scholarly journals Influence of Inoculation Method on Systemic Fusarium moniliforme Infection of Maize Plants Grown from Infected Seeds

Plant Disease ◽  
1997 ◽  
Vol 81 (2) ◽  
pp. 211-216 ◽  
Author(s):  
G. P. Munkvold ◽  
W. M. Carlton

Two greenhouse and two field experiments were conducted in 1994 and 1995 to quantify the incidence of maize kernel infection resulting from systemic infection of maize plants by Fusarium moniliforme. Seeds were infected by two methods: (i) spray-inoculation of maize silks during seed development (field-infected), and (ii) soak-inoculation of mature seeds in a spore suspension (laboratory-infected). Plants were grown from infected seeds and assayed for systemic infection by the seed-inoculated strain, determined by vegetative compatibility of recovered isolates with the original strain. The seed-inoculated strain was recovered from stalks and kernels of plants grown from both types of infected seed. Mature plants grown from field-infected seeds had a higher percentage of their kernels infected with the seed-inoculated strain compared with plants from laboratory-infected seed. Mean incidence of infection by the seed-inoculated strain was 9.9 to 29.4% of all kernels (33.0 to 55.9% of F. moniliforme-infected kernels) in the plants grown from field-infected seed. Some plants from infected seed were subsequently silk-inoculated, and the silk-inoculated strain was recovered from a much higher percentage of kernels (26.5 to 37.5% of all kernels or 77.9 to 78.4% of F. moniliforme-infected kernels) than was the seed-inoculated strain; furthermore, silk inoculation significantly reduced incidence of kernel infection by the seed-inoculated strain. Seed infection by F. moniliforme resulted in systemic infection of plants and kernels. However, local infection (via silks) was a more important pathway to kernels than was systemic infection, and strains infecting the silks competed successfully against those entering the kernels through systemic development.

1997 ◽  
Vol 87 (2) ◽  
pp. 209-217 ◽  
Author(s):  
G. P. Munkvold ◽  
D. C. McGee ◽  
W. M. Carlton

The relative importance of several infection pathways (silks, stalks, and seed) leading to kernel infection of maize hybrids by Fusarium moniliforme was investigated in field experiments in 1993 and 1994. Systemic movement of specific fungal strains within plants was detected by using vegetative compatibility as a marker. Transmission of F. moniliforme from inoculated seed to stalks and developing kernels was detected in two of three field experiments; the seed-inoculated strain was detected in kernels on approximately 10% of ears. The percentage of kernels infected with the seed-inoculated strain ranged from 0 to 70%, with a mean of 0 to 2.5% (0 to 8.3% of F. moniliforme-infected kernels). Other pathways to kernel infection were more effective than seed transmission and systemic infection. F. moniliforme strains inoculated into the crowns and stalks of plants were found throughout the stalks and in up to 95% of the kernels in individual plants. Infection through the silks was clearly the most effective pathway to kernel infection. This was the only inoculation method that significantly increased overall incidence of F. moniliforme infection in kernels; the silk-inoculated strain infected up to 100% of the kernels in individual ears, with a treatment mean as high as 83.7% of kernels. When plants were silk-inoculated, the percentage of kernels infected by other F. moniliforme strains from the seed or stalk was reduced, apparently due to competition among strains. This study provides evidence that systemic development of F. moniliforme from maize seed and stalk infections can contribute to kernel infection, but silk infection is a more important pathway for this fungus to reach the kernels.


Plant Disease ◽  
2008 ◽  
Vol 92 (12) ◽  
pp. 1695-1700 ◽  
Author(s):  
A. Murillo-Williams ◽  
G. P. Munkvold

