Boll positioning and seed ageing effects on seed quality of cotton in Busia County, Kenya

La graine de coton ( Gossypium hirsutum ) est un produit agricole susceptible de se d\ue9t\ue9riorer pendant le stockage. L\u2019objectif de cette \ue9tude \ue9tait de d\ue9terminer l\u2019effet de la position de la capsule sur les graines de la plante et la p\ue9riode de stockage sur la qualit\ue9 des graines de coton. La vari\ue9t\ue9 de coton KSA 81M a \ue9t\ue9 plant\ue9e au Centre de Formation Agricole de Busia (ATC) et les capsules ont \ue9t\ue9 r\ue9colt\ue9es dans les branches basale, centrale et sup\ue9rieure. Les graines ont \ue9t\ue9 stock\ue9es puis test\ue9es pour d\ue9terminer la qualit\ue9 des graines. En g\ue9n\ue9ral, le pourcentage de germination des graines a diminu\ue9 pendant la p\ue9riode de stockage; tandis que la conductivit\ue9 \ue9lectrique et le temps moyen de germination augmentaient. Remarquablement, la capacit\ue9 germinative des graines provenant des tiges basales est tomb\ue9e en dessous de la capacit\ue9 germinative des graines des branches m\ue9dianes et sup\ue9rieures, apr\ue8s six mois malgr\ue9 un pourcentage de germination initial plus \ue9lev\ue9. En revanche, la conductivit\ue9 \ue9lectrique et le temps moyen de germination des graines des branches basales ont montr\ue9 une augmentation significative apr\ue8s six mois par rapport aux branches moyennes et sup\ue9rieures. Nos r\ue9sultats sugg\ue8rent que la qualit\ue9 des graines de coton des branches basales \ue0 la r\ue9colte est sup\ue9rieure \ue0 la qualit\ue9 des graines des branches m\ue9dianes et sup\ue9rieures. Cependant, lorsqu\u2019elles sont soumises au stockage, les graines des branches basales pr\ue9sentent des changements de d\ue9t\ue9rioration plus \ue9lev\ue9s que ceux obtenus des branches moyenne et sup\ue9rieure. Cela pourrait \ueatre li\ue9 \ue0 la dur\ue9e du d\ue9veloppement des graines et \ue0 l\u2019augmentation des fuites de solut\ue9 apr\ue8s l\u2019imbibition, qui s\u2019accompagne g\ue9n\ue9ralement d\u2019une fuite in\ue9vitable des m\ue9tabolites n\ue9cessaires \ue0 la germination et \ue0 la croissance normale des semis

