谷子播期对谷子/花生间作系统生产力的影响

间作作物的播期会影响其共生期,进而影响作物生产力和种间相互作用。为探究谷子(Setaria italic L. Beauv)播期对谷子/花生(Arachis hypogaea L.)间作系统生产力的影响,以谷子金选6号和花生大花生606为试验材料,固定花生播期为5月15日,谷子从5月15日至6月9日每5天播种1期,共设置6个播期处理(S1~S6)。通过对单间作系统中作物产量、产量构成因素等指标的测定,分析不同谷子播期条件下谷子/花生间作的作物产量、系统生产力、种间竞争力的变化。结果表明,随着谷子播期的推迟,间作系统中谷子和花生的产量均表现为先升高后降低的趋势,5月25日播种时(S3)谷子产量(4.07 t·hm^-2)和土地当量比(LER=1.24)最大,5月30日播种时(S4)花生产量(2.51 t·hm^-2)、间作总产值(4.64万元·hm^-2)和间作系统生产力(SP=2.93 t·hm^-2)最大;谷子/花生间作系统的实际产量损失大于0,具有产量优势。谷子的侵占力大于0、竞争比率大于1,花生的侵占力小于0、竞争比率小于1,间作系统中的谷子是竞争优势作物,对资源的竞争能力高于花生且受谷子播期影响较大。相关性分析及通径分析发现,在间作系统中,谷子产量与穗长呈显著正相关,与穗粗、穗重、穗粒重呈正相关,且穗长对谷子产量的贡献作用最大。本研究结果对谷子/花生间作实践具有指导意义。     

Enhancing nutrient translocation,yields and water productivity of wheat under rice–wheat cropping system through zinc nutrition and residual effect of green manuring

Abstract

Efficient nutrient and water use are two important considerations to obtain good harvests of wheat. This necessitates the development of an effective nutrient management technique that not only increases yield, but simultaneously can save nutrient and water use. In this context, a field experiment was conducted at Indian Agricultural Research Institute, New Delhi, India to evaluate the residual effect of sesbania and rice bean (in-situ), subabul (ex-situ) green manuring and Zinc (Zn) fertilization, using chelated Zn-ethylenediaminetetraacetic acid (Zn-EDTA) on nutrient use, yields and water productivity of wheat under rice–wheat cropping system. Among residual effects of green manure crops and Zn fertilization, sesbania and foliar spray of 0.5% chelated Zn-EDTA at 20, 40, 60 and 80 days after sowing (DAS) recorded significantly higher nutrient content and uptake and yields than other green manure crops and Zn treatments. Residual effect of sesbania saved about 46.5?×?10³ and 30.5?×?10³ L irrigation water per tonne of wheat over subabul and rice bean, respectively. Foliar spray of 0.5% chelated Zn-EDTA at 20, 40, 60 and 80 DAS saved about 55.5?×?10³, 47?×?10³ and 13?×?10³ L irrigation water per tonne wheat over residual effect of 5?kg Zn ha^?1 through chelated Zn-EDTA as soil application, 2.5?kg Zn ha^?1 through chelated Zn-EDTA as soil application + 1 foliar spray of 0.5% chelated Zn-EDTA at flowering and foliar spray of 0.5% chelated Zn-EDTA at active tillering?+?flowering?+?grain filling, respectively. Correlation analysis showed positive correlation between Zn uptake and grain yield.     

外源放线菌对谷子生长和成熟期根际可培养微生物的影响

为研究外源放线菌对谷子生长及成熟期根际可培养微生物的影响，本研究通过盆栽和田间试验分析施加放线菌微白黄链霉菌（Streptomyces albidoflavus，T4）和密旋链霉菌（Streptomyces pactum，Act12）后成熟期谷子生物量、产量形成指标及根际可培养微生物结构组成的差异，并对谷子生长与根际微生物之间相互关系进行分析。结果表明，①T4促进了盆栽和田间试验中谷子生物量的增加，而T4和Act12也使田间试验中单株谷子籽粒干重和产量增加了13.7%～22.6%。②对于根际微生物，T4处理使培养箱盆栽试验中谷子根际可培养细菌（B）、真菌（F）、放线菌（A）及微生物总数量增加了29.5%～56.9%。T4和Act12使室外盆栽试验中根际真菌数量分别提高了73.3%和222.0%，A/F和B/F降低了34.7%～72.4%。③相关分析表明，成熟期谷子茎叶干重、单株谷子籽粒干重与根际B、F、A和总微生物数量显著正相关（r = 0.748～0.971，P < 0.01），而与A/F和B/F显著负相关（r = -0.764 ～ -0.906，P < 0.01）。综上，供试放线菌通过调整根际可培养微生物群落结构促进了谷子生长，增加了谷子产量。因此，通过外源施加放线菌优化根际可培养微生物群落结构是谷子促生增产的可行途径之一。     

