led to significant increase in protein contents in barley grains in comparison with other treatment. ABSTRACT The study was conducted in the wiry house in order to study the effect of treated soil with (Boric acid, Magnesium sulphat, calcium chloride) with concentrations (0.1%, 0.2%, 0.3%)Kg soil each one treated separately.on yield, carbohydrate, protein and metal composition of barley cultivar (402). Results showed that treated soil in (calcium chloride) especially in concentration (0.2%) led to improve the yield by increasing the number of the spike grains, weight of crop /plant, biological yield spike length and weight. Also led to significant increase in protein contents in barley grains in comparison with other treatment. However the result showed that treated soil with Boric acid especially in concentration (0.3%) led to decreasing in number grains/ spike, biological yield the weight of (100) grains, weight of grains / plant, spikes weight and Ca, Mg, K contant of grains and also led to increase concentration Na , Cl in barley grain plant comparing to other treatment.

Early development and enlargement of wheat floret primordia suggest a role of partitioning within spike to grain set

Spike grain number, a major component in the yield of wheat, is suspected of being determined by the sudden death of most of the initiated floret primordia, which occurs at around booting. By counting twice weekly the number of floret primordia in the middle and top spikelets, the onset time for the death of floret primordia ( T d) was assessed in six genotypes of differing earliness and fertility subjected to three treatments that were applied during stem elongation. The variation in T d was positively correlated with overall earliness, as well as with spike fertility. Ovary development and enlargement were quantified in eight specified positions within the spikes, but T d could not be assigned to a developmental stage attained by any ovary. Development and enlargement were very strongly correlated with each other throughout the floret lifetime, yet with significant effects of genotype, treatment and position within spikes. In each position within a spike, the proportion of florets that set a grain correlated to the initial delay of development as compared to the most advanced floret ( r 2 = 0.64), but this correlation was severely biased by genotype and the floret position effect. Better correlations were obtained with either the development or width of each ovary at T d, thus highlighting the role of the preceding phase. The best prediction ( r 2 = 0.93) was obtained from the ratio of ovary width to that of the most advanced floret at T d. The importance of this width ratio emphasized the role of partitioning in grain set: only florets able to divert nutrients survived after T d and eventually set a grain. This relationship was no longer biased by floret position, while some remaining variability due to genotype suggested potential for plant breeding: width ratios at T d were generally related to the growth duration of various primordia, as well as to their relative growth rate.

RESPONSE OF YIELD AND YIELD ATTRIBUTES OF SOME BREAD WHEAT VARIETIES TO IRRIGATION LEVELS AND SEEDING RATE UNDER OLD LAND CONDITIONS

