The question of grain content and forage quality in maize: comparisons between isogenic fertile and sterile plants

Abstract

Results are presented from four experiments in which comparisons were made between isogenic sterile and fertile plants of maize to study the effects of grain content on yield and quality of shoot dry matter. In two experiments comparisons were made over a range of densities, extending from 5 to 25 plants/m 2 in 1972 and 5 to 20 plants/ m a in 1973. The other two experiments, grown in 1974 at a density of 10 plants/m 2 , were sampled 30, 60 and 90 days after flowering.In 1972 and 1973 yield of shoot dry material was about 10 % higher in fertile plants at the lowest density, 5 plants/m 2 , but grain formation had a negligible effect at higher densities. In 1974, at 10 plants/m 2 , the yield advantage for fertile plants was 6-7 %. These results are in line with other European data, but show a much smaller effect of grain formation on shoot dry matter yield than is normally recorded in USA trials. The discrepancies probably reflect differences in environmental conditions. Absence of grain had little effect on contents of nitrogen, ash and in vitro digestible dry matter, and increased content of pepsin soluble material and hot water soluble carbohydrates. Percentage content of dry matter in the shoot was higher in fertile plants in 1973, and during the later stages of crop development in 1974.The results suggest that the importance attached to high grain content as an essential requirement for yield and quality in forage maize is exaggerated, and that the restriction of maize breeding and testing programmes to assessments of grain production, in the belief that the best grain varieties will also be best for forage, can no longer be justified in northern European countries.

Effect of plant population and time of harvest on yield and quality of maize (Zea maysL.) grown for silage

“…However, no further yield increment was obtained from ... maize grown at the high plant population (Treatment 3) (Table 4c). This confirms English reports (Bunting 1971;Harris 1976;Iremiren & Milbourn 1976) of maximum DM yields from maize grown at popUlations of 100 000-170 000 phtnts per hectare.…”

“…Rutger & Crowder 1967;Bunting 1971;Douglas & Dyson 1972;Bunting & Gunn 1974;Phipps 1975). This relationship was confirmed in the present study when widely different plant populations were established, representing the extremes likely to be used in farming.…”

“…Since the yield:plant population relationship for total DM is asymptotic and for grain DM is parabolic (Holliday '1960;Bunting 1971;Downey 1971), the grain content of silage will be reduced if plant population is increased to give maximum total DM yield. A high grain content is considered an important determinant of the feeding value of maize silage for cattle (Owen 1967;Eddowes 1969; Montgomery et al 1974); it is therefore generally recommended that maize be grown at low plant population densities.…”

Comparison of Grain Yield and Whole-Plant Silage Production of Recommended Corn Hybrids

“…commun.). However, recent literature (Bunting 1975:-Hunter 1978 has suggested that the relationship between grain yield at maturity and whole-plant yield and quality may not be adequate for selection of the best silage hybrids on the basis of grain yield per se. The study reported herein was conducted to examine the relationship between grain yield after physiological maturity and forage DM yield and quality determined at the stage desirable for silage production.…”

Hybrid Maturity and the Relative Importance of Grain and Stover for the Assessment of the Forage Potential of Maize Genotypes Grown in Marginal and Non-Marginal Environments

“…L'objet 6tait de scruter la nature des rapports qui relient les caractbres de rendement importants du mais, que ce soit pour la production de fourrage (plante entidre) ou de grain. Le rendement fourrager a conserv6 une relation lin6aire avec le rendement de (Bunting 1975;Hunter 1978). The need fora radical re-appraisal and rationalization of official evaluation procedures for maize varieties intended for forage production has also been emphasized by Gunn (197 5, 1977) and Gallais et al (19'16 Brown (1975 (84) 87(77) 117(18) 104(33) l9l (1) 63 (9'7) 74(93) 68(96) 90(65) 92(76) 16r (7) 84 (8s) 92(68) 84(8r) 105(36) 109(20) 151 (12) 79 (88) 94(60) '76(90) 93(60) 89(84) ls0 (13) 106 (32) l 16(17) l 16(15) 133 (8) l3l (1) 169(4) 103 (42) l 10(26) 122(8) 136(6) l l4(| l) 144( 18) 124 (7) 135 (2) r44(r\ rs2 (1) 109(18) ro2 (43) t22 (8) 141(l) 106(34) r22 (r3) 125(4) 141(19) 126 (3) 125(ll) 1r'7(r4) tr2 (26) r2r(s) 68(78) 106 (30) 104(40) ro9(2'7) r22 (r4) 108 (23) 92(s4) 105 (33) r0s (37) 128 (4) 125(10) I 15(10) 125(28) e6 (64) 63(e7) 108 (30) 86 (73) 94 (66) s6 (88) to6 (29) rto (24) 105 (40) rr2(2'7) 106(30) 109(36) 122(9) l l0(2s) l 12(19) …”