Recurrent selection for downy-mildew resistance in pearl millet

One population of pearl millet (Pennisetum glaucum (L.) R. Br.) highly susceptible to downy mildew (Sclerospora graminicola (Sacc.) Schroet.) was subjected to two cycles of recurrent selection for downy mildew resistance using a modified greenhouse screening method. The response to selection was evaluated under greenhouse and field conditions using 50 random S₁ progenies and 50 random full-sib progenies from each cycle bulk. Significant progress over cycles of selection was observed in all evaluation trials. These results demonstrated that, in a susceptible population, recurrent selection effectively increased the level of resistance to downy mildew. The modified greenhouse method for assessing resistance to downy mildew effectively differentiated genotypes and had the advantages of greater rapidity and suitability for use throughout the year, independent of season. A rapid decline of genotypic variance was observed in advanced cycles of selection, indicating that a small number of genes controls downy-mildew resistance in this population. The comparison of genotypic and error variance components from S₁ progenies and full-sib progenies suggested that full-sib progenies can be used successfully in recurrent selection for increased downy-mildew resistance.     

Direct and correlated responses to three S1-recurrent selection strategies for increasing protein yield in oat

Summary The objectives of this study were to evaluate the efficacy of S₁-recurrent selection for increasing groat (caryopsis)-protein yield in oat (Avena sativa L.) and to compare the effects of three selection strategies on correlated responses in groat yield and groat-protein concentration. Three S₁-recurrent selection programs were conducted for five cycles. Selection criteria in each program (line of descent) emphasized different components of protein yield; high grain yield in HG, both high grain yield and high groat-protein concentration in HP, and protein yield per se in HGP. Thirty to sixty random S₀-derived lines from each cycle and ten check lines were evaluated in one year at two locations to estimate the response to selection. Groat-protein yield increased 4.4% cycle^-1 in HG, 3.4% cycle^-1 in HP, and 2.2% cycle^-1 in HGP. Gains in groat yield were 7% cycle^-1 in HG, 1% cycle^-1 in HP, and 3% cycle^-1 in HGP. Mean groat-protein yield and groat yield in the cycle 5 (C5) populations of all three lines of descent were equal to or slightly higher than those of high yielding cultivars. The HG line of descent showed a significant decrease from 193 to 175 g kg^-1 groat protein, while the HP line of descent showed a significant increase from 202 to 218 g kg^-1. The HGP line of descent showed a small but significant decline in groat protein from 200 to 192 g kg^-1. In comparison, the high-protein commercial cultivars contained about 210 g kg^-1 groat protein. The C5 population of the HP line of descent had a unique combination of high groat yield and high groat-protein concentration. Genotypic variances for groat-protein yield, groat yield, and groat-protein concentration were not always significant in the various cycles of the three lines of descent, but in no instance was there a consistent change from C0 to C5. S₁-recurrent selection was effective for increasing groat-protein yield of oat, and with the proper germplasm and selection strategy both groat yield and groat-protein concentration can be improved simultaneously.Abbreviations C - cycle - GPC - groat-protein concentration (a groat is the part of an oat grain that is the actual seed or caryopsis, rather than the hull) - GPY - groat-protein yield - GTY - groat yield - HG - selection for protein yield through high grain yield - HGP - selection for protein yield per se - HP - selection for protein yield through high grain yield and high protein concentration Journal Paper No. J-15287 of the Iowa Agriculture and Home Economics Experiment Station, Ames, IA 50011, USA. Project No. 2447.     

Recurrent selection for yield in Glycine max using genetic male-sterility

Summary Recurrent selection, using genetic male sterility to facilitate intermating in Glycine max, was evaluated when selecting among individual space-planted S₀ soybean plants for three yield-related traits: 1) seed yield per se (YLD), 2) apparent harvest index (AHI), and 3) a selection index in which seed yield was regressed on maturity (REG). The original intermating population was a combination of the cultivar Century and two F₂ populations segregating for male sterility. The selection intensity through three cycles of selection was 20%. The YLD population increased in mean yield by 2.8±2.2 g plant^-1 cycle^-1 buf shifted significantly toward late maturity by 3.9±0.6 days cycle^-1. The AHI population decreased in yield by 4.4±2.6 g cycle^-1 while maturity shifted slightly earlier; there was very little change in AHI. The REG population increased in yield by 5.7±2.4 g plant^-1 cycle^-1 while shifting toward later maturity by only 0.8±0.5 day cycle^-1. We concluded that selection among S₀ plants in these populations, using the selection index of yield regressed on maturity, was affective in increasing single plant yields without causing a significant shift in maturity. Selecting for yield per se caused an unacceptable shift toward late maturity and selection for AHI was ineffective for increasing yield or AHI.     

