不同杀菌剂对小麦赤霉病及籽粒DON毒素的控制效果

为探明不同杀菌剂对小麦赤霉病和小麦籽粒DON毒素(包括DON、3-ADON和15-ADON)的控制效果, 采用菌丝生长速率法测定了12种药剂对禾谷镰刀菌野生型菌株PH-1的室内活性, 同时采用液相色谱-串联质谱法(LC-MS)测定了这些药剂对DON毒素的抑制效果, 并开展了小麦赤霉病及籽粒DON毒素的田间防治试验。结果表明, 12种原药对菌丝生长抑制活性强弱依次为氟唑菌酰羟胺>咪鲜胺>戊唑醇>丙硫菌唑>叶菌唑>氰烯菌酯>氟环唑>多菌灵>甲基硫菌灵>吡唑醚菌酯>嘧菌酯>井冈霉素A。氟环唑EC50和EC90离体胁迫均刺激DON毒素产生, 其他杀菌剂EC50和EC90胁迫均抑制DON毒素产生。田间试验结果表明, 200 g/L氟唑菌酰羟胺SC、30%丙硫菌唑OD和20%叶菌唑WP病指防效和DON防效为87.68%~94.77%; 430 g/L戊唑醇SC、25%氰烯菌酯SC、45%咪鲜胺EW、25%氟环唑SC、50%多菌灵WP和70%甲基硫菌灵WP病指防效和DON防效为57.63%%~85.49%; 250 g/L吡唑醚菌酯EC和250 g/L嘧菌酯SC病指防效分别为72.18%和51.98%, DON防效分别为43.06%和-7.96%; 24%井冈霉素A AS病指防效和DON防效分别为42.37%和62.87%。药剂离体和田间控毒效果不完全一致, 赤霉病有效防控是DON防控的前提, 病害防效与DON防效不完全一致, 本研究为小麦赤霉病及籽粒DON毒素防控提供了科学依据。     

多种杀菌剂对小麦赤霉病及其DON毒素的防效

通过田间试验与室内检测,研究不同杀菌剂对小麦赤霉病的防治效果、对DON(脱氧雪腐镰刀菌烯醇)毒素的控制效果以及对小麦产量的影响。结果表明,200 g/L氟唑菌酰羟胺悬浮剂180 g/hm~2、48%丙硫菌唑悬浮剂288 g/hm~2和40%丙硫·戊唑醇悬浮剂240 g/hm~2对小麦赤霉病的防效较高,药后25d病指防效均达到90%以上。药剂处理有一定增产效果,相比对照区,各处理区产量增幅16.39%~31.91%,千粒重增幅29.69%~36.17%。各处理对小麦病粒率和籽粒中的DON毒素也有一定控制效果。200g/L氟唑菌酰羟胺悬浮剂180g/hm~2和40%丙硫·戊唑醇悬浮剂240 g/hm~2控制病粒率的效果最好,对应处理的病粒率分别为0.31%和0.32%。200 g/L氟唑菌酰羟胺悬浮剂180 g/hm~2和48%丙硫菌唑悬浮剂288 g/hm~2控制DON毒素的效果最好,对应处理的DON毒素检出量分别为197.33μg/kg和197.07μg/kg。     

不同杀菌剂防治小麦赤霉病及减少籽粒中DON毒素积累的效果

为明确不同杀菌剂防治小麦赤霉病和减少小麦籽粒中DON(脱氧雪腐镰刀菌烯醇)毒素积累的效果,于大田人工接菌条件下进行了不同杀菌剂对小麦赤霉病的防治试验,并于收获期测定了不同药剂处理的小麦籽粒中DON毒素含量。结果表明:两种处理方式下,50%多菌灵WP,30%多·酮SC,25%戊唑醇WP,25%氰烯菌酯SC和70%甲基硫菌灵WP处理中,除先喷药后接菌条件下25%戊唑醇WP在病粒率和籽粒中DON积累上没有显著防治效果,接菌后1d喷药条件下50%多菌灵WP、25%戊唑醇WP在病粒率上没有显著防治效果;30%多·酮SC在病粒率和籽粒中DON积累上没有显著防治效果外,各处理对小麦的病穗率、病情指数、病粒率和籽粒中DON积累都有显著的防治效果(P0.05)。各处理的病穗率防效在42.4%~83.5%,病情指数防效在44.9%~88.2%,病粒率防效在34.7%~69.4%,籽粒中DON防效在48.0%~86.9%。上述几种杀菌剂具有明显的保护作用,其在先喷药后接菌条件下的防治效果均明显优于接菌后1d喷药的防治效果。两种处理方式下,30%己唑醇悬浮剂、25%嘧菌酯悬浮剂和12.5%烯唑醇可湿性粉剂处理在病穗率、病情指数、病粒率和籽粒中DON积累与清水对照处理没有显著性差异(P0.05)。     

