Diplodia Maydis Research Articles

Production of Rhamnolipids using WFSO and its application in the development of antifungal nanoemulsion using Hydnocarpus Wightiana, Garcinia Cambogia - Seed oils

Presently, Industrial-scale demands for manufacturing rhamnolipids (RhLs) are not so developed; probably due to the high cost of the substrates and the rare demand for costlier surfactants. Therefore, the use of waste frying oils (WFSO) as substrates in RhLs manufacturing using Pseudomonas aeruginosa could be a notable substitute for the regularly used sources of oils and fatty acids to minimize manufacturing charges. WFSO as a byproduct normally consists of Linoleic acid as a prime fatty acid constituent. In the present work, P. aeruginosa yielded RhLs at an uttermost concentration of 7.4 g L−1; while constructional characteristics proved the presence majority of di-RhLs in the mixture. Also, on testing, the SFT (Surface Tension) reduced to 34.6±0.1 mN m−1; and an interfacial tension against heptane went down to 5.2±0.05 mN m−1. The oils from kernels of Hydnocarpus Wightiana and Garcinia cambogia were extracted separately; further, the detailed analysis showed the presence of their corresponding active fatty acids. In the initial screening of antifungal efficacy against Fusarium oxysporum (fusarium wilt) and Diplodia maydis (Diplodia ear and stalk rot of maize), RhLs shown the minimum inhibitory concentration (MIC) between 250 and 500 ppm, both extracted oils shown the MIC between 5 % and 10 %. Therefore, we decided to prepare the nanoemulsions (NEs) using 0.5 % RhLs, and 10 % of each respective extracted oil; which upon analysis showed the globule size as low as 110.9 nm and 147.0 nm respectively. The turbiscan study revealed that NEs made using RhLs as an adjuvant were found more stable than the alkyl polyglucosides, and the nanoemulsions containing RhLs showed higher levels of antifungal activity against F. oxysporum and D. maydis in the antifungal study. Thus, a successful utilization of the WFSO for the production of RhLs; and reduction in the probable water or soil pollution was achieved, as well as our RhLs bio-synthesis cost was much less as compared to the existing manufacturing process.

Failure of diplodiatoxin to induce diplodiosis in juvenile goats.

Diplodiosis is an important neuromycotoxicosis of ruminants in South Africa when grazing on harvested maize fields in winter. It is believed to be caused by mycotoxin(s) synthesised by Stenocarpella (Diplodia) maydis. Although several metabolites have been isolated from S. maydis culture material, none of these have been administered to ruminants to reproduce the disease. The objectives of this study were to isolate diplodiatoxin and to administer it to juvenile goats. Diplodiatoxin, considered as a major metabolite, was purified from S. maydis-infected maize cultures (Coligny 2007 isolate). Following intravenous administration of 2 mg and 4 mg diplodiatoxin/kg body weight for five consecutive days to two juvenile goats, no clinical signs reminiscent of diplodiosis were observed. Based on previous experimental results and if diplodiatoxin was the causative compound, the dosage regimen employed was seemingly appropriate to induce diplodiosis. In addition, intraruminal administration of 2 mg/kg diplodiatoxin to one goat for three consecutive days also did not induce clinical signs. It appears as if diplodiatoxin alone is not the causative compound. Other metabolites and/or mixtures of diplodiatoxin and other mycotoxins, when available in sufficient quantities, should also be evaluated.

In vitro selection of rhizobacteria for control Diplodia maydis cause of ear rot disease in maize

Rahma H, Arneti, Nofrianti S. 2018. In vitro selection of rhizobacteria for control Diplodia maydis cause of ear rot disease inmaize. Pros Sem Nas Masy Biodiv Indon 4: 225-230. Maize is an important food crop in Indonesia both for consumption and for animalfeed. One of the plant-disturbing organisms in corn plants is a fungus Diplodia maydis (Barkeley) Saccardo which causes cob rot.Biological control using rhizobacteria is one alternative for controlling D. maydis. The objective of this research was to get therhizobacterial of maize plant that has the ability as antagonist to D. maydis. The research was carried out in 2 stages, the first was theability of 16 rhizobacteria isolates to inhibit the growth of D. maydis. Second Rhizobacteria inhibitory test on D. maydis used anexperimental method with a completely randomized design using 11 treatments and 4 repetitions. Rizobacteria were selected based ontheir inhibitory effect on D. maydis using the dual culture method. Activity test of bioactive compounds from rizobacterial supernatantusing disc diffusion and medium poisoning method. The results showed that isolate KJTSB 7.2 and LMTSA 5.4 have the ability as anantagonist with inhibitory ability in dual culture method of 51.10% and 50.00%. The antibiosis test of supernatant bioactive compoundsof these isolates with disc diffusion method was 7.77 and 17.73%. Meanwhile the dry weight of D. maydis in the antibiotic test usingmedium poisoning method was 0.12 g and 0.18 g with an effectiveness of 82.85% and 74.28%.