Two field experiments were performed in the experimental Farm, at Zankalon, Water Requirements Research Station, El-Sharkia Governorate, Water Management and Irrigation Systems Research Institute, National Water Research Center (NWRC), Egypt during two successive seasons at 2005/2006 and 2006/2007 to study the response of yield and yield attributes of some bread wheat varieties i.e., (Sakha 93 , Giza 168 and Gimmeiza 9) to irrigation levels ( 100% of field capacity , 80% of field capacity and 60% of field capacity) and seeding rates ( 60 , 70 and 80 Kg./feddan) under in old land conditions. The obtained results could be summarized as follows: Increasing irrigation levels from I3 ( 60% of field capacity) to I1 ( 100% of field capacity) gives significant for plant height, number of grains/spike , number of spikes/m2, 1000 grain weight, grain yield/feddan and straw yield/feddan with in significant differences between I1( 100% of field capacity) and I2 (80% of field capacity). Increasing irrigation levels from I3 (60% of field capacity) to I1 (100% of field capacity) was in significantly affect for spike length, number of spikelets/spike and spike grain weight. The cultivar Giza 168 gave taller plants followed by Gimmeiza 9, while Sakha 93 had shorter plants. The cultivar Gimmeiza 9 gave the longest spikes and much number of spikelets and grains /spike and number of spikes/m2 followed by Sakha 93 and Giza 168 cultivars Gimmeiza 9 and Sakha 93 cultivars. significantly surpassed Giza 168 for 1000-grain weight and grain yield/feddan. Meanwhile, Giza 168 significantly surpassed Sakha 93 and Gimmeiza 9 cultivars in straw yield/feddan. However significant was showing with increasing seeding rate for plant height, number of spikes/m2, and grain and straw yields/feddan with no significant differences between 60 to 70 Kg. /feddan in one side and from 70 to 80 Kg. /feddan for both grain and straw yield /feddan. However, the increasing seeding rate from 60 to 80 Kg. /feddan significantly increased plant height and number of spikes/m2. However, increasing seeding rates from 60 to 80 Kg./feddan decreased significantly, number of spikelets/spike, number of grains /spike and 1000-grain weight with no significant difference between 60 to 70 Kg./feddan. Raising seeding rates from 60 to 70 or 80 Kg./feddan did not significantly affect spike grain weight. Grain yield (ardab/feddan) was positively and significantly correlated with each of plant height (0.598919*) and number of spikes/m2 (0.679488*). While the relation was positive and insignificant with each of spike length ( 0.212270 ) , number of spikelets/spike (0.448344) , number of grains/spike (0.268315) spike grain weight (0.539816),1000-grain weight(0.457077) and straw yield/feddan (0.331902). Results of interactions between irrigation levels and varieties , between irrigation levels and seeding rates and between seeding rates and varieties recommended that Gimmeiza 9 cultivar. should be sown at irrigation levels I2 ( 80% 0f field capacity ) and at seeding rates of 80 Kg./feddan. While Giza 168 cultivar. should be sown at irrigation levels I2 (80% 0f field capacity) and at seeding rates of 70 Kg./feddan. However, Sakha 93 cultivar. should be sown at irrigation levels I1 (100% 0f field capacity) and at seeding rates of 70 Kg. /feddan.

Genotypic variation in linear rate of grain growth and contribution of stem reserves to grain yield in wheat

Grain growth in wheat depends on current photosynthesis and stem water-soluble carbohydrates (WSC). In semiarid regions with terminal drought, grain filling in wheat crops may depend more on stem WSC content than on current assimilates. Reduction in grain yield under drought is attributed to shorter duration of linear grain growth despite increased contribution of stem reserves to grain yield. The amount of stem reserves is measured either by changes in stem dry weight (indirect method) or by stem WSC content (direct method). Genotypic variation in the rate and duration of linear grain growth and in percent contribution of stem reserves to grain yield has not been evaluated in wheat. The objectives of this study were: (i) to quantify the relationship between the direct and indirect measurement of stem reserves during and across the grain-filling period and (ii) to measure the extent of genotypic variation in rate and duration of linear grain growth and in percent contribution of stem reserves to grain yield. Dry weight, WSC content and grain yield of the main stem were measured at 10-day intervals in 11 diverse wheat genotypes under well-watered and droughted-field conditions across 2 years. Drought reduced stem WSC content from 413 to 281 mg and grain yield from 4.6 to 2.5 t ha −1. Stem WSC content and dry weight were positively correlated. Genotypic differences in linear rate of grain growth were significant in well-watered (ranging from 48.9 to 72.4 mg spike −1 day −1) and in droughted-field (ranging from 33.2 to 59.9 mg spike −1 day −1) conditions. Drought, on average, reduced the linear rate and duration of grain growth by 20 and 50%, respectively. Reduction in linear rate ranged from 13 to 43%. The amount of current assimilates and stem reserves contributed to grain yield was reduced, respectively, by 54 and 11% under drought. Genotypic differences in percent contribution of stem reserves to grain yield were significant in well-watered (ranging from 19.1 to 53.6%) and in droughted-field (ranging from 36.6 to 65.4%) conditions. The wheat genotypes responded differently to drought. Main spike grain yield was reduced by 43% under drought due to 26 and 11% reduction in grain weight and number of grains, respectively. Grain yield was correlated with linear grain growth under well-watered ( r = 0.96) and droughted ( r = 0.83) conditions. The genotypic variation observed indicates that breeding for a higher rate of linear grain growth and greater contribution of stem reserves to grain yield should be possible in wheat to stabilize grain yield in stressful environments.

