Gaswechselmessungen an Fababohnen-Blättern (Vicia faba L.)

Measurement of gas exchange in faba-bean leaves ( Vida faba L.)
By means of gas-exchange measurements (minicuvette system and porometer), photosynthesis and its light dependence was investigated on attached leaves of different varieties of faba beans. The results showed no relevant difference in photosynthetic capacity for the varieties. This is true also for parameters calculated from light dependence, i.e. light compensation point, light saturation, and quantum yield. Generally, the light compensation point lay under 50 μE PAR/m²/s and light saturation was reached at about 1400 μE PAR/m²/ s. Photosynthesis was strongly dependent on leaf age and difference in photosynthetic capacity due to different varieties could be excluded as an essential reason for different rates of flowers dropping and pod dropping in faba beans.     

A Rapid Method for Measuring Freezing Resistance in Crop Plants

The objective of this study was to develop a technique based on chlorophyll fluorescence to assess freezing injury and resistance of leaves. Optimization was done with faba bean leaves and applicability to other crops was examined at winter and spring with types of barley, oats, rape and faba beans. Selected leaves from young hardened beans were subjected to standardized freezing tests with different minimum temperatures ( T _min) and fluorescence was monitored. After a dark period basic fluorescence ( F _O was induced by 0.2 μmol m⁻² s⁻¹ pulsed red light and maximum fluorescence ( F _m) was assayed at different light intensities. 1500 μmol m⁻² s⁻¹ rendered to give the maximum possible output of Fm and best differentiation of differently damaged leaves by F _n= F _m - F _O. Leaf temperature during measurement and during a short storage (± 2 h) should be kept at about 0°C to avoid biases between differently damaged leaves. The measuring spot on the leaf must be standardized since fluorescence response differed at the tip and base of a leaflet, but not between the two leaflets of a faba bean leaf. The applicability of F _rr (ratio of F _r of stressed to unstressed leaves) as a measure of resistance was demonstrated by comparison of winter hardiness of cultivars with freezing resistance calculated from the relationship of F _vr and the T _min used in freezing tests.     

Einfluß des Lichtangebotes auf das Wachstum und die biologische Stickstoff-Fixierung von Weißklee (Trifolium repens L.)

Influence of light quantity on growth and biological nitrogen fixation of white clover ( Trifolium repens L.)
The influence of photon irradiance (E_p; 100 to 500 μmol m⁻² s⁻¹) and of the photoperiod (16 or 11 h) on growth and nitrogenase activity of nodulated white clover plants was studied in growth chambers at two nitrate levels (1.0 and 7.5 mM NO₃⁻).
Total dry mass production, the root proportion and nitrogenase activity increased with increasing E_p and photoperiod. Nitrogenase activity generally increased proportionally to root mass. Only at low E_p (100 μmol m⁻² s⁻¹) and under a short photoperiod (11 h) was the specific nitrogenase activity per unit root mass reduced. An abrupt change in E_p led to a rapid and parallel change in nitrogenase activity and relative growth rate.
A higher NO₃⁻ concentration in the nutrient solution (7.5 mM) led to a marked decrease in specific nitrogenase activity, but increased growth between 200 and 500 μmol m⁻² s⁻¹ during early development only. At 100 μmol m⁻² s⁻¹, there was no growth response to nitrate, although its effect on nitrogenase activity was more marked than at a higher E_p.
The results show that with changing light quantity, biological nitrogen fixation of white clover adapts to the existing demand for nitrogen and does not limit growth except during early development, even when light supply is low.     

N2-Fixierung und Ertragsstruktur der Weißen Lupine (Lupinus albus L.) im Vergleich zu Vicia faba L. und Glycine max (L.) Merr. auf verschiedenen Standorten

N₂-Fixation and Yield Structure of White Lupin ( Lupinus albus L.) in Comparison to Vicia faba L. and Glycine max (L.) Merr. on Different Sites
In field studies white lupin ( Lupinus albus L., Eldo ) was compared with faba bean ( Vicia faba L., Herz Freya ) in 1986 and soybean ( Glycine max [L.] Merr., Gambit ) in 1988 on five sites respectively. Total N₂-fixation, which was determined by the extended difference method, and yield components were correlated to weather and soil conditions:
1. While faba bean responded to low pH with delayed nodulation, white lupin showed no decrease in N₂-fixation at pH less than 5.5 as far as soil was not calcareous.
2. The white lupin developed its root system most quickly into further soil depths and produced a root dry weight six times as large as that of faba bean in the soil layer 60-90 cm until the end of July (Bayreuth).
3. Despite on the calcareous sites the white lupin showed the highest total-N₂-fixation (max. 36 g N/m²) throughout, the N-gain for the succeeding crop was up to 8 g N/m² for white lupin and faba bean as well. In contrast the N-balance of soybean was mostly negative.
4. Seed yields of white lupin (48-450 g/m²) ranged between those of faba bean (145-549 g/m²) and of soybean (89-290 g/m²); its raw protein yields were the highest found (max. 158 g/m²) though.     

Seed Composition, Seedling Emergence and Early Seedling Vigour of Red Kidney Bean Seed Produced at Elevated Temperature and Carbon Dioxide

Understanding the influence of growth temperature and carbon dioxide (CO₂) on seed quality in terms of seed composition, subsequent seedling emergence and early seedling vigour is important under present and future climates. The objective of this study was to determine the combined effects of elevated temperature and CO₂ during seed-filling of parent plants on seed composition, subsequent seedling emergence and seedling vigour of red kidney bean ( Phaseolus vulgaris ). Plants of cultivar 'Montcalm', were grown at daytime maximum/nighttime minimum sinusoidal temperature regimes of 28/18 and 34/24 °C at ambient CO₂ (350 μmol mol⁻¹) and at elevated CO₂ (700 μmol mol⁻¹) from emergence to maturity. Seed size and seed composition at maturity and subsequent per cent emergence, early seedling vigour (rate of development) and seedling dry matter production were measured. Elevated CO₂ did not influence seed composition, emergence, or seedling vigour of seeds produced either at 28/18 or 34/24 °C. Seed produced at 34/24 °C had smaller seed size, decreased glucose concentration, but significantly increased concentrations of sucrose and raffinose compared to 28/18 °C. Elevated growth temperatures during seed production decreased the subsequent per cent emergence and seedling vigour of the seeds and seedling dry matter production of seed produced either at ambient or elevated CO₂.     

Differential Nitrogen Uptake, Utilization and Biomass Accumulation by Some Sorghum Cultivars

Five cultivars of sorghum viz: PU-7, Sarokartuho, Bagdar, Redjanpur and Potobar 4–8 were studied for their growth, N uptake and utilization efficiency at 5 mM N in solution culture. These cultivars differed significantly in their dry matter accumulation and relative growth rate of shoot. Differences in shoot/root of the cultivars were also notable. Markedly different mean N intake rate among the sorghum cultivars was 108 μmol g⁻¹ root dry wt. hr⁻¹ in Bagdar and 53 μmol g⁻¹ root dry wt. hr⁻¹ in PU-7 and Redjanpur. Both relative accumulation rate of N and efficiency of biomass accumulation per unit N absorbed also differed appreciably among the cultivars.     

Organic Recycling for Soil Quality Conservation in a Sub-tropical Plateau Region

The long-term effect of organic recycling on some aspects of quality in a lowland rice soil of an Indian plateau region was studied. The experiment was set up at the agricultural experimental farm of the Indian Statistical Institute, Giridih, Bihar, India. Two rice cultivars, and treatments with four organic supplements (cowdung manure, Leuceana leaves, decomposed farm residue and Sesbania ), chemical fertilizers (urea, superphosphate and muriate of potash) and no input were arranged in a factorial randomized block design. Organic supplements improved soil quality parameters such as water holding capacity, total organic C, microbial biomass C, urease and acid phosphatase activities of soils in comparison to chemical fertilizers and no input. Among the organic supplements, cowdung manure gave significantly higher organic C (1.39%), microbial biomass C (276.46 μg g⁻¹ dry soil), urease activity (32.79 and 21.22 μg urea hydrolized g⁻¹ dry soil h⁻¹ at 37 °C by the buffer and non-buffer method, respectively) and acid phosphatase activity (1.99 μmol p-nitrophenol released g⁻¹ dry soil h⁻¹ at 37 °C) than the others. The conversion of organic C into biomass C (2.46%) was highest in Leuceana -treated soil.     

Influence of Solar Radiation and Vapour Pressure Deficit on Transpiration Efficiency of Rainfed Sorghum

Besides assimilation, plant water relations are important aspects of physiological basis of productivity of crops in water limited environment. The relationships of photosynthesis rate, transpiration rate, leaf water potential and stomatal conductance with photosynthetically active radiation (PAR) and vapour pressure deficit (VPD) during pre-flowering (panicle initiation to ear emergence) and grain filling (from anthesis to maturity) stages of a sorghum hybrid (cv. CSH-6 ) grown under rainfed conditions were studied. Photosynthesis rate declined when PAR was above 1300 μmol m⁻² s⁻¹. during both the growth stages. Higher transpiration rate during grain filling stage at higher PAR caused the transpiration efficiency to be lower than during pre-flowering stage when PAR was above 1200 μmol m⁻²s⁻¹.Leaf water potential and stomatal conductance decreased with increase in PAR. Leaf water potential was higher during pre-flowering than during grain filling stage but maximum photosynthesis rate was similar during both the growth stages. Changes in VPD did not qualitatively alter the relationships of the physiological variables with PAR.
Decreasing photosynthesis rate and LWP at high PAR suggest that photosynthesis rate was limited by low leaf water potential when PAR was optimal, and by low PAR even when leaf water potential was high in rainfed sorghum during rainy season.     

Das optimale N-Angebot im Frühjahr bei unterschiedlicher Keimdichte von Winterweizen

The optimal N-supply in spring for different plant densities of winter wheat
The influence of plant density (plt./m²) on the optimal N-supply in spring (N_min-content + N-fertilization) has been tested at three sites. The different plant density was produced by different seed rates in autumn of about 150, 250, 350, 450 and 550 grains/m². The N-supply in spring was - apart from a non-fertilized field (N_min-content) 80, 100, 120, 140 and 160 kg N/ha. Additionally, 80 kg N/ha were applicated as N-topdressing. Moreover the optimal N-supply in spring has been tested on a winter wheat field thinned out due to winterkilling. In detail we got the following results:
1. The reduction of the N_min-content due to the N-uptake by the plants slowed down in accordance with minor plant density.
2. The same N-supply in the soil produced a higher N-supply per individual plant in accordance with decreasing plant density and lead to a considerable increase of N-nutrition.
3. Thin crops showed a higher tillering. The differences in plant density between 150 and 550 plt./m² in spring diminished to about 90 ears/m² at harvest.
4. Independently of plant density the maximum yield was obtained by a N-supply (N_min+ N-fertilization) in spring of about 120 kg/ha N. Due to the abundant N-nutrition of the individual plants and the minor increase of yield a higher N-supply is not necessary with a minor plant density.
5. Essentially the yield level was only diminished with the lowest plant density (100-140 plt./m²).     

Influence of Oil Seed Rape and Faba Bean as Green Manure on Nitrogen Utilization in a Spring Cereal Rotation

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.     

Intra-specific Variation for Salt Tolerance in Linseed (Linum usitatissimum L.)

Thirty-six accessions of linseed ( Linum usitatissimum L.) were screened for salt tolerance at the seedling stage after 2 weeks growth in solution culture salinized with 150mol m⁻³ NaCL Considerable variation in salt tolerance was observed in this set of germplasm. Two salt-tolerant accessions, T-5(69-S9)B and LS-2 and two salt-sensitive accessions P-70 and Aver-Rer-Seic, selected at the seedling stage, were grown to maturity in sand culture salinized with 0 (control), 70, 140, and 210 mol m⁻³ NaCl. Both the salt-tolerant accessions exceeded the two salt-sensitive accessions in biomass production, seed yield, and yield components, but the accessions did not differ significantly in seed oil content in the salt treatments. The tolerant accessions accumulated greater amounts of Na⁺ in the shoots and less in the roots compared with the salt-sensitive accessions. The shoot K⁺, K: Na ratios, and K⁺ versus Na⁺ selectivity were lower in the salt-tolerant accessions compared with the salt-sensitive accessions; the reverse was true for their roots. Contributions of Na⁺ and Ca²⁺ to osmotic adjustment were much higher in the two salt-tolerant accessions than in the salt-sensitive ones.
It has been established that there is a great deal of variation for salt tolerance in linseed. The degree of salt tolerance of this crop does not vary during ontogeny. The physiological basis of salt tolerance of this species appears to be associated with the inclusion of Na⁺ in the shoots.     

Correlation Studies on Ammonium/Nitrate Concentrations in Soil and Growth and Yield of Wheat

A field experiment was conducted at the Indian Agricultural Research Institute, New Delhi to study the growth and yield of wheat as influenced by the concentrations of ammonium-N and nitrate-N in soil. A series of ammonium and nitrate nitrogen concentrations in soil on a time frame was developed by treating prilled urea with nitrification inhibitors DCD or neem cake as well as by changing the dose and time of N application. The study revealed that number of tillers m^-1 as well as ears m^-1 row length were significantly positively correlated with ammonium-N concentration at 15 and 30 DAS and nitrate-N concentration at 30 and 45 DAS. Number of grains ear^-1 was significantly positively correlated with ammonium-N at 30, 45 and 60 DAS and nitrate-N at 45 and 60 DAS. Ultimately grain yield in wheat was significantly positively correlated with ammonium-N concentration at 15 and 30 DAS and nitrate-N concentration at 30, 45 and 60 DAS. The response between grain yield and concentrations of both ammonium and nitrate forms of N was quadratic. The optimum concentration of ammonium-N in soil for maximum grain yield gradually decreased with the age of the crop from 54.6 to 63.6 μg g^-1 at 15 DAS to 22.7 to 26 μg g^-1 at 30 DAS. In the case of nitrate-N its optimum concentration for maximum grain yield increased with age of the crop from 25.1 to 30 μg g^-1 at 15 DAS to 31.6 to 34 at 45 DAS and it decreased thereafter.     

Ergebnisse zur Ertragsbildung bei ökologisch orientiertem Winterweizenanbau auf Lößschwarzerdeböden in trockenen Lagen

Results of yield formation at ecological oriented winter wheat cultivation on Calcic Chernozem soil in arid areas
The influence were examined in field experiments of wheater elements (air temperature, precipitation), nitrogen fertilization, sowing rate and irrigation on the yield and yield formation of winter wheat stands. The average level of yields amounts to 81.3 dt/ha (76…93.8 dt/ha). Limiting factor for yields is the availability of water in the soil. In humide seasons 9…12 % higher yields were obtained then in dry seasons. Without nitrogen fertilization yields of winter wheat are lower by 18 % than with nitrogen fertilization. At very high level of N fertilization only vegetative biomass increases, and the water use efficiency decreases.
Increase in plants/m² caused a rise of vegetative biomass and of ears/m², kernels per ear strongly decreased in the same time. At winter wheat cultivation in low input farming systems without nitrogen fertilization high yields will be obtained with 320…370 plants/m² and 15,000 kernels/m². Nitrogen uptake from the soil amounts to 180 kgN/ha. Because of great amounts of inorganic in the soil (70…200 kgN/ha) sufficient nitrogen is available until heading of the wheat plants. The nitrogen supply of wheat plants in later stages of development is influenced by wheater conditions.     

Path Analysis of Important Growth Functions of Indian Mustard (Brassica juncea L. Czern and Coss)

Field experiment conducted at the Viswavidyalaya Farm during the winter seasons of 1980—81 to 1983—84 to study the effects of major six productive functions viz. number of inflorescence bearing primary branches, number of inflorescence bearing secondary branches, leaf area indices at flowering, number of seeds/siliqua, number of siliqua/m² and test weight of grains on the grain yields of eight elite varieties of Indian mustard ( Brassica juncea L. Czern and Coss) when sown on three different times revealed that correlations between them were close and positive in all the varieties. Path analysis of the data, further, showed that except the inflorescence bearing primary branches and the seeds/siliqua all other attributes showed high direct influences on grain yield; the maximum direct influence was obtained from number of siliqua/m².     

CO2浓度升高条件下不同氮素水平对小叶章光合特性和生长的影响

为阐明大气CO₂浓度升高和不同氮素水平对湿地植物光合生理特性和生长的影响,本研究以三江平原湿地优势植物小叶章(Calamagrostis angustifolia)为研究对象,通过野外原位控制试验,利用开顶式气室(OTC)模拟环境大气CO₂浓度变化,设置E₀(380 ±20 µmol/mol)、E₁(550 ±20 μmol/mol)和E₂(700 ± 20 μmol/mol)3个CO₂浓度;在每个OTC内设置 N₀(0 g N/m²)、N₁(4 g N/m²)和N₂(8 g N/m²)3个氮素水平。结果表明,N₀条件下,与E₀处理相比,E₁和E₂处理（72 天）后小叶章叶片净光合速率分别降低11%和12%(P<0.05),其叶片可溶性蛋白含量、氮素含量（CO₂熏蒸72 天）、小叶章株高（CO₂熏蒸86 天）均显著低于E₀处理(P<0.05);N₁条件下,与E₀处理相比,E₁和E₂处理（72 天）后小叶章叶片净光合速率降低5%(P>0.05)和10%(P<0.05),其叶片氮素含量(P<0.05)、小叶章株高均低于E₀处理;N₂条件下,E₁和E₂处理（72 天）小叶章净光合速率均呈稍增加的趋势(P>0.05),其叶片可溶性蛋白含量显著增加(P<0.05),氮素含量和小叶章株高无显著变化(P>0.05)。N₀、N₁和N₂条件下,CO₂浓度升高均显著增加了小叶章叶片可溶性糖含量。本研究表明长期CO₂浓度升高可能通过降低小叶章叶片光合酶活性,进而降低了其净光合速率,而施加高浓度的氮肥可以缓解长期高CO₂浓度对湿地植物光合及生长的负面影响。     

5种狼尾草属观赏草光合特性研究

为了解东方狼尾草(Pennisetum orientale)、绒毛狼尾草(P. setaceum)、‘小兔子’狼尾草(P. alopecuroide‘s Little Bunny’)、羽绒狼尾草(P. villosum)和‘紫光’狼尾草(P. alopecuroide‘s Ziguang’)5种观赏草光合特性,为引种驯化、园林应用提供理论依据,采用Li-6400便携式光合分析仪测定其光合特性指标。结果表明：5种狼尾草光合日进程均呈单峰型,无“午休”现象,‘紫光’狼尾草净光合速率和蒸腾速率在11∶30达最大值29.5μmolCO2/(m²·s)、5.94 mmolH2O/(m²·s),为5种狼尾草中的最高;东方狼尾草光补偿点最高为58.70μmol/(m²·s),绒毛狼尾草、‘小兔子’狼尾草、羽绒狼尾草相近,‘紫光’狼尾草最低为32.41μmol/(m·2 s);羽绒狼尾草光饱和点最高为2563.6μmol/(m·2 s),东方狼尾草最低为1615.4μmol/(m·2 s);5种狼尾草表观量子效率与耐荫植物接近,在0.059~0.061之间,其光能利用效率和水分利用效率均较高,表明5种狼尾草均为耐荫的阳性节水园林植物。     

白海棠不同类型枝条光合能力比较研究

为比较不同类型白海棠枝条光合能力的差异,以白海棠为试材,通过试验测定和数学模拟的方法研究长枝、中枝和短枝的光合能力差异。长枝、中枝和短枝的最大光合速率分别为16.3、14.5、9.68 μmol/(m² · s),光量子效率分别为0.053、0.047、0.042 μmol/μmol,这说明长枝的光合能力最强,其次为中枝和短枝。计算表明,在高辐射条件下[PAR=1500 μmol/(m² · s)],单位地面上长枝叶片的。光合总量为18.82 μmol/(m² · s),占整个树冠的73.15%,中枝和短枝只有5.19、1.73 μmol/(m² · s)。研究表明,长枝叶片的光合总量最大,这与其较强的光合能力和较大的叶面积有关。     

Effect of Foliar Applications of Glycinebetaine on Stress Tolerance, Growth, and Yield of Spring Cereals and Summer Turnip Rape in Finland

Crop losses caused by environmental stresses might be reduced by applying osmoprotectans to crop canopies. Glycinebetaine is endogenously accumulated by some halophytes under stress conditions and represents such a compound. Glycinebetaine was applied exogenously to barley ( Hordeum vulgare L.), oat ( Avena sativa L.), spring wheat ( Triticum aestwum L.), and summer turnip rape ( Brassica rapa ssp. oleifera DC.) canopies and its optimal concentration was monitored in the greenhouse. In field experiments the response of crop plants to betaine applications was assessed by measuring accumulation of above ground biomass, leaf area index (LAI), leaf chlorophyll, and yield. The optimum betaine concentration producing advantageous effects on growth and crop physiology in turnip rape was close to 0.1 M and for wheat 0.3 M. Such concentrations promoted accumulation of betaine similar to that of halophytes under stress conditions [ca. 200 μmol (g DM)⁻¹]. In the 1993 field experiment peak LAIs were recorded in irrigated wheat and barley treated with 17.5 kg ha⁻¹ betaine applied at 300 1 ha⁻¹. Green leaf area was slightly more persistent in wheat treated twice with 1 kg ha⁻¹ betaine applied at 200 1 ha⁻¹ in 1994, although it was not associated with increased grain yield. Our results indicated that betaine has no actual potential in Finland for the principal grain crops but further studies are needed in stress prone environments to assess the potential of betaine treatments for preventing crop failures.     

Micrometeorological Influences at High Crop Density on Different Genotypes of Silage Maize

In the year 1979, 1981 and 1982 two-factorial experiments with the factors genotypes and crop densities were conducted, connected with the following agrometeorological analyses:
a) outside the canopies: determination of air temperature, air humidity, wind velocity, precipitation, global radiation and photosynthetically active radiation (PAR)
b) in the interior of the canopies: measurements of air temperature at cobheight, of precipitation components, of the penetration of PAR and of the leaf area index.
The following results were obtained:
a) Influence of high crop densities
1. In high crop densities the greatest part of radiation was absorbed, so that at 30 plants/m² 57% and at 70 plants/m² only 28% of the PAR reached cob height.
2. As a consequence of temperature and decrease of radiation the contents in the leaves of biological energy, of water soluble K.H. and rough protein were reduced.
b) Influence of the leaf posture
3. For genotypes with erected leaf posture the leaf temperatures increased by 0.3°C, on the ground even by 1.2°C above the values of the stand with horizontal leaf posture.
4. Higher air temperatures were measured in the stands with erected leaf posture than in those with a horizontal one.
5. In the cool year 1981 on days with temperatures above 27°C outside the stands, those temperatures were exceeded during 7 hours in canopies with erected leaf posture at a higher plant density (30 plants/m²) and only during 2 hours in canopies with a horizontal leaf posture.     

Exogenously Applied Nitric Oxide Enhances the Drought Tolerance in Fine Grain Aromatic Rice (Oryza sativa L.)

Drought stress is a severe threat to the sustainable rice production, which causes oxidative damage and disturbs plant water relations, while exogenously applied nitric oxide (NO) may have the potential to alleviate these effects in rice plants. In this study, the role of NO to improve drought tolerance in fine grain aromatic rice ( Oryza sativa L. cv. Basmati 2000) was evaluated. Sodium nitroprusside, a NO donor, was used at 50, 100 and 150  μ mol l⁻¹ both as seed priming and foliar spray. To prime, the seeds were soaked in aerated NO solution of respective solution for 48 h and dried back to original weight. Primed and non-primed seeds were sown in plastic pots with normal irrigation in a greenhouse. At four leaf stage, plants were subjected to drought stress except the controls, which were kept at full field capacity. Drought was maintained at 50 % of field capacity by watering when needed. Two controls were maintained; both receiving no NO treatments as foliar application or seed treatment, one under drought conditions and the other under well-watered conditions. Drought stress seriously reduced the rice growth, but both methods of NO application alleviated the stress effects. Drought tolerance in rice was strongly related to the maintenance of tissue water potential and enhanced capacity of antioxidants, improved stability of cellular membranes and enhanced photosynthetic capacity, plausibly by signalling action of NO. Foliar treatments proved more effective than the seed treatments. Among NO treatment, 100  μ mol l⁻¹ foliar spray was more effective.