Yield, Nutritional Composition, and Digestibility of Conventional and Brown Midrib (BMR) Pearl Millet as Affected by Planting and Harvesting Dates and Interseeded Cowpea

Abstract

The objective of this study was to evaluate the yield, nutritional composition, and digestibility of conventional (CON) and brown midrib (BMR) pearl millet (PM) with different establishment dates, maturity at harvest and when mixed with cowpea (CWP). In trial 1, CON and BMR were planted on two different dates. In trial 2, CON and BMR, mixed or not with CWP, were harvested when PM was at the boot or heading stages. In trial 1, dry matter (DM) yield was similar between both PM genotypes but delaying establishment reduced DM yield by 30%. Additionally, BMR had a lower concentration of acid detergent lignin (ADL) and a higher in vitro neutral detergent fiber digestibility (IVNDFD) compared to CON. In Trial 2, the DM yield was 7.3% higher for CON compared to BMR, and PM with the BMR trait had a lower level of ADL and higher IVNDFD compared to CON. Mixing PM with CWP had negligible effects on nutritional composition but reduced DM yield by 8.3%. Results of these studies indicated that fiber from BMR PM is more digestible than CON but, in one of the trials, this occurred at the expense of lower DM yield. Mixing CWP with PM negatively impacted DM yield.

Pearl Millet-Cowpea Forage Mixture Planting Arrangement Influences Mixture Yield and Nutritive Value in Semiarid Regions

“…Similar to VU DM yield, the PG DM yields measured in this study as monoculture and in mixtures (Table 3) also were considerably greater than those reported by [22] for monoculture FS and FS mixed with legumes (7.38 Mg DM ha −1 ). They were also greater than those measured by Machicek et al [2] for PG harvested 90 DAP and by Oskey et al [18] for a first harvest monoculture PG at early heading. The PG DM yields measured in this study as monoculture and in mixtures (Table 3) were slightly greater than those for monoculture PG reported by others [9,16].…”

“…That said, Fontaneli et al [13] reported no difference in CP among SxS and PG cultivars, measuring somewhat greater CP for both forages compared to the PG in the present study (Table 3). Oskey et al [18] reported a negligible influence of PG-VU mixtures on total forage nutritive value other than CP, which generally led to a 10 g kg −1 increase over monoculture PG. They [18] stated that the 10 g kg −1 increase was unlikely to significantly influence animal response.…”

“…As also reported by [19], the PG yield in all mixtures, except millet-cowpea 2:2, was reduced in the present study (Table 3). Oskey et al [18] attributed reduced PG DM yield in mixtures to reduced plant populations due to the seeding rate compared to the monoculture. In the present study, within-row seeding rates were equivalent across all treatments for both PG and VU, based on their respective monoculture seeding rates, except for millet-cowpea in which the seeding rates were 50% of the monoculture.…”

“…Nitrogen is required by WSAG to maximize productivity and nutritive value, particularly CP. Increasing the CP content of harvested forage by planting with a legume [5,11,[14][15][16][17][18] also generally leads to increased crop productivity [19]. It also leads to reduced applications of nitrogen fertilizer [17,20] as well as a reduced need to supplement livestock rations with protein to meet animals' requirements [16].…”

“…Comparing FS and PG, Bhattarai et al [7] reported that PG generally yielded less dry matter (DM) than forage sorghum (FS; Sorghum bicolor) at 60, 75, and 90 days after planting (DAP). Either crop would be harvested for hay at 60-90 DAP, depending on the stage of maturity [18].…”