Effect of Organic Materials on Yields and Nutrient Accumulation of Wheat

ABSTRACT This experiment was conducted under greenhouse conditions using a sandy clay loam treated with garbage and mushroom composts, cattle and chicken manures, or municipal sludge at rates of 0, 30, or 60 ton ha−1. The organic materials were applied to the pots and incubated for 15 d. The soil samples were watered at field capacity. In this experiment, wheat (Triticum aestivum L.) was used as a test crop. At the end of the experiment, it was found that treating sandy clay loam with the organic materials increased plant total and grain yields, protein content, 1000-kernel weight, number of grains in spike, and accumulation of nitrogen (N), phosphorus (P), potassium (K), iron (Fe), zinc (Zn), and manganese (Mn) by wheat compared with the control treatment, depending on the organic material applications. Thus, the increases were found to be statistically significant (P ≤ 0.05). Among the types of organic materials, the sewage sludge was the most effective material in increasing N, P, K, Fe, Zn, and Mn content of leaf, grain, and stem samples of the wheat plant. It was followed by mushroom compost and cattle manure. Based on the results, sewage sludge and garbage compost are suggested for use as an amendment for the soil studied. Comparing the beneficial effects of the organic materials applied for improving plant growth and nutrient accumulation, the materials can be arranged in the following descending order: municipal sludge > chicken manure > cattle manure > garbage compost > mushroom compost. It is suggested that recycling of organic materials for agricultural usage as an organic-matter resource is an alternative, organic fertilization option in Turkey.

ESTIMATES OF GENETIC COMPONENTS, PREDICTION AND GENETIC CORRELATION IN WHEAT (TRITICUM AESTIVUM,L.) USING NORTH CAROLINA DESIGN III

North Carolina Design III was used to estimate gene effects in bread wheat crosses. Twelve Egyptian bread wheat genotypes i.e. Sakha 69, Sakha 8, Gemmeiza 1, Gemmeiza 3, Gemmeiza 7, Giza 160, , Giza 162, Giza 164, Giza 165, Sids 1, Sids 3 and Sids 4, each was crossed back to testers, high performing (Gemmeiza 9) and low performing parent (Sakha 92) during three winter successive seasons i.e. 2002/2003, 2003/2004 and 2004/2005, to study; heading date (days) plant height (cm), flag leaf length (cm) flag leaf width (cm), flag leaf area (cm)2, extrusion length (cm), number of spikelets/spike, spike grain weight (g.), number of spikes/plant, number of grains/spike, 1000-grain weight (g.) and grain yield/plant (g.) characters. Results indicated that epistasis played great role in the inheritance of all studied characters except number of spikes/plant. Additive(D)and dominance(H) genetic variances were significant in all studied characters except number of spikes/plant and number of grains/spike. The additive genetic variance was more than dominance for heading date, plant height, flag leaf length, flag leaf width, extrusion length, spike length and 1000- grain weight. The ratio of (H./D) 0.5 was less than one for these characters but for the remaining characters the dominance genetic variance was more than additive. The values of(F) indicated that dominance was unidirectional for flag leaf length and flag leaf area, whereas it was ambidirectional for the remaining characters Prediction results revealed that it could be possible to derive reasonable proportion of new recombinants which are falling out side parental range for heading date, flag leaf length, flag leaf width, spike length, number of spikelets/spike, number of spikes/plant, 1000- grain weight and grain yield/plant. Genetic correlation indicated that additive, dominance and epistasis gene effects controlling grain yield/plant and spike grain weight, number of spikes/plant, number of grains/spike, 1000- grain weight, were signifant, suggesting common genetic pool or pleiotropy. Thus, selection based on additive genetic correlation indicated that indirect selection via, spike grain weight, number of spikes/plant, number of grains/spike and 1000- grain weight would be effective and enhance its importance as selection criteria .

