Response of okra plants to root and foliar applied boron.

Abstract

The response of okra plants (Hibiscus esculentus) to root‐and foliar‐applied B at 0, 2 and 4 ppm was investigated in solution culture. Root‐B application higher than 2 ppm resulted in severe root burn and toxicity in the plants, whereas foliar‐B application up to 4 ppm produced adequate plant growth. Chlorophyll and carotene content of the leaves, flower number, stem diameter, plant height and dry matter production were drastically reduced at high root‐applied B when compared to the foliar treatments. Significant negative correlation between root‐applied B and plant height, stem diameter, leaf and flower number was established. Except for a significant negative correlation with leaf number, all other growth components were positively correlated with foliar application of B. At 2 ppm B, leaf‐B, ‐P, ‐K and ‐Ca were higher at the root‐B than at the foliar‐B treatments. Foliar application of B was superior to root‐application as was observed in the healthy growth of the okra plant.     

Assessing soil properties and nutrient availability under conservation agriculture practices in a reclaimed sodic soil in cereal-based systems of North-West India

Soil quality degradation associated with resources scarcity is the major concern for the sustainability of conventional rice-wheat system in South Asia. Replacement of conventional management practices with conservation agriculture (CA) is required to improve soil quality. A field experiment was conducted to assess the effect of CA on soil physical (bulk density, penetration resistance, infiltration) and chemical (N, P, K, S, micronutrients) properties after 4 years in North-West India. There were four scenarios (Sc) namely conventional rice-wheat cropping system (Sc1); partial CA-based rice-wheat-mungbean system (RWMS) (Sc2); CA-based RWMS (Sc3); and CA-based maize-wheat-mungbean (Sc4) system. Sc2 (1.52 Mg m^?3) showed significantly lower soil bulk density (BD). In Sc3 and Sc4, soil penetration resistance (SPR) was reduced and infiltration was improved compared to Sc1. Soil organic C was significantly higher in Sc4 than Sc1. Available N was 33% and 68% higher at 0–15 cm depth in Sc3 and Sc4, respectively, than Sc1. DTPA extractable Zn and Mn were significantly higher under Sc3 and Sc4 compared to Sc1. Omission study showed 30% saving in N and 50% in K in wheat after four years. Therefore, CA improved soil properties and nutrient availability and have potential to reduce external fertilizer inputs in long run.     

Temporal Variations in Primary,Secondary, and Micronutrient Contents in Soil of Litchi Orchard

Litchi is one of the important subtropical fruit crops in the state of Jharkhand, occupying around 33,000 ha with production of about 165,000 metric tons. Considering the importance of soil analysis in litchi crops, the present investigation was carried out in an established orchard (begun in 1979) at the Horticulture and Agroforestry Research Program, Indian Council of Agriculture Research Complex for Eastern Region, Plandu (Ranchi), Jharkhand, India, to study the nutrient concentrations in soils of litchi and the interrelationships among available nutrient concentrations present in soil, and crop productivity in order to develop a sound fertilizer management program. Periodic collection of soil samples from the established orchard was carried out on the second week of every month during 2006–2007. Analysis of soil samples were carried out for macro- and micronutrients in soil. Mean soil nutrient contents for nitrogen (N), phosphorus (P), and potassium (K) were 232 kg ha^?1, 53 kg ha^?1, and 420 kg ha^?1, respectively. The greatest contents of N and K were observed at full canopy distance, whereas for that for P was at one-third and two-thirds the canopy distance. Mean soil nutrient contents were 1.52 C mol (P⁺) kg^?1, 1.11 C mol (P⁺) kg^?1, and 23 ppm for calcium (Ca), magnesium (Mg), and sulfur (S), respectively. The greatest contents of Ca and Mg were observed at one-third the canopy distance whereas that for S was at two-thirds the canopy distance. However, mean soil nutrient contents were 1.03, 53, 65, and 1.42 ppm for copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn), respectively. The greatest content of Fe was observed at two-thirds the canopy distance whereas that for Cu was at one-third the canopy distance. The greatest Mn content was observed for both two-thirds and full canopy distance whereas Zn contents had no significant differences among the canopy distances. However, soil sampling at two-thirds canopy distance from the trunk was observed to be ideal for soil analysis.     