多效唑和乙烯利对谷子穗颈、穗部性状及灌浆的影响

为探究既能抑制谷子植株的贪青徒长,又不影响谷子产量的最佳多效唑和乙烯利处理,以农大8号为试验材料,采用随机区组设计,在谷子不同生育时期分别叶面喷施多效唑和乙烯利,研究2种植物生长调节剂单施[多效唑分别于拔节期前(A1)、拔节期(A2)、孕期期(A3)喷施;乙烯利分别于孕穗期(B1)、抽穗期(B2)、灌浆期(B3)喷施]和互作(A1B1、A1B2、A1B3、A2B1VA2B2、A2B3VA3B1、A3B2、A3B3)对谷子穗颈、穗部性状及灌浆的影响。结果表明,多效唑、乙烯利单施处理下,谷子穗颈粗、穗颈干物质显著提高,但其他穗颈参数无显著差异;谷子穗粗显著增加,在A1处理下达到最大值,较CK增加5.39%,穗重、穗粒重均在B2处理下最高,较CK分别增加7.25%、6.94%,穗长、穗码数无显著差异;籽粒灌浆速率有所提高,但秕谷率无显著变化。多效唑、乙烯利互作处理下,谷子穗颈粗、穗颈抗折力及干物质重显著增加,穗颈弯曲力矩、穗颈重心高度及含水量明显下降;谷子的穗长、穗码数显著减少,穗粗显著增加,在A1B3处理下达到最大,与CK相比,其穗长、穗码数分别减少20.11%、9.75%,穗粗增加10.15%,穗重、穗粒重均在A2B2处理下达到最大值,较CK分别增加11.45%、9.50%;随着籽粒灌浆速率的提高,秕谷率显著降低,在A2B2处理下达到最小值,较CK降低50.00%。表明与单施相比,两种调节剂互作效应更显著。在谷子拔节期前或拔节期喷施300 mg·L^-1多效唑后,在抽穗期或灌浆期追施400 mg·L^-1乙烯利最为适宜,而在孕穗期追施乙烯利会降低穗粒重,导致产量下降。本研究结果为谷子的化学调控和高产栽培提供了理论依据。     

Increased yield of direct seeded rice (Oryza sativa L.) by foliar fertilization through multi-component fertilizers

Foliar application of fertilizers can guarantee the availability of nutrients to rice for obtaining higher yield. Rice responds favorably to macro- and micronutrients and the tolerance to salinity hazards improves by decreasing the N/S ratio. In this study, results showed that nutrient concentrations (g L^?1) for rice are: nitrogen (N) 108.0, phosphorous (P₂O₅) 6, potassium (K₂O) 81.0, calcium (CaO) 15.0, and magnesium (MgO) 6 g L^?1; and for iron (Fe), manganese (Mn), zinc (Zn), cupper (Cu), boron (B), molybdenum (Mo) and silicon (Si) the recommended concentrations are 0.6, 0.45, 0.21, 0.06, 0.09, 0.0002 and 0.004 g L^?1, respectively. A significant increase was recorded in number of panicles m^?2, 1000 grain weight, biological yield and grain yield with foliar application of nutrients. Five foliar applications of nutrients resulted in maximum number of panicles m^?2, grains panicle^?1, 1000 grain weight and biological yield. It is concluded that five foliar applications of balanced amounts of fertilizers at the seedling stage (two sprays), tillering (single spray) and at panicle initiation and panicle differentiation (two sprays) helped in enhancing yield and yield components of rice. In this research, five foliar applications produced the smallest damaging effects of blast (Pyricularia oryzae) in rice.     