Indirect selection for resistance to ear rot and leaf diseases in maize lines using biplots.

Leaf disease and ear rot have caused reductions in maize yield in Brazil and other producer countries. Therefore, the aims of this study were to analyze the association between husked ear yield and the severity of maize white spot, gray leaf spot, helminthosporium, and ear rot caused by Fusarium verticillioides and Diplodia maydis using biplots in a mixed-model approach. The responses of 238 lines introduced to Brazil and four controls were evaluated using an incomplete block design with three replicates in two locations: Lavras and Uberlândia, Minas Gerais, Brazil. Two experiments were conducted in each location, one with F. verticillioides and the other with D. maydis. The mixed models elucidated the relationship between yield, leaf disease, and ear disease. Significant genotype x environment and genotype x pathogen interactions were observed. In conclusion, husked ear yield is more associated with ear rot than with the leaf diseases evaluated, justifying the indirect selection for resistance to kernel rot in maize-F. verticillioides and maize-D. maydis pathosystems by yield evaluation.

English

The herbicides application can be reduced with alternative methods, as pathogenic fungi use, that produces several secondary compounds in growth medium, which has phytotoxicity. Thus, the aim of this study was to determine the allelopathic activity of culture filtrate produced by pathogenic fungi: Fusarium solani , Macrophomina phaseolina Fusarium graminearum and Diplodia maydis, on germination and development of horseweed ( Conyza canadensis ), hairy beggarticks ( Bidens pilosa ) and wild poinsettia ( Euphorbia heterophylla ). This effect was also tested on soybean and corn crops. The experimental design was completely randomized with twenty treatments (four filtrates of fungi culture, with 0, 5, 10, 15 e 20% concentrations) and four replications. Data were submitted to analysis of variance and regression. The results indicated that filtered of Fusarium solani culture presented a negative effect on horseweed, hairy beggarticks and wild poinsettia without affecting negatively soybeans crop. Diplodia maydis provided some reduction on horseweed and wild poinsettia growth without causing damage to maize crop.The while Macrophomina phaseolina filtrate decreased a seedlings growth of wild poinsettia without affecting negatively corn. This suggests filtrates can be used to control weeds in a sustainable ecological way as well as an alternative to reduce herbicides application, thus, protecting the environment.

Secondary metabolites from Diplodia maydis and Sclerotium rolfsii with antibiotic activity

Ethyl acetate extracts of the phytopathogenic fungi Diplodia maydis and Sclerotium rolfsii presented antibacterial activity against multidrug resistant bacteria isolated from patients in the University Hospital (HUOP-Unioeste, Brazil).

Studies on the application of fungi and bacteria controlling insect pests in Azad Jammu and Kashmir, Pakistan

