Efficient nitrogen (N) nutrition has been reported to have the potential to alleviate the drought stress damages by maintaining metabolic activities even at low tissue water potential. The goal of our research was to find a correlation on the genotype level between the effect of different amounts of nitrogen nutrition and water supply at different growth stages. A small-plot experiment was established with three maize hybrids and three levels of nitrogen, and two different amounts of water supply were applied during the vegetation period of 2018 and 2019. Chlorophyll fluorescence parameters were detected, as well as potential and actual photochemical efficiency of PSII, at three growth stages: eight-leaf stage, tasseling, silking. At physiological maturity, the yield of hybrids was also measured. While only genotype differences were described among the investigated parameters in the V8 stage, treatment effects were also realized based on the measured chlorophyll fluorescence parameters during the tasseling and silking stages. Beyond the significant effect of irrigation, a similar impact was declared in the case of 80 kg ha⁻¹ N treatment at the later growth stages. Pronounced correlation was described between chlorophyll fluorescence parameters and yield mainly under irrigated conditions. Our result suggested that lower N nutrition may be sufficient mainly under irrigated conditions, and in vivo chlorophyll fluorescence parameters are appropriate for detecting the effect of environmental factors in different growth stages.

Currently, one of the most important objectives of agriculture is to maintain the principles of the sustainability. The use of precision technologies in agriculture belongs to this topic. The use of precision technologies is increasingly widespread in the cultivation of various agricultural crops, including maize. Sensing is an important part of these techniques. In our experiment we compared two methods: measuring relative chlorophyll content and the method of determine the extractable chlorophylls. The experimental plant was maize (Zea mays L.) and the measurements were performed at an early development stage (V8) of three genotypes. Three levels of nitrogen (0; 80; 160 kg ha-1) were applied during the experiment. The relative chlorophyll content was measured by SPAD-502 (Minolta, Japan) and a handheld GreenSeeker (Trimble, USA) device. The extractable total chlorophyll content decreased in parallel with the increased nitrogen level. The obtained SPAD values were diversified furthermore the NDVI values have not been changed for the effect of different nitrogen fertilization. In the early stages of development of maize, these parameters need to be complemented with other measurements to provide reliable information about the crops nitrogen status.

Pumpkin seeds are crucial for both human and animal nutrition. Furthermore, the importance of pumpkin seed oil, the snack seed trade and even the medicinal uses of pumpkin seed products have been taken into account for the attempts to improve oil pumpkin seed yield, seed quality and other parameters. The climatic conditions may have a considerable effect on both the vegetative and the reproductive growth as well, and can influence the quality and quantity of the yield. Large-scale field experiment was set up to investigate the climatic sensitivity of hull-less pumpkins. Three groups of fields in different regions of Eastern-Hungary; Southern, Northern and Middle regions were involved in this study. Monthly average temperature and precipitation and soil chemical characteristics were analyzed. Based on the results, the lowest yield was achieved in the Northern region, potentially because of the higher amount of precipitation during the vegetation period. The higher precipitation can possibly increase the sensitivity of pumpkin plants to diseases. The highest amount of the seeds was achieved in the Middle region, where the distribution of the rainfall was moderate. From the investigated soil parameters, the pH had a measurable effect on the final seed yield. It could be concluded that higher precipitation and lower pH can lower pumpkin seed yield. Maximum yield might rely on continuously monitoring the soil moisture status and on the irrigation scheduling management, in addition to the nutrient availability in the soil. Further studies, however, are necessary to prove these hypotheses and to provide more useful data.