Yield and yield components of white bean (Phaseolus vulgaris L.) cultivars affected by boric acid rates and methods of application

To investigate the effect of boric acid on yield and yield components of three white bean cultivars consisted of Jules, G11867, and Shekoofa, a 2-year field split-plot experiment was carried out based on a randomized complete block design with three replications during 2013 and 2014. Boron treatments consisted of 1 – control (no boric acid), 2 and 3 – application of 2 and 4?kg ha^?1 of boric acid by irrigation water, respectively, 4 and 5 – foliar spray of 0.025% and 0.05% of boric acid solutions, respectively, and 6 – combination of 2?kg ha^?1 of boric acid in irrigation water?+?foliar spray by 0.025% boric acid solution. Boron application significantly increased yield and its components in respect to control. The highest grain yields of all cultivars were obtained from application of 2?kg ha^?1 boric acid mixed in irrigation water?+?foliar spray by 0.025% of boric acid solution.     

谷子光合特性及产量最优的氮磷肥水平与细胞分裂素6-BA组合研究

【目的】谷子的干物质90%来源于光合作用,提高谷子群体光能利用,维护中上部叶片较大的光合速率及持续时间对于产量形成十分重要。研究合理施肥对谷子光合特性的影响将为谷子生产提供合理施肥依据。【方法】以张杂谷5号为试材,采用三因素二次通用旋转组合设计进行田间试验。设5个氮水平为22、 69、 138、 207、 254 kg/hm2; 5个磷(P2O5)水平为11、 36、 72、 108、 133 kg/hm2;细胞分裂素6-BA [0.5%(v/v)]于开花期开始,每天16:00左右叶面喷施,连喷4 d。灌浆期调查旗叶叶绿素含量、净光合速率、叶面积系数和产量。【结果】随着施磷量的增加,叶片净光合速率、叶面积系数先迅速上升后缓慢下降;随着喷施6-BA浓度的增加,叶片净光合速率、叶面积系数先迅速上升后下降明显。叶绿素含量受氮、磷、6-BA影响显著,三个因素变化趋势比较一致,随着施氮、磷的用量和喷施6-BA的浓度升高,叶绿素含量均呈先增后降的趋势,产量也随氮、磷、6-BA的水平变化显著。根据一次项对产量的作用方程来看,增产作用磷6-BA氮。在供试施用水平内,氮、磷、6-BA对产量的影响均呈抛物线状,随着施磷的增加,产量先迅速增加后缓慢下降,随着施氮量、6-BA用量的增加,产量先迅速增加后下降明显。氮肥和细胞分裂素6-BA之间交互作用对叶绿素含量、净光合速率、叶面积系数和产量均有显著影响。【结论】在供试条件下,适宜氮磷施用水平配合喷施6-BA可显著增加谷子的叶面积系数、叶绿素含量和净光合速率,超过适宜用量后,降低作用也很明显。氮、磷、6-BA与产量间回归关系极显著,拟合程度较高,可用于实际产量预测。对于张杂谷5号,最高产量为N175.0 kg/hm2,P2O5 94.3 kg/hm2,喷施6-BA 11.8 mg/L,预期产量为6629 kg/hm2。     

Zinc fertilization approaches for agronomic biofortification and estimated human bioavailability of zinc in maize grain

Maize (Zea mays L.) is generally low in bioavailable zinc (Zn); however, agronomic biofortification can cure human Zn deficiency. In the present experiment, Zn was applied in pots as ZnSO₄ · 7H₂O to maize cultivar DK-6142 as foliar spray (0.5% w/v Zn sprayed 25 days after sowing and 0.25% w/v at tasseling), surface broadcasting (16 kg Zn ha^?1), subsurface banding (16 kg Zn ha^?1 at the depth of 15 cm), surface broadcasting + foliar and subsurface banding + foliar in comparison to an unfertilized control. As compared to control, all treatments significantly (P ≤ 0.05) increased growth, yield and nutritional attributes in maize. Grain Zn and protein concentrations were correlated and ranged from 22.3 to 41.9 mg kg^?1 and 9 to 12 %, respectively. Zinc fertilization also significantly reduced grain phytate and increased grain Zn concentration. Zinc fertilization, especially broadcasting and subsurface banding combined with foliar spray decreased grain [phytate]:[Zn] ratio to 28 and 21 and increased Zn bioavailability by trivariate model of Zn absorption to 2.04 to 2.40, respectively. Conclusively, broadcasting and subsurface banding combined with foliar spray is suitable for optimal maize yield and agronomic Zn biofortification of maize grain. This would also be helpful to optimize Zn and protein concentration in maize grain.     