The diversity of interrelationships between fungi, bacteria and insects presents unlimited opportunities for studying antagonistic fungi and bacteria causing mortality in insects by producing disease and toxins which are detrimental to insect life and can be used to control harmful insects. Fungal and bacterial parasitism has been used effectively for controlling agricultural pests all over the world. Its application has a great advantage, for example, the effectiveness of synthetic insecticides can be controlled by using entomogenous fungi and bacteria as natural insecticides. Fungi and bacteria from different localities of Azad Jammu and Kashmir were collected and their insecticidal properties were searched out. A total of 40 species of fungi and two bacterial species were tested for their insecticidal habits on maize stem borer (Chilo partellus). These species were Aspergillus clavatus, A. fumigatus, A. fischeri, A. ruber, A. unguis A. sydowi, A. versicolor, A. flavipes, A. ustus, A. terreus, A. niger, A. wentii, A. flavus, A. bisporus, A. candidus, A. oryzae, A. ochraceous, A. giganteus, A. tamarii, A. luchuensis, Penicillium chrysogenum, P. expensum, P. viridicatum, P. commune, P. soltium, P. roquefortii, Paecilomyces elegans, P. carnes, P. varioti, P flavescens, P. fumoso-roseus, Metarrhizium anisopliae, M. brunneum, Venturia inequalis, Helminthosporium maydis, Alternaria tenussima, Ceratocystis paradoxa, Colletotrichum capsici, Diplodia maydis, Beauveria bassiana, Bacillus thuringiensis and Bacillus sphaericus. Eleven species Aspergillus flavus, A. fumigatus, A. oryzae, A. candidus, A. bisporus, A. tamarii, Metarrhizium anisopliae, M. brunneum, Beauveria bassiana, Bacillus thuringiensis and B. sphaericus caused mortality in larvae, pupae, dewaxed pupae and adult of maize stem borer (Chilo partellus). Eight species of insects were collected from natural conditions and their susceptibility was measured for all the described species of fungi and bacteria. Five species of insects – Triporhiza incertula, T. innotata, Cydia pomonella, Pieris brassicae, and Mythimna seperata – showed susceptibility to A. flavus, A. fumigatus, A. oryzae, A. tamarii, A. bisporus, M. anisopliae, M. brunneum, Bacillus thuringiensis and B. sphaericus. Food substrate of fungi and bacteria were also used against maize stem borer. Nine fungi and two bacterial species herein described gave positive results. Field trials of fungi and bacteria were also performed against maize stem borer.

DETECTION OF CORN KERNELS INFECTED BY FUNGI

Single-kernel reflectance spectra (550 to 1700 nm), visible color reflectance images, x-ray images, multi-spectral transmittance images (visible and NIR), and physical properties (mass, length, width, thickness, and cross-sectional area) were analyzed to determine if they could be used to detect fungal-infected corn kernels. Kernels were collected from corn ears inoculated with one of several different common fungi several weeks before harvest, and then collected at harvest time. It was found that two NIR reflectance spectral bands centered at 715 nm and 965 nm could correctly identify 98.1% of asymptomatic kernels and 96.6% of kernels showing extensive discoloration and infected with Aspergillus flavus, Aspergillus niger, Diplodia maydis, Fusarium graminearum, Fusarium verticillioides, or Trichoderma viride. These two spectral bands can easily be implemented on high-speed sorting machines for removal of fungal-damaged grain. Histogram features from three transmittance images (blue and red components of color images and another at 960 nm) can distinguish 91.9% of infected kernels with extensive discoloration from 96.2% of asymptomatic kernels. Similar classification accuracies were achieved using x-ray images and physical properties (kernel thickness, weight, length). A neural network was trained to identify infecting fungal species on single kernels using principle components of the reflectance spectra as input features.

Diplodia maydis: a cause of death of cattle in Argentina

CASE HISTORY: This report describes an outbreak of high mortality of heifers after they consumed harvested maize fields parasitised with the fungus Diplodia maydis. CLINICAL FINDINGS: Clinical signs observed were generalised muscle tremors, incoordination, ataxic hindquarters, paralysis and death. The morbidity of the outbreak was 27/500 (5.4 %) and mortality 10/27 (37%). No gross lesions were observed, however histopathological examination revealed moderate to severe degeneration of myelin shafts in the white matter of the cerebellum. Diplodia maydis infection of maize was identifi ed from visual characteristics of mycelia and pycnidia. DIAGNOSIS: Diplodia toxicity (diplodiosis). CLINICAL RELEVANCE: This is the first description of the poisoning of cattle by maize contaminated with D. maydis in Argentina, where feeding cattle on harvested maize fields is common practice. It is possible this disease could occur in other countries, like New Zealand, where this fungus is known to be present.

Fungicide control of Stenocarpella Maydis in the Nigerian Savanna

A survey of farmers' fields in the Savanna zone of Nigeria in 1999 indicated the presence of stalk and cob rots of maize at incidence rates of 15 – 43% and disease severity of 2.0 – 6.7. The causal organism was identified as Stenocarpella maydis ( = Diplodia maydis). S. maydis was found to reduce seed germination by up to 29.2%. Laboratory and screen house experiments were used to evaluate the efficacy of six seed treatment fungicides indicated that Luxan (a local fungicide of unknown composition), benomyl (Benlate) and mancozeb (Dithane M-45) were more effective than metalaxyl + carboxin + furathiocarp (Apron-plus), carbendazin + maneb (Delsene M) and tetramethylthiuram disulphide + hexachlorobenzene (thiram + HCB) in controlling S. maydis. Stalk rot severity increased with increasing fertilization rates.

