scholarly journals Impact of sowing time, hybrid and environmental conditions on the contamination of maize by emerging mycotoxins and fungal metabolites

Author(s):  
Massimo Blandino ◽  
Valentina Scarpino ◽  
Debora Giordano ◽  
Michael Sulyok ◽  
Rudolf Krska ◽  
...  

Mycotoxins and other fungal metabolites represent the most insidious safety risks to cereal food and the feed chain. Optimising agronomic practices is one of the main strategies adopted to minimise the contents of these undesirable substances in grain-based commodities. The aim of this study was to investigate the effect of the combination of sowing times and hybrids on the occurrence of emerging mycotoxins and fungal metabolites in maize. Field experiments were carried out in 2 sowing times (early vs late) and 3 maize hybrids were compared in the 2014 and 2015 growing seasons. Overall, 37 fungal metabolites produced by Fusarium and Alternaria species were detected. Apart from fumonisins type B (FBs), other metabolites produced by Fusarium verticillioides and F. proliferatum, such as fumonisins type A, fusaric acid, bikaverin and fusaproliferin, were also detected in all of the samples. Fusarin C was found in 61% of the samples. Deoxynivalenol (DON), deoxynivalenol-3-glucoside, culmorin and zearalenone, all of which are produced prevalently by Fusarium graminearum and F. culmorum, were found in all the samples. Their contents were clearly affected by the meteorological trend: the highest contamination was detected in the 2014 growing season, which was characterised by abundant rainfall and lower temperatures from flowering to maize ripening. Among the mycotoxins produced by other Fusarium species, aurofusarin was found to clearly be associated with DON, while moniliformin and beauvericin followed the same behaviour as the FBs. A late sowing time significantly increased the FBs and fumonisin- associated mycotoxins in both growing seasons. The increase in contamination with the delay of sowing was more pronounced in the 2015 growing season, as the environmental conditions were less favourable to the infection of other Fusarium species. The effect of sowing time on DON and DON-associated mycotoxins produced conflicting results for the two growing seasons, because contamination by these metabolites depends more on the conditions that occur during maize flowering than those that occur during ripening. A clearer hybrid susceptibility was observed for these compounds. Other metabolites, such as enniatins, equisetin, T-2 and HT-2 toxins and Alternaria toxins, were always found in traces. The occurrence of these metabolites seems to be influenced less by the considered agronomic practices. The results, obtained under naturally-infected field conditions, underline the key role that the sowing date and hybrid susceptibility play in influencing, in a variable way, the contamination of mycotoxins produced by different Fusarium species in maize subjected to different meteorological conditions. The content of mycotoxins produced by Fusarium spp. section Liseola is more directly and steadily related to late sowing time, while the contamination of mycotoxins associated to Fusarium spp. section Discolor depend more strongly on the environmental conditions at maize flowering and on hybrid susceptibility.

Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.


2006 ◽  
Vol 96 (11) ◽  
pp. 1214-1222 ◽  
Author(s):  
Mathew M. Abang ◽  
Michael Baum ◽  
Salvatore Ceccarelli ◽  
Stefania Grando ◽  
Celeste C. Linde ◽  
...  

Competition among eight Rhynchosporium secalis isolates was assessed during parasitic and saprophytic phases of the disease cycle in field experiments conducted at two locations and over two growing seasons. The eight isolates were inoculated onto six barley populations exhibiting varying degrees of resistance. Microsatellite analysis of 2,866 isolates recovered from the field experiments showed significant, and sometimes opposite, changes in the frequencies of R. secalis genotypes during the growing season (parasitic phase) and between growing seasons (saprophytic phase). Isolates that showed the most complex virulence in greenhouse seedling assays had the lowest fitness in the field experiment. Significant differences in isolate fitness were found on different host populations and in different environments. Selection coefficients were large, indicating that evolution can occur rapidly in field populations. Although inoculated isolates had the lowest overall fitness on the moderately resistant landrace cv. Arabi Aswad, some isolates were more virulent and consistently increased in frequency on this landrace, suggesting a risk of directional selection and possible erosion of the resistance following its widespread deployment in monoculture. These results provide the first direct evidence that R. secalis pathogen genotypes differ in their saprophytic ability and parasitic fitness under field conditions.


2019 ◽  
Vol 56 (2) ◽  
pp. 239-252 ◽  
Author(s):  
Adriana Derejko ◽  
Marcin Studnicki

SummaryTriticale (Triticosecale Wittmack) is obtained through the crossing of wheat (Triticum ssp.) and rye (Secale cereale L.) and is characterized by high yield potential, good health and grain value, and high tolerance to biotic and abiotic stress. Poland is a very important region for progress in triticale breeding, since it is home to most cultivars, and numerous genetic studies on triticale have been carried out. Despite the tremendous interest in triticale among both breeders and researchers, there are no studies assessing the adaptation of cultivars to environmental conditions across growing seasons. This study was conducted to investigate the influence of cultivar, management, location and growing season on grain yield. At the same time, this approach provides a new way to determine whether there is any dependency between the eight seasons, and to find the cause of the yield response to environmental conditions in a given growing season.