禾谷镰孢单端孢霉烯族毒素在小麦组织中的积累

 本试验将禾谷镰孢一高产毒菌株B4-1采用单小花注滴法接种于小麦抗赤霉病品种苏麦3号和感病品种宁麦6号,用气/质联检法测定接种后4、8、12、16和20 d组织中的单端孢霉烯族毒素积累量。结果显示,在病组织中有脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)、15-乙酰脱氧雪腐镰刀菌烯醇(15-acetyldeoxynivalenol,15-ADON)和3-乙酰脱氧雪腐镰刀菌烯醇(3-acetyldeoxynivalenol,3-ADON)等3种单端孢霉烯族毒素,但未发现雪腐镰刀菌烯醇(nivalenol)和镰刀菌酮-X (fusarenon-X)等毒素。抗病品种病穗组织中,DON平均含量由接种后4 d的29.5 μg/g dry weight (gdw)下降到20d时的15.7μg/gdw,15-ADON和3-ADON量则较低,分别为1.5~3.6μg/gdw和<1.7μg/gdw;而同期感病品种病穗组织中的DON量则由23.1μg/gdw上升到47.7μg/gdw,15-ADON和3-ADON量均较高,分别达8.6~10.0μg/gdw和2.6~8.3μg/gdw。在抗、感病品种无症状穗组织中,3种毒素的含量均很低(<0.5 μg/gdw)。同时,本研究还首次在感病品种的穗颈(总花梗,peduncle)组织中检测到大量的DON和15-ADON及少量的3-ADON。     

“15％丙硫唑·戊唑醇”防治小麦赤霉病试验

<正>小麦赤霉病是世界上普遍发生的病害之一,该病不仅引起小麦大幅减产,威胁粮食安全,而且赤霉病菌分泌产生的脱氧雪腐镰刀菌烯醇(DON)毒素可造成人畜中毒,严重危害身体健康。根据国家重点研发项目《湖北麦区小麦化肥农药减施增效技术集成研究与示范》(编号:2018YFD0200506)要求,我省在天门市、枣阳市分别进行了15%丙硫唑·戊唑醇防治小麦赤霉病的效果试验示范,为小麦赤霉病的防治技术的推广提供理论依据和数据支撑。     

山东省小麦赤霉病菌种群组成及其致病力分化

由禾谷镰孢菌群Fusarium graminearum clade引起的赤霉病是小麦的重要病害。为明确山东省小麦赤霉病菌的种群组成及其致病力,于2011年和2012年从山东省15地市分离了95株小麦赤霉病菌,在形态和分子生物学鉴定种的基础上,采用鉴定B型毒素化学型的特异性引物进行毒素化学型分析。在95个菌株中,93株分离物为禾谷镰孢菌F.graminearum,2株为燕麦镰孢菌F.avenaceum。94株分离物为脱氧雪腐镰孢菌烯醇(deoxynivalenol,DON)化学型,1株为雪腐镰孢菌烯醇(nivalenol,NIV)化学型。在94株DON毒素化学型菌株中,90株为15-乙酰脱氧雪腐镰孢菌烯醇(15-acetyldeoxynivalenol,15-AcDON)化学型,4株为3-乙酰脱氧雪腐镰孢菌烯醇(3-acetyldeoxynivalenol,3-AcDON)化学型。在小麦扬花期,采用单花滴注接种法对29个菌株进行了致病力测定,供试菌株的致病力分化明显。表明在山东省冬小麦产区,产15-AcDON毒素的F.gra-minearum是小麦赤霉病菌的优势种群。     

