Investigation of the effects of humic acid and 20-20-20 fertilizer applications on the yield characteristics and harvest time of lettuce (Lactuca sativa L.) by foliar fertilization method

Fertilizer use is one of the important factors in successful, productive and healthy agriculture applications. Despite the rapid increase in population in the World, it has been obligatory to ensure a healthy increase in productivity and production increases. Vegetable consumption is recommended and gaining importance in balanced and functional nutrition and it is important to prevent obesity. Lettuce is preferred with its nutritional content and low calorie content. The aim of thesis research is to investigate the effects of various foliar applications on determining yield and optimum harvesting time. In this research, four different kinds of fertilizer given from the leaves and the varieties were tested. Humic Acid 1 and 2 were administered in two separate doses (HA1 and HA2) and leaf fertilizer (20 -20 - 20) in two separate doses (LF1 and LF2). The crop yield parameters were measured in four different periods during the harvest period and also the optimum harvest time was determined according to the yield parameters. Main yield parameters investigated; Lettuce (Lactuca sativa L.); weight, head diameter, head height, weight of leaf thrown, number of leaf thrown, root collar diameter, number of roots, head weight after thrown leaf was determined at each harvest period. Weight changes were observed in HA2 and HA1 fertilizer applications with a maximum of 53% and 31%. Head diameter; 14% HA2 fertilizer application, head height; The highest variation values were obtained with 15% and 58 % in terms of disposed weight. It was found that the highest exchange values were 8% HA2, root diameter 15%, root number 46%, as number of leaves thrown. On the other hand, the change in the number of leaves remained the same in all fertilizer applications. According to the data obtained in the research thesis project, none of the fertilizer applications had any negative effects, on the contrary, it contributed positively in certain change rates (0-58 %). The fertilizer effects applied to the foliar timings were evaluated by taking into consideration the plant yield parameters and it was found that the last selected harvest time was optimal in normal climate and weather conditions according to the research period. The foliar fertilizer applications performed in the thesis research project were considered to be advisable to the producer in real agricultural applications.