Integrated nutrition for wheat in Gypsiferous soils under center pivot sprinkler irrigation system

Field experiment was conducted in gypsiferous desert soil in western desert of Iraq/ to the west of Baghdad 260km. at the season 2003-2004 to study the response of wheat (Ebba-99 ) to integrated nutrition and the method of nutrient application under center pivot sprinkler irrigation system. Experiment consisted of seven treatments which were : Control, chemical fertilization treatment according to the recommendation of ministry of agriculture 160 kg./hec.DAP +300Kg./hec.( 33.6kg P/hec., 160 kg N/hec.)Urea.Ferrous and Zinc sulfate were used at rate 4 kg./hec. With water plus to the fertilizer recommendation Also DAP was used with water or soil besides fertilizer recommendation at the same levels. Treatments were distributed according to completely randomized design with three replicates for experimental units with area300 m2 .Measurements were carried out after 50,100 days and at harvesting which consisted of morphological properties like number branches, plant height, leaf area, dry weight , number of spikes , number of grains in spike , weight of 1000 grain , biological yield, grain yield and harvesting index. Same physiological and qualitative properties were estimated that are chlorophyll a,b and total , carbohydrate, protein, total nitrogen ,available phosphorus in soil and plant. Also water use efficiency was calculated. Results showed that Fe+ Z n+ DAP with water achieved significant increasing in yield which was 3250 kg./hec with increasing percentage 15.6% as compared with recommended fertilization.The followed treatment was (Fe+Zn+DAP with soil) with significant increasing percentage 12.45%.The highest percentage of carbohydrate and protein in grains were corresponded by treatment (Fe+Zn+DAP with water and soil) and ranged between 112.5-106.6 gm./ plant for carbohydrate and between 17.5-19.3% for protein . All treatments conserved good level cover the requirement of plant from nitrogen in soil to age 100 days without control treatment. But for phosphorous the decreasing appeared under minimum limits which cover plant requirement after 50 days. That is mentioned the importance of phosphorous application with water at stages after 50 days. It will be concluded the importance of fertilization with more than recommended rates by ministry of agriculture under gypsiferous soils conditions and adding the elements with water after age 50 days.

Abscisic acid content and growth of spring barley plants treated with triazoles

Effects of triazolium compounds (paclobutrazol, uniconazole, and azovit), applied under laboratory and greenhouse conditions, on growth of barley plants (Hordeum vulgare L., cvs. Moskovskii 2 and Zazerskii 85) and ABA content in their tissues were studied for the first time. At various application techniques, the retardants suppressed growth of axial organs, promoted thickening and strengthening of lower internodes, and caused a considerable increase in ABA content. These changes were observed already on the next day after spraying plants with retardants and maintained for two weeks after the spraying treatment. At the same time, the retardant action sustained for 42 days when the retardants were applied to soil. The triazoles had positive effects on plant productivity characteristics, such as the number of filled grains in the main spike, total weight of grain per plant (grain collected from the main and lateral spikes), and the weight of 1000 grains. It was concluded that the retardant effect of triazoles on spring barley plants is related to elevated ABA content in plant tissues over a prolonged growth period.

RESPONSE OF TOW WHEAT CULTIVARS FOR HIGH RATES OF FERTILIZATION IN GYPSIFEROUS SOILS UNDER CENTER PIVOT SPRINKLER IRRIGATION SYSTEM

Field experiment was conducted in gypsiferous desert soil in western desert of Iraq/ to the west of Baghdad 260km. at the season 2003-2004 to study the response of wheat (Ebba-99 and Rabeha-2) to high rates of fertilization and the method of nutrient application under center pivot sprinkler irrigation system. Treatments were distributed according to the factorial experiments by using completely randomized design with three replicates in experimental units with area 300 m2. Four treatments of fertilization were used: Control, fertilization according to the recommendation of ministry of agriculture (160 kg./hec.DAP +300Kg./hec.Urea), and 40 kg. /ha. DAP was used with water or brad casting to the soil besides to recommendation fertilization. Measurements were carried out after 50,100 days and at harvesting which consisted of morphological properties like number of branches, plant height, leaf area, dry weight, number of spikes, number of grains in spike, weight of 1000 grain, biological yield, grain yield and harvesting index. Some physiological and qualitative properties were estimated that are chlorophyll a, b and total, carbohydrate, protein, total nitrogen, available phosphorus in soil and plant. Also water use efficiency was calculated. Results showed that class of Ebba-99 cultivar achieved significant increasing in yield as compared with Rabea-2. The yield was 3086 kg. /hec. For the treatment of DAP with water by significant increasing percentage about 9.82% as compared with recommended fertilization treatment ,and increased 12.6%as compared with Rabea-2 cultivar. The followed treatment was DAP added to the soil with significant increasing percentage 6.04%.The highest percentage of protein in grains were corresponded by DAP with water and reached to 17.8%. Treatments of DAP added with water or to the soil conserved good level of Nitrogen whorl cover the requirement of plant to age 100 days. But for phosphorous there was decreasing under minimum limits which cover plant requirement after 50 days. That is mentioned the importance of phosphorous application with water at later stages (after 50 days). It will be concluded the importance of fertilization with rates more than recommended quantities in gypsiferous soils conditions and adding the elements with water after age 50 days.