Levantamento de fungos associados às podridões do colmo e quantificação de danos em lavouras de milho do Planalto Médio gaúcho e dos Campos Gerais do Paraná

Os danos causados pelas podridões da base do colmo, a incidência de colmos doentes e as espécies de fungos envolvidas foram determinados em amostragem procedida em 29 lavouras de milho (Zea mays) destinadas à produção de grãos e de sementes, localizadas nas regiões do Planalto Médio gaúcho (RS) e dos Campos Gerais do Paraná (PR), nas safras 1997/98 e 1998/99. Os danos na safra 1997/98 variaram de 213 a 3.089 com média de 678 e na safra 1998/99 de 358 a 3.086 com média de 1.151 kg.ha-1. A incidência de colmos doentes no primeiro ano variou de 11,2 a 71,4 com média de 40,9 e no segundo de 21,9 a 79,3 com média de 45,9%. Não foi observada correlação entre os danos e a incidência de colmos doentes provavelmente pela diversidade das lavouras quanto aos fatores como genótipos, sistema de cultivo e forma de semeadura, fertilidade do solo, adubação e condições ambientais. A espécie de fungo que apresentou a maior incidência na primeira safra foi Colletotrichum graminicola e, na segunda, Fusarium graminearum. Além dessas, identificou-se outras espécies, como Diplodia maydis, D. macrospora, Fusarium moniliforme e F. subglutinans.

Desfolha, população de plantas e precocidade do milho afetam a incidência e a severidade de podridões de colmo

As relações entre fonte e dreno interferem sobre a ocorrência de podridões de colmo na cultura do milho (Zea mays). O estudo foi conduzido em Lages, SC, para avaliar o efeito da desfolha, população de plantas e híbridos sobre as podridões do colmo do milho. O delineamento experimental foi de blocos ao acaso com parcelas sub-subdivididas e três repetições. Os híbridos P32R21 (superprecoce), Premium (precoce) e C333B (tardio) foram testados sem desfolha e com 50% de desfolha no estágio de espigamento nas populações de 25.000, 50.000, 75.000 e 100.000 plantas ha-1. Avaliaram-se a incidência e a severidade das podridões do colmo causadas por Colletotrichum graminicola, Diplodia maydis e Fusarium moniliforme. O híbrido P32R21 foi o mais afetado pelos fungos causadores de podridões. Nos híbridos P32R21 e Premium, as plantas desfolhadas foram mais severamente infectadas pelos patógenos do que as intactas. O aumento da população de plantas aumentou a intensidade (incidência ou severidade) de podridões de colmo nas plantas intactas e diminuiu a ocorrência nas desfolhadas.

Reação de híbridos de milho à podridão branca da espiga

Neste trabalho, avaliou-se a reação de seis híbridos de milho (Zea mays)(AG 9012, C 808, P 3041, C 901, XL 212 e X 9403) de germoplasmas diferentes, a Diplodia maydis inoculados artificalmente nas espigas e à infecção natural de D. maydis e de D. macrospora. O híbrido X 9403 apresentou a menor incidência de grãos infetados e o rendimento de grãos superior dos demais híbridos; o híbrido XL 212 apresentou incidência e rendimento de grãos intermediários. Esses dois híbridos possuem textura de grãos dentados. Os híbridos P 3041, AG 9012 e C 808, com textura de grãos duro, apresentaram rendimentos inferiores e reações variáveis a D. maydis e a D. macrospora. Esses resultados mostraram que existe variabilidade entre híbridos quanto à reação à podridão da espiga causada por D. maydis e a D. macrospora. Na identificação de materiais resistentes, se sugere utilizar métodos artificiais de inoculação, visando aumentar a pressão de seleção e confiabilidade nos resultados.