不同浓度指数施肥方法下马来沉香与土沉香苗期需肥规律

设置每株施 N 0、 1000、 2000、 3000、 4000、 5000 mg 的6个氮素水平处理,进行珍贵树种马来沉香与土沉香苗期指数施肥试验,探讨不同氮素供应水平对其苗期生长、 叶片养分含量以及根系形态指标的影响,旨在揭示马来沉香与土沉香苗期的氮素需求特征,确定其适宜施氮量。结果表明,马来沉香与土沉香苗期的地径、 苗高以及生物量随着氮素供应水平的增加而增大,当每株施氮量大于3000 mg 后其生长和生物量趋于稳定; 施氮处理为3000 mg/plant时的马来沉香与土沉香根系各生长和形态指标均显著大于其他处理; 运用临界浓度法确定出马来沉香苗期叶片氮、 磷、 钾含量的临界值分别为35.55、 1.75、 17.99 g/kg,最适含量范围分别为35.55~53.11、 1.75~2.73、 17.99~26.63 g/kg; 土沉香苗期叶片氮、 磷、 钾含量的临界值分别为37.78、 3.08、 18.89 g/kg,最适含量范围分别为37.78~58.56、 3.08~4.44、 18.89~29.28 g/kg。综合3种养分的最适含量范围,推断出马来沉香和土沉香苗期的最适施氮量均为3000 mg/plant。     

Lettuce (Lactuca sativa L.) growth,yield and quality response to nitrogen fertilization in a non-circulating hydroponic system

The objective of this study was to determine the effect of nitrogen fertilization rate on growth and quality of leafy lettuce grown during the winter season in non-circulating hydroponic system. Plants were subjected to seven nitrogen (N) concentrations, i.e. 0, 30, 60, 90, 120, 150 and 180 mg L^?1 N using ammonium nitrate. Nitrogen treatments did not have a significant effect on leaf fresh and dry mass, root fresh and dry mass, number leaves and leaf area. Leaf ascorbic acid and total phenolic content, and antioxidant capacity peaked at 100 and 120 mg L^?1 N, whereas leaf chlorophyll concentration linearly increased with increasing N application. The results indicate that a solution N concentration of 100 and 120 mg L^?1 may be sufficient to improve growth, yield and quality parameters of leafy lettuce grown in non-circulating hydroponic system.     

Nutrient Stress,Ecophysiological, and Metabolic Aspects of Olive Tree Cultivars

This research, aimed at evaluating stress on the olive tree, utilized cultivars ‘Meski’ and ‘Chetoui’ in regards to the removal of major elements such as nitrogen (N), phosphorus (P), magnesium (Mg), and potassium (K). The experiment was conducted under greenhouse conditions in hydroponics culture. Measurements of leaf area showed a non-substantial and weak effect due to phosphorus, potassium, or magnesium deficiency compared to nitrogen. The growth analysis of dry matter showed an early depressive effect of nitrogen deficiency and a similar, but less important effect concerning phosphorus.

The induced nutritional stresses showed an important increase in stomata resistance, caused primarily by nitrogen or potassium deficiency, accompanied by a reduction of chlorophyll concentration, which resulted from the removal of phosphorus, magnesium, and mainly nitrogen supply. Remarkable starch synthesis and storage was also revealed following nitrogen deficiency, but it was very weak after the suppression of magnesium, which may provoke a weakening of growth and development of these plants.     

Nitrogen nutrition of guava trees in response to byproduct of fruit processing

Studies of the effect of organic fertilization of perennial crops are scarce due to the time necessary for the plants to present the first results. The objective of this study was to assess the leaf nitrogen (N) content, the direct and indirect measures of chlorophyll content, fruit yield and their correlations in an orchard of adult guava trees of the Paluma cultivar, through five consecutive harvests, in function of application of a byproduct of guava processing. The following doses of the byproduct were applied: 0, 9, 18, 27 and 36 t ha^?1. The material was applied on the surface, without incorporation, once a year between 2006 and 2010. The byproduct doses influenced the nitrogen concentrations, SPAD index, chlorophyll b level and fruit production.     

Effect of molybdenum,phosphorus, and lime application to acid soils on dry matter yield and molybdenum nutrition of lentil

Deficiency of molybdenum (Mo) in acid soils causes poor growth of pulses. An experiment was, therefore, conducted in greenhouse to study the effect of Mo, phosphorus (P), and lime application on the dry matter yield and plant Mo concentration of lentil (Lens esculenta L.) in two Mo‐deficient acid alluvial soils. The experiment was conducted using a factorial design with three levels of lime (no lime, half, and full lime requirement), three levels of P (0, 25, and 50 mg kg^‐1), and two levels of Mo (0 and 1.0 mg kg^‐1). Plants were grown for 60 days and at harvest their dry matter yield and Mo concentration were recorded. The three treatments significantly increased dry matter yield, Mo concentration and Mo uptake, the increase being most pronounced with Mo application followed by lime and P. Increases due to applied Mo were greater in presence than in absence of added P; while the reverse was true with the liming treatments. Liming and P application at their lower levels also interacted positively for better Mo nutrition of plants. Results thus indicated that the severity of Mo deficiency in the lentil plants may be reduced by lime and P application in Mo‐deficient acid alluvial soils.     

Interactions of soil microorganisms on growth and disease incidence of pepper (Capsicum annum)

The effect of interactions between soil borne pathogen, Phytophthora infestans the antagonistic organism Trichoderma viride and Arbuscular mycorrhizal Glomus etunicatum on growth and disease severity of pepper Capsicum annum was investigated in a greenhouse experiment. Pepper seedlings inoculated with the pathogen alone had sever disease symptoms. While those inoculated with mycorrhizal alone had the highest flowering and fruiting values, followed by the pepper seedlings inoculated with Trichoderma viride. But pepper seedlings simultaneously or dually inoculated with the three microorganisms also had good growth parameters, such as early and high flowering incidence, fruit maturity increase in leaf number, height and growth, while the effect of the pathogen was highly suppressed.     

Response to lime and P by several genetic sources of corn (Zsa mays L.) on a low pH and P soil in the greenhouse 1

The objective of this study was to investigate the response of 16 different genetic sources of corn (Zea mays L.) to lime and P application on a low pH and P Parsons silt loam soil in the greenhouse. A highly significant lime x P interaction was found for both dry matter production and P concentration. Phosphorus increased both dry matter production and P content of plant tissues with or without lime application. However, liming produced a detrimental effect when P was applied but no effect when no P was applied. Corn genetic sources showed a highly significant interaction with P treatment, but not with lime for both dry matter production and P concentration. The results suggest that improvement in corn growth could be achieved in a low P soil environment by genetic selection.     

黄土高原旱地小麦产量差异与产量构成及氮磷钾吸收利用的关系

【目的】针对我国黄土高原旱地小麦低产田块多、分布范围广、农户地块间产量差异大的问题,探索影响旱地小麦产量的关键因素,为缩小产量差异、提高旱地小麦产量提供理论依据。【方法】对分布在我国黄土高原的山西、陕西旱地小麦主产区的282个农户麦田0—100 cm土壤和小麦植株取样分析。将小麦产量分为高、中、低三组,分析了小麦产量差异与产量构成、氮磷钾吸收利用的关系。【结果】调查农户冬小麦产量平均为3815 kg/hm2,中、低产组分别比高产组低32%和57% (P < 0.05);高产组籽粒平均含氮量较低产组低7%,但磷钾含量和茎叶氮磷钾含量差异不显著。与高产组相比,中、低产组生物量分别低27%和50%,收获指数低5%和13%,穗数低15%和31%,穗粒数低19%和41% (P < 0.05);地上部吸氮量低28%和51%,吸磷量低32%和55%,吸钾量低28%和50% (P < 0.05)。低产组氮收获指数分别比高、中产组低5%和4%,磷收获指数低4%和3%,钾收获指数低13%和8%。高产组小麦的需氮量较中、低产组分别低5%和12% (P < 0.05),需磷量没有显著差异;高、中产组小麦的需钾量亦无显著差异,但分别较低产组显著低5%和15%。高产组小麦的氮生理效率较中、低产组分别高4%和11%,产量分组间小麦的磷生理效率同样没有显著差异;高、中产组小麦的钾生理效率无显著差异,分别较低产组显著高16%和10%。【结论】黄土高原旱地农户田块小麦产量存在显著差异,其中由氮素营养不同引起的干物质累积转移、产量构成和养分吸收分配的变化是导致产量差异的重要原因。缩小旱地小麦产量差异的切入点在于氮素调控。基于作物产量形成的养分需求优化肥料投入,结合改进栽培,促进小麦干物质累积,提高穗数和穗粒数,从而实现产量普遍提升。     

