ADAPTABILITY AND STABILITY OF FORAGE SORGHUM CULTIVARS SOWED IN DIFFERENT TIMES OF THE YEAR

Abstract

To obtain information about the forage yield of sorghum cultivars a trial was set up in the Experimental Field of the Department of Plant Science at the Universidade Federal de Viçosa, during the agricultural year of 1999/2000 to verify the yield adaptability and stability of different forage sorghum cultivars. A group of eight experiments was used, starting in the first fortnight of October 1999 through May 2000. Each experiment was arranged in randomized blocks with four replications. The sorghum cultivars used were the AG 2002, BR 501, BR 506, BR 601, BR 602 and BR 700 (forage), AG 2005E and Massa 03 (dual purpose) and AG 2501C and BR 800 (cutting and grazing). The forage yield adaptability and stability of the cultivars were evaluated using the method of the quadratic trapezes weighted by the variation coefficient. The cultivars BR 506 and AG 2002 had a higher green matter yield, behavior predictability and adaptation to favorable and unfavorable environments. For dry matter, AG 2002 and AG 2501C presented a higher behavior predictability and adaptation to unfavorable environments, with BR 506 and AG 2002 being the most adapted to favorable environments. For crude protein, AG 2501C and Massa 03 presented a higher yield, behavior predictability and adaptation to unfavorable environments, with AG 2501C being the most adapted to favorable environments.

Keywords

• sorghum
• sowing time
• adaptation
• stability