Efeito da rotação de culturas, da monocultura e da densidade de plantas na incidência das podridões da base do colmo e no rendimento de grãos do milho

Quantificou-se neste trabalho o efeito da rotação de culturas, da monocultura e da densidade de plantas na incidência de doenças e no rendimento de grãos, associados às podridões da base do colmo (PBC) do milho (Zea mays), em experimentos de campo conduzidos na área experimental da Universidade de Passo Fundo (RS) durante a safra 1998/99. Utilizou-se o genótipo Pioneer 3071, semeado em parcelas de quatro linhas de 5 m distribuídas em blocos ao acaso e cinco tratamentos (30, 40, 50 ,60, e 70 mil plantas ha-1) com quatro repetições. As avaliações da incidência das PBC foram realizadas a cada sete dias. A incidência das PBC variou de zero a 12,9% sob rotação de culturas e de 1 a 46,8% em monocultura. Os fungos Diplodia maydis (8,4%) e D. macrospora (4,8%) foram as espécies isoladas com maior freqüência de colmos sintomáticos em monocultura. Na área de rotação de culturas, a maior incidência foi de D. maydis, com 3,4% seguida de D. macrospora, com 3,3%.

Incidência e severidade de doenças de quatro híbridos de milho cultivados com diferentes densidades de plantas

Os híbridos modernos de milho apresentam maior potencial produtivo do que os cultivares utilizados no passado, especialmente sob situações de estresse, como densidade de semeadura elevada e deficiência hídrica. É possível que o maior rendimento de grãos dos genótipos modernos nessas condições se deva, em parte, a sua melhor sanidade. Este trabalho foi conduzido em Lages, SC, com o objetivo de avaliar a incidência e severidade das principais doenças foliares, de colmo e espiga de híbridos de milho cultivados no Planalto Catarinense, em diferentes densidades de semeadura. Utilizou-se o delineamento experimental de blocos ao acaso com parcelas subdivididas. Na parcela principal, foram testadas três populações de planta, equivalentes a 50000, 75000 e 100000pl ha-1. Nas subparcelas, testaram-se quatro híbridos: Ag 12, Ag 28, Ag 303 e Ag 9012, os quais foram cultivados de forma expressiva nas décadas de 60, 70, 80, e 90, respectivamente. O aumento da população de plantas promoveu um incremento na incidência das doenças de colmo causadas por Fusarium moniliforme, Colletotrichum graminicola e Diplodia maydis. Esse aumento na quantidade de doenças foi mais intenso nos híbridos Ag 12 e Ag 28, contribuindo para aumentar a percentagem de plantas acamadas e quebradas destes materiais na colheita. O híbrido Ag 9012 apresentou menor incidência e severidade das doenças de espiga causadas por Fusarium moniliforme e Diplodia maydis, independentemente da densidade de semeadura. Não foi constatada menor severidade a doenças foliares no híbrido Ag 9012, em relação aos híbridos mais antigos.

Enfermidades do sistema nervoso dos ruminantes no sul do Rio Grande do Sul

Descrevem-se os aspectos epidemiológicos, clínicos e patológicos das enfermidades do sistema nervoso central dos ruminantes, diagnosticadas na região Sul do Rio Grande do Sul, incluindo: abiotrofia cerebelar; hipoplasia cerebelar; hipermetria hereditária; artrogripose; hipomielinogênese congênita; abscesso cerebral; listeriose; tétano; botulismo; necrose simétrica focal; raiva; leucose; encefalite por herpesvírus bovino-5; febre catarral maligna; intoxicações por Solanum fastigiatum, Claviceps paspali, Ramaria flavo-brunnescens, Halimium brasiliense e Diplodia maydis; encefalopatia hepática causada por Senecio spp. e Echium plantagineum; cetose; coenurose; e síndrome espinhal.

