Intercropping is an ancient and worldwide agricultural practice expected to become more prevalent in Hungary due to the accumulating impact of climate change. In this study, the plant association of pure winter wheat (Triticum aestivum L.) and pure winter pea (Pisum sativum L.) was analyzed without weed control and with applied herbicides at different intervals (pre-emergence, early and late post-emergence) and different active herbicide ingredients. Two growing seasons, 2018–2019 and 2019–2020 were examined to compare weed composition and weed cover to evaluate the effect of the applied herbicides at different timings. To determine weed control efficiency, weed surveys were conducted six times in each growing season. The effect of cultivation methods (pure and mixed plots) on the development of plants was also measured by yield production analysis. Findings from these investigations indicate that there were significantly more weed species and occurrences of weeds in pure wheat and pure pea plots compared to mixed plots. In addition to cultivation and weed control treatments, meteorological events significantly influenced the development of the plants, and thus the yield components.

The future of wheat production depends on our ability to adapt to changing growing conditions. It is expected that intercropping will be more emphasized where natural source of nitrogen may increase the resilience of cereals. Our investigation was made in two growing seasons (2020–2021, 2021–2022) with three winter wheat varieties (GK Szilárd, Cellule, GK Csillag) and a winter pea variety (Aviron) in Szeged-Öthalom. Each plot was 10 square meters in four repeats in randomized block design. We used a seed mixture of both species with three sowing densities. In this study, we represent a development process of two winter-sown species, then yield components evaluated by cumulative yield production analysis and multivariate regression. Mixtures were only beneficial for wheat in the case of GK Szilárd 50% and Aviron 75%, Cellule 75% and Aviron 100% (in 2021), Cellule 100% and Aviron 50% (in 2022), GK Csillag 75% and Aviron 50%. The yield was determined by the number and weight of grains in both species (and also number of pea pods). Knowledge of the development process of the companion plants is a key issue in creating an effective intercrop. This self-sustaining, low input and energy efficient cropping practice has a great potential in temperate areas.

This research examined the effectiveness of zinc foliar fertilizers. Two winter wheat varieties, GK Pilis and Zvezdana, were tested in a Zn-limited meadow chernozem soil. Crop yields and chlorophyll concentrations of the leaves were examined in the growing seasons of 2020/2021 of favorable weather conditions and 2021/2022 of drought weather conditions. In the experiment, three treatments were carried out with monozinc foliar fertilizer of a concentrated 12% (w/v) zinc sulfate heptahydrate solution, and the fourth plot was designed as the untreated control. The first monozinc treatment was applied at a dose of 1 L ha−1 and the second monozinc treatment at a dose of 2 L ha−1. These treatments were applied at tillering (BBCH 21–22). The third monozinc treatment was applied at a dose of 1 L ha−1 at tillering and flag leaf emergence (BBCH 21–22, BBCH 37). Samples were taken several times in the vegetation period, and measurements were made using different methods (SPAD, determination of total chlorophyll concentration from acetone solution) before and after Zn treatments. In 2020/2021 of favorable weather conditions, the yield of Zvezdana was 5.47 t ha−1 and that of Gk Pilis was 6.11 t ha−1, compared to 2021/2022 of drought weather conditions, in which year the yield of Zvezdana was 3.14 t ha−1 and that of Gk Pilis was 2.79 t ha−1. Yields of both varieties increased with increasing NPK nutrient doses. In 2021/2022, even at nutrient level D (NPK basal fertilizer and two-times N topdressing), we harvested on average twice as much as in 2020/2021 at nutrient level A (N basal fertilizer and once N topdressing). No significant effects were found between the foliar fertilizers in 2020/2021. In 2021/2022, Zn treatments, mainly at four nutrient levels tended to increase the yields of both varieties. The first treatment resulted in a grain yield reduction of 3% for GK Pilis, and the second treatment resulted in a grain yield reduction of 1.2% for Zvezdana. After the second and third treatments, grain yield reductions were 0.1%–0.5%. Although there was no significant difference in terms of the main averages, foliar fertilizer was found to be effective in the second year. The relationship between chlorophyll and grain yield was found to depend on the year and variety. A weak correlation (r = 0.33, p < 0.05) was found between the total chlorophyll concentration in leaves for Zvezdana in 2021, and a medium correlation for GK Pilis (r = 0.67, p < 0.05). Concerning grain yield and chlorophyll concentration, a strong correlation (r = 0.81, p < 0.05) was found for Zvezdana in 2022, and a weak correlation (r = 0.44, p < 0.05) for GK Pilis. A strong correlation was found between the total leaf chlorophyll concentration and SPAD index in both years (r = 0.81, p < 0.05)

Winter wheat is one of the most important crops globally and also in Hungary. Hungary has excellent crop production potential including seed production. The aim of our experiment is to determine the effects of different amounts and proportions of nutrients and those of the seed size of winter wheat in laboratory seed tests on the seed parameters (germination percentage, germination power, seedling health and vigour), as well as in field tests of the seed parameters (emergence percentage and yield of next crop year). Laboratory seed tests of winter wheat variety GK Petur were conducted with seeds that underwent ten nutrient treatments and of three seed size fractions over four crop years, together with field experiments in three growing seasons. Compared to the untreated control group, N treatments significantly decreased the health of the seedlings in the next generation of winter wheat. PK treatments without N increased the germination percentage, vigour value and emergence percentage significantly, but the health of the seedlings decreased. In contrast, NPK treatments with a ratio of 2:1:1 improved all the tested parameters compared to those of the control group. The increase in seed sizes significantly increased the germination power, seedling health, vigour value, emergence percentage and the yield of the next crop year. It can be concluded that the factors of nutrient supply, crop year of the seed production and the seed size significantly influence the quality of the seed (germination percentage, germination power, seedling health, vigour and emergence percentage), thus also the yield of the next generation.

Growing two or more crops together in the same area at the same time, called intercropping, is a well-known agroecological method of weed suppression. Cereal-legume intercropping systems are of great importance in increasing biodiversity in arable lands. In cereal-legume mixtures, cereals provide physical support to legumes and enhance weed suppression. Cereals have a stronger weed suppression ability than peas. The aim of our research was to determine the weed composition and weed cover of pure winter wheat, pure barley, pure triticale and pure winter pea, as well as associated wheat-pea, barley-pea, and triticale-pea crops in two locations (Szeged and Fülöpszállás) and in two growing seasons (2020/2021 and 2021/2022). In Fülöpszállás, the average weed cover was significantly higher than in Szeged. When comparing the years and crop production methods, significant differences were observed in weed cover in the pure legume plots. More weed species appeared in Szeged and Fülöpszállás in the second year than in the first year. Cereal-pea intercropping reduces the need for herbicides; we can achieve more sustainable and effective weed management without herbicide treatment.