Recurrent selection for maturity and percent seed protein in Glycine max based on S0 plant evaluations

Summary Progress was evaluated after four cycles of recurrent selection among S₀ plants of Glycine max (L.) Merr. in which selection was either for maturity (MAT) or seed protein (PRO). The two populations, MAT and PRO, were developed from an initial population that was a combination of a line with 48.4% seed protein and two F₂ populations segregating for male sterility. Intermating was facilitated by genetic male-sterility and the selection intensity was 20% in each cycle of the two populations. Selection for early maturity advanced the average maturity a significant 2.7±0.34 days cycle^–1 and reduced seed yield a non-significant 9.1±2.95 g plant^–1 cycle^–1. Selection increased mean seed protein a significant 0.8±0.15 percentage points cycle^–1 and decreased percent seed oil a non-significant 0.5±0.17 percentage points cycle^–1. Correlation coefficients between seed protein and seed yield varied from 0.18 to –0.21 in the four cycles indicating plants with favorable combinations of seed yield and seed protein could be identified. Selection in these two populations would be effective for early maturity and for increased seed protein.     

Improvement of maize populations for resistance to downy mildew

Upgrading levels of disease resistance are a primary objective of maize breeding programmes. Efficacy of S₁ recurrent selection in improving levels of resistance to downy mildew (DM) infection was assessed in Nigeria from 1997 to 2000 in six maize populations. Improvement procedures consisted of evaluating S₁ progenies under artificial infection with DM spores and in disease‐free environments and using a selection index to combine selection for reduced DM infection with appropriate agronomic characters from more than one environment. Three to four cycles of selection were completed in each of the populations. Products from the different cycles of selection were evaluated and data collected on DM infection parameters and agronomic traits. Result obtained showed 3–4 cycles of selection were adequate to reduce DM infection levels significantly and increase grain yield. Downy mildew infection decreased by between 58 and 100% while grain yield increases ranged from 10 to 98% for the 2‐4 cycles of selection relative to the C0 (original). Selection increased grain yield with acceptable changes in plant height while maintaining maturity in disease‐free environments.     

Grain Yield of Intercropped Sorghum and Pearl Millet as Influenced by Sorghum Genotype and Cropping Pattern

Intercropping of sorghum and pearl millet with different growth cycles is used widely in third-world countries to ensure and increase yields. However, it is questionable whether yield increases because of intercropping can be maintained under more developed systems, since temporal differences are necessary to allow mechanized planting and harvesting.
Three sorghum hybrids with expected growth cycles from 90 to 110 days were planted in sole stands and in alternate rows and mixed within the rows with a pearl millet hybrid having a growth cycle similar to that of the early sorghum. Sole stands of millet also were included. The plots were planted at three locations in Kansas, two dryland and one including dryland and irrigated. Results show that yields were consistently highest in sole stands of sorghum, owing to the higher yield level of sorghum. No yield increase could be found on a land equivalent ratio basis, indicating no intercropping advantages. However, under good moisture conditions, a tendency toward yield increase was observed with the later maturing sorghums, which had 1–2 weeks of grain filling after the millet was mature. When moisture supply was insufficient, millet showed higher competitiveness for water than sorghum, and sorghum was adversely affected more than pearl millet was favored. It was concluded that moisture conditions have to be good and that temporal differences between sorghum and millet have to be greater than those used in this experiment to achieve intercropping yield advantages.     

A Test of the 'Tall-Dwarf" Hypothesis in Pearl Millet, Pennisetum glaucum (L.) R. Br.

Positive height-grain yield relationships exist for many cereals, but cannot be fully used in breeding because of lodging and harvestability problems in tall cultivars. Law et al. (1978) proposed a “tall-dwarf” hypothesis for wheat, in which the positive effects of minor height genes could be exploited by selecting for them in a major dwarfing gene background. The applicability of this hypothesis to pearl millet was tested by crossing a set of dwarf S₁ progenies (from a single population) which varied in height onto two male-sterile lines. Mean (by S₁ pollinator) hybrid grain yield was closely related to mean hybrid height (r²= 0.60) over a range of mean yields of 3.0–3.9 t ha^?1 and a range of mean heights of 126–165 cm. The effect of height was expressed as an increase in grain number in one cross and as an increase in grain mass in the other, indicating the importance of background genetic effects on yield-height relationships in dwarf hybrids. The concept of “tall-dwarfs” appears to be applicable to pearl millet.     

Effect of d2 dwarfing gene on grain yield and yield components in pearl millet near-isogenic lines

Summary A d₂ dwarfing gene in pearl millet [Pennisetum glaucum (L.) R. Br.] is currently being extensively used for the development of hybrid parents. Its effect on grain yield and yield components is poorly understood. Twelve pairs of tall and dwarf near-isogenic lines developed in the diverse genetic background of three composites were evaluated for grain yield and yield components for 2 years at two locations in southern India. The d₂ gene or the genes linked to it, on an average, reduced plant height by 42%, grain yield by 14%, and head girth by 8% but increased head length and number of tillers per plant by about 5–6%. Large variations were observed among pairs (genetic background) for the difference between tall and dwarf near-isogenic lines for all of the above yield components resulting in no significant difference in five pairs and 17–35% less yield in dwarfs as compared to their tall counterparts in six pairs. Days to 50% flowering and seed weight were least affected by the d₂ gene with the average difference between tall and dwarf groups of near-isogenic lines being of the order of 1–2%. These results indicate that the advantageous effects of d₂ dwarfing gene can be effectively exploited by manipulating the genetic background. The difference between the average grain yields of tall and dwarf groups of near-isogenic lines showed considerable variation across environments with the dwarfs yielding as much as tall group in one environment and up to 30% less than the tall group in the other, thus, indicating that the d₂ gene effect may be substantially modified by the environments.Submitted as JA No. 979 by the International Crop Research Institute for the Semi-Arid Tropics (ICRISAT).     

Responses to selection and changes in combining ability after three cycles of a modified reciprocal recurrent selection in maize

This research reports responses to selection and changes in general (GCA) and specific (SCA) combining abilities after three cycles of a modified reciprocal recurrent selection procedure (MRRS) in EPB-4 and EPB-5 maize populations. In the MRRS procedure a cycle can be completed in 1 or 2 years depending on the availability of winter breeding nurseries. The original and the three selection cycles of the two populations per se (eight entries) and the partial diallel developed from the crosses between them (16 entries) were evaluated in six environments. Realized response to selection on the population cross was 7.25% cycle⁻¹ for grain yield, −13.63% cycle⁻¹ for plant lodging, and 11.93% cyle⁻¹ for prolificacy, whereas plant and ear heights remained unchanged. GCA estimates increased with selection cycles for both populations for grain yield and prolificacy, and decreased for plant lodging, indicating that the frequency of favorable alleles with additive effects for these traits increased with the MRRS cycles in both populations. SCA estimates increased for grain yield and prolificacy indicating that the frequency of favorable complementary alleles at loci with non-additive effects in the reciprocal populations increased with the MRRS cycles. For grain yield, SCA effects increased more than GCA effects with selection cycles, indicating that MRRS exploited more the non-additive effects than the additive effects for the improvement of this trait. The overall results showed that the MRRS procedure was highly effective in improving the population cross, exploiting both GCA and SCA effects.     

Are ordinal rating scales better than percent ratings? a statistical and “psychological” view

Cytoplasmic male sterility (CMS) is considered an efficient genetic tool in pearl millet hybrid breeding. Of the several CMS sources available in pearl millet, A₁ is the only CMS widely exploited to produce commercial hybrids in India. To explore the possibility of using alternate CMS sources, we studied the cytoplasmic effects of different CMS sources on agronomic characters in pearl millet. Five CMS (A) lines representing A₁, A₂, A₃, A₄ and A₅ cytoplasms, their respective maintainer (B) lines and eight restorer (R) lines were used to generate 40 A × R and B × R experimental crosses. The experimental material was evaluated at two different locations in India. Analysis of combining ability and heterosis revealed that A₄ and A₅ cytoplasms had desirable effects for earliness. The A₅ CMS was found to be particularly promising, as compared to other CMS sources for improving grain yield. The study also indicated that the cytoplasmic effects on general combining ability (GCA) for various agronomic characters were largely non-significant. However, cytoplasmic effects on specific combining ability and heterosis were found to be modulated by cytoplasmic-nuclear interactions and influenced by the environmental conditions. The study also demonstrated the advantage of utilizing diverse male-sterile and restorer combinations in maximizing the productivity as well as for genetic and cytoplasmic diversification of hybrids in pearl millet.     

Identification of genomic regions linked to blast (Pyricularia grisea) resistance in pearl millet

Blast disease causes serious economic yield losses in pearl millet. Identification and introgression of genomic regions associated with blast resistance can help to develop resistant cultivars to minimize yield losses incurred from blast outbreaks. In this study, 384 advanced pearl millet genotypes were screened against six blast pathotype-isolates (major pearl millet growing agro-ecologies of India), namely, Pg 45, Pg 118, Pg 138, Pg 186, Pg 204 and Pg 232. Analysis of variance showed significant (P < .001) variation among genotypes for blast reaction (susceptible to resistance). ICMR 08111 and ICMR 10888 genotypes showed resistance to all six blast pathotypes. A genome-wide association study performed with 264,241 single nucleotide polymorphic markers could successfully identify 15 SNPs (P = 1.26 × 10⁻⁷ to 9.22 × 10⁻¹²) underlying the genomic regions governing blast-resistance across five different chromosomes. The SNPs reported had a significant association in at least two of the three models tested (GLM, MLM and Farm CPU). These SNPs can be used in pearl millet-resistant breeding programmes after their function has been validated across different genetic backgrounds.     

Effects of S1-recurrent selection for protein yield on seven agronomic traits of oat

Summary Three S₁-recurrent selection programs (designated HG, HP, and HGP) for increasing protein yield of oat (Avena sativa L.) were conducted for five cycles of selection. The selection criteria in each program (line of descent) emphasized different components of protein yield; high grain yield in HG, both high protein concentration of the groats (caryopsis) and high grain yield in HP, and high protein yield per se in HGP. Heading date and height were restricted to no net change. The objectives of this study were to evaluate the agronomic performance of these three lines of descent and the correlated responses in agronomic traits due to selection. Thirty to sixty random S₀-derived lines from each cycle and ten check lines were grown in hill-plot experiments at two locations in 1989. Grain yield increased in all three lines of descent; HG showed the greatest rate of gain followed by HGP and then HP (0.20, 0.10, and 0.07 Mg ha^-1 per cycle, respectively). Test weight decreased in HGP by 2.6 kg m^-3 per cycle and in HP by 4.0 kg m^-3 per cycle, but remained constant in HG. Cycle 5 (C₅) means for straw yield, height, and seed weight were not significantly different from the C₀ means for any line of descent. Groat percent remained unchanged in HGP, increased from 70.1 to 71.7% in HG, and decreased from 69.9 to 67.6% in HP. Heading date decreased by 3 d in HG and HGP, but remained unchanged in HP. HG compares most favorably with commercial cultivars because of its high yield and acceptable agronomic traits, while HP tends to be low in test weight, seed weight, and groat percent.Abbreviations BM- above ground biomass - GP- groat (caryopsis) percent, fraction of average seed weight that is groat rather than hulls - GPC- groat-protein concentration - GPY- groat-protein yield - GTY- groat yield - GY- grain yield - HD- heading date - HG- selection for protein yield through high grain yield - HGP- selection for protein yield per se - HP- selection for protein yield through high grain yield and high groat-protein concentration - HT- height - PY- protein yield - SDWT- seed weight - SY- straw yield - TWT- test weight     

Mitochondrial Genome Diversity within a Cultivar of Daucus carota (ssp. sativus) Revealed by Restriction Fragment Analysis of Single Plants

Despite a fovourable environment during seed filling, ripening and harvest, and good storage conditions subsequent to harvest, there is variation for the ability of seeds of progeny of pearl millet (Pennisetum glaucum [L.] R. Br.) composites to emerge under favourable conditions in pots, or in the field. Seedling emergence in pots and in the field was found to be a heritable trait in at least two of four composites that had not been specifically constructed for improvement of seedling emergence. The predicted genetic advance from selection for ability to emerge in pots is appreciable. From examination of genotypic correlations, there will be smaller but useful gains over selection cycles in ability to emerge in the field by selection for improved emergence in pots. Direct selection under carefully controlled conditions in the field will produce higher gains, but is more resource consuming than a pot test. We conclude that screening progenies in a pot test in a glasshouse and discarding progenies with poor emergence before a field progeny trial will reduce missing plots due to poor seedling emergence. Selection for improved emergence in pots should lead to an appreciable improvement in seedling emergence in the field over cycles of selection. The pot test is, therefore, a cost effective selection method for the important trait of high seedling emergence.     