EFFECT OF RIDGING AND INTERCROPPING ON SORGHUM PRODUCTIVITY IN ARID AND SEMI-ARID LANDS OF EASTERN KENYA

Soil moisture deficit is a key constraint to sorghum ( Sorghum bicolor ) productivity in arid and semi-arid lands globally. The objective of this study was to determine the effect of ridging and sorghum-bean intercropping (additive system) on soil moisture conservation and sorghum productivity. Sorghum (gadam) was grown either as a sole crop or intercropped with two bean ( Phaseolus vulgaris L.) varieties (KATx56 and KAT B1), under two types of ridging (open ridges and tied ridges), and a control without ridges for two years. The study was set up in split plot arrangement, in a randomised complete block design, at the Kenya Agricultural and Livestock Research Organization, Kiboko, in 2019 and 2020. There was no significant interaction between ridging and intercropping. Soil moisture content increased by 11-26% due to ridging; and decreased by -11 and -7% due to sorghum-KAT B1 and Sorghum-KAT X56 intercropping, respectively. Higher moisture content due to ridging was attributed to formation of basin-like structures, which increased water harvesting and infiltration compared to the no ridges where surface run-off was predominant. The highest moisture content was attained on sole bean, followed by sole sorghum and then sorghum/bean intercropping. The decrease in moisture content in intercrops of sorghum/bean relative to their specific sole crops was attributed to higher crop density, which reduced crop spacing, thus triggering competition for available soil moisture. The highest sorghum grain and equivalent yields were obtained in the ridged plots. Intercropping resulted into decrease in sorghum grain yield, but led to increase in sorghum equivalent yield (SEY) and Land Equivalent Ratio (LER). The results show that both ridging and intercropping are suitable for higher water use efficiency and land productivity in ASALs of Kenya.Le d\ue9ficit d\u2019humidit\ue9 du sol est une contrainte majeure \ue0 la productivit\ue9 du sorgho (Sorghum bicolor) dans les terres arides et semi-arides \ue0 l\u2019\ue9chelle mondiale. L\u2019objectif de cette \ue9tude \ue9tait de d\ue9terminer l\u2019effet du billonnage et de la culture intercalaire sorgho-haricot (syst\ue8me additif) sur la conservation de l\u2019humidit\ue9 du sol et la productivit\ue9 du sorgho. Le sorgho (gadam) \ue9tait cultiv\ue9 soit en monoculture, soit en association avec deux vari\ue9t\ue9s de haricot (Phaseolus vulgaris L.) (KATx56 et KAT B1), sous deux types de billons (billons ouverts et billons li\ue9s), et un t\ue9moin sans billons pendant deux ann\ue9es. L\u2019\ue9tude a \ue9t\ue9 mise en place en parcelles divis\ue9es, dans une conception en blocs complets randomis\ue9s, \ue0 l\u2019Organisation de recherche sur l\u2019agriculture et l\u2019\ue9levage du Kenya, Kiboko, en 2019 et 2020. L\u2019\ue9tude n\u2019a montr\ue9 aucune interaction significative entre le billonnage et la culture intercalaire. La teneur en humidit\ue9 du sol a augment\ue9 de 11 \ue0 26 % en raison du billonnage ; et diminu\ue9 de -11 et -7% en raison des cultures intercalaires sorgho-KAT B1 et Sorgho-KAT X56, respectivement. La teneur en humidit\ue9 plus \ue9lev\ue9e due aux cr\ueates a \ue9t\ue9 attribu\ue9e \ue0 la formation de structures de type bassin, ce qui a augment\ue9 la collecte et l\u2019infiltration de l\u2019eau par rapport \ue0 l\u2019absence de cr\ueates o\uf9 le ruissellement de surface \ue9tait pr\ue9dominant. La teneur en humidit\ue9 la plus \ue9lev\ue9e \ue9tait sur le haricot unique, suivi du sorgho unique, puis de la culture intercalaire sorgho/haricot. La diminution de la teneur en humidit\ue9 dans les cultures intercalaires de sorgho/haricot par rapport \ue0 leurs cultures uniques sp\ue9cifiques a \ue9t\ue9 attribu\ue9e \ue0 une densit\ue9 de culture plus \ue9lev\ue9e, qui a r\ue9duit l\u2019espacement des cultures, d\ue9clenchant une comp\ue9tition pour l\u2019humidit\ue9 disponible du sol. Les rendements les plus \ue9lev\ue9s en grain de sorgho et en \ue9quivalent ont \ue9t\ue9 obtenus dans les parcelles butt\ue9es. La culture intercalaire a entra\ueen\ue9 une diminution du rendement en grains de sorgho, mais a entra\ueen\ue9 une augmentation du rendement \ue9quivalent en sorgho (SEY) et du rapport d\u2019\ue9quivalent en terres (LER). Les r\ue9sultats montrent que le billonnage et la culture intercalaire conviennent \ue0 une plus grande efficacit\ue9 de l\u2019utilisation de l\u2019eau et \ue0 la productivit\ue9 des terres dans les TASA du Kenya

Screening for host plant resistance to Helicoverpa armigera in selected chickpea (Cicer arietinum L) genotypes in Kenya

Hellicoverpa armigera (poad borer) is a major pest of chickpea (Cicer aurientinum) in many areas of the world, In Kenya, it causes up to 80% yield losses of the crop

Qualitative and Quantitative Assessment of African Eggplant Seed Germination in Relation to Seed Maturation

The final germination expressed as a percentage alone is unsatisfactory for reporting results related to the germination capacity of a seed lot. Information on other quantitative variables are thus important to judge the agronomic value of a seed lot. To evaluate the seed germination characteristics of the African eggplant, seeds were extracted from fruits harvested at different maturity stages produced under both tropical and temperate oceanic climates. The seed germination behaviour was assessed by germinability, germination rate, homogeneity and synchrony of the seed lots. The data for each environment was analyzed separately in a two-way ANOVA constituting harvesting maturity stages and cultivars as factors. The results showed that seed germinability increased with maturation and maximum when fruits were harvested 76 DAA under both climates. Seeds harvested precociously failed to germinate regardless of the production environment. All seed quantitative variables measured were positively related to the final seed germinability. The seed germination rates measurements significantly increased with seed maturity, indicating seed vigour and final germinability improves with maturation. Coefficient of variation of germination time (CVt) was a good measure of uniformity in seed germination. The results further showed a strong and positive correlation with seed germination parameters such as GI, GV, MDG, CVG and U to final germination. It is recommended that for maximum seed quality, fruits should be harvested at 76 DAA. It is further suggested that seed germination results should be enriched by measuring other quantitative parameters as it communicates different aspects of the germination process