18 research outputs found
In vitro clonal multiplication of Cardiospermum halicacabum L.
A simple and efficient protocol for in vitro multiplication of mature plants of Cardiospermum halicacabum using nodal and shoot segments has been successfully developed. The stem of C. halicacabum being soft and delicate is very sensitive to physical handling and sterilization. In case of C. halicacabum extra care must be taken while selecting the explant and surface sterilizing it. Three to four shoots were initiated per auxiliary meristems on Murashige and Skoog (MS) medium supplemented with 2.0 mgl/1 BAP and 0.5mgl/1 IAA within two weeks, while less numbers of shoots produced on MS medium augmented with Kinetin (KIN). Repeated transfer of the initial explants for up to five passages on MS medium with 0.5 mgl/1 BAP and KIN + 0.5 mgl/1 IAA yielded maximum numbers of shoots. Healthy and elongated shoots were rooted on 1/2 MS medium + 2.0 mgl/1 Indole-3 butyric acid (IBA). The plantlets thus obtained were successfully hardened in green house and transferred to the field
Role of vectors and their host plants in the epidemiology of Maize Lethal Necrosis Disease
Termite species and functional groups in maize intercrop systems in Machakos County, Kenya
Termites are important ecosystem engineers in the tropics but certain termite species cause damage to economically important crops. In Africa, termites cause >50% damage in maize. This study evaluated the effect of intercropping maize with soybean, common beans and sorghum on the level of termite damage, abundance of termite species and functional groups in Machakos County, Kenya during two cropping seasons. In both seasons, Macrotermes herus, M. subhyalinus, Coptotermes formosanus, Odontotermes badius, O. longignathus and Cubitermes ugandesis were recorded. There was a low percentage of lodged plants in maize-sorghum intercrop which also had low population densities of M. herus and O. badius in both seasons. There was no difference in the number of C. formosanus in both seasons. The lowest number of fungus-cultivators was in the maize-sorghum intercrop while soil feeders occurred in low populations. Intercropping maize and sorghum can be further explored alongside other integrated termite management techniques. The observed low populