The purpose of the study is to evaluate the efficiency of the technological flow for harvesting winter wheat (Lovrin 34 variety) in the specific pedoclimatic conditions of the Răcășdia area (Caraș-Severin county), focusing on the impact of atypical climatic factors (high humidity and 90% fall rate) on the performance of high-capacity combines. The objective of the study was to estimate the productive potential, determine biological production through biometric indicators (Nsp, Nb, MMB). The research was carried out in July 2025, on an area of 240 ha, using two combines: Claas Lexion 600 and John Deere W 650. The metric frame sampling method (1 m2) was applied to determine the density and stubble losses. The working speed was measured by the standard sector method (33 m), and the technological losses were calculated by collecting unthreshed ears and loose grains after the passage of the aggregates. Regarding the productivity results, an average production of 6108 kg/ha was obtained, with a MMB of 42 g. Kinematic indices, in fields with a slope of 90%, the actual forward speed decreased drastically to 0.422 m/s, compared to the theoretical value of 0.919 m/s, to ensure a constant mass flow. Losses during cutting, due to the absence of plant lifters on the header in lying conditions, average losses of 107.2 kg/ha were recorded. The impact of humidity, at a humidity of 23%, total losses due to unthreshed ears and poor separation ranged between 45.6 and 48.2 kg/ha. Combine performance is strongly conditioned by the vegetative state; fallen grain requires reducing the working speed by over 50% to minimize losses at the header. In high humidity conditions, it is mandatory to operate the thresher at higher speeds to compensate for the adhesion of the grains in the ear, while equipping the header with plant lifters is critical for recovering approx. 100 kg/ha in years with crop drop phenomena.

wheat, evaluation, technology, harvesting

mechanical engineering

Presentation: poster