Effect of Different Nitrogen Doses on Dry Matter Ratio,Chlorophyll and Macro/Micro Nutrient Content in Sweet Herb (Stevia rebaudiana Bertoni)

With this study, the effect of different nitrogen (N) doses applied to sweet herb (0, 50, 100, 150 and 200 N kg ha^?1) on the macro/micro nutrient element content, dry matter ratio and on the chlorophyll amount in the plant leaves is examined. The research was carried out in the research and trial field of Faculty of Agriculture Agronomy department, Akdeniz University, during the 2012–2013 growing season under field conditions for 2 years with four replications according to the randomized block trial design. Chlorophyll amounts were determined and the average was obtained with three readings from each leaf by a chlorophyll meter when the plants were in the beginning of flowering. Post-harvest macro and micro nutrient elements of the sweet herb were also investigated. According to the obtained data, while the highest chlorophyll and N amounts in the leaf for both the first and second years were determined as 46.97 SPAD (Minolta Corp, NJ, USA) and 1.34 N% 44.9 SPAD, 1.42 N%, respectively, under 200 kg ha^?1 N application, the lowest chlorophyll and N amounts were determined in the control group. In addition, N application in different doses for both years increased the phosphorus (P) and potassium (K) contents and increased the microelement contents, especially in the second year. At the same time, a correlation between the chlorophyll content in the plant leaves and the N amount was determined and a linear increase was observed in the chlorophyll amount with the increased green part.     

Corn yield response to crowding stress and cropping season

Corn (Zea mays L.) is planted in two seasons per year in northern Iran (mid-April as a main crop and mid-June as a second crop). The main objective of this study was to determine whether corn yield response would differ between these two seasons and different plant populations. Two field experiments were conducted at the Agricultural Research Center of Golestan – Iran in 2007 and 2008 at different planting densities. The results showed that the values of grain yield and most traits were significantly lower in the second season. Maximum grain yield was observed at planting densities of 6.5 plants m^?2 in the first season, whereas in the second season grain yield was the same for planting densities between 2.5 and 12.5 plants m^?2. Based on the second-year experimental results, the following functions were fitted to show the relationship between yield ha^?1 (Y) and planting densities (X) for the first and second seasons, respectively: (Y = ?167.6X ² + 2672.2X + 511.77; R ² = 0.992) and (Y = 1200.1 ln(X) + 2924.4; R ² = 0.935). This study found that the optimum plant population was 6.5 plants m^?2 under low heat stress, and should be reduced to 2.5–4.5 plants m^?2 under heat stress conditions.     

Foliar fertilization of nickel affects growth,yield component and micronutrient status of barley (Hordeum vulgare L.) grown on low nickel soil