我国不同麦区小麦镰刀菌毒素检测及毒素污染分析

为明确镰刀菌毒素在我国不同小麦产区的污染与分布,利用超高效液相色谱-串联质谱仪对全国214个小麦品种籽粒中的7种镰刀菌毒素含量进行了测定和比较分析。结果表明:7种镰刀菌毒素的平均回收率在95.02%～116.52%之间,相对标准差为6.32%～21.50%。所有测试小麦样品均被镰刀菌毒素污染,7种毒素中以雪腐镰刀菌烯醇(nivalenol,NIV)含量最高,即使在NIV含量最低的长江中下游冬麦区,平均含量也高达182.56μg/kg,虽然目前并没有关于NIV的相关限量标准,但也应该予以足够重视;脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)含量较高,在8.07～337.23μg/kg之间,低于国家限量标准1 000μg/kg;T-2含量在4.05～78.05μg/kg之间,低于现有国际限量标准100μg/kg;玉米赤霉烯酮(zearalmone,ZEA)含量在5.30～12.50μg/kg之间,低于国家限量标准60μg/kg;其它3种毒素含量较低,均低于17.73μg/kg。不同麦区间毒素比较发现,DON和3-乙酰脱氧雪腐镰刀菌烯醇的含量在长江中下游冬麦区最高,分别为43.09μg/kg和6.39μg/kg,且显著高于其它麦区;来自长江中下游冬麦组和黄淮冬麦区南片水地组的小麦品种籽粒中毒素T-2和HT-2的含量显著高于其它麦区;其余毒素在不同麦区间均无显著差异。     

几种杀菌剂防控小麦赤霉病穗腐及籽粒脱氧雪腐镰刀菌烯醇(DON)毒素的评价

小麦赤霉病是小麦穗期的主要病害之一。化学防控一直是小麦主产区防控赤霉病的主要措施。为明确几种新型杀菌剂对小麦赤霉病的防效和对小麦籽粒DON毒素含量的影响,于2018年进行了氰基丙烯酸酯类和三唑类杀菌剂单剂及其复配剂对赤霉病的防效试验。结果表明:30%戊唑·多菌灵悬浮剂(SC)1500 mL/hm^2处理对赤霉病病穗防效达92.40%,病指防效达93.20%,小麦籽粒DON毒素检出量较不用药对照降低80.38%;25%氰烯菌酯SC 2000 mL/hm^2处理对赤霉病的病穗防效达86.80%,病指防效达88.78%,小麦籽粒DON毒素检出量较不用药对照降低88.19%;48%氰烯·戊唑醇SC 900 mL/hm^2和40%丙硫·戊唑醇SC 600 mL/hm^2对小麦赤霉病的病穗防效分别为77.20%、78.00%,病指防效分别为80.27%和79.59%,对籽粒DON毒素检出量较不用药对照分别降低73.87%和81.42%。在小麦赤霉病较重发生的情况下,上述4种杀菌剂单剂或复配剂1次用药既能高效控制病情,又能有效控制小麦籽粒DON毒素不超标。本试验研究进一步阐明,氰烯菌酯、戊唑醇、丙硫菌唑等杀菌剂及其复配剂均能有效控制小麦赤霉病的危害,并能有效降低小麦籽粒DON毒素含量;吡唑醚菌酯单剂及其复配剂虽然对小麦赤霉病的病穗和病指防效也较高,但控制小麦籽粒DON毒素含量效果相对较差。研究结果为小麦穗期赤霉病化学防控提供了科学参考。     

江苏垦区小麦赤霉病菌对多菌灵的抗性监测及其替代杀菌剂的防病效果

近年来的调查结果表明,江苏垦区小麦赤霉病菌群体中抗多菌灵菌株的频率逐年上升,多菌灵防效逐年下降,部分农场采用多菌灵防治几乎失效。为了筛选替代多菌灵的药剂,我们在白马湖等6个农场对几种新杀菌剂进行了田间药效试验。结果表明,25%氰烯菌酯SC、40%叶菌唑SC和25%丙硫菌唑WP在所有农场都有较好的防治效果,其中25%丙硫菌唑WP对小麦赤霉病的防治效果最好,在所有农场其防效都超过80%,防治后乳熟期和成熟期病穗率变化不大。40%叶菌唑SC、25%丙硫菌唑WP以及25%氰烯菌酯SC和43%戊唑醇SC混用有显著增产作用,并能大幅度降低籽粒中DON含量。作者认为赤霉病的防治应立足种植抗(耐)病品种,扬花期选用有效杀菌剂适期进行防治。氰烯菌酯、叶菌唑和丙硫菌唑可作为多菌灵的替代药剂。     