Fusarium verticillioides causes seedling decay, stalk rot, ear rot, and mycotoxin contamination (primarily fumonisins) in maize. Systemic infection of maize plants by F. verticillioides can lead to kernel infection, but the frequency of this phenomenon has varied widely among experiments. Variation in the incidence of systemic infection has been attributed to environmental factors. In order to better understand the influence of environment, we investigated the effect of temperature on systemic development of F. verticillioides during vegetative and reproductive stages of plant development. Maize seeds were inoculated with a green fluorescent protein-expressing strain of F. verticillioides, and grown in growth chambers under three different temperature regimes. In the vegetative-stage and reproductive-stage experiments, plants were evaluated at tasseling (VT stage), and at physiological maturity (R6 stage), respectively. Independently of the temperature treatment, F. verticillioides was reisolated from nearly 100% of belowground plant tissues. Frequency of reisolation of the inoculated strain declined acropetally in aboveground internodes at all temperature regimes. At VT, the high-temperature treatment had the highest systemic development of F. verticillioides in aboveground tissues. At R6, incidence of systemic infection was greater at both the high- and low-temperature regimes than at the average-temperature regime. F. verticillioides was isolated from higher internodes in plants at R6, compared to stage VT. The seed-inoculated strain was recovered from kernels of mature plants, although incidence of kernel infection did not differ significantly among treatments. During the vegetative growth stages, temperature had a significant effect on systemic development of F. verticillioides in stalks. At R6, the fungus reached higher internodes in the high-temperature treatment, but temperature did not have an effect on the incidence of kernels (either symptomatic or asymptomatic) or ear peduncles infected with the inoculated strain. These results support the role of high temperatures in promoting systemic infection of maize by F. verticillioides, but plant-to-seed transmission may be limited by other environmental factors that interact with temperature during the reproductive stages.


1998 ◽  
Vol 88 (6) ◽  
pp. 550-555 ◽  
Author(s):  
T. K. Cotten ◽  
G. P. Munkvold

The roles of residue size and burial depth were assessed in the survival of Fusarium moniliforme, F. proliferatum, and F. subglutinans in maize stalk residue. Stalk pieces (small or large sizes) were soaked in a spore suspension of F. moniliforme, F. proliferatum, or F. subglutinans and placed in a field on the soil surface or buried at 15- or 30-cm depths. Residue pieces were recovered periodically, cultured on a selective medium, and microscopically examined for the presence of the inoculated Fusarium species. After 630 days, the inoculated Fusarium species were recovered from 0 to 50% of the inoculated stalk pieces in a long-term, continuous maize field, from 0 to 28% of the inoculated stalk pieces placed in a maize/soybean/oat rotation field, and from 0 to 25% of the noninoculated stalk pieces at both locations. Residue size and residue depth had significant effects on survival, but there were significant interactions among strain, depth, residue size, and time. Up to 343 days after placement in the field, survival of the three Fusarium species was not consistently different between buried residues and surface residues, but after 630 days, survival was greater from surface residues. Overall, fungus survival decreased more slowly in the surface residues than in the buried residues. Linear coefficients of determination ranged from 0.35 to 0.82 for the surface residues and from 0.81 to 0.98 for the buried residues. Decline in survival over time followed a more linear pattern in buried residues than in surface residues. Vegetative compatibility tests confirmed that F. moniliforme, F. proliferatum, and F. subglutinans strains can survive at least 630 days in surface or buried maize residue. These results demonstrate that maize residue can act as a long-term source of inoculum for infection of maize plants by these three Fusarium species.


2019 ◽  
Vol 11 (18) ◽  
pp. 5086 ◽  
Author(s):  
Libing Song ◽  
Jiming Jin ◽  
Jianqiang He

In this study, we investigated the effects of water stress on the growth and yield of summer maize (Zea mays L.) over four phenological stages: Seedling, jointing, heading, and grain-filling. Water stress treatments were applied during each of these four stages in a water-controlled field in the Guanzhong Plain, China between 2013 and 2016. We found that severe water stress during the seedling stage had a greater effect on the growth and development of maize than stress applied during the other three stages. Water stress led to lower leaf area index (LAI) and biomass owing to reduced intercepted photosynthetically active radiation (IPAR) and radiation-use efficiency (RUE). These effects extended to the reproductive stage and eventually reduced the unit kernel weight and yield. In addition, the chlorophyll content in the leaf remained lower, even though irrigation was applied partially or fully after the seedling stage. Severe and prolonged water stress in maize plants during the seedling stage may damage the structure of the photosynthetic membrane, resulting in lower chlorophyll content, and therefore RUE, than those in the plants that did not experience water stress at the seedling stage. Maize plants with such damage did not show a meaningful recovery even when irrigation levels during the rest of the growth period were the same as those applied to the plants not subjected to water stress. The results of our field experiments suggest that an unrecoverable yield loss could occur if summer maize were exposed to severe and extended water stress events during the seedling stage.


Plant Disease ◽  
1999 ◽  
Vol 83 (7) ◽  
pp. 690-693 ◽  
Author(s):  
Douglas J. Jardine ◽  
John F. Leslie

Four strains each of Fusarium moniliforme (syn. Fusarium verticillioides) and Fusarium thapsinum were tested for aggressiveness toward two maize inbred lines grown under greenhouse conditions. All strains induced significantly longer stalk lesions than those observed in the controls. Mean lesion length resulting from inoculation with strains of F. moniliforme was longer than the mean lesion length resulting from inoculation with strains of F. thapsinum. Within each species, however, there was a broad range of lesion lengths observed, and all tested strains of both species probably should be regarded as potential pathogens of maize. No isolate × inbred interaction was detected. Fumonisins may play a role in aggressiveness, but under our conditions, stalk rot and the ability to produce fumonisins in vitro were not correlated.


1994 ◽  
Vol 45 (7) ◽  
pp. 1395 ◽  
Author(s):  
AM Bwye ◽  
RAC Jones ◽  
W Proudlove

During 1990-92, narrow-leafed lupins (Lupinus angustifolius) cv. Gungurru, were grown in six field experiments in which plots were sown with healthy seed or seed that carried 0.5-5% infection with cucumber mosaic virus (CMV). Seed-infected plants were the primary source for subsequent virus spread by aphids. The rate of CMV spread and the extent of infection in plots depended on the level of infection in the seed sown, the proportion of infected seeds that successfully developed into established plants and the time of arrival and number of aphid vectors. In general, higher seed infection levels, better establishment of seed-infected plants and early aphid arrival favoured greater virus spread, yield loss and infection in the harvested seed. In 1991, in two experiments, late arrival of aphids resulted in minimal CMV spread, no effect on yield and much less infection in the harvested seed than in the seed sown. In the other four experiments, significant yield losses (25-42%) always resulted when seed with 5% or 3% infection was sown. Sowing 1% infected seed resulted in significantly decreased yields in two experiments, while 0.75% and 0.5% infected seed caused significant losses in one experiment (16-19% losses). Yield decreases were due to both fewer seeds being formed and decreased seed size. Levels of infection in harvested seed did not exceed 15%. In a further field experiment in 1991, individual plants that developed CMV symptoms before initiation of flowering or during flowering had significantly smaller yields than those that developed symptoms after flowering had finished. In four field experiments during 1990-91, 10-15% CMV-infected lupin seed was sown at rates of 20-150 kg ha-1 to generate a range of plant densities. The numbers of seed-infected plants were recorded at different times. The extent of loss of seed-infected plants due to shading by neighbouring healthy plants depended on plant density and the time when canopy closure developed. Where no canopy formed there was little or no loss of seed-infected plants, while early canopy formation at high plant density was most effective in removing them. Current-season spread was also decreased by early canopy formation and high plant density, but this effect was smaller when aphids arrived early. This work supports recommendations for management of CMV infection in lupins by sowing seed with low infection (<0.5%) to minimize infection sources, and sowing early at high seeding rates to remove seed-infected plants through improved canopy formation.


2020 ◽  
Vol 12 (8) ◽  
pp. 212
Author(s):  
A. M. Sheha ◽  
Haytham Mostafa El-Shahed ◽  
Abd El Nabi Hamed Mohamed Diab