Risk Assessment of Fumonisins Produced by Fusarium moniliforme in Corn

Four important toxigenic species of fungi are associated with corn (Zea mays) intended for human and animal consumption in South Africa, ie Aspergillus flavus, Diplodia maydis, Fusarium graminearum, and Fusarium moniliforme. Com infected by these fungi causes outbreaks of the following mycotoxicoses in animals: aflatoxicosis, diplodiosis, hyperestrogenism and leukoencephalomalacia. The five most important mycotoxins known to occur naturally in corn in South Africa are aflatoxins, deoxynivalenol, nivalenol, zearalenone and fumonisins. The following mycotoxins in foods have been implicated in human diseases in South Africa: aflatoxins in acute toxic hepatitis, kwashiorkor and liver cancer and fumonisins in oesophageal cancer. Tolerance levels of mycotoxins in grain are essential to protect human health and to assess grain quality from the viewpoint of mycotoxin contamination. Tolerance levels are established by means of risk assessment studies. Risk assessment of mycotoxins in grains has two major components, ie exposure assessment and hazard assessment. Exposure is calculated from naturally occurring levels of a mycotoxin in foodstuffs and food intake and expressed as the Probable Daily Intake (PDI). Hazard is calculated from toxicological studies in experimental animals by dividing the No Observed Effect Level (NOEL) by a Safety Factor (ranging from 100 to 5000) and expressed as the Tolerable Daily Intake (TDI). Several estimates of PDI and TDI values of fumonisins in corn are compared and a tolerance level of 100 to 200 μg/kg for fumonisins in corn intended for human consumption is suggested. However, more work remains to be done to establish scientifically sound and economically reasonable tolerance levels for fumonisins in corn.

Effect of Steryl Cinnamic Acid Derivatives from Corn Bran on Aspergillus flavus, Corn Earworm Larvae, and Driedfruit Beetle Larvae and Adults

Steryl esters of ferulic and p-coumaric acids were tested for their effect on corn fungal pathogens and insects. The steryl ester fraction from corn bran had no effect on corn earworm larvae or driedfruit beetle adults, but driedfruit beetle larvae showed a significant increase in weight and the triglyceride fraction was active. Bioassays of pure ferulate esters and the ester fraction from both corn and rice showed no appreciable effect at 100 ppm on spore germination or germ tube growth of Aspergillus flavus, Fusarium moniliforme, or Diplodia maydis. Sclerotinia sclerotiorum was inhibited 75−90% by the total steryl ester fraction from corn and approximately 50% by the ester fraction from rice bran oil. Stigmastanyl and campestanyl ferulate showed little or no inhibition. The steryl ester fraction increased aflatoxin B1 level in A. flavus NRRL 6536 significantly at 0.33 and 1.0 mg/mL. However, the esters had no effect on A. flavus NRRL 3357. The steryl ferulate and p-coumarate ester fraction from corn was...

Ultrastructural Histopathology of Infection and Colonization of Maize by Stenocarpella maydis (= Diplodia maydis)

AbstractThe mode of penetration and colonization of stalk, shank and leaf sheath tissues of maize by Stenocarpella maydis (=Diplodia maydis) was determined by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) observations. Detached plant tissues, inoculated with a conidial suspension and examined by SEM at various intervals, showed that S. maydis conidia germinated on all plant material types after 5 h incubation at 30 °C. After 72 h incubation, appressoria had formed at the hyphal tips. Similar observations were recorded on plants inoculated in the glasshouse except that germination was delayed by 7 days after inoculation. TEM studies showed that penetration was affected by a penetration hypha which resulted in the inter‐ and intracellular colonization of the plant tissues. Colonization was accompanied by degradation of cell walls suggesting that host colonization is facilitated by enzyme activity.

Assessment for animal feed of maize kernels naturally-infected predominantly with Fusarium moniliforme and Diplodia maydis. II. Nutritive value as assessed by feeding to rats and pigs

Four batches of ear-rot damaged maize grain and a batch of reportedly sound maize were assessed by rat and pig growth assay and digestibility determination in pigs. All batches were the yellow hybrid, Dekalb XL81, except one which was a white variety, Dekalb DS456W. The fungus most frequently isolated from damaged kernels was Fusarium monilifome, with the exception of one batch where Diplodia maydis was equally prevalent. Traces of aflatoxin were detected in two samples but ochratoxin A, sterigmatocystin, zearalenone, T-2 toxin, deoxynivalenol, nivalenol, diacetoxyscirpenol and moniliformin were not detected. In the growth assays, no illness was apparent in any of the rats but scouring, vomiting and a persistent and generalized muscle tremor were observed in a number of pigs. Diets based on sound maize resulted in better (P < 0.05) growth performance of both rats and pigs than those based on mouldy maize. The apparent digestibility of the sound maize was better than each batch of mouldy yellow maize, but no better than the batch of mouldy white maize. Differences in nutritive value between the batches of maize were more closely related to the degree of fungal damage and the nature of the endosperm than to either the proximate chemical or amino acid composition of the grain. The muscle tremor observed in some pigs might have been due to undetected mycotoxins.