Foliar application of nickel (Ni) has higher use efficiencies and is preferred over soil application in view of its very low requirement. Pot experiments were conducted during winter season of 2012-2013 and repeated during 2013-2014. Treatments consisted of twelve Ni levels applied as nickel sulphate (NiSO4.7H₂O) spray (T₁-Ni_0%, T₂-Ni_0.05%, T₃-Ni_0.1%, T₄-Ni_0.2%, T₅-Ni_0.3%, T₆-Ni_0.4%, T₇-Ni_0.5%, T₈-Ni_0.6%, T₉-Ni_0.7%, T₁₀-Ni_0.8%, T₁₁-Ni_0.9%,and T₁₂-Ni_1.0%,) with recommended doses of fertilizers (RDF) applied in all pots. The result showed that growth and yield attributes viz. plant height, leaf greenness index, number of tillers, number of ears pot^-1, number of grains ear^-1, straw yield, grain yield and weight of 1000 grains of barley was the maximum with three foliar application of 0.2% of NiSO4.7H₂O (T₄-Ni_0.2%) at 20, 40, and 60 days after sowing (DAS) during both the years. The concentration of Fe, Mn and Zn in grain increased significantly up to T₄-Ni_0.2% and after this level, a significant decline was recorded during both the years. As regards to the concentration of Ni is concerned, it increased significantly both in grain and straw with increasing levels of Ni spray and the maximum concentration was at T₁₂-Ni_1.0%, during both the years. The uptake of Fe, Mn, Cu and Zn in grain of barley increased significantly during both the years up to T₄-Ni_0.2%,thereafter, it declined significantly with successive increase in dose of Ni spray. Thus 0.2% foliar spray of NiSO4.7H₂O significantly increased growth, yield and Fe, Cu, Mn, Zn (micronutrients) status in barley.     

钼氮配施对烤烟钼吸收和分配的影响

通过盆栽试验研究了钼、氮配施对烤烟钼吸收、积累和分配的影响。结果表明,3个氮水平下,施钼均可显著增加烤烟团棵期、旺长期、打顶期和成熟期的烟叶钼含量和钼累积量,且钼含量和钼累积量随施钼量增加而增加;钼、氮对烟叶的钼含量和钼累积量有显著的负交互效应,随着氮水平的提高,烤烟烟叶的钼含量和积累量呈下降趋势;旺长期到打顶期是烤烟烟叶的钼累积速率快速增长期,烟叶的钼累积高峰均出现在移栽后62 d;在N2(0.24 g/kg)和N3(0.42 g/kg)水平下施钼可增加钼在上部叶中的分配比例,降低钼在下部叶的分配比例。     

黑龙江大豆-玉米轮作体系氮磷调控的产量效应与养分平衡

为探究适宜于黑龙江垦区大豆-玉米轮作体系下最优的施肥模式,在黑龙江省九三管局鹤山农场科技园区进行田间定位试验,以大豆-玉米轮作体系作为研究对象,为保证一个轮作周期施肥总量不变,于大豆茬口实施减氮增磷方案,玉米茬口实施增氮减磷方案,来研究不同氮磷调控处理对大豆-玉米轮作体系作物生长、养分累积量、土壤收支平衡及经济效益的影...     

Differential response of soybean genotypes to two lime rates

Soybean [Glycine max (L.) Merril] is the leading food crop worldwide, and selection of soybean genotypes for different levels of soil acidity may raise crop yield without the need to increase in planted area. An experiment in greenhouse conditions was conducted to determine the effects of two lime rates on soil chemical properties, grain yield (GY), yield components, nutritional status and physiological components of 15 soybean genotypes adapted to tropical and subtropical conditions. Genotypes BMX Apolo RR, BMX Potência RR, BRS 295RR, BRS 359RR, FPS Solar IPRO and TMG 716 IRR were the least responsive to soil acidity reduction, and BMX Turbo RR and BRS 360RR were the most responsive. Number of pods per pot, shoot dry weight yield, GY, photosynthesis, stomatal conductance, transpiration and chlorophyll increased significantly with increase in lime rate. Cultivar FPS Solar IPRO showed the highest foliar P, K, Ca and Mg concentrations in soybean, which was not observed in the grain, indicating the presence of genetic factors and the dilution effect on nutrient uptake.     

