Forage Production and Nutritive Value of Selected Pigeonpea Ecotypes in the Southern Great Plains

Stocker cattle production in portions of southern Great Plains depends on wheat (Triticum aestivum L.) and warm‐season perennial grasses. Nutrient supply is limited in both quantity and quality from late July through November. To determine if pigeonpea [Cajanus Cajan (L.) Millsp.] could fill this deficit, a field study was conducted from 1996 to 1998. Seasonal forage production patterns, yield, and quality of three pigeonpea ecotypes (ICP8151, ICPX910007, and PBNA) were evaluated. Pigeonpeas produced 5 Mg ha−1 dry matter by 26 August, with N concentration >20 g kg−1 and digestible dry matter (DDM) > 500 g kg−1 Ecotype ICPX910007 accumulated greatest dry matter in 136 d (16 Mg ha−1), followed by ICP8151 (13 Mg ha−1) and PBNA (9.5 Mg ha−1). Mean N concentration for PBNA was 28.6 g kg−1 as compared with 23.3 and 23.0 g kg−1 for ICP8151 and ICP910007, respectively. Digestible dry matter of PBNA was 614 g kg−1, followed by 576 and 572 for ICP8151 and ICP910007, respectively. Leaf dry matter yield averaged across sampling dates and years for all ecotypes ranged from 2360 to 2600 kg ha−1 Leaf quality was similar to that of alfalfa for all ecotypes. Environmental conditions such as cooler spring and summer temperatures and excess rainfall (1997) or extreme drought (1988) reduced yield of all ecotypes. Pigeonpea can provide high‐quality forage that could be used as a primary or supplementary forage for grazing livestock at a time when other forages are less productive.