禾谷镰孢菌对氟唑菌酰羟胺敏感性基线的建立及药剂田间防效

为明确琥珀酸脱氢酶抑制剂类新型吡啶酰胺杀菌剂氟唑菌酰羟胺在中国小麦赤霉病防治中的应用潜力,分别采用菌丝生长速率法和孢子萌发法,测定了氟唑菌酰羟胺对湖北省6个地区106株禾谷镰孢菌的室内毒力、田间防效及其与多菌灵和氰烯菌酯的交互抗性。结果显示:氟唑菌酰羟胺对106株禾谷镰孢菌菌丝生长的EC₅₀值为 (0.018 0 ± 0.209 0) mg/L,平均值为 (0.072 8 ± 0.025 9) mg/L;对分生孢子萌发的EC₅₀值为 (0.052 7 ± 0.473 2) mg/L,平均值为 (0.176 0± 0.059 6) mg/mL;且其EC₅₀值频率分布均呈单峰曲线,因此可分别将菌丝生长和孢子萌发的平均EC₅₀值作为禾谷镰孢菌对氟唑菌酰羟胺的敏感性基线。初步的交互抗性测定结果表明,抗多菌灵或氰烯菌酯的菌株对氟唑菌酰羟胺均未表现出抗性。田间试验显示,氟唑菌酰羟胺有效剂量200 g/hm2处理的防效 (超过90.0%) 显著高于对照药剂氰烯菌酯600 g/hm2的防效 (78.0%),与空白对照相比增产效果在127%~135%之间。经氟唑菌酰羟胺处理后,小麦籽粒中由禾谷镰孢菌产生的毒素脱氧雪腐镰刀菌烯醇 (DON) 的含量比空白对照降低了55.09%。研究表明,氟唑菌酰羟胺对禾谷镰孢菌呈现出较高的室内活性且田间防效优越,同时还能降低小麦籽粒中DON毒素的含量及提高小麦产量,因此可作为生产中防治小麦赤霉病的替代或后备药剂,同时也可考虑用作为禾谷镰孢菌对多菌灵抗性治理的替代药剂。     

Trichothecene mycotoxin genotypes of Fusarium graminearum sensu stricto and Fusarium meridionale in wheat from southern Brazil

A total of 82 fungal isolates was obtained from wheat kernel samples affected by fusarium head blight collected from 20 locations in southern Brazil. Polymerase chain reaction (PCR) assays were used to characterize trichothecene mycotoxin genotypes [deoxynivalenol (DON), nivalenol (NIV) and two acetylated derivatives of DON]. To identify isolates that producing DON and NIV, portions of the Tri13 gene were amplified. To identify 3-acetyl-deoxynivalenol (3-ADON) and 15-acetyl-deoxynivalenol (15-ADON) genotypes, portions of Tri3 and Tri12 were amplified. Nearly all of the isolates studied (76/82) were of the DON/15-ADON genotype. Six of the isolates were of the NIV genotype. The DON/3-ADON genotype was not observed. Portions of three genes were sequenced from representative isolates of the NIV and DON/15-ADON genotypes and compared with sequences from curated reference isolates of Fusarium in GenBank. blast queries for individual gene sequences and pairwise comparisons of percentage identity and percentage divergence based on 1676 bp of concatenated DNA sequence suggested that the isolates representing the DON/15-ADON genotype were Fusarium graminearum sensu stricto and the isolates representing the NIV genotype were Fusarium meridionale . This is the first detailed report of trichothecene mycotoxin genotypes of F. graminearum and F. meridionale in Brazil.     

