Climate change has become the biggest global challenge, being a real danger especially for crops and an inevitable threat to food security. This paper presents the results of a study conducted in the Transylvanian Plain during 2012–2021, regarding the influence of climatic factors, such as temperature, rainfall, water reserve in the soil and hours of sunshine, on the development stages and yield of maize. During 2012–2021, the soil water reserve determined for maize cultivation was above the minimum requirements (1734.8 m³ ha⁻¹) in the spring months, but fell below this limit in the months when the water consumption for maize was the highest, but without reaching the withering index (1202.8 m³ ha⁻¹). The hours of sunshine in the maize vegetation period have been significantly reduced from 1655.5 h (2012) to values between 1174.6 and 1296.7 h, with a significant decrease in this parameter being observed. The coefficient of determination (R₂ = 0.51) shows the importance of rainfall during the period of emergence of reproductive organs in maize production. During 2019–2021, there was a decreasing trend of temperatures in May compared to the multiannual average of this month, and therefore the processes of emergence and growth of plants in the early stages were affected. During the period of the study, all parameters analyzed (temperature, rainfall, water reserve in the soil, hours of sunshine) deviated from the multiannual average, with negative variations compared to the requirements of maize. Climatic conditions, especially during the growing season, have a significant influence on the yield of a crop, especially when the interaction between several parameters is manifested.

The flag leaf can be an important vehicle for high grain yield due to its position and photosynthetic characteristics. To identify the most adaptive and stable yielding genotype, three winter wheat genotypes were studied during two experimental years under field conditions to quantify the influence of flag leaf removal in different phenological stages on the grain yield and grain quality. To quantify the influence of the flag leaf on the main yield components, the flag leaf was removed every 7 days, starting from the booting stage to ripening. Chlorophyll a, chlorophyll b, and carotenoids were determined from the removed leaves. As a complex trait, the number of grains/spikes and the weight of the grains/spikes were highly influenced by the flag leaf removal during the early generative stages, causing a yield loss from 9% to more than 40%, depending on the variety. It was established that the photosynthetic pigments were highly influenced by the plant phenology stages and the environmental conditions, especially carotenoids, which act as photoprotective and antioxidant agents under stress conditions. Regarding grain quality, flag leaf removal had a significant influence on the accumulation of grain protein and the wet gluten content, the variability of these quantitative traits being also influenced by the climatic conditions.

Maize is affected by drought and heat, abiotic stress factors that have been encountered more often in recent years in various parts of Europe. In the area of Turda, Romania, extreme temperatures and heat waves combined with an uneven distribution of precipitation have been recorded that had an unfavorable influence on the maize crop. In this study, the ASI (anthesis-to-silking interval), yield, and stability of 35 old and new maize hybrids created at the Agricultural Research and Development Station Turda were studied under drought and heat conditions. An increase in temperature was observed during vegetative growth and grain filling, and rainfall was deficient during and after flowering. These conditions had a negative influence on ASI, grain filling, and, indirectly, yield, which varied significantly during the seven experimental years. The five newest hybrids (Turda335, Turda2020, Turda380, Sur18/399, and HST148) stood out, with average yields of over 8400 kg ha⁻¹ in unfavorable years and over 15–16,000 kg ha⁻¹ under favorable conditions. They generally outperformed the mean by 29–33%. In contrast, the old hybrids achieved yields up to 22% lower than the experimental mean. Yield was 43.1% lower in 2022 and 31.8% lower in 2023 compared to the best year (2021).

The main objective of this paper is to evaluate the yield potential of 25 different varieties of oat as a reaction to seeding distance and fertilization for improvement of crop technology and identification of the most adapted varieties. Based ANOVA test, the main influence on yield is due to climate, followed by the amount of fertilizers. The sowing distance reveals its influence when combined with the fertilization, this aspect pointing out the differences between studied varieties. The triple interactions gradually reduce the influence of the factors, their combination being very significant in the case year X sowing distance X variety. The spatial comparative analysis of the three experimental years presents an overlap in the median area of the PCA ordering of the 12.5 cm sowing distance, fertilized with N₅₀P₅₀ with the 25 cm sowing distance fertilized with N₁₀₀P₅₀. There are differences between the oat varieties regarding the reaction to the nitrogen fertilization, highlighting especially the Mureşana variety where comparable yields are obtained on both levels of fertilization: 5.18 t ha⁻¹ (N₅₀P₅₀) and 5.59 t ha⁻¹ (N₁₀₀P₅₀).

The main purpose of the paper is to highlight the impact of foliar fertilization during the various growth stages of winter wheat and its role in achieving high-quality and superior production. Foliar fertilizers play a crucial role in calibrating and forming active growth intervals correlated with productivity factors. The research was conducted over a two-year period using the Andrada winter wheat variety. It involved the application of four different foliar fertilizers: basic mineral fertilization, FoliMAX Orange (two treatments and three treatments), FoliMAX CerealsMIX (two treatments and three treatments), and Microfert U (three treatments). Depending on the treatment, two or three applications of foliar with foliar fertilizers were carried out at various stages of winter wheat development, including pre-flowering and grain formation. The research method used to record physiological parameters was non-destructive (the leaves were not detached from the plant) and was based on the use of the CIRAS-3 foliar gas analyzer, which simultaneously determines several physiological and environmental indicators. As an indicator read by the device, photosynthesis was chosen for leaf temperature and leaf transpiration, correlated with production and quality indices. By applying the foliar fertilizer treatments to the wheat culture, we managed to increase production and improve the quality. After using different foliar fertilizers, the assimilation and physiological parameters had higher values of over 30 μmolm⁻²·s⁻¹. Foliar fertilization applied to the winter wheat variety resulted in an average production increase between 450 and 765 kg·ha⁻¹ and quality indices with a protein percentage between 11.5 and 12.6%, gluten content between 21.5 to 24.0% and the Zeleny index between 29.0 and 39.0%, and the mass of one thousand grains was between 48.0 and 50.5 g.

The complexity of NP and NPK fertilizers in stationary and long-term system yields is proven to determine substantial changes in soil fertility, revealing interaction possibilities related to the chemistry and requirements of other nutrients (S, Ca, Mg, and microelements), while sustainable fertilization can exert control over them through rational fertilization practices and complex nutritive management. Revealing the extent of the modifying effects in the application of S, Ca, and Mg correlated to the soil-plant system conditions relates to the hypothesis of the present research in the context of long-term experiments in Romania at the Office of Pedological and Agrochemical Studies Alba (OSPA Alba) and the Turda Agricultural Research and Development Station (SCDA Turda) with 55 years of a fertilizing effect over the 1967–2022 period, but not solely. This study shows that for sustainable fertilization systems, the complementary application of S, Ca, and Mg with NP and NPK has proven to be effective and unitarily constitutes a measure for the sustainable protection and enhancement of soil fertility.