Maize (Zea mays L.) is a major cereal used for food, feed, and industrial applications. This study assessed genetic diversity and biochemical variability among 49 maize genotypes to identify promising material for grain quality improvement. RAPD profiles were used to calculate Jaccard similarity coefficients and construct the UPGMA dendrogram. Total nitrogen, crude protein, starch, crude fat, and β-carotene were measured using standardized ISO/EN ISO procedures, Soxhlet extraction, and spectrophotometry. RAPD markers generated 42 amplified DNA fragments, of which 39 were polymorphic. Mean RAPD PIC values ranged from 0.187 to 0.424, with OPC-2 showing the highest value. RAPD-based clustering suggested two main groups of genotypes. Biochemical traits varied significantly among genotypes, with genotype means ranging from 8.67 to 13.72 g/100 g for crude protein, 62.50 to 74.50 g/100 g for starch, 2.61 to 5.06 g/100 g for crude fat, and 0.55 to 1.32 mg/100 g for β-carotene. HSF hybrids exhibited higher mean crude fat and lower mean starch than commercial cultivars, while crude protein and β-carotene showed no significant differences at the genotype level. These analyses identified maize genotypes with promising grain composition for further breeding evaluation aimed at improving nutritional quality. Their responses to environmental stress and the stability of their grain composition require assessment in dedicated stress experiments and multi-environment trials.

This paper presents a five-year study concerning monitoring the cotton bollworm (Helicoverpa armigera) flight dynamics using pheromonal traps and a study relating to the behavior of nine maize hybrids from two maturity groups to this pest attack in 2024. The monitoring and field assessments were made in south-east Romania, Călărași County, at the NARDI Fundulea. During the monitoring period, from 2020 to 2024, air temperature was higher than average in the summer months while rainfall was below average, except in June 2021. Total captured moths in the traps were 246 in 2020, 406 in 2021, 5064 in 2022, 1024 in 2023, and 4145 in 2024. In the middle of July 2022, the average captured moths per trap was 483.3; in the middle of September, it was 589.0 catches. In 2024, in the last 10 days of July, the average captured moths per trap was 311.7, in the last 10 days of August, it was 358.0, while in the middle of September, it was 362.3. In 2024, at the beginning of August, the attack incidence of corn earworm on maize hybrids ranged from 43.75 to 53.75 %, and on 13 September, it was 100 % at all hybrids. This is the first report from southeast Romania that mentioned a higher population of cotton bollworm in the late summer and beginning of autumn, and the first report that mentioned high pest attacks on maize cobs in September.