A comparison of aggressiveness and deoxynivalenol production between Canadian <Emphasis Type="Italic">Fusarium graminearum</Emphasis> isolates with 3-acetyl and 15-acetyldeoxynivalenol chemotypes in field-grown spring wheat

Twenty four isolates of Fusarium graminearum, half of which were 3-acetyldeoxynivalenol (3-ADON) and half 15-acetyldeoxynivalenol (15-ADON) chemotypes, were tested for their ability to produce deoxynivalenol and to cause Fusarium head blight (FHB) in spring wheat cultivars. The objectives of this study were to determine (1) whether 3-ADON isolates differ in aggressiveness, as measured by the FHB index, and DON production from 15-ADON isolates under field conditions, and (2) whether the performance of resistant host cultivars was stable across isolates. Field tests of all isolates were conducted with three replicates at each of two locations in Canada and Germany in 2008 with three host genotypes differing in FHB resistance level. The resistant host genotype showed resistance regardless of the chemotype or location. The differences between mean FHB indices of 3-ADON and 15-ADON isolates were not significant for any wheat genotype. In contrast, average DON production by the 3-ADON isolates (10.44 mg kg⁻¹) was significantly (P < 0.05) higher than for the 15-ADON isolates (6.95 mg kg⁻¹) at three of the four locations where moderately resistant lines were tested, and at both locations where susceptible lines were evaluated. These results indicate that 3-ADON isolates could pose a greater risk to food safety. However, as the mean aggressiveness and DON production of 3-ADON and 15-ADON chemotypes was similar on highly resistant lines, breeding and use of highly resistant lines is still the most effective measure of reducing the risks associated with DON in wheat.     

几种杀菌剂对小麦茎基腐病的防治效果

小麦茎基腐病是小麦上重要的真菌性茎基部病害,在黄淮海冬麦区呈广泛流行态势,对我国小麦生产安全构成严重威胁.本研究评价了不同拌种剂、拔节期喷施杀菌剂以及两者结合使用对小麦茎基腐病的防治效果.药剂拌种防治结果表明:60 g/L戊唑醇FS、25 g/L咯菌腈FS和25％氰烯菌酯SC拌种处理能显著降低苗期病株率,其病株防治效果...     

Efficacy of triazole-based fungicides for fusarium head blight and deoxynivalenol control in wheat: a multivariate meta-analysis

The effects of propiconazole, prothioconazole, tebuconazole, metconazole, and prothioconazole+tebuconazole (as a tank mix or a formulated premix) on the control of Fusarium head blight index (IND; field or plot-level disease severity) and deoxynivalenol (DON) in wheat were determined. A multivariate random-effects meta-analytical model was fitted to the log-transformed treatment means from over 100 uniform fungicide studies across 11 years and 14 states, and the mean log ratio (relative to the untreated check or tebuconazole mean) was determined as the overall effect size for quantifying fungicide efficacy. Mean log ratios were then transformed to estimate mean percent reduction in IND and DON relative to the untreated check (percent control: C(IND) and C(DON)) and relative to tebuconazole. All fungicides led to a significant reduction in IND and DON (P < 0.001), although there was substantial between-study variability. Prothioconazole+tebuconazole was the most effective fungicide for IND, with a C(IND) of 52%, followed by metconazole (50%), prothioconazole (48%), tebuconazole (40%), and propiconazole (32%). For DON, metconazole was the most effective treatment, with a [Formula: see text](DON) of 45%; prothioconazole+tebuconazole and prothioconazole showed similar efficacy, with C(DON) values of 42 and 43%, respectively; tebuconazole and propiconazole were the least effective, with C(DON) values of 23 and 12%, respectively. All fungicides, with the exception of propiconazole, were significantly more effective than tebuconazole for control of both IND and DON (P < 0.001). Relative to tebuconazole, prothioconazole, metconazole, and tebuconzole+prothioconzole reduced disease index a further 14 to 20% and DON a further 25 to 29%. In general, fungicide efficacy was significantly higher for spring wheat than for soft winter wheat studies; depending on the fungicide, the difference in percent control between spring and soft winter wheat was 5 to 20% for C(IND) and 7 to 16% for C(DON). Based on the mean log ratios and between-study variances, the probability that IND or DON in a treated plot from a randomly selected study was lower than that in the check by a fixed margin was determined, which confirmed the superior efficacy of prothioconazole, metconazole, and tebuconzole+prothioconzole for Fusarium head blight disease and toxin control.     