Two field experiments were carried out at the Experimental Farm of Gemmeiza Agriculture Research Station, Agricultural Research Center (ARC), Egypt after 2018 and 2019 summer growing seasons to determine the effect of intercropping pattern of yellow maize hybrid (single cross 168: &ldquo;SC 168&rdquo;) with watermelon pulp at three plant distributions (20 cm between hills and one plant/hill, 40 cm between hills and two plants/hill and 60 cm between hills and three plants/hill) and different levels of nitrogen fertilizer (25, 50, 75 and 100% of the recommended dose &ldquo;120 kg N fad-1&rdquo;) as well as their interactions on maize and watermelon pulp growth, yield and its attributes as well as competitive relationships and yield advantages. The experiments were carried out in split-plot design with four replicates. The main-plots were assigned to plant distributions of maize, the sub-plots were allocated to levels of nitrogen fertilizer for maize. The obtained results showed that planting maize plants on one side of terraces of 140 cm width with 20 cm between hills and leaving one plant/hill and planting watermelon pulp on the other side of the terraces produced the highest values of plant height, ear height, number of kernels row-1, 100-kernel weight and grain yield fad-1, at the same time the lowest values of ear leaf area, ear length, ear diameter and number of rows ear-1 of maize as well as the lowest values of growth, yield and its attributes of watermelon pulp during the both seasons. Mineral fertilizing maize plants with 75% of the recommended dose (90 kg N/fad) and watermelon pulp with the recommended dose produced the highest values of all studied growth characters, yield and its attributes of maize and watermelon pulp in both seasons. The highest values of land equivalent ratio (LER), relative crowding coefficient (RCC), area time equivalent ratio (ATER), land equivalent coefficient (LEC), aggressivity index (AI), monetary advantage index (MAI), actual yield (L.E.) of watermelon, Total income (L.E.) and economic return (L.E.) were obtained from planting maize plants on one side of terraces of 140 cm width with 60 cm between hills and leaving three plants/hill and planting watermelon pulp on the other side of the terraces besides fertilizing maize plants with 75% of the recommended dose (90 kg N/fad) and watermelon pulp with the recommended dose in both seasons. It can be recommended that planting maize on 60 cm between hills and leaving three plants/hill and planting watermelon pulp on the other side of the terraces besides fertilizing maize plants with 90 kg N/fad and watermelon pulp with the recommended dose to obtain the maximum values growth, yield and its attributes of watermelon pulp and competitive relationships and yield advantages of both crops under the climates conditions of Middle Delta, Egypt.


2019 ◽  
Vol 52 (3) ◽  
pp. 248-253
Author(s):  
ADINA PETRUȚA JIPA ◽  
DANELA MURARIU

Nitrogen is an important element required for plant growth and development. It is a key component in many biological compounds that play a major role in photosynthetic activity and crop yield capacity. Variation in nitrogen availability can affect plant development and productivity in maize. One of the ways of soil pollution through agricultural technology is over-fertilization and, in particular, the administration of high doses of nitrogen fertilizers. Excess of nitrogen fertilizers, as well as their empirical application, have negative effects on harvest quality. Excessive use of fertilizers with nitrogen, produces of ion nitric accumulation in the soil (temporary) and in plants, which disturbs the balance of photosynthesis, causes the appearance of necrosis and burns on leaves, severe intoxication and even death by asphyxiation phenomena and cyanosis at ruminants, children and old people. The main aim of this study was to determine the effect of different nitrogen levels and different type of fertilizers on nitrates levels in maize leaves and on morphological traits of maize plants. Field experiments were conducted in two growing seasons (2017 and 2018) with five nitrogen levels (80 kg/ha, 120 kg/ha, 160 kg/ha, 200 kg/ha and 240 kg/ha) and two type of nitrogen fertilizers (ammonium nitrate and urea).


Author(s):  
Gabriel Viana de Araújo ◽  
Alfredo Junior Paiola Albrecht ◽  
Leandro Paiola Albrecht ◽  
Hudson Wallace Pereira de Carvalho ◽  
Rafaela Alenbrant Migliavacca ◽  
...  

The aim of this study was to check the tolerance level of maize possessing the transgenes cp4epsps and pat, exposed to high rates of glyphosate or glufosinate. Field experiments were carried out in 2016/17 at the first growing season; and the other in the second growing season, in Palotina, state of Paraná (PR), Brazil. The design was completely randomized block with 4 replications, which were set up with variations of rates of herbicides: glyphosate (0; 2,160; 4,320; 6,480 and 8,640 g ae ha-1) (experiment 1) and glufosinate (0; 1,500; 3,000; 4,500 and 6,000 g ai ha-1) (experiment 2). The application was performed at the V4 stage. Plants were evaluated for injuries, final plant height, stem diameter, 100-grain mass, yield and content of P, K, S, Fe, Cu and Zn. The results show that there was no reduction in yield and 100-grain mass, as well as changes in nutrient contents, even with the use of high rates of glyphosate and glufosinate. This is explained by the rapid recovery of maize hybrids under favorable developmental conditions. Despite causing injuries and decreased height, application of glyphosate (up to 8,640 g ae ha-1) or glufosinate (up to 6,000 ai ha-1) did neither reduce yield and 100-grain mass nor the nutrient contents of grains. This shows the high selectivity of these herbicides. Nonetheless, crop injury and reduction in height were observed in maize plants for herbicide application. This indicates the risks of using herbicides above the rates recommended in the package insert, despite the absence of deleterious effects on yield


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