Caractérisation de quelques écotypes performants de sorghos Burkinabés

Cinquante-huit (58) écotypes de sorgho ont été sélectionnés dans la collection de sorghos de l’Université de Ouagadougou et caractérisés dans le cadre de l’évaluation de leur performance. Le choix des écotypes a porté sur leur productivité et les qualités liées à leur appréciation par les paysans. La caractérisation agronomique a révélé l’existence d’une très grande variabilité autour des caractères liés à la productivité. L’analyse de la matrice de corrélation a révélé des associations positives entre les caractères de production et ceux de rusticité telle l’aptitude au tallage. La comparaison réalisée avec l’évaluation de 1991 a montré des différences dont la plus importante est celle liée au rendement potentiel. L’identification des écotypes performants et des géniteurs de caractères a permis de ressortir quelques écotypes dont les qualités liées tant à la production qu’à la rusticité sont des atouts autour de quoi, l’espoir peut être fondé dans l’accroissement des productions et l’amélioration de sorghos du Burkina Faso.Mots clés : Sorghos performants, géniteurs de caractères, variabilité, productivité

Assessment of Photoperiod Sensitivity and the Effect of Sowing Date on Dry-Season Sorghum Cultivars in Southern Chad

The cultivation of dry-season sorghum on residual moisture in West and Central Africa is highly affected by sowing dates and ecotypes used. Fifty-five dry-season sorghum ecotypes collected from three zones in southern Chadian were sown on two dates, early and late, in 2013 and 2014, in an α-Lattice, and replicated five times to evaluate the effect of sowing date on potential yield, flowering time, and other agro-morphological traits and to determine their photoperiod sensitivity. Trials were conducted in the research fields at the Agricultural Research Extension Farm in Youé, Chad. Year, sowing date, and their interaction significantly affected most of the assessed traits. Delaying sowing significantly decreased potential yield, duration of vegetative phase, and other agro-morphological traits, except staygreen. All cultivars were photoperiodic with late sowing requiring a lower cumulative growing degree unit to flower. The flowering window was not affected by sowing dates across cultivars; however, the flowering time was affected by a decrease in daylength, but not low night temperatures. Generally, late sowing decreased potential yield across cultivars. However, this decrease varied with the region of origin, with seven cultivars having average potential yields at or above the regional potential yield of 1 t/ha, irrespective of year or sowing dates

Characterization of semi-arid Chadian sweet sorghum accessions as potential sources for sugar and ethanol production

Sweet sorghum (Sorghum bicolor (L.) Moench) is an important crop in Chad that plays an economic role in the countryside were stalks are produced mainly for human consumption without any processing. Unfortunately, very little information exists on its genetic diversity and brix content. Studies performed in 2014 and 2015 showed that there were significant variations (p < 0.001) for all assessed quantitative traits. Potential grain yield (0.12–1.67 t ha−1), days to 50% flowering (68.3–126.3 days), and plant height (128.9–298.3 cm) were among traits that exhibited broader variability. Brix content range from 5.5 to 16.7% across accessions, was positively correlated to stalk diameter and plant height, but negatively correlated to moisture content in fresh stalk and potential grain yield. Fresh stalk yield range from 16.8 to 115.7 Mg ha−1, with a mean value of 58.3 Mg ha−1 across accession. Moisture content in fresh stalk range from 33.7 to 74.4% but was negatively correlated to fresh stalk yield. Potential sugar yield range from 0.5 to 5.3 Mg ha−1 across accession with an average of 2.2 Mg ha−1. Theoretical ethanol yield range from 279.5 to 3,101.2 L ha−1 across accession with an average of 1,266.3 L ha−1 which is significantly higher than values reported under similar semiarid conditions. Overall, grain yields were comparatively low. However, two accessions had grain yield of more than 1.5 t ha−1; which is greater than the average 1.0 t ha−1 for local grain sorghum varieties in Chad. These could have multi-purpose uses; grains, sugar and bioenergy production

Caractérisation agromorphologique des sorghos à grains sucrés (Sorghum bicolor (L.) Moench) du Burkina Faso

Au Burkina Faso, le sorgho à grains sucrés [Sorghum bicolor (L.) Moench] est une culture marginale dont les grains sont consommés frais au stade pâteux. Afin de recueillir les connaissances paysannes sur la gestion du sorgho à grains sucrés et de déterminer le niveau et la structuration de la diversité agromorphologique de ces sorghos du Burkina, une prospection-collecte d’accessions a été réalisée dans les quatre zones agro-écologiques du pays. Au total, 126 accessions ont été collectées dans 102 villages parmi lesquelles 97 ont été caractérisées à partir de 12 caractères qualitatifs et 12 quantitatifs suivant un dispositif blocs de Fisher à trois répétitions. L’étude a montré d’une part que ce sorgho est cultivé surtout dans les champs de case et principalement par l’ethnie mossi et d’autre part que la nomenclature paysanne est basée surtout sur les caractères phénotypiques visibles. Une importante variabilité agromorphologique a été observée au niveau de tous les caractères quantitatifs et une répartition des 97 accessions en 3 groupes : les accessions à cycle long et à rendement grains élevé, les accessions à cycle court et à rendement grains faible et les accessions à cycle et rendement moyens. Les races botaniques caudatum (45,4 %) et caudatum-guinea (48,5%) sont les plus prédominantes dans la collection. Cette diversité génétique est un atout important pour les programmes de sélection et d’amélioration génétique du sorgho.Mots clés : Prospection-collecte, variabilité agromorphologique, Burkina Faso

