Coriander (Coriandrum sativum L.) response to different levels of agronomic factors in Poland

Crop yields are determined by complex interactions between various agronomic factors. Knowledge of crop responses to various levels of agronomic inputs and their interactions is essential for developing high-yielding production technologies. Field experiments with the s(k-P) fractional factorial design are highly useful for selecting the optimal production technology for crops whose agronomic requirements have been insufficiently researched under specific agroecological conditions. A field experiment with the s(k-2) fractional factorial design and resolution IV, with five factors (k = 5) at three levels (s = 3), was performed at the Agricultural Experiment Station in Balcyny (north-eastern Poland) in 2006-2008. Experiments with the 3(5-2) fractional factorial design offer a rapid and relatively cheap method for determining the influence of various agronomic factors and their interactions on crop yields. The results of multifactorial experiments conducted under the same weather and soil conditions facilitate the choice of the optimal production technology and the determination of the optimal intensity of the main agronomic treatments. This study analyzed the responses of coriander to the key yield-forming factors (seeding date, rates of phosphorus, potassium, magnesium, sulfur, and micronutrient fertilization) and yield-protection factors (weed control and fungal disease management). In the agroecological conditions of north-eastern Poland, weed control had a significant influence on the yield of coriander fruits. The highest fruit yield was obtained in the treatment where herbicide (1500 g ha(-1) metobromuron) was applied to the soil after sowing. Mechanical weed control (single inter-row treatment in the two leaves unfolded stage) reduced fruit yields by nearly 20%, whereas the absence of weed control decreased fruit yields by 62%. The treatments where various weed control methods were applied differed in the number of coriander plants m(-2). Chemical weed control increased stem length, the number of primary branches, the number of inflorescences (umbels), and fruit mass. The responses of coriander plants to delayed sowing were determined by precipitation levels during the growing season. In seasons with abundant precipitation (398-425 mm), delayed sowing decreased fruit yield by around 15-19%. In years with low precipitation (193-319 trim), a 14-day delay in sowing was well tolerated by coriander plants. Mineral fertilization (P, K, S, Mg, and micronutrients) had no significant effect on the growth, development or yield of coriander. Coriander plants also demonstrated a weak (non-significant) response to chemical disease control.