1978 ◽  
Vol 91 (3) ◽  
pp. 633-638 ◽  
Author(s):  
S. U. Remison ◽  
Dele Akinleye

SummaryField experiments were carried out in the early and late growing seasons in the rainforest zone of Nigeria to find out the relationship between lodging, morphological characters and yield of maize.Morphological characters associated with lodging were plant height, ear height and length of basal internode. There was a negative correlation between lodging and yield. Much of the lodging recorded, especially in the early growing season, was due to weak stems. Earliness, diameter of stem and leaf area had no relationship with lodging.


2016 ◽  
Vol 40 (4) ◽  
pp. 521-528
Author(s):  
M Ataur Rahman ◽  
M Mohabbatullah ◽  
CK Das ◽  
UK Sarker ◽  
SMM Alam

The field experiment was conducted at the Hill Agricultural Research Station, BARI, Khagrachari for the two consecutive years (2009-10 and 2010-11) to find out the wheat variety suitable for hilly environment and investigate the interaction of sowing dates and varieties to recommend the promising variety with proper sowing time. The experiment was laid out in split-plot design with three replications where three dates of sowing (Nov. 20, Nov. 30 and Dec. 10) were assigned in the main plots and five modern wheat varieties (Shatabdi, Sufi, Sourav, Bijoy and Prodip) were tested in the sub-plots. The yield responses of wheat varieties during the two years showed that there were significant varietal differences under the experimental soil and environmental conditions. The variety Bijoy gave maximum grain yield closely followed by Sourav in both years. Shatabdi produced higher yield under early sowing (Nov. 20) but yield was decreased due to late sowing (Dec. 10). Initially the plant population and finally spikes/m2 were affected by late sowing that caused less yield in Shatabdi. The mean yield of all varieties pulled over the sowing time indicated that wheat yield was not affected due to delay sowing up to 10th December. The experimental result demonstrated that Shatabdi could be recommended only for early sowing whereas Bijoy and Sourav could be recommended both for early and late sowing under the experimental soil and environmental conditions at hilly region of Khagrachari.Bangladesh J. Agril. Res. 40(4): 521-528, December 2015


1983 ◽  
Vol 61 (12) ◽  
pp. 3207-3216 ◽  
Author(s):  
Roseann Densmore ◽  
John Zasada

Seeds of the 24 common Salix species of the Alaskan boreal forest and tundra were set to germinate in laboratory and field experiments, and seed dispersal times were observed. During the growing season, 16 species disperse short-lived, nondormant seeds. At the end of the growing season, eight other species, all tundra willows, disperse conditionally dormant seeds. These fall-dispersed seeds are fully developed in the same length of time as summer-dispersed seeds, but they develop dormancy while being held on the plant until the leaves senesce. At the time of dispersal, some seeds are capable of germinating at high temperatures, but no seeds can germinate at the low soil temperatures occurring then. Cold stratification gradually widens the range of temperatures at which seeds can germinate, and seeds germinate at low soil temperatures in the spring shortly after snowmelt. Salix species dispersing dormant seeds during the fall appear to have evolved, as an adaptation to short growing seasons in cold climates, from taxa dispersing nondormant seeds during the summer.


1975 ◽  
Vol 55 (1) ◽  
pp. 95-99 ◽  
Author(s):  
C. B. WILLIS ◽  
L. S. THOMPSON

The effects of a preseeding application of the nematicide carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate) and the fungicide benomyl (methyl-1-(butylcarbamoyl)-2-benzimidazole carbamate), alone and in combination, on birdsfoot trefoil (Lotus corniculatus L.) were determined in the field. The nematicide and fungicide + nematicide treatments controlled root lesion nematodes (Pratylenchus spp.) in soil and roots for two growing seasons and increased forage yield for the same periods. The reduction in the number of root sections with Fusarium spp. was comparable for the nematicide and fungicide treatments and greater for the fungicide + nematicide treatment for two growing seasons. Nematode numbers were greater in fungicide-treated plots and forage yields were lower for two growing seasons. The nematicide and fungicide had no effect on forage yield, nematode numbers or fungus recovery in the third growing season. Plant persistence was not affected by the nematicide or fungicide, alone or in combination.


