Title : Examination of the relative chlorophyll content and yield of maize in different crop years
Abstract:
The correlation between Soil-Plant Analysis Development (SPAD) values and maize yield was examined using two maize hybrids of different genotypes (Armagnac, Fornad) with results from 2016-2022. Our objective was to determine the nitrogen requirement of maize, the optimal timing of nutrient application and the effect of N, on yield. The studies were carried out at the University of Debrecen Látókép Experimental Station in a one and a half hectare long-term experiment. In addition to the non-fertilised (A0) treatment, six fertilisation treatments were applied (spring basal fertilisation: 60 and 120 kg N ha-1, A60; A120). The basal fertilisation was followed by two top dressing treatments in the phenological phases V6 and V12, with an application rate of +30-30 kg N ha-1 (V690 and V6150, and V12120 and V12180).
It can be concluded that SPAD values measured in the different phenological phases (V6, V12, R1) increased during vegetative development. The highest values were measured for all fertiliser treatments in the R1 phenological phase, except for treatments A0, V690, and V12120 in the 2022 growing season. Increasing fertiliser doses increased SPAD values. The highest SPAD value (49.00±8.94) was statistically confirmed for the V12180 fertiliser treatment (p<0.05).
Increasing doses of the active ingredient applied during the basal fertilisation significantly positively influenced yield. The A60 treatment resulted in 34.3% and the A120 fertilizer treatment in 75.7% higher yields compared to the A0 treatment on average across years and genotypes. The additional 30 kg N ha-1 applied at the V6 phenological stage resulted in an increase in yield (+12.6%) on average for years and genotypes, but the top dressing applied at the 12-leaf phenological stage had no further yield increasing effect. In most cases, the statistically significant highest yields were obtained with A120 fertilisation for the years and genotypes studied.
The correlation between SPAD value and yield was found to vary between years and genotypes as the phenological stages progressed. The strongest correlations were found in the V12 and R1 growth stages.