Caracterização de genótipos de trigo do bloco de cruzamento da Embrapa Trigo, RS, Brasil

No Centro Nacional de Pesquisa de Trigo (CNPT - Embrapa Trigo), em 1999, genótipos de trigo integrantes do bloco de cruzamento foram avaliados quanto à altura de planta, à duração do ciclo até o espigamento, ao comprimento do pedúnculo e ao número de grãos por espiga. Relacionando essas características, foram estudados 122 genótipos em duas épocas de semeadura, que consistiram os blocos. Foram medidos dez pedúnculos do afilho principal, de cada genótipo, e contou-se o número total de grãos de cada espiga. Para a apresentação dos resultados, foram considerados os valores médios dessas avaliações. Para a análise estatística, considerou-se o experimento como blocos casualizados. Dos resultados obtidos, concluiu-se que os genótipos de trigo BR 18, BR 42 e Sonora 64 destacam-se por porte baixo e ciclo precoce, enquanto Florida 301 e "Trigo de chapéu" destacam-se por porte alto e ciclo longo até o espigamento. A altura de planta mostra elevada correlação com comprimento do pedúnculo e duração do ciclo até o espigamento, e esta, com o comprimento de pedúnculo. Os genótipos de trigo CNT 10 e PF 92130 são indicados com finalidades artesanais por suas características de pedúnculo longo e número de grãos por espiga acima da média. O estudo mostra grande variabilidade genotípica em trigo quanto às características avaliadas, fornecendo informações sobre os genótipos que poderão ser utilizados por melhoristas, técnicos e agricultores.

RESPONSE OF TOW WHEAT CULTIVARS FOR HIGH RATES OF FERTILIZATION IN GYPSIFEROUS SOILS UNDER CENTER PIVOT SPRINKLER IRRIGATION SYSTEM

Field experiment was conducted in gypsiferous desert soil in western desert of Iraq/ to the west of Baghdad 260km. at the season 2003-2004 to study the response of wheat (Ebba-99 and Rabeha-2) to high rates of fertilization and the method of nutrient application under center pivot sprinkler irrigation system. Treatments were distributed according to the factorial experiments by using completely randomized design with three replicates in experimental units with area 300 m2. Four treatments of fertilization were used: Control, fertilization according to the recommendation of ministry of agriculture (160 kg./hec.DAP +300Kg./hec.Urea), and 40 kg. /ha. DAP was used with water or brad casting to the soil besides to recommendation fertilization. Measurements were carried out after 50,100 days and at harvesting which consisted of morphological properties like number of branches, plant height, leaf area, dry weight, number of spikes, number of grains in spike, weight of 1000 grain, biological yield, grain yield and harvesting index. Some physiological and qualitative properties were estimated that are chlorophyll a, b and total, carbohydrate, protein, total nitrogen, available phosphorus in soil and plant. Also water use efficiency was calculated. Results showed that class of Ebba-99 cultivar achieved significant increasing in yield as compared with Rabea-2. The yield was 3086 kg. /hec. For the treatment of DAP with water by significant increasing percentage about 9.82% as compared with recommended fertilization treatment ,and increased 12.6%as compared with Rabea-2 cultivar. The followed treatment was DAP added to the soil with significant increasing percentage 6.04%.The highest percentage of protein in grains were corresponded by DAP with water and reached to 17.8%. Treatments of DAP added with water or to the soil conserved good level of Nitrogen whorl cover the requirement of plant to age 100 days. But for phosphorous there was decreasing under minimum limits which cover plant requirement after 50 days. That is mentioned the importance of phosphorous application with water at later stages (after 50 days). It will be concluded the importance of fertilization with rates more than recommended quantities in gypsiferous soils conditions and adding the elements with water after age 50 days.