镰刀菌毒素脱氧雪腐镰刀菌烯醇脱毒菌及脱毒酶研究进展

 脱氧雪腐镰刀菌烯醇(Deoxynivalenol,DON)是由镰刀菌在侵染小麦等禾谷类作物过程中产生的一种有毒次级代谢产物,是目前小麦及其制品中污染最为普遍的一种真菌毒素。DON能够对真核细胞产生多种毒性作用,严重危害人畜健康。DON又是一种毒力因子,促进镰刀菌扩展蔓延,加重赤霉病发病程度。利用脱毒菌、脱毒酶对DON毒素进行生物脱毒是最好的脱毒方式之一,其可将DON转化成低毒或无毒代谢产物,减少毒素对人畜健康的危害。脱毒基因还可作为新型抗源用于小麦赤霉病抗性改良,加速抗性品种的选育,从源头防止DON毒素的污染。本文概述了DON毒素生物脱毒的类型、代谢产物的毒性、脱毒基因的鉴定以及脱毒材料的应用等方面的研究进展,以期为DON毒素的生物防控和小麦赤霉病抗性改良提供参考。     

镰刀菌毒素脱氧雪腐镰刀菌烯醇脱毒菌及脱毒酶研究进展

 脱氧雪腐镰刀菌烯醇(Deoxynivalenol,DON)是由镰刀菌在侵染小麦等禾谷类作物过程中产生的一种有毒次级代谢产物,是目前小麦及其制品中污染最为普遍的一种真菌毒素。DON能够对真核细胞产生多种毒性作用,严重危害人畜健康。DON又是一种毒力因子,促进镰刀菌扩展蔓延,加重赤霉病发病程度。利用脱毒菌、脱毒酶对DON毒素进行生物脱毒是最好的脱毒方式之一,其可将DON转化成低毒或无毒代谢产物,减少毒素对人畜健康的危害。脱毒基因还可作为新型抗源用于小麦赤霉病抗性改良,加速抗性品种的选育,从源头防止DON毒素的污染。本文概述了DON毒素生物脱毒的类型、代谢产物的毒性、脱毒基因的鉴定以及脱毒材料的应用等方面的研究进展,以期为DON毒素的生物防控和小麦赤霉病抗性改良提供参考。     

江苏小麦赤霉病综合防控关键技术研究

近年来气候变暖、秸秆还田和赤霉病菌对多菌灵的抗性上升使江苏省小麦赤霉病流行频率提高。本研究通过田间小区试验,对小麦赤霉病的综合防控关键技术进行了比较。试验结果表明,目前赤霉病菌对多菌灵抗药性频率已达60%以上,多菌灵的防效明显下降,低于60%。研究明确了赤霉病的防控适期和防治次数,对淮南、淮北主要小麦品种进行赤霉病自然发病鉴定,并阐述了品种抗性和药剂防治间的互作效应。研究结果揭示,选育推广对小麦赤霉病具有抗性的品种是小麦赤霉病防控的基础,把握适期于小麦扬花期施用非多菌灵类的戊唑醇、氰烯菌酯、丙硫菌唑等其他杀菌剂可有效控制病害的发生。     

Silicon amendment improves wheat defence against Fusarium graminearum and complements the control by fungicide of Fusarium head blight

A three-year field experiment with two wheat cultivars evaluated the effect of soil-applied silicon (Si), with and without fungicide spraying, on Fusarium head blight (FHB) control. Silicon treatment alone reduced FHB severity and the percentage of damaged wheat kernels, regardless of the cultivar. The best disease control was obtained for the cultivar with moderate disease resistance (MR), supplied with silicon and treated with fungicide during flowering. Silicon treatment alone promoted an increase in deoxynivalenol (DON) concentration in the disease-susceptible cultivar; however, in the MR cultivar, silicon amendment associated with fungicide treatment led to a reduction in DON concentration. Greenhouse experiments evaluated the effect of silicon combined with different timings of fungicide application on wheat defences against Fusarium graminearum. Plants supplied with silicon had a longer pathogen incubation period, lower FHB severity and lower DON concentration when compared to plants without silicon. In addition, silicon-supplied plants had higher soluble phenolic content and altered antioxidant enzyme activities (SOD, CAT, POX and PPO) that favoured early accumulation of hydrogen peroxide when compared to plants without silicon. Greater control of FHB and lower DON concentration in plants treated with silicon and fungicide before inoculation and up to 1 day after inoculation was associated with increased levels of defence-associated metabolites. Silicon contributed to the reduction of FHB and DON concentration in wheat, especially for the MR cultivar and, when combined with fungicide spraying, both MR and disease-susceptible cultivars had enhanced performances upon silicon amendment.