Effect of Seeding Rate and Nitrogen Fertilization on Proso Millet Under Dryland and Irrigated Conditions

Proso millet (Panicum miliaceum L.) is a short-season grain crop in semi-arid regions of North and South America and Asia. The objective of this study was to evaluate seeding rates and nitrogen (N) fertilization on proso millet seed yield, crude protein levels, and biomass yield under irrigated and dryland conditions in a Mediterranean-type transition climate near Bursa, Turkey. Seeds per panicle, panicle length, seed weight per panicle, fertile tillers, protein yield, and plant height were also evaluated. Results indicated seeding rate did not affect seed yield significantly. Seed and protein yield increased with increasing N doses although biomass did not significantly increase. Panicle length, seeds per panicle, and seed weight per panicle decreased with increasing seeding rates. This study proved proso millet can be grown for grain and forage as a short-season dryland and irrigated rotational crop in a Mediterranean-type climate.     

大气CO2浓度升高对谷子生长发育及玉米螟发生的影响

人类活动导致全球大气CO_2浓度持续升高,研究大气CO_2浓度升高对C4作物谷子(Setaria italica)生长发育及虫害发生的影响,可以为谷子等C4作物制订应对气候变化栽培措施提供理论依据。本研究利用OTC(Open Top Chamber)系统,设两个CO_2浓度梯度(正常大气CO_2浓度、正常CO_2浓度+200μmol·mol-1)模拟CO_2浓度升高对谷子生长发育的影响。结果表明:大气CO_2浓度升高后,谷子净光合速率(Pn)、气孔导度(gs)、叶片蒸腾速率(Tr)和水分利用率(WUE)分别增加38.73%、27.53%、6.93%和40.56%;谷子叶片光系统Ⅱ最大光化学量子产量(Fv/Fm)和非光化学淬灭系数(NPQ)显著下降,光系统Ⅱ实际光化学量子产量(ΦPSII)和表观电子传递效率(ETR)显著增加,而对光化学淬灭系数(q P)无显著影响;此外,谷子株高、茎粗和小穗数分别增加3.41%、13.28%和13.11%;而叶重、茎重、千粒重、单株粒数和产量无显著变化,穗重和地上部分生物量分别显著下降12.8%和7.44%;大气CO_2浓度升高后,谷子灌浆期和收获期玉米螟(Ostrinia furnacalis)发生数量显著增加。大气CO_2浓度升高将有利于谷子的生长发育,但会增加玉米螟危害。     

种植草本植物狗牙根改良滨海黏性盐碱地的研究

为探明不同轮作模式对宁夏南部山区旱地农田土壤肥力和谷子产量的影响，基于连续8年定位试验，研究了谷子连作（R0）、谷子–小麦–糜子轮作（R1）、谷子–胡麻–豌豆轮作（R2）和谷子–豌豆–马铃薯轮作（R3）处理对谷子产量及土壤物理和化学性质的影响。结果表明：经过两个轮作周期后，与R0处理相比，R2处理谷子产量增加13.10%，R1处理产量略有降低，R3处理产量显著降低（P<0.05）。各轮作模式均有利于降低土壤容重，提高土壤田间持水量，并且R1和R2处理土壤容重显著低于R0处理；除R3处理外，R1和R2处理有利于增加土壤孔隙度，与R0处理相比增幅分别为15.09%和21.18%。各轮作模式均有利于增加土壤>0.25 mm大团聚体总量，其中R1和R2处理可以显著降低土壤中<0.25 mm和2~0.25 mm团聚体数量（P<0.05），并显著增加>2 mm团聚体比例。各轮作模式土壤有机质含量均高于R0处理，土壤全量养分含量差异不明显；各轮作模式均有利于增加土壤微生物生物量碳、氮和有效磷含量，同时R2处理还有利于增加土壤碱解氮、速效钾和微生物生物量磷含量。综上，轮作有利于旱地土壤有机质积累，降低土壤容重，增加大团聚体数量，提高土壤微生物生物量，但不同轮作模式间存在差异，其中，R2处理更有利于增加谷子产量、改善土壤结构、培肥土壤，可以作为宁夏南部山区雨养农业旱作区的优选作物轮作模式进行推广。     

