Yield Of Flax Research Articles

Nitrogen source and placement effects on stand density, pasmo severity, seed yield, and quality of no-till flax

Field studies were conducted at two locations in western Manitoba over three years to evaluate the impact of rate, source, and placement of nitrogen (N) fertilizer on seedling emergence, disease severity, crop yield, and seed quality of flax (Linum usitatissimum L.). Urea, urea ammonium nitrate (UAN), and ammonium nitrate (AN) fertilizers were applied at 0, 30, 60, and 90 g N ha−1, pre-plant banded or side-banded 2.5 m to the side and 2.5 m below the seed-row, using a hoe-type opener with 20 m row spacing. Differences in stand emergence occurred from year to year, depending on the moisture conditions after seeding. Nitrogen fertilizer occasionally decreased stand density when side-banded, with effects being greatest with urea and UAN. The magnitude of stand decrease was generally low, although it may have restricted seed yield with high rates of urea fertilization in some years. Nitrogen applications frequently increased leaf and stem pasmo, but the effects of fertilizer source and placement were variable. Seed yield increased with N application except at a single site where soil N levels were high. Where differences existed among sources, yield was generally lower with urea than with the other sources, possibly related to seedling damage from the urea at higher rates of application, or to physiological effects of high ammonia:nitrate ratio nutrition during early growth. Seed quality for oil production tended to decline with increasing N applications due to lower oil concentration, lower iodine number, and a decrease in the concentration of high-quality linolenic and linoleic fatty acids. However, seed protein concentration increased with increasing N concentration. While risk of seedling damage and pasmo may increase with increasing levels of N fertilizer, either side-banded or pre-plant banded N applications still resulted in increased flaxseed yield. However, increasing N rate slightly decreased quality for oil production.

Fiber cell development and fiber yield of flax (Linum usitatissimum L.) affected by the seasonal temperature pattern

Du, G.-H., Liu, F.-H. and Rowland, G. 2015. Fiber cell development and fiber yield of flax (Linum usitatissimum L.) affected by the seasonal temperature pattern. Can. J. Plant Sci. 95: 1215–1220. Three fiber flax cultivars ‘Ariane’, ‘Argos’ and ‘Viking’ were cultured in growth chambers under three seasonal temperature patterns (STPs) [parabolic (P), anti-parabolic (AP) and quasi-horizontal (QH) configurations]. The effect of STP was studied on fiber cell development and on fiber yield. The results indicated that, compared with the quasi-horizontal seasonal temperature pattern (QH-STP), the size of fiber cell cavity (SFCC) and fiber content (FC) decreased under parabolic seasonal temperature pattern (P-STP). However, the size of fiber cell (SFC) and SFCC decreased, but the number of fiber cells per bundle (NFCB) increased under anti-parabolic seasonal temperature pattern (AP-STP). Moreover, there was a significant positive correlation between fiber weight (FW) and width of fiber bundle (WFB), also between FC and NFCB. Considering the response of fiber flax cultivars to the different STPs, ‘Ariane’ had smaller SFC and SFCC, thinner thickness of fiber cell wall (TFCW) under AP-STP, and smaller SFCC and thicker TFCW under P-STP than under QH-STP, while ‘Argos’ had smaller SFC and SFCC, and higher NFCB under AP-STP, and smaller SFC under P-STP than under QH-STP. However, STPs had little effect on the fiber cell development of ‘Viking’. All three cultivars had high FC under AP-STP than under P-STP. These observations indicate that the fiber cell development and fiber yield of flax were related to the STP and suggest that AP-STP are the most favorable temperature conditions for fiber flax growth.

