1 Field Crops Institute, 2 Georgi Dimitrov Blvd, 6200 Chirpan, Bulgaria
2 Institute of plant genetic resources “K. Malkov”, 2 Drujba str., 4122 Sadovo, Bulgaria
Резюме
The aim of the study was to determine the effect of increasing rates of the main nutrients N and P under cotton productivity. In 1966, at the Field Crops Institute-Chirpan, a stationary fertilizer experiment was set up in a two-field crop rotation - cotton-durum wheat. The data represent the period 2014-2018. The Darmi variety was tested under non-irrigated conditions. In the study were tasted 40, 80, 120 and 160 kg N ha, and 40 and 80 kg P ha. For control was adopted N0P0. Fertilization with N120P80 had the strongest effect on the height of cotton plants (47.0% above control). The highest boll weight was reported under the influence of the N80P80 rate (28.34% above the control). Yield and number harvested bolls per plant were increased the most by the high fertilizer combination N160P80 (152.2% and 55.42% above the control, respectively). The strongest and most significant correlation was observed between plant height and boll weight (0.693 ***).