Hermetic cold storage without previous drying (wet–cold storage) was experimented for the preservation of yam pollen grains. Pollens collected from white yam D. rotundata and a wild relative, D. praehensilis, were stored at -80, -20, 5, and 150C in sealed packs for 2 years. Pollen samples were drawn for in vitro germination tests after 100 and 700 days, and hand pollination was conducted after 365 and 730 days in storage. Pollen germination responses were not significantly different among the two ...

The East African highlands, home to more than 80 cultivated varieties of locally evolved bananas, constitute a secondary centre of banana diversity. Uganda is the leading producer and consumer of banana in the region and also enjoys the highest diversity of a group of bananas uniquely adapted to this region. These East African highland bananas comprise cooking and brewing types. The former is a staple for more than 7 million people and thus important for food security. Little is known about the ...

Mulch supported more vigorous plants and repressed nematode activity. Plant parasitic nematodes were responsible for damage to the roots of plantain cv. Agbagba, resulting in reduction in the number of functional leaves on the plants. Inoculated plants had better suckering than the uninnoculated ones when mulched, suggesting that the cumulative effect may result in heavier toppling in the inoculated plots during later growth stage, especially at flowering and fruit filling when the roots of the ...

When predation risk varies in space and time and with predator species, successful prey defence requires specific responses to each predator. In cassava fields in Africa, the herbivorous cassava green mite (Mononychellus tanajoa) is attacked by three predatory mite species that are segregated within the plant: the leaf-dwelling Typhlodromalus manihoti and Euseius fustis occur on the middle leaves, whereas the apex-inhabiting T. aripo migrates from the apex to the top leaves only during the night. ...

Leaf resistances of 14 cultivated potato genotypes ( Solanum spp.) and three tuber-bearing wild Solanum species were compared when plants were grown under water stress at two tropical sites. Factors investigated were diurnal changes in leaf resistance, the effect of plant age, transient drought versus well-watered conditions of potted and field-grown plants. These measurements were carried out in order to determine the stomatal behaviour of tuber-bearing genotypes and species. Significant genotypic ...

Anthracnose, caused by Colletotrichum gloeosporioides, is the most severe foliar disease of water yam (Dioscorea alata) worldwide. The tetraploid breeding line, TDa 95/00328, is a source of dominant genetic resistance to the moderately virulent fast growing salmon (FGS) strain of C. gloeosporioides.Bulked segregant analysis was used to search for random amplified polymorphic DNA (RAPD) markers linked to anthracnose resistance in F1 progeny derived from a cross between TDa 95/00328 and the susceptible ...

Experiments were conducted at Ibadan, Nigeria to assess the effect of leaf trichome characteristics (pubescence intensity index, length, and orientation) on field resistance of cassava to the green spider mite, Mononychellus tanajoa (Bondar). There were significant (P < 0.01) differences in M. tanajoa density, damage score and leaf trichome characteristics among the cultivars. During the dry season (February, 1993 and 1994) and the early part of the rainy season (May, 1993), there were significant ...

In field trials on Premier rabbit eye blueberry, individual shoots were selected and tagged in the fall of 2001, 2002, and 2003 to quantify the effects of Septoria leaf spot severity and disease-induced premature defoliation on flower bud set and return yield. Experiments were carried out similarly on Blue crisp southern high bush blueberry using shoots tagged after fruit harvest in the summer of 2002 and 2003. Leaves on the distal 20-cm segments of these shoots were monitored for disease severity ...

Weekly Prostephanus truncatus (Horn) ßight activity, measured as the density of captured beetles in pheromone baited traps, was monitored for 76 consecutive weeks at 16 sites inside the Lama forest in southern Benin and at four sites in maize farmland just outside the forest. Prostephanus truncatus ßight activity was consistently higher and the ßight activity pattern signiÞcantly different near maize stores than at sites inside the forest. Although P. truncatus is known to infest girdled branches ...

Integrated soil management with grain legumes was studied at two villages (Ugwan Shamaki) and Tashan Kaya) in Kaduna State, northern Guinea Savanna zone of Nigeria (190 day growing season). Impacts of one year rotation of Soybean and Cowpea on soil chemical properties were compared with sole maize and maize-cowpea mixture. All plots were Striga infested. Organic carbon decreased by 4 and 2% in maize after maize (SM) plots in Ugwan Shamaki and Tashan Kaya respectively. Sole soybean, SC and MC mixture ...