A kukorica (Zea mays L.) paramétereinek értékelése a fenofázisokban – a hőösszegek függvényében – öntözéses termesztésben

In Hungary, maize is one of the most widely grown crops, with a stable area of 0.8–1 million hectares. The reason for this is the exceptional yield of the crop, which allows a significant amount of value to be produced per unit area. Domestic production is mainly used for animal feed, particularly in the poultry and pig sectors, and for feeding ruminants. Its use is not only as food or fodder crops, but is also increasingly important for the production of oil, bioethanol and energy. The intrinsic values of maize – protein, starch and oil – are crucial for its use in industry, feed and food. The nutrient supply of maize is essential to ensure plant development. Adequate nutrient supply is essential to ensure sustainable farming and high yields. The nutrient rates applied must be adapted to the needs of the crop so that the hybrids tolerate stress caused by seasonal effects well and yield security is maintained. Water deficit is one of the most serious abiotic stresses that negatively affect plant growth, development and yield. Extreme weather conditions reduce yields and threaten stable production. The content, quality and industrial use of maize are closely linked to genetic, ecological and agrotechnical factors. By selecting the appropriate hybrid and applying the appropriate cultivation technology, yield indicators can be adapted to different purposes. In the agrotechnical studies for 2024, the main yield determinants were analysed, and weather was evaluated for each agrotechnical element and phenophase. The research is mainly based on meteorological measurements at the Látókép Experimental Station of the University of Debrecen. In the winter period 2023/24, 283 mm of precipitation fell in 6 months, 69 mm above the long-term average. In June, the weather was free of extremes, with evenly distributed temperatures, but above the multi-year average. The above average rainfall (66 mm), combined with soil moisture in the deeper layers of the soil, ensured a good water supply. The average temperatures in both July and August were close to record highs (24.2 °C). The exceptional warmth in August (mid to late August) was mainly due to the shortening of the ripening phase. The 29 mm of precipitation in July was less than half the multi-year average and the following month of August was also dry (33 mm). The summer total was 128 mm. In early September, the unseasonably warm weather continued, with the first decade showing a positive anomaly of nearly 7 °C. The physiological maturity of the maize and its rapid drainage and drying allowed early harvesting. The year 2024 was marked by a marked dichotomy in terms of maize production. Our field maize experiments allowed us to record the phenophases of the plants throughout the growing season (Hanway scale). As a new result, our analyses showed that, especially in the generative phase, more accurate data were obtained when taking into account the useful heat sum (HU) calculations. From emergence to silking, 60 days passed using 545 HU of heat sum. From silking to waxy maturation (R4) 32 days and 422 HU were needed. It was found that from silking to physiological maturation, typical of the genotype, 815 HU were required. The yield of maize hybrid H470 under irrigation is excellent (20.76 t/ha). The dry matter incorporation dynamics of the hybrid is outstanding. Dry matter gain was measured weekly. At the physiological maturation phenophase (30 August 2024), using 1360 HU, the dry matter content was 77.1%. The dry matter measurements allowed the evaluation of the water loss dynamics of a maize hybrid with excellent yield potential. Measurements and analyses were performed every seven days. The water loss rate was 5.5% in the first week, 5.8% in the second week, 4.6% in the third week and 6.9% in the fourth week. At physiological maturation, grain moisture showed a favourable value (22.9%). After physiological maturation, the daily water loss was 0.23% during the 21-day period.