Optimizing the Performance of Natural Fiber Reinforced Plastics Composites: Influence of Combined Optimization Paths on Microstructure and Mechanical Properties

This study investigated the combination of two different optimization paths (phase compatibilization and manufacturing process optimization) on the microstructure (fiber dimensions, matrix crystallinity and matrix molecular properties) and mechanical properties (flexural and tensile moduli, impact strength, and tensile stress at yield) of flax fiber/postconsumer recycled plastic composites. A two-step optimization methodology was adopted. First, the material composition was optimized by phase compatibilization using maleic anhydride grafted polypropylene (MAPP) and maleic anhydride grafted ethylene octene metallocene copolymer (EO-g-MAH) as additives. Then, the manufacturing process (extrusion followed by injection) was optimized in terms of temperature profile and screw speed for extrusion, as well as barrel temperature profile, mold temperature, injection speed, injection pressure, injection time and back pressure for injection. The results showed that, besides good fiber-matrix interfacial adhesion, the combination of both optimization paths promoted an optimum balance between components degradation and composite homogeneity (good fiber and additives dispersion in the matrix), leading to better mechanical properties. It is shown that this optimization procedure was able to improve all the mechanical properties of the composites, as well as being effective in terms of performance and costs.

Effect of Nitrogen Fertilizer on Nitrogen Accumulation, Translocation, and Use Efficiency in Dryland Oilseed Flax

Oilseed flax (Linum usitatissimum L.) yields are primarily fertilizer‐limited, especially by N supply in the semiarid regions of North China. This study was conducted to determine whether N accumulation, translocation and N use efficiency (NUE) could be manipulated through N. The effects of N on N translocation, oilseed flax yield, oil content and NUE were studied at Zhangjiakou, China. Plants were grown at 0, 45, 90, and 135 kg N ha−1 (designated as the control, low N, moderate N, and high N, respectively), in 2011 and 2012. We found that N accumulation in leaves and capsule pericarps reached the maximum at anthesis and kernel developmental stage, respectively, then decreased rapidly before maturity. Averaged over 2 yr, N translocation from leaves to the seeds increased by 43, 150, and 150% under low N, moderate N, and high N, respectively, compared to the control; similarly, N translocation in capsule pericarps increased by 43, 243, and 190%, respectively. We discovered that leaves contributed the largest proportion of the seed N (averaging 80% in both years), and secondarily by the capsule pericarp N, which contributed 12% (in 2011) and 9% (in 2012) of the seed N. The highest seed yields were 2270 kg ha−1 (in 2011) and 1903 kg ha−1 (in 2012) which were obtained with the moderate N. Oil content was not affected by N. Nitrogen use efficiency decreased with progressively higher rates of N. The results suggest the moderate‐N supply was adequate for promoting N translocation, and increasing N harvest index, NUE, and the productivity of oilseed flax.

EFFECT OF NITROGEN, PHOSPHOR AND POTASSIUM FERTILIZATION ON YIELD OF FLAX AND QUALITY UNDER SANDY SOILS.

Genotypes selection and optimizing mineral nitrogen, phosphorus and potassium fertilization are important factors that influence flax growth, yield and quality. Two field experiments were conducted at the Experimental Research Station in Esmailia, Field Crops Research Institute, Agricultural Research Center, Egypt during the growing seasons of 2012/2013 and 2013/2014 seasons to study the effect of mineral nitrogen, phosphorus and potassium fertilization on yield and quality of some flax genotypes under sandy soils conditions. The experiments were carried out in a split-plot design with three replicates. The main-plots were assigned to flax genotypes (Giza 10, Sakha 2 and strain 22). The sub-plots were allocated to mineral fertilization treatments (fertilizing with mineral N, P, K, NPK and without mineral fertilization). The results indicated that significant differences among the three studied flax genotypes i.e. Giza 10, Sakha 2 and strain 22 were detected in all studied characters, except number of seeds/capsule in both seasons. Fertilizing flax plants with 75 kg N + 23.25 kg P2O5 + 24.0 K2O/fed significantly increased all studied characters and produced the highest values as compared with other studied mineral fertilization treatments in both seasons. Control treatment (without mineral fertilization) gave the lowest values of all studied characters. On the basis of the results obtained, maximum straw and seed yields and its components of flax could be achieved through fertilizing Strain 22 or Sakha 2 genotypes with 75 kg N + 23.25 kg P2O5 + 24.0% K2O/fed. However, maximum fiber flax yield resulted from fertilizing Giza 10 cultivar with 75 kg N + 23.25 kg P2O5 + 24.0 K2O/fed under sandy soils conditions in Esmailia Governorate.

Effect of herbicides on yield and quality of straw and homomorphic fibre in flax (Linum usitatissimum L.)

Fibre flax (Linum usitatissimum L.) is a very poor competitor with weeds, and to obtain acceptable yields, weeds should be effectively controlled. Very little information is available on the tolerance of flax to herbicide applications. Types of applied herbicides determine not only the yield of flax but can also affect yield of fibre, its quality and may affect processes (physical, chemical and enzymatic) used in the refining of homomorphic fibres to increase their thinness and divisibility. Presented basic field research was carried out in the years 2011–2012. In the studies the impact of three herbicides (with a.i. linuron, bentazon and chlorsulfuron) was examined on the control of weeds, course of vegetation and yield and quality of flax homomorphic fibre. The applied herbicides had a significant impact on the weed control, the length of the vegetation, straw yield, the percentage of fibre in the straw, weight and length of the fibre and its thinness and divisibility. The lowest number and mass of weeds and the highest flax straw yield and fibre quality was obtained after chlorsulfuron application. Bentazon, despite its high herbicidal effectiveness, reduced both the amount and quality of fibre yield when compared to chlorsulfuron, due to its phytotoxic effect on flax. Pre-emergence linuron application resulted in the longest fibres and highest fibre content in flax straw.

Cultivation of Fiber and Oil Flax (Linum usitatissimum L.) in No-Tillage and Conventional Systems. Part II. Influence of No-Tillage and Use of Herbicides on Yield and Weed Infestation of Oil Flax and the Physical and Biological Properties of the Soil

No-tillage methods can help to reduce expenditures and improve profitability of the agricultural production. This issue has been widely discussed for the cultivation of many species, but there are no data on the subject concerning oilseed flax. The field experiments were conducted in the years that vary widely in the course of temperature and precipitation. Tillage method significantly affected the yield of flax in the interaction with the weather conditions. In the dry year, the cultivation method did not differentiate the flax yield, while in the optimum moisture year no-till resulted in a reduction of yield compared to conventional tillage. Weed control with herbicide has contributed to increased yield of linseed but the level of increase was higher with no-till compared to conventional cultivation. The number and weight of weeds in no-tillage flax was 50% lower comparing to conventional plowing in both variants of weed control. Weed control decreased the number and weight of weeds also by 50% regardless of cultivation method applied. Cultivation systems affect the size and composition of the soil microbial populations. No-tillage contributed to an increase of humic substances content in the soil environment, the quantity of soil bacteria, and the population structure.

The Impact of Environmental Factors and Applied Agronomy on Quantitative and Qualitative Traits of Flax Fiber

According to the Liebieg’s law—in many regions of Europe, the main limiting factor that affects very often flax yield are weather conditions (precipitation). Resistance to drought stress of 51 flax genotypes was evaluated in pot trials (2002–2012). Controlled drought stress (62.5% optimal soil humidity) caused a decrease in fiber yield by 39.7–49.3% and a substantial drop in quality. Among the tested cultivars, the ones that gave relatively promising yields in conditions of water deficit were: Sara [PL], Ilona [NL], Modran [PL], Escalina [NL], Luna [PL], Alizĕe [FR], Artemida [PL], Selena [PL], Modran [PL], Nike [PL], and Venica [CZ]. Relatively good yields of fiber for these varieties were the result of the good yields of straw.In field trials carried out on two types of soil (pseudosolic and black soil), the highest fiber yield with good quality was obtained using: (1) sowing density of 2 800 seeds m−2, (2) row sowing, (3) harvesting time at green-yellow maturity stage (BBCH 83). Higher plant densities using row sowing resulted in higher fiber content (% in straw) together with better quality (tex). Earlier harvest times (BBCH 75, BBCH 79) allowed for obtaining very thin fiber. The content of pectin and lignin in the fiber increased with harvesting delay.

Flax (Linum usitatissimum L.) production system performance under organic rotational no-till and two organic tilled systems in a cool subhumid continental climate

Studies comparing crop agronomic response in organic production systems under contrasting tillage practices are lacking. The objective of the study was to compare the effect of organic rotational no-till and two organic tilled systems on the basis of mulch biomass, soil chemical properties, weed control, and subsequent crop productivity. A field study consisting of two-year sequences was conducted three times at three close sites in Carman, Manitoba, Canada (2009–2010 at site A, 2010–2011 at site B, and 2011–2012 at site C), on Chernozem soils. Three management systems of cover crops were tested, in a randomized complete block design. A barley (Hordeum vulgare L.)/hairy vetch (Vicia villosa Roth) cover crop was grown in the first year of the study and terminated by rolling (no-till), rolling and tillage (Roll+Till), or haying and tillage (Hay+Till). Flax (Linum usitatissimum L.) was seeded the following year. Our first hypothesis that a full-year growth of barley/hairy vetch cover crop allows the production of between 6 and 8Mgha−1 of mulch biomass for the subsequent crop was confirmed in two of three years. Flax was no-till seeded into 6.7, 7.7, and 4.2Mgha−1 of mulch at sites A, B, and C, respectively. At two of three sites, flax seed yields were significantly higher in no-till than in the two tillage treatments. There was no penalty on flax seed yield for haying the cover crop in mid-summer instead of incorporating it into the soil by tillage, across all three sites. There was an overall trend towards lower contents of soil nitrate-N in no-till, although it did not greatly influence total plant nitrogen uptake at two of three sites. This corroborates our second hypothesis that while flax N uptake would be reduced by the reduced soil N status in no-till, there will be sufficient N for optimum flax yield. The third hypothesis that barley/hairy vetch cover crop mulches have the ability to provide adequate weed control was generally supported, though there were important exceptions when insufficient mulch biomass was produced. Success of flax crop grown in an organic rotational no-till system in southern Manitoba depended on weather, mulch biomass production (>6.7Mgha−1), and weed species present. The fourth hypothesis that there is no yield penalty for eliminating tillage for 1.5 years in an organic flax crop in southern Manitoba held true only if that minimum mulch biomass benchmark of 6.7Mg ha−1 was reached.

Application and validation of AquaCrop model in simulating biomass and yield of oil flax in Northwest China

为了预测水分和养分对胡麻籽粒产量、生物量与水分生产率的影响, 使用FAO研发的水分驱动作物模型AquaCrop对胡麻在不同灌溉与氮磷水平下的生长情况进行模拟和验证。试验分别于2011年、2012年在甘肃省榆中县良种场进行, 试验设置4个灌溉水平, 3个氮水平, 3个磷水平。模型性能的评价采用模型效率(<i>E</i>)、决定系数(<i>R</i>²)、均方根误差(<i>RMSE</i>)和平均绝对误差(<i>MAE</i>)等统计指标。分析结果表明: AquaCrop模型校正的籽粒产量和生物量在不同灌溉与氮磷水平处理下的预测误差统计值为: 0.97<<i>E</i><0.99, 0.11<<i>RMSE</i><0.33, 0.11 t·hm^-2< MAE<0.42 t·hm^-2, 与2012年的试验观察数据(0.96<<i>E</i><0.99, 0.11<<i>RMSE</i><0.42, 0.11 t·hm^-2<<i>MAE</i><0.39 t·hm^-2)基本一致; 同时, 群体覆盖(<i>CC</i>)与生物量的模拟结果与测定值也非常拟合。AquaCrop模型在充分灌溉处理下预测胡麻产量, 比非充分灌溉处理下具更高的准确性。因而, 水分驱动模型AquaCrop在西北胡麻区不同的灌溉与田间管理措施下有较高的模拟精确性, 具有广阔的应用前景和价值。

Simultaneous optimization of the mechanical properties of postconsumer natural fiber/plastic composites: Processing analysis

In this work, manufacturing steps of composites were simultaneously analyzed to optimize four mechanical properties (flexural and tensile moduli, impact strength, and tensile stress at yield) of flax fiber/postconsumer recycled plastic composite. Eight parameters of the extrusion-injection process (extrusion: temperature profile and screw speed; injection: temperature profile in the barrel, mold temperature, injection speed, injection pressure, injection time, and back pressure) were selected. Process optimization, taking into account simultaneously all the mechanical properties (multi-responses optimization), required four steps: determination of influential factors by a screening design and an evaluation of the selected factors effects on the mechanical properties, modeling of the relationships between mechanical properties and significant factors by a Box–Behnken experimental design and a multiple linear regression analysis, identification of the potentially optimum conditions using the desirability function approach (Derringer–Suich model), and determination the optimum composite manufacturing conditions by a comparative analysis of the material relative qualities.

Using Bacteria Addition and Reusing Retting Water Technologies to Accelerate Flax Degumming

Two pectinase-producing strains, HDYM-01 and HDYM-02, were added into retting tanks to accelerate the water-retting of flax after they were amplified in liquid medium. The results show that the yields of fiber flax retted with bacteria addition are higher than the control, and the difference is significant with F test. When reusing the retting water to the next tank to perform the water-retting with bacteria addition, the yields of fiber flax are also higher and the difference is significant with F test. The retting time would be shortened for 24 hr and the flax strength is raised for 20-30 Newton (N) with bacteria addition method and reusing retting water method.

Association of Flax Seed Yield and Its Components in Southeast Texas Using Path Coefficient and Biplot Analyses

In addition to numerous health and industrial uses, flax (Linum usitatissimum L.) has been evaluated throughout the United States as a potential biodiesel crop. One approach for improving flax yields was to identify the physiological characteristics contributing the most to flax yield. Two locations in southern Texas were selected to evaluate the association between tiller number, number of pods per tiller, number of seeds per pod, seed weight, and overall yields. Tiller number was the most significant positive contributing trait (P < 0.05) to seed yield of flax at both locations. However, the effect of tiller number was almost equally negated by that of pods per tiller (compensatory) at both locations. Seed per pod and seed weight were not significant (P > 0.05) components of seed yield in flax in this study. Selection for higher tiller number would increase grain yield of flax in southern Texas and should be the focus of plant breeders to further enhance seed yield for this area.

Effect of levels of phosphorus and iron on growth, yield and quality of flax

This study was conducted during the growing season of 2012-2013 from 1st December ,2012 to 26th of May, 2013 to study the effect of three levels of phosphorus(0, 50 and 100 kg TSP ha -1 and the three levels of Cheated iron (0, 4 and 8 kg Fe-EDDHA ha -1 ) and their combinations on growth characters ,yield and quality of flax using split plot design with three replicates. The results indicated that the highest values of oil%, oil yield , P% , protein% and Fe concentration (23% , 346.47 kg .ha -1 ,6.65 %, 27.47 % and 151.90 ppm) were recorded from treatment combinations (P0 Fe1, P1 Fe0, P2Fe1, P1Fe0 and P2Fe2) respectively. On the other hand increase in levels of applied phosphorus and iron caused increase in seed index from (5.65 to 6.53 g) and from (5.24 to 6.39 g) respectively.

Effect of Humic Acid, Mycorrhiza Inoculation, and Biochar on Yield and Water Use Efficiency of Flax under Newly Reclaimed Sandy Soil

In order to examine the application of different soil and foliar organic fertilizers as well as biofertilizing flax under sandy soil conditions, two field experiments were carried out at the Research and Production Station of the National Research Centre (NRC), Al Nubaria district, El-Behaira Governorate, Egypt during 2012/2013 and 2013/2014 winter seasons. The trials aimed to study the effect of humic acid (HA) as low cost natural fertilizer, inoculation with mycorrhiza, and biocharcoal on on yield, quality and water use efficiency of flax variety (Amon) under newly reclaimed sandy soil. The treatments consisted of HA (25 kg/feddan), inoculation with mycorrhiza (1 kg/ feddan), and biochar (4 tons/feddan) and all the combinations among the treatments. Results showed that the treatment combination of (humic acid + mycorrhiza + biochar) was significantly superior compared to all the other treatments in number of capsules/plant, biological yield/plant (g), seed yield/plant (g), seed yield (kg/feddan), straw yield (tons/feddan), oil percent (%), and oil yield (kg/feddan). However, it gave the highest fruiting zone length (cm) but not significantly different from (mycorrhiza + biochar) and (humic acid + biochar), also it gave the highest seed index (g) but not significantly different from humic acid and (humic acid + mycorrhiza). The treatment combination of (humic acid + biochar) gave the highest plant height (cm), technical stem length (cm), and number of branches/plant.

Pasmo disease and lodging in flax as affected by pyraclostrobin fungicide, N fertility and year

Vera, C. L., Irvine, R. B., Duguid, S. D., Rashid, K. Y., Clarke, F. R. and Slaski, J. J. 2014. Pasmo disease and lodging in flax as affected by pyraclostrobin fungicide, N fertility and year. Can. J. Plant Sci. 94: 119–126. Severe infection of the fungal disease known as pasmo, caused by Septoria linicola (Speg.) Garassini, reduces seed yield of flax (Linum usitatissimum L.) in western Canada. Pasmo may also indirectly affect seed yield by predisposing flax plants, under favorable weather and soil fertility conditions, to lodge. With the objective of studying the possible association of this disease with the occurrence of lodging and their effect on seed yield, a study was conducted at Melfort, Saskatchewan, Canada, during 4 consecutive years (2009, 2010, 2011 and 2012), with two fungicide regimes (application and no application) and five rates of nitrogen (N) fertilization (0, 33, 66, 100 and 133% of recommended). The application of pyraclostrobin fungicide reduced disease severity and increased seed yield of flax in the 3 yr (2010, 2011 and 2012) that pasmo infection was detected, and prevented or reduced the occurrence of lodging in the 2 yr (2010 and 2012) with favorable weather conditions for the occurrence of lodging. Increasing rates of N resulted in increased seed yield in 2009 and 2012, regardless of whether fungicide was used or not. Increasing rates of N also increased the severity of pasmo disease in 2010, 2011 and 2012, and of lodging severity in 2010 and 2012. The increase in disease severity due to N occurred in the absence of fungicide in 2011 and when fungicide was applied in 2012, while in 2010 just the effect of N on the two fungicide treatments combined was significant. Only low levels of disease severity (near 20%) were observed when fungicide was applied in 2011, while extreme disease severity (near 100%) occurred in 2012 at all levels of N when fungicide was not applied. The increase in lodging, as N rates increased, was observed only in the absence of fungicide, in both years. The occurrence of lodging took place late in the development of flax.

Cultivation of Fiber and Oil Flax (Linum usitatissimum L.) in No-tillage and Conventional Systems. Part I. Influence of No-tillage and Conventional System on Yield and Weed Infestation of Fiber Flax and the Physical and Biological Properties of the Soil

Studies on planting crops no-till have been carried out extensively in many countries. So far, studies have not been conducted in the cultivation of flax. The purpose of this study was to compare no-till and conventional cultivation of flax on weed control, yield of fiber flax and seed, and the physical and biological properties of the soil. Precipitation in the years of study was significantly different and modified the effect of the treatments. Yields of whole flax plants with seeds and yields of straw in the dry year were higher, and in the year with optimal rainfall lower with no-tillage than conventional cultivation. Flax seed yield, regardless of the year, was higher in the no-till system. No-tillage, regardless of weed control, reduced the number and weight of weeds, compared to conventional cultivation with plowing. No-tillage resulted in a higher moisture content and lower soil capillary capacity than with conventional tillage. Cultivation systems did not affect the bulk density of topsoil but no-tillage contributed to an increase of humic substances content in the soil environment.

半干旱区旱地春小麦全膜覆土穴播对土壤水热效应及产量的影响

以春小麦"陇春27"为试材,研究半干旱区旱地全膜覆土穴播对土壤水热效应及小麦产量的影响。结果表明:与裸地平作(CK)相比,全膜覆土穴播(PM)和全沙覆盖平作(SM)增温效果呈"挂钩型",增温效果在小麦拔节期前最为明显,PM 0-25 cm土壤平均温度较CK提高1.8 ℃,全沙覆盖平作提高1.4 ℃,拔节后PM和SM的增温效果逐渐减弱直至消失,而在成熟期又呈现较弱的增温效果。PM和SM能提高小麦出苗后耗水速度并加大耗水量,其中,小麦拔节到扬花期耗水量增加最多,分别较CK平均增加54.93%和31.54%,且此阶段越是干旱,促进耗水作用越明显,PM促进作用大于SM。PM和SM能显著提高小麦阶段性水分利用效率(<em>WUE</em>_b),其中PM以苗期提高最多,2a平均较CK提高365.17%,SM拔节期提高最多,2年平均较CK提高119.00%。PM和SM在增温、促进耗水作用下使小麦各生育期提前并增加单株干重,产量较CK分别平均增加432.28%和375.82%, 水分利用效率(<em>WUE</em>)分别平均增加351.51%和338.29%,而且越干旱年份增产效应愈加明显。可见,PM和SM在越为干旱的年份促进耗水、增产和提高<em>WUE</em>的作用越显著,PM效果强于SM。;The differences between the timing of natural rainfall and demands of crops for water during seasonal drought is one of the main factors restricting crop production in semi-arid areas.As a new agricultural technology, the use of plastic film as mulch to cover the entire soil surface, combined with bunch planting of wheat with no-tillage has several effects; the plastic captures evaporating water and so suppresses evaporation and maintains soil moisture.This significantly improves rainfall use efficiency, allows the full use of light and heat resources, and significantly increases yield of wheat, flax and other crops.Therefore, the use of plastic film as mulch with bunch planting has been widely applied in dryland agriculture in the middle and eastern parts of Gansu Province, China.However, systematic methods for the use of plastic mulch in wheat production are still lacking; in particular, research is lacking on the effects of plastic film mulching with bunch planting on soil temperature, moisture, water consumption, water use efficiency (<em>WUE</em>), and effects on the various growth stage of wheat and on dry matter accumulation.To understand how this new technology improves crop development and yield and how it affects soil hydrothermal conditions, we designed and implemented a field experiment using three treatments: the use of plastic film as mulch to cover the entire soil surface with bunch planting (PM), the use of sand mulching on the entire field and traditional scattered seed planting (SM) and un-mulched planting and with traditional scattered seed planting (CK).The study was carried out to determine the effects of different mulching methods on soil temperature, moisture and yield of spring wheat (<em>Triticum aestivum </em>L.) in the semi-arid area in drylands in central Gansu.In this experiment, we used Long Spring 27 (<em>Triticum aestivum </em>L.) as the test material to study the effects of different mulching methods on soil temperature, moisture and spring wheat yield in a semi-arid area.The results showed that PM and SM increased soil temperature in the entire growth period for spring wheat; this increase in soil temperature is most obvious before the jointing stage of wheat.PM and SM could result in a 1.8 ℃ and 1.4 ℃ increase in average soil temperatures in the 0-25 cm soil layer, respectively, compared with CK.After the jointing stage, the warming effect of PM and SM gradually weakened or disappeared, although it reappeared in a weaker state as the wheat matured.PM and SM could improve the rate of water consumption and increase water consumption after seedling emergence.Water consumption was largest during the jointing-flowering stage and PM and SM increased water consumption up to 54.93% and 31.54%, respectively, compared with CK.With increased drought intensity the effects of the treatments were more obvious at the jointing-flowering stage.PM and SM could improve biomass water use efficiency of wheat (<em>WUE</em>_b) significantly; the improvement was highest (up to 365.17%) at the seedling stage of PM and at the jointing stage of SM (up to 119.00%), compared with CK.PM and SM treatments resulted in increased soil temperatures and improved soil water consumption; therefore, these treatments extended the growing period for spring wheat and increased the dry matter weight per plant.Also PM and SM increased yield by 432.28% and 375.82% and increased <em>WUE</em> by 351.51% and 338.29%, respectively, compared with CK; with increased drought intensity, yield increased more obviously with the PM and SM treatments.Therefore, PM and SM can significantly promote water consumption, increase yield and improve <em>WUE</em> by a higher percentage in a drought year, although the effect is stronger with PM than with SM.

Effect of different organic manures on oil flax dry matter accumulation, distribution and yield

To realize oil flax(Linum usitatissimum Linn) high yield and good quality,field experiments were conducted in Baiyin and Lanzhou Cities of Gansu Province and Ordos City of Inner Mongolia Autonomous Region.The study compared the effects of the applications of four different fertilizers on oil flax dry matter accumulation and distribution and yield.The four fertilizers included farmyard manure(T3),oil flax residue(T4),and "Qingtiaobu"(T5) and "Woliheng"(T6) bio-fertilizers.Treatments without fertilizer(T1) and with chemical fertilizer(T2) were used as controls.The results showed similar trends in oil flax dry matter accumulation under all the fertilizer treatments in three different experiment sites with the order of T4 T2 T3 T6 T5 T1.Fitted logistic equations of oil flax dry matter accumulation in all the three sites were significant at P 0.01.The maximum rate of dry matter accumulation generally occurred at squaring stage,or at young fruit stage when planting date was delayed.Days for dry matter accumulation increasing with time in straight line and maximum accumulation rate in the three sites were in the order of T3 T2 T4 T5 T6 T1 and T4 T2 T3 T6 T5 T1,respectively.Dry matter distribution ratios of flowers and fruits at ripping stage under different organic fertilizer applications were higher than that under the controls.Pod number per plant,seed number per pod and thousand-grain weight of T4 were significantly(P 0.01) higher than those of the controls.Pod number per plant,seed number per pod and thousand-grain weight of T3 were higher than those of T2,but the differences were insignificant across the three experimental sites.Both T3 and T4 yields increased by 22.85%～45.40% and 62.83%～88.13% over treatments without fertilizer.Also yields of T5 and T6 increased by 15.14%～18.10% and 17.65%～21.01% over treatments without fertilizer.Yield of T4 significantly increased by 9.58%～39.49% over the treatment with chemical fertilizer.Yields of T5 and T6 significantly decreased by 14.63%～20.52% and 12.77%～18.57% over treatments with chemical fertilizer.Though yield of T3 decreased by 1.50%～8.91% over treatments with chemical fertilizer,the difference was not significant.Oil residue and farmyard manure were therefore the recommended fertilizers for enhanced development of organic production of oil flax.

Influence of Arbuscular Mycorrhizal Fungi and Pseudomonas fluorescens at Different Superphosphate Levels on Linseed (Linum usitatissimum L.) Growth Response

The aim of this study was to investigate the influence of arbuscular mycorrhizal fungi (AMF) Glomus mosseae (T.H. Nicolson & Gerd.) Gerd. & Trappe and Acaulospora laevis (Gerd. & Trappe) on linseed (Linum usitatissimum L.) growth response with phosphate solubilizing bacteria Pseudomonas fluorescens; different doses of superphosphate were used: 20 kg ha -1 (half recommended dose), 40 kg ha -1 (recommended dose), and 80 kg ha -1 (double recommended dose) in earthen pots filled with sterilized soil under greenhouse conditions. Among all the growth parameters, the following were the highest in the G. mosseae + P. fluorescens combination at the medium concentration (recommended superphosphate dose): plant height (78.74 ± 1.8 cm), fresh shoot weight (3.45 ± 0.294 g), dry shoot weight (0.57 ± 0.007 g), fresh root weight (0.223 ± 0.023 g), dry root weight (0.036 ± 0.004 g), root length (17.67 ± 0.48 cm), AM spore number (94.4 ± 9.86), shoot (1.14 ± 0.115%) and root (1.29 ± 0.110%) P content, and acidic (0.447 ± 0.012 IU g -1 FW) and alkaline phosphatase activity (0.119 ± 0.008 IU g -1 FW). The percentage mycorrhizal root colonization with the A. laevis + P. fluorescens (86.86 ± 2.17%) combination and chlorophyll content with the G. mosseae + A. laevis + P. fluorescens (0.474 ± 0.009 mg g -1 FW) combination recorded the highest values at the low concentration (half recommended superphosphate dose) as compared with non-mycorrhizal plants (control). The high superphosphate dose clearly reduced or decreased all the growth parameters. Therefore, vigorous growth and maximum flax yield can be achieved by inoculating plants with AM fungi and P. fluorescens with the recommended dose or less than the recommended dose of superphosphate.