不同生态区骨干谷子品种表型鉴定与遗传分析

骨干谷子品种对谷子产业发展发挥了重要的作用,为了解其优异性状遗传基础及利用价值,选用来源于不同生态区的12个骨干谷子品种,进行表型鉴定和遗传差异分析。结果表明,12个来源于不同生态区的骨干品种在株高、穗长、穗粗、穗下节间长、单穗重、生育期以及黄色素含量等方面差异较大。79对SSR多态性标记共检测到258个多态性变异位点,平均3.265 8个;SSR标记多态性(PIC)的变幅为0.141 1~0.711 6,平均为0.510 1;其中PIC>0.5的SSR标记有50对,占多态性标记的63.3%。12份材料的遗传距离变幅为0.140 2~0.801 1,平均为0.473 7;来自华北夏谷区的豫谷1号和沧谷4号遗传距离最近,而沧谷4号和来自内蒙高原的地方品种金香玉距离最远;总体而言,华北夏谷区品种和西北早熟春谷区品种遗传距离相对较大。相似性系数为0.594时,12个品种可聚为两类,华北夏谷区的豫谷1号、矮88、冀谷19号、沧谷4号和济谷12聚为一类,来自西北春谷早熟区、晚熟区和东北春谷区的7个品种聚为一类,聚类分析结果和品种的生态类型具有较高的一致性。群体结构分析和聚类分析的结果相似,华北夏谷区品种和春谷区品种之间存在基因交流。总之,不同生态区来源品种间遗传差异较大,同一生态区来源品种遗传差异较小;华北夏谷区骨干品种之间遗传差异较春谷区品种遗传差异相对较小;华北夏谷区品种和西北早熟春谷区品种间遗传差异较大,丰富华北夏谷区遗传变异,应加强与西北早熟春谷区品种之间的交流。本研究结果为优异谷子品种培育及种质资源利用提供了一定依据。     

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.     

Efficiency of Potassium Fertilization and Salicylic Acid on Yield and Nutrient Accumulation of Sugar Beet Grown on Saline Soil

Rising soil salinity has been a major problem in the soils of Egypt in recent decades. Potassium fertilization and salicylic acid (SA) play an important role in promoting plants to tolerate salt stress and increased the yield of sugar beet crop. A field experiment on sugar beet (Beta vulgaris L.) grown on saline soil was carried out during 2014 growing season in Port Said Governorate, Egypt, to study the effect of potassium fertilization of the soil at applications of 0, 100, 150, and 200 kg potassium (K) ha^?1 and foliar spray of SA by solution of 1000 mg L^?1, twice (1200 L ha^?1 each time) on yield and nutrient uptake. Application of 200 kg K ha^?1 in combination with salicylic foliar spray gave the highest root length, root diameter, shoot and root yield, sucrose, juice purity percentage, gross sugar yield, and white possible extractable sugar, nitrogen (N), phosphorus (P), and potassium (K) content, and uptake of sugar beet. The highest increase in sucrose (20%) as well as white possible extractable sugar (184%) was obtained by 200 kg K ha^?1 in combination with salicylic foliar spray compared with untreated soil with potassium fertilization and without salicylic foliar spray.     

Zinc bioavailability and nitrogen concentration in grains of wheat crop sprayed with zinc sulfate,ammonium sulfate,ammonium chloride,and urea

Abstract

It is still unclear if different sources of nitrogen (N) can variably influence grain accumulation of zinc (Zn), N, and phytate. We tested foliar treatments of 0 or 0.25% Zn as zinc sulfate in combination with 0 or 1% N as ammonium chloride, ammonium sulfate or urea sprayed on field-grown-wheat (Triticum aestivum L.) foliage at anthesis and 10 days later. Leaf burning caused by ammonium chloride significantly decreased grain yield. Grain N concentration was the highest in the urea +0.25% Zn treatment. Foliar N application influenced grain Zn concentration only if Zn was included in the spray. Grain phytate concentration was significantly decreased by both N and Zn sprays. Estimated Zn bioavailability in grains was the highest at 0.25% Zn and was not influenced by the N sources. Based on grain yield, grain N concentration, and Zn bioavailability in grains, foliar application of Zn?+?urea is an optimal strategy.     