营养液对鸭儿芹幼苗生长、抗氧化酶活性及叶绿素荧光参数的影响

为了探索适合鸭儿芹幼苗生长的营养液浓度,分别研究了6种山崎营养液浓度（1/12s、1/10s、1/8s、1/4s、1/2s和1s)对鸭儿芹幼苗生长及叶绿素荧光参数的影响。结果表明,在1/8s浓度下,鸭儿芹幼苗的各生长因子（株高、单株叶面积、茎粗、地上部鲜重、干重,地下部鲜重、干重,株鲜重、干重）均达到最大。壮苗指标随着营养液浓度的增大出现先上升后降低的趋势,在1/8s浓度下亦达到最大,且显著高于其它处理(P 0. 05)。在1/12s～1/8s的浓度变化下,随着营养液浓度的增大,POD、CAT以及SOD活性在逐渐上升,MDA含量在逐渐降低,而在1/8s~1s的浓度变化下,随着营养液浓度的增大,POD、CAT以及SOD活性在逐渐降低,MDA含量在逐渐上升,在1/8s浓度下POD、CAT以及SOD活性达到最大,MDA含量达到最小。叶绿素a、叶绿素b及叶绿素总量出现先上升后下降的趋势,在1/8s浓度下均达到最大。1/4s～1s浓度,初始荧光（Fo）值均高于1/12s～1/10s处理,而最大荧光（Fm）、PSⅡ的潜在活性（Fv/Fo）、PSⅡ最大光化学效率（Fv/Fm）值分别低于1/12s～1/10s处理;1/8s浓度的Fo值达到最小,而Fm、Fv/Fo、Fv/Fm值达到最大。实验表明了营养液浓度对鸭儿芹幼苗具有双重作用,即低浓度下随浓度的升高,营养胁迫逐渐减低,促进幼苗生长;高浓度下随浓度的升高,营养胁迫逐渐增强,抑制幼苗生长。结果得出,采用1/8浓度的山崎配方是鸭儿芹幼苗生长的最适营养液浓度。     

Foliar application of iron,zinc, and manganese nano-chelates improves physiological indicators and soybean yield under water deficit stress

Abstract

To investigate the effect of foliar application of nano-chelates of iron, zinc, and manganese subjected to different irrigation conditions on physiological traits, and yield of soybean (cultivar M9), a split plot experiment was conducted in a completely randomized block design with three replications in two crop years (2016–2017). The main plot included four levels of irrigation (I): full irrigation (I ₁), irrigation withhold at flowering stage (I ₂), irrigation withhold at podding stage (I ₃), and irrigation withhold during the grain filling period (I ₄). Also, the subplot included eight levels of foliar application with Fe, Zn, Mn, Fe?+?Zn, Fe?+?Mn, Zn?+?Mn, Fe?+?Zn?+?Mn nano-chelates, and distilled water (control). The results of combined analysis of variance suggested that the effect of irrigation and foliar application of nano-chelate was significant on all traits. Water deficit stress significantly reduced the grain yield. The minimum numbers of pods per plant, number of grains per plant, 100-seed weight per plant, leaf area index, leaf chlorophyll concentration, total dry weight of plant, and the grain yield were obtained by irrigation withhold at podding stage. Foliar application of combined nano-chelates increased the soybean resistance against water shortage more considerably than the separate consumption of these elements. Under drought stress in podding stage, the application of Fe?+?Zn led to the highest yield with a mean of 2613.84?kg ha^?1 where this increase was 61.1% higher than control.     

在施钾条件下灌溉水稻的养分吸收和利用效率研究

Potassium is one of the most important nutrients for rice production in many areas of Asia, especially in southeast China where potassium deficiency in soil is a widespread problem. Field experiments were conducted for four consecutive years in Jinhua City, Zhejiang Province, to determine utilization of nutrients (N, P and K) by inbred and hybrid rice and rice grain yields as affected by application of potassium fertilizer under irrigated conditions. Grain yield and nutrient harvest index showed a significant response to the NPK treatment as compared to the NP treatment. This suggested that potassium improved transfer of nitrogen and phosphorus from stems and leaves to panicles in rice plants. N and P use efficiencies of rice were not strongly responsive to potassium, but K use efficiency decreased significantly despite the fact that the amount of total K uptake increased. A significant difference between varieties was also observed with respect to nutrient uptake and use efficiency. Hybrid rice exhibited physiological advantage in N and P uptake and use efficiency over inbred rice. Analysis of annual dynamic change of exchangeable K and non-exchangeable K in the test soil indicated that non-exchangeable K was an important K source for rice. Potassium application caused an annual decrease in the concentration of available K in the soil tested, whereas an increase was observed in non-exchangeable K. It could be concluded that K fertilizer application at the rate of 100 kg ha^-1 per season was not high enough to match K output, and efficient K management for rice must be based on the K input/output balance.