Influence of agrotechnological factors on the rate of development and progression of phenological phases in maize (Zea mays L.)

The objective of this study was to determine the influence of soil tillage system, plant density, and herbicide background on the rate of maize phenological development under the continental climatic conditions of the Polissia region of Ukraine. The experiment was conducted during 2023-2025 and included three tillage systems (deep plowing, disking, and rotary tillage), two levels of plant density (1.1 and 1.3 seed units ha-1), and two herbicide backgrounds (with and without herbicides) arranged in a three-factor design with three replications. Phenological phases (from SeedGerm to FullRip) were recorded based on the calendar dates of their occurrence. Statistical analyses were performed using analysis of variance (ANOVA), regression modelling, and comparison of adjusted means. The results revealed that soil tillage was the dominant factor determining the rate of maize development. Minimal and shallow tillage accelerated the progression of phenological phases by 2-5 days compared with deep plowing. The herbicide background had a critical effect on the middle and late development phases: the absence of herbicides increased the duration of the ThrowPanic-FullRip interval by 6-10 days due to enhanced weed competition. The interaction F1×F3 was statistically significant in most phases and determined the overall developmental rate. Plant density had a secondary effect, expressed only through its interaction with the herbicide background. The fastest development was observed in the S3H1A2 combination (rotary tillage, herbicides, increased density), whereas the slowest was recorded in S1H2A2 (deep plowing, no herbicides, increased density). The study concluded that optimising the soil tillage system in combination with effective weed control is crucial for accelerating maize development and ensuring stable productivity in the Polissia region. Minimal tillage combined with herbicide protection can be recommended as the most effective strategy for improving growth rates, shortening the vegetation period, and enhancing the agrobiological resilience of maize under regional conditions