Development of EST-SSR in foxtail millet (<Emphasis Type="Italic">Setaria italica</Emphasis>)

The development of EST-SSR in foxtail millet (Setaria italica) for polymorphism and transferability study was reported here. From 1213 EST sequences, 30 SSRs were obtained and primers were designed for 26 SSRs. Among them, four pairs of SSR primers amplified polymorphic products in 12 foxtail millet cultivars and one accession of Setaria viridis, a wild relative of foxtail millet, with 10 alleles detected for the four loci and 2.5 alleles per locus. In addition, ten SSR markers could be transferred to other nine Gramineae species. The putative functions of 11 ESTs containing polymorphic and transferable SSRs were also identified.     

Effect of seaweed sap as foliar spray on growth and yield of hybrid maize

Seaweeds are important marine renewable resources. Use of seaweeds as fertilizers has allowed for substitution in place of conventional synthetic fertilizers. This study was conducted to examine the effect of seaweed liquid extract (SLE) on growth, yield, and nutrient uptake by hybrid maize. The experiments were conducted in ZARS, Vishweshwaraiah Canal farm, Mandya (Karnataka, India) during the rabi season of 2011–2013 to study the effect of foliar applications of Kappaphycus alvarezii (K sap) and Gracilaria edulis (G sap) sap on growth and yield response of hybrid maize “NAH 1137”. Three foliar sprays of both saps were applied at the rate of 2.5, 5.0, 7.5, 10, and 15.0% (v/v) along with water spray as a control at different stages of the crop. It was found that grain yield increased significantly by 18.54% and 26.04% for plants receiving 10% concentrations of both K. alvarezii and G. edulis sap respectively, over control. The increase in yield was attributed to increase in the number of rows in cob, cob length, and 100 grain weight. This investigation concludes that application of both the saps at 10% increased the nutrient uptake, grain, and stover yield over control.     

A critical assessment of the suitability of phosphite as a source of phosphorus

Marketing of phosphite‐containing preparations for foliar application, together with recent reports of positive yield responses, has revived the question as to whether phosphite (HPO ) is a suitable P source for plants. Two experiments using zucchini (Cucurbita pepo L. convar. giromontina) have been conducted to evaluate the P‐nutritional effect of phosphite either provided via the substrate or as a foliar spray. Plants grown in a P‐deficient substrate were severely damaged when phosphite was applied as foliar fertiliser and more drastically when provided via the substrate. Growth of P‐deficient plants receiving phosphite as a foliar spray was impaired in a dose‐dependent manner after foliar P application (concentrations 0.0, 0.9, 2.7, and 4.5 g P L^–1), while foliar provision of phosphate improved plant growth and yield. In the youngest leaves of phosphite‐treated plants, which had developed after foliar spray, phosphite accumulated to considerable extent, reaching a similar concentration as phosphate at tissue level. These results confirm that P‐deficient plants are very sensitive to phosphite, which represents a nutritionally ineffective form of P. It should thus not be considered as a form of P suitable for fertiliser manufacture.     

Why no tetraploid cultivar of foxtail millet?

Autotetraploid material was induced by colchicine treatment of a pure line of foxtail millet and an interspecific hybrid between foxtail millet and giant green foxtail. Compared with diploid material, tetraploids were smaller, flowered later, and had a two-fold reduced fertility (number of grain per cm of spike). Grain weight increased by 20% with polyploidy, but total grain yield decreased by 46%. This work illustrates the difficulty of breeding polyploid lines of foxtail millet that are of agronomic use.     

Iron nutrition in low chill peach for improving yield and fruit quality

Foliar fertilization and microbe supplemented iron (Fe) bioavailability can fulfill iron demand of plants. An experiment was performed to examine the effect of Psuedomonas fluorescens along with foliar spray ferrous sulfate on low-chill peach plants suffering from iron deficiency. Number of leaves per shoot, leaf area, chlorophyl content, Fe: Mn ratio of leaves, fruit yield and fruit physico-chemical parameters were recorded. The results showed a significant increase in leaves chlorophyl content, iron: manganese ratio of leaves, fruit yield, fruit length, fruit breadth, total soluble solids (T.S.S) and T.S.S and acid ratio with the inoculation of Pseudomonas fluorescens as well as foliar spray of ferrous sulfate, whereas, acidity of fruit pulp was decreased. Significantly higher number of leaves per shoot was also noted with foliar spray of ferrous sulfate. Pseudomonas fluorescens inoculation along with foliar spray of ferrous sulfate significantly increased leaves chlorophyl content, fruit length, T.S.S and T.S.S : acid ratio of fruit pulp.