Agromorphological characterization of some rice species in the main rice cropping area of Chad

Rice is the basic cereal of the populations of the areas of Tandjil&eacute; and Western Mayo Kebbi, in the south of Chad. The rice productivity is, however, low: less than 1 t/ha. This is related to several factors, of which the strong infestation of rice plantation into adventitious and lack of improved varieties with highproductivity. Among the bad frequent grasses, harmful for cultivated rice, the species like Oryza sativa, Oryza barthii and Oryza longistaminata show the strong dynamic ones of infestation in the rice plantations of flooded plains of the areas of Tandjil&eacute; and Western Mayo Kebbi. The agromorphological characterization of the samples of the prospection-collection from October 2005 to Mars 2006 revealed the existence of three types of rice in the zone: wild rice, adventitious rice and cultivated rice. The group of cultivated rice breaks up into three pennies groups on the basis of duration of sowing-heading cycle. The objective of this study was to characterize the agromorphological features of these groups

Phenotypic variability and correlation estimates for traits of Burkina Faso\u2019 sweet grain sorghum genotypes

Sweet grain sorghum [ Sorghum bicolor (L.) Moench] is a neglected crop mainly grown for its sweet grains in the pasty form. Although its taste is the main character of interest, knowledge of protein related content of the grain, especially when linked to its value for infant porridge appears equally important. The objective of this study was to evaluate the status of crude protein content of pasty grains and to determine genetic correlations between morphological and biochemical traits among sweet grain of sorghum genotypes in Burkina Faso. Eight sweet grain sorghum cultivars (BTO2, BZI1, KBZ4, PBO5, PGO3, SBR7, SPI2, STO4) were evaluated through 13 morphological and two biochemical variables. Crude protein content of these genotypes was also compared with the composition of two controls of sweet stalk sorghum (ETS) and ordinary grain sorghum or common sorghum (EBS). The analysis of variance revealed variability within sweet grain sorghum accessions, mainly on the biochemical traits (crude protein and water content) and two morphological traits (peduncle and panicle lengths), which discriminated significantly in the thresholds of 1 and 5%, respectively. In addition, sweet grain sorghum had low crude protein content compared to other types of sorghum, except, two genotypes of sweet grain sorghum (BZI1 and STO4) which recorded higher protein content compared to the common sorghum. An important and negative correlation was noted between sowing-flowering cycle and protein content.Le sorgho grains sucr\ue9s [ Sorghum bicolor (L.) Moench] est une culture n\ue9glig\ue9e produite essentiellement pour ses grains sucr\ue9s au stade p\ue2teux. Bien que la saveur sucr\ue9e du grain soit le principal caract\ue8re d\u2019int\ue9r\ueat, une connaissance de la teneur en prot\ue9ines totales du grain au stade p\ue2teux pourrait favoriser son utilisation pour impl\ue9menter les bouillies infantiles et contribuer \ue0 sa meilleure valorisation. La pr\ue9sente \ue9tude vise donc \ue0 d\ue9terminer la teneur en prot\ue9ines totales des grains au stade p\ue2teux du sorgho grains sucr\ue9s et \ue9tablir les corr\ue9lations g\ue9n\ue9tiques entre les caract\ue8res morphologiques et biochimiques. Ainsi, huit g\ue9notypes de sorgho grains sucr\ue9s (BTO2, BZI1, KBZ4, PBO5, PGO3, SBR7, SPI2, STO4) ont \ue9t\ue9 \ue9valu\ue9s \ue0 l\u2019aide de 13 caract\ue8res morphologiques et deux caract\ue8res biochimiques. La teneur en prot\ue9ines totales de ces g\ue9notypes a \ue9t\ue9 ensuite compar\ue9e \ue0 celle de deux t\ue9moins dont un sorgho \ue0 tige sucr\ue9e (ETS) et un sorgho ordinaire (ESB). L\u2019analyse de variance a r\ue9v\ue9l\ue9 une variabilit\ue9 au sein des cultivars de sorgho grains sucr\ue9s observ\ue9e surtout au niveau des traits biochimiques (teneur en prot\ue9ines totales des graines et teneur en eau des graines) et de deux traits morphologiques (longueur du p\ue9doncule et longueur de la panicule) qui ont significativement discrimin\ue9 les accessions aux seuils de 1 et 5%, respectivement. De plus, le sorgho grains sucr\ue9s a pr\ue9sent\ue9 une faible teneur en prot\ue9ines totales comparativement aux autres types de sorgho \ue0 l\u2019exception de deux g\ue9notypes (BZI1 et STO4) qui ont montr\ue9 une teneur en prot\ue9ines plus \ue9lev\ue9e que le sorgho ordinaire. Une forte corr\ue9lation significative et n\ue9gative a \ue9t\ue9 \ue9galement not\ue9e entre le cycle semis-floraison et la teneur en prot\ue9ines totales