2002 ◽  
Vol 92 (5) ◽  
pp. 534-541 ◽  
Author(s):  
D. W. Stewart ◽  
L. M. Reid ◽  
R. W. Nicol ◽  
A. W. Schaafsma

Fusarium spp. in maize can contaminate the grain with mycotoxins if environmental conditions are favorable for fungal growth. To quantify the relationship between growth of Fusarium spp. and environmental conditions, a mathematical model was developed to simulate growth of F. graminearum and F. verticillioides on maize ears following silk inoculation in field experiments from 1992 to 1995. Each species was inoculated separately and as a mixture of the two for 3 of the 4 years on one maize hybrid. Disease progress in ears was measured by a visual rating scale that was converted to percent visual infection. Measurements were made at regular time intervals after silks were inoculated 5 days after silk emergence. Differential equations were used to relate growth rates of Fusarium spp. in maize ears to hourly air temperature and relative humidity and to daily precipitation. Integration of these equations over time produced quantitative estimates of fungal growth. Model calculations compared well with measurements (R2 = 0.931, standard error of estimate [SEE] = 2.11%) of percent visual disease infection of maize ears over 3 years. The model was tested against a second set of data (R2 = 0.89, SEE = 5.9%) in which silks were inoculated at nine different times after first silk emergence for each of 2 years (1994 and 1995) with the two species of fungi on the same maize hybrid. At this time, a silk function was developed to account for changes in the susceptibility of silks to disease. F. graminearum responded to wet conditions more than F. verticillioides, and for the conditions of this experiment, grew much faster than F. verticillioides when inoculated separately. When they were inoculated together, F. graminearum growth rates were much lower, indicating some interference by F. verticillioides. During 1993, weather conditions before inoculation reduced the growth of both species in silks.


2006 ◽  
Vol 46 (3) ◽  
pp. 395 ◽  
Author(s):  
K. L. Regan ◽  
K. H. M. Siddique ◽  
N. J. Brandon ◽  
M. Seymour ◽  
S. P. Loss

Chickpea has become an important grain legume crop in Australia over the last decade. New varieties with improved seed yield and quality are being developed in Australia with varied phenological and agronomic traits. This study examined the optimum time of sowing of several desi chickpea varieties (Dooen, T1587, Sona and Tyson) varying in phenology over a range of dryland Mediterranean-type environments in south-western Australia. Chickpea showed good adaptation, particularly in the northern grain belt of Western Australia where growing conditions are warmer than southern areas. Seed yields varied widely depending on the time of sowing, location and seasonal conditions. Mean seed yields greater than 1000 kg/ha and up to 2000 kg/ha were achieved, but in some cases seed yields were less than 800 kg/ha. In the northern region, seed yield was almost doubled by sowing in early-May (1625 kg/ha) compared with late-June (754 kg/ha). In contrast to this, seed yields were generally lower in the southern regions and greater from late-June sowings (865 kg/ha) compared to earlier mid-May sowings (610 kg/ha). Seed yields were not clearly increased by altering sowing time to match the phenology of the variety to the growing season rainfall and temperatures, except at the early sowing times (April and early-May) where Tyson out-yielded all other varieties. This is most likely due to the lack of photoperiod-responsive, long-duration varieties to match early sowing and low temperatures limiting vegetative and reproductive growth in all varieties, especially in southern areas. However, it is likely that early flowering varieties will show greater adaptation and yield performance in short growing seasons, while later flowering varieties will be better suited to longer growing seasons. The study found that there were significant differences in the optimum sowing time between northern, central and southern sites, based on differences in mean daily temperatures and length of the growing season. Generally, the greatest seed yields were produced by sowing between mid to late June at southern sites, and early May at central and northern sites.


2020 ◽  
Vol 8 (4) ◽  
pp. 19
Author(s):  
Alan Serafini Betto ◽  
Rafael Dysarz ◽  
Rafaela Cinelli ◽  
Rubens Antonio Polito ◽  
Tamara Heck ◽  
...  

The use of ACCase-inhibiting herbicides without the correct addition of an adjuvant is a major cause of inefficient poaceous weed control. As such, this study aimed to assess the efficiency of a new clethodim/adjuvant formulated mixture in postemergence weed control for soybean crops. Two field experiments were conducted in the 2015/16 and 2016/17 growing seasons. A randomized block design, consisting of ten treatments with four repetitions, was used. The treatments and doses were: clethodim (108 g a.i. ha-1) + Lanzar® (0.5%), clethodim (108 g a.i. ha-1) + Nimbus® (0.5%), clethodim/adjuvant formulation at doses of (84 g a.i. ha-1), (96 g a.i. ha-1), (108 g a.i. ha-1), (120 g a.i. ha-1), (132 g a.i. ha-1), and (144 g a.i. ha-1), and a control with and without weeding. The formulated clethodim/adjuvant mixture showed high control at 7 days after application (DAA) in the 2015/16 growing season. At 28 DAA, formulation doses of 108 g a.i. ha-1 and higher exhibited superior weed control and the highest crop yields. Therefore, the use of correct adjuvant or formulated mixture is essential to increase the efficiency of clethodim herbicide.


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