Differential Competitive Ability and Growth Habit of Pearl Millet and Clusterbean Cultivars in a Mixed Cropping System in the Arid Zone of India

Dryland sustainable agriculture in the arid zone of India depends upon the choice of suitable cultivars for pure and mixed crop stands. Field experiments were conducted for two years to examine the response of two contrasting cultivars each of pearl millet (Pennisetum glaucum) and clusterbean (Cyamopsis tetragonoloba) in pure stands and in mixed pearl millet‐clusterbean stands. The differential response of cultivars of both crops to pure and mixed stands resulted in a significant genotype × cropping system interaction. Reduction in seed yield of both clusterbean cultivars was greater in mixed stands with tall and long duration pearl millet MH 179 than with medium statured and early maturing HHB 67. The degree of reduction was greater in Naveen, the branched clusterbean cultivar, than in RGC 197, the single stemmed cultivar. Mixing of pearl millet HHB 67 with medium duration clusterbean cultivar Naveen produced maximum pearl millet equivalent total yield. Higher land equivalent ratios (LERs) were also observed when clusterbean cultivars were mixed with early maturing and short statured pearl millet HHB 67.     

Peroxidase Isozyme Pattern in Pearl Millet Lines Resistant and Susceptible to Downy Mildew

Peroxidase isozyme patterns of five downy mildew (DM) resistant inbred lines (PIB-57-1, PIB-1248, PIB-1356, PIB-1364 and PIB-1440), five susceptible lines (PIB-1335-1-1, PIB-1314-2-2, PIB-2231-1, 7042 and PIB-1530-1-1) and DM free plants from the susceptible lines of pearl millet were studied. The results suggested a possible involvement of an isoperoxidase (C9) in imparting the resistance. The involvement of two other isozymes (C5 and C6) was also indicated in the1 resistance mechanism. The specific differentiation m particular isozyme pattern can be a useful criterion for characterization of resistance to downy mildew.     

Evaluation of landrace topcross hybrids of pearl millet for arid zone environments

Pearl millet (Pennisetum glaucum (L.) R. Br.) cultivars for marginal, arid environments need to combine the adaptation to stress conditions of indigenous landraces with an improved yield potential and disease resistance, to allow them to both perform well in farmers fields and to meet the requirements for cultivar release. This paper evaluates landrace-based topcross hybrids (adapted landraces crossed on high-yielding male-sterile lines), as a quick and efficient way of achieving this objective. Topcross hybrids showed a consistent increase in biomass production across all test environments, including the harsh arid zone environments. Depending upon the plant type of the male-sterile used to make the hybrid, this was expressed as increased grain yield only, or increased grain and fodder yields. The downy mildew (Sclerospora graminicola) reaction of the topcross hybrids was determined by the reaction of the male-sterile line used, with the resistant male-sterile producing resistant topcross hybrids and vice-versa. Topcrossing adapted landraces on high-yielding male-sterile lines thus provides an opportunity to improve disease resistance and grain and/or fodder yields, with no apparent loss of adaptation to the marginal environments in which the landraces have evolved.ICRISAT Journal Article no. 1575     

Prospects of breeding biofortified pearl millet with high grain iron and zinc content

Development of crop cultivars with elevated levels of micronutrients is being increasingly recognized as one of the approaches to provide sustainable solutions to various health problems associated with micronutrient malnutrition, especially in developing countries. To assess the prospects of this approach in pearl millet (Pennisetum glaucum), a diverse range of genetic materials, consisting of 40 hybrid parents, 30 each of population progenies and improved populations, and 20 germplasm accessions, was analysed for grain iron (Fe) and zinc (Zn) content, deficiencies of which adversely affect human health. Based on the mean performance in two seasons at ICRISAT, Patancheru, India, large variability among the entries was found, both for Fe (30.1–75.7 mg/kg on dry weight basis) and Zn (24.5–64.8 mg/kg). The highest levels of grain Fe and Zn were observed in well‐adapted commercial varieties and their progenies, and in the parental lines of hybrids, which were either entirely based on iniari germplasm, or had large components of it in their parentage. There were indications of large within‐population genetic variability for both Fe and Zn. The correlation between Fe and Zn content was positive and highly significant (r = 0.84; P < 0.01). These results indicate that there are good prospects of simultaneous selection for both micronutrients, and that selection within populations, especially those with the predominantly iniari germplasm, is likely to provide good opportunities for developing pearl millet varieties and hybrid parents with significantly improved grain Fe and Zn content in pearl millet.     

