Chemical and in Vitro Digestible Dry Matter Composition of Maize Stalks after Selection for Stalk Strength and Stalk‐Rot Resistance¹

Abstract

Although maize (Zea mays L.) is a major forage crop, little attention has been given to possible alteration of forage quality associated with breeding for increased resistance to stalk lodging. This study was designed to evaluate changes in stalk composition and digestibility resulting from three cycles of recurrent selection each for improved stalk strength (BSlMS) and stalk‐rot [Diplodia maydis (Berk.) Sacc.] resistance (BSlSR). The second elongated internmode plus half of each adjacent internode from plants of the original population (BSlCO) and from C1 to C3 for the BSlMS and BSlSR populations were sampled approximately 35 days after midsilking for chemical and in vitro digestible dry matter (IVDDM) evaluation. Major composition changes from the BSlCO to BSlMSC3 and BSlSRC3 populations, respectively, were: concentration of cell wall constituents, 616 to 520 and 542 g kg−1; concentration of acid detergent fiber, 422 to 353 and 373 g kg−1; concentration of lignin, 57 to 42 and 47 g kg−1; concentration of total nonstructural carbohydrates (TNC), 184 to 258 and 244 g kg−1; and concentration of IVDDM, 514 to 621 and 594 g kg−1. Both selection regimes increased TNC concentration, which diluted stalk fiber concentration and resulted in a net increase in IVDDM. Recurrent selection for traits associated with improved stalk lodging resistance did not have negative effects on the forage quality of maize stalks in late reproductive stages.

Influence of stage of maturity on bromatological quality of corn forage

“…Albrecht et al (1986) evaluated two populations before and after three recurrent selection cycles with a view toward increasing resistance to lodging and stalk rot. In both situations, total concentrations of non-structural carbohydrates increased and were sufficient for promoting dilution in the stalk fibers, also increasing the in vitro degradability of this part.…”

Effect of Plant Density on Forage Yield and Quality of Intercropped Corn and Lablab Bean

“…Starch concentrations diminish as the curve approaches a corn density of 20,000 plants ha −1 , with the lowest starch concentration (256 g kg −1 DM) occurring at a bean density of 92,000 plants ha −1 Bean concentration in mixtures had a significant ( P < 0.0001) Pearson correlation coefficient of r = −0.78 to starch concentration in mixtures (data not shown). In corn harvested for silage, most of the starch is found in the grain, but some is also found in the stover (Albrecht et al, 1986). Corn kernel development requires remobilization and translocation of starch in the stover to fill the sink created by corn kernels (Coors et al, 1997).…”

Relevant traits, genetic variation and breeding strategies in early silage maize

“…GCA effects of these root traits were preponderant (Hébert et al, 1992 (Holbert and Kochler, 1924;Hayes and Johnson, 1939; Thompson, 1968), ii) the force necessary to pull a plant out vertically (Nass and Zuber, 1971;Arihara and Crosbie, 1982;Peters et al, 1982;Kerven and Hallauer, 1983;Fincher et al, 1985;Melchinger et al, 1986), or else iii) the intensity of the force when pushing plants laterally (Kushibiki, 1979;Koinuma et al, 1990;Fouéré et al, 1985). The (Undersander et al, 1977;Hawk et al 1984;Pinheiro, 1984;Albrecht et al, 1986;Hébert et al, 1996). The understanding of what is conducive to resistance to root lodging and to good ingestibility or digestibility will thus make it possible to combine good resistance to lodging with high feeding values, both for silage cultivars and for dual purpose (grain and silage) cultivars.…”