The occurrence of diseases in the cultivation of maize (Zea mays L.) leads to the loss of grain yield and the simultaneous deterioration of its quality. Fungi of the genus Fusarium spp. pose the greatest threat to maize cultivation. These fungi occur at all stages of the plant’s development, causing Fusarium seedling blight, root rot, foot rot, and ear rot, including grains. Therefore, the aim of the conducted field studies was to determine the influence of selected agriculture factors on mycotoxin contents in maize grain and ear core. Moreover, it should be noted that the presence of mycotoxins in food products in terms of legal regulations is quite a fundamental barrier both in domestic and international trade. The field experiment was carried out at the Department of Agronomy of Poznań University of Life Sciences, on the fields of the Experimental and Educational Unit in Swadzim, Poland, in 2013–2014, in four field replicates. The study involved the following factors: soil sowing preparation method, types of variates, and fertilization method, all of which shape mycotoxin accumulation. The results indicated that the main effects of years were significant for all observed traits for both the core and grain. The concentrations of deoxynivalenol, nivalenol, and zearalenone were higher in 2014 than in 2013 for both core and grain. The concentrations of fumonisin B₁ and fumonisin B₂ were higher in the first year of study for core and grain. The direct sowing of maize significantly affects plants’ health status, expressed by an increase in mycotoxin accumulation. Traditional hybrid SY Cooky characterized higher values of observed traits than “stay-green” hybrid Drim (except fumonisin B₂ for cob). The positive effect of the row method of NP fertilizer application is based on a decrease in mycotoxin content.

The effects of growth stimulants consist of activating plant physiological processes, which positively affects vegetative and generative growth, increasing the yield and its quality. The aim of the experiment was to study the effect of microbial and amino acid products on the quality of grassland silage; their application in different combinations was an experimental factor. According to the results, the foliar application of the amino acid and microbial products had a statistically significant effect on the chemical composition of silage. In comparison to control, silage produced from plants treated with those growth stimulants contained significantly more total protein in dry matter, while crude fiber content changed only slightly. In addition, due to higher lactic acid content, the quality of silage treated with the stimulants was higher than the quality of control plants. To sum up, the foliar treatment of plants with microorganisms in combination with amino acids resulted in a significant increase in the content of desired components, with a higher nutritional value of the silage.

Limited genetic variability is a major problem in rapeseed breeding, whose strict selection, limited geographical range and a short period of domestication has led to a reduction in genetic and phenotypic diversity. Assessing specific populations for the greatest genetic diversity for many traits simultaneously, requires the evaluation of multi-feature characteristics. The aim of this study was to estimate the variability of DH (doubled haploid) lines and two generations of winter oilseed rape hybrids. In addition, the relationship between the Mahalanobis distances of parental forms and the effect of heterosis in hybrids was investigated. The results of MANOVA showed that the genotypes and years as well as genotype × year interaction were significantly different (p < 0.001) for all eight observed traits. The first (V₁) and the second (V₂) canonical variate explained 38.57% and 27.55% of the total variation in 2015, and 50.19% and 31.84% in 2016, respectively Canonical variate analysis showed that the traits, flowering time and number of branches per plant had a very large influence on the differentiation of genotypes. Graphs demonstrated that the tested DH lines and hybrids are characterized by a similar, wide range of variability. It was observed, that when using a diverse population of DH lines for crossbreeding with only one CMS/Rfo line, there was no significant reduction of variation in hybrid generations and between these generations. The phenotypic distance values determined by the results of Mahalanobis analysis were similar in both years, but slightly wider in 2016. The observed minimum and maximum ranged from 1.324 to 22.356 in 2015, and from 1.105 to 27.792 in 2016, respectively. No significant correlation was observed between the hybrid heterosis effect and the Mahalanobis distance of the parental lines.

This paper presents an estimation of the parameters connected with the additive (a) effect, additive by additive (aa) epistatic effect, and additive by additive by additive (aaa) interaction gene effect for nine quantitative traits of maize (Zea mays L.) inbred lines. To our knowledge, this is the first report about aaa interaction of maize inbred lines. An analysis was performed on 252 lines derived from Plant Breeding Smolice Ltd. (Smolice, Poland)—Plant Breeding and Acclimatization Institute-National Research Institute Group (151 lines) and Małopolska Plant Breeding Ltd. (Kobierzyce, Poland) (101 lines). The total additive effects were significant for all studied cases. Two-way and three-way significant interactions were found in most analyzed cases with a considerable impact on phenotype. Omitting the inclusion of higher-order interactions effect in quantitative genetics may result in a substantial underestimation of additive QTL effects. Expanding models with that information may also be helpful in future homozygous line crossing projects.

This paper presents the analytical and numerical comparison of two methods of estimation of additive × additive × additive (aaa) interaction of QTL effects. The first method takes into account only the plant phenotype, while in the second we also included genotypic information from molecular marker observation. Analysis was made on 150 doubled haploid (DH) lines of barley derived from cross Steptoe × Morex and 145 DH lines from Harrington × TR306 cross. In total, 153 sets of observation was analyzed. In most cases, aaa interactions were found with an exert effect on QTL. Results also show that with molecular marker observations, obtained estimators had smaller absolute values than phenotypic estimators.

This paper proposes the use of weighted multiple linear regression to estimate the triple3interaction (additive×additive×additive) of quantitative trait loci (QTLs) effects. The use of unweighted regression yielded an improvement (in absolute value) in the QTL×QTL×QTL interaction effects compared to assessment based on phenotypes alone in three cases (severe drought in 2010, control in 2012 and severe drought in 2012). In contrast, weighted regression yielded an improvement (in absolute value) in the evaluation of the aaa_gw parameter compared to aaa_p in five cases, with the exception of severe drought in 2012. The results show that by using weighted regression on marker observations, the obtained estimates are closer to the ones obtained by the phenotypic method. The coefficients of determination for the weighted regression model were significantly higher than for the unweighted regression and ranged from 46.2% (control in 2010) to 95.0% (control in 2011). Considering this, it is clear that a three-way interaction had a significant effect on the expression of quantitative traits.