A comparative assessment of the utility of PCR-based marker systems in pearl millet

A set of 22 pearl millet inbred lines including the parents of eleven mapping populations, was screened with 627 markers including 100 pearl millet genomic SSRs (gSSRs), 60 pearl millet EST-SSRs (eSSRs), 410 intron sequence haplotypes (ISHs), and 57 exon sequence haplotypes (ESHs). In all, 267 (59%) of the markers were informative for at least one of the 11 mapping populations, which segregate for traits like drought and salinity tolerance; host plant resistance to downy mildew, rust and blast; fertility restoration and sterility and maintenance of cytoplasmic male sterility etc. An average of 116 polymorphic markers was identified per mapping population. The average PIC values and number of profiles (P) per polymorphic marker were: gSSRs (PIC = 0.62, P = 6.1), ISHs (PIC = 0.39, P = 2.6), eSSRs (PIC = 0.36, P = 3.1) and ESHs (PIC = 0.35, P = 3.1). A high correlation (r > 0.97, P < 0.05) was observed between the patterns of diversity exposed by the different marker systems. The polymorphic markers identified are suitable for the de novo construction, or the supplementation of pearl millet linkage maps. The genetic relationships identified among the panel of inbred lines may be useful in designing strategies to improve the use of available genetic variation in the context of pearl millet breeding.     

Effects of Tillage and Cropping Systems on Soil Moisture Balance and Pearl Millet Yield

A 2-year study was conducted to determine the effects of tillage and cropping systems on soil moisture balance, growth and yield of pearl millet (Pennisetum glaucum (L.) R.Br.). Three tillage treatments, viz. minimum tillage (one harrowing), conventional tillage (two harrowing, cross) and deep tillage (ploughing followed by two har-rowings), and four cropping systems, viz. monoculture of pearl millet, pearl miliet-clusterbean (Cyamopsis tetra-gonoloba (L.) Taub.) rotation, monoculture of pearl millet with 5 t ha⁻¹ farm yard manure (FYM), and intercropping of pearl millet and clusterbean, were compared. Deep tillage improved the soil moisture storage, water use efficiency and grain yield of pearl millet while consumptive use of water was higher with minimum tillage. Total dry matter yield with deep tillage and conventional tillage was 23.2 and 10.2% higher than minimum tillage in the season 1, and the corresponding values for season 2 were 30.7 and 13.3%. The Pearl millct-clusterbean rotation and monoculture of pearl millet with the application of 5 t ha⁻¹ FYM gave 17.2 and 6.1% higher yield than monoculture of pearl millet, respectively. Maximum water use efficiency was observed in rotation followed by FYM application.     

Stability analysis of yield and capsaicinoids content in chili (<Emphasis Type="Italic">Capsicum</Emphasis> spp<Emphasis Type="Italic">.</Emphasis>) grown across six environments

Pearl millet (Pennisetum glaucum) is the most important cereal in crop-livestock production systems in arid and drier semi-arid environments valued for its grain and dry stover. The conventional approach of improving grain yield through greater partitioning of biomass to the grain and decreased stover yield is not a viable strategy for arid regions where biomass also needs to be improved. The current research tested the hypothesis whether biomass can be improved without extending the crop duration. The 232 F₅ lines derived from a cross (J28 × RIB 335/18) were evaluated in their testcross form along with three commercial hybrids under arid zone conditions. Biomass, grain and stover yields, panicle number, grain size and grain number panicle⁻¹ varied 1.8 to 2.7 fold in progeny testcrosses. Variation in duration of flowering time accounted for only 2% of variation in biomass, indicating that considerable scope existed for selection of testcrosses, and by implication, of F₅ progenies with high biomass independent of crop duration. Stover yield accounted for 72% of differences in total biomass with remaining accounted for by grain yield. From among 92 and 132 testcrosses that had flowering time comparable to two early checks, most had significantly higher biomass, grain and stover yields than these early checks but none of the testcrosses had earliness on par with extra-early maturing hybrid HHB 67. Mean superiority of best 5% testcrosses over early checks was 58% for biomass, 68% for stover yield and 53% for grain yield. The results indicated that there are good prospects of improving biomass in arid zone pearl millet without significantly compromising crop duration.