Response of winter rye to long-term monoculture under the conditions of varied chemical plant protection level

The response of winter rye to a 26-34 year monoculture cultivation was followed in 9-year investigations carried out on loess-based, dusty, medium-heavy soil in the years 1993-2001. Parallel rye cultivation in a 6-plot crop rotation was the control object. The study included 3 levels of chemical plant protection of the corn: O - no protection, H - protection against weeds, HF - protection against weeds and diseases. The mean rye grain yield in the crop rotation amounted to 6.22 t ha m 1 during the period of study. The monoculture decreased its productivity by 26.4% on average. A negative response of rye to being sown after itself was dependent on the protection level. The rye yield decrease in the monoculture became lower with an intensification of the crop protection: 0-38%; H-20.5%; HF-19.9%. Lower rye yields in the monoculture are the result of crop thinning and deterioration of the spike yield and grain size.

Differential responses of BA injection on yield and specific grain growth in contrasting genotypes of wheat (Triticum aestivum L.)

The effect of exogenous cytokinin (benzyladenine) was investigated on location specific grains in three contrasting wheat genotypes tolerant or susceptible to post anthesis high temperature conditions. Seeds were sown in earthen pots under natural environment in November and January for normal and late sowings, respectively. Grain weight was increased by the application of benzyladenine at anthesis under late sown stress only in those genotypes, which are known, to posses temperature tolerance in developing grains. However, under normal sowing conditions BA application was effective irrespective of genotype response to late sown stress. The effect was most visible in distal spikelets in the spike and distal grains in the spikelet which resulted in higher increment in weight of younger grains (c and d) as compared to older grains (a and b). It has been suggested that the responsiveness of the genotype to BA application under late sown stress is important and may be developed as an indicator to screen wheat genotypes for relative tolerance to late sown stress under irrigated conditions.

Testing disease resistance in autumn wheat genotypes by means of field experiments

According to our scientific results we can state that we have to use integrated pesticides management in crop protection against the diseases of winter wheat. One of the most important elements of IPM is to select a genotype characterised by good resistance to diseases (and by high yield ability and excellent baking quality). It is especially important that the wheat variety have tolerance against not only to one or two leaf and spike (grain) diseases, but „complex” tolerance. It is not necessary to give up the growing of a variety which has susceptibility to different diseases because we can protect it using appropriate chemical management. In the intensive growing stage of wheat (BBCH 32-37) we can use a noncompulsary fungicide-treatment (depending on e. g. the infection, ecological conditions) and, at the beginning of the flowering stage(BBCH 59-65), we have to use a compulsary fungicide-treatment (in spite of e. g. special weather conditions, resistance genotype)to ensure high yield and good quality.

ESTIMATIVAS DE HERDABILIDADES E CORRELAÇÕES ENTRE PRODUÇÃO DE GRÃOS E SEUS COMPONENTES PARA CRUZAMENTOS BIPARENTAIS DE TRIGO

Visando estimar a herdabilidade, em sentido restrito, para número de espigas por planta, número de grãos por espiga, peso de cem grãos e produção de grãos, bem como as correlações entre essas características, foram efetuados cruzamentos entre o cultivar IAC-227 (P1), de porte alto e quatro linhagens mexicanas, de porte baixo: CMH 78.390/ CMH 77A. 917// CMH 79.215 (P2), CMH 79.959/2* CNO 79 (P3), CMH 79.481/ CMH 77A. 917 (P4) e CMH 80A. 747 (P5). Foram estudadas as gerações parentais, F1, F2 e os retrocruzamentos para ambos os pais sendo as avaliações realizadas em plantas individuais. O valor da herdabilidade, em sentido restrito, para número de grãos por espiga foi de 0,717, para o cruzamento P1 x P2, indicando que as seleções para esse caráter poderiam ser feitas nas gerações F2 ou F3. Os valores médios a baixos da herdabilidade, em sentido restrito, para número de espigas por planta (0,157-0,547), número de grãos por espiga (0,047-0,321), exceto para o cruzamento P1 x P2, peso de cem grãos (0,125-0,476) e produção de grãos (0,421-0,550) sugerem que a seleção para esses caracteres poderia ser postergada para gerações mais avançadas, onde testes de progênies seriam realizados. As correlações genéticas aditivas indicaram ser possível selecionar progênies apresentando ao mesmo tempo elevado potencial produtivo, com maior número de espigas por planta e grãos por espiga e com grãos mais pesados desde que grandes populações F2 sejam obtidas para permitir a obtenção dos recombinantes desejáveis. Em virtude das correlações genéticas aditivas terem sido positivas entre todos os caracteres avaliados para o híbrido P1 x P4, seleções das plantas com as características desejáveis poderiam ser realizadas em reduzidas populações segregantes.

Interactive effects of salinity and macronutrient level on wheat. I. Growth

Plant growth response to salinity is known to change under different fertility levels. The objective of this study was to investigate interactive effects of salinity and macronutrient level on growth and yield of spring wheat (Triticum aestivum L. cv. Lona), grown in hydroponic culture in growth chambers until grain maturity. Eight salinity levels, 0 to 150 mM NaCl, were established and 1, 0.2, and 0.04 strength Hoagland macronutrient solution (x HS) were designed as the levels of nutrient supply. Only small decreases in the grain yield of the main spike were found at 1 and 0.2 x HS with low and medium salinity (0 to 40 and 40 to 100 mM NaCl, respectively). Larger decreases in the grain yield of the main stem were found at either 0.04 × HS or at high levels of salinity (125–150 mM NaCl), being more marked at 0.2 than at 1 × HS. In contrast to the main spike grain yield, which was only slightly affected at 1 and 0.2 × HS with low and medium salinity, increasing salinity strongly decreased plant yield components except thousand grain weight. The salinity level associated with a 50% grain yield decrease was about 84, 72, and 31 mM NaCl for 1,0.2, and 0.04 × HS, respectively. Salt tolerance was higher at high (full HS) macronutrient concentration. At all macronutrient levels, plant grain yield decreases were mainly and closely related to decreased leaf and tiller numbers. This result suggests that salinity exerts its main effects during the early growth stages. The most promising strategies for increasing wheat yields in saline soils will be (i) increasing nutrient supply in nutrient‐poor soils, (ii) creating favorable conditions in the root zone during germination, seedling stage, and early tillering by salt elimination, and (iii) increasing main stem population density by increasing seeding density. The second and third measures will increase yields to a greater extent at moderate and sufficient nutrient levels than additional supplies of nutrients.

Genetic variation and interrelationships of agronomic characters in landraces of bread wheat from southeastern Iran.

There is renewed interest in wheat landraces as important sources of genetic variation for agronomic characters. Fifty-three pure lines of bread wheat (Triticum aestivum L.) derived from seven landraces collected from southeastern Iran were used to estimate genetic variation and heritability for 13 developmental and quantitative characters. Path-analysis was used to partition the genetic correlations between grain yield and six grain yield-related traits. Mean values of landraces were also compared with three improved cultivars from California and Iran. Genotypic differences among the landraces and among the pure lines collected from the landraces were highly significant for all characters considered. Compared with the modern cultivars, the landrace genotypes were, on average, later in days to heading and taller than the cultivars but had lower values for number of grains per spike, 1000-grain weight, grain yield and harvest index. Some landrace genotypes were similar to the modern cultivars for grain yield. Moderate to high genetic variation was displayed by number of grains per spike, number of spikes per plant, 1000-grain weight, and harvest index. The heritability estimates ranged from 59% for grain yield to 99% for days to anthesis. Expected genetic advance (as % of the mean) was ≈34% for number of spikes per plant, number of grains per spike, and 1000-grain weight. Days to heading and to anthesis correlated positively with number of spikes per plant, shoot biomass, and straw biomass but negatively with number of grains per spike and harvest index. The strong direct effect of number of spikes per plant on grain yield was completely counterbalanced by its indirect negative effects via number of grains per spike and 1000-grain weight. Number of grains per spike and 1000-grain weight were positively correlated with grain yield, and they had large direct effects. These two characters, however, were negatively correlated and exhibited a substantial counterbalance effect via one another and via number of spikes per plant. The landraces could be improved by intercrossing the promising genotypes identified in this study, with simultaneous selection for earliness, fewer number of spikes per plant, greater number of grains per spike and heavier grains. For further improvement, crossing programs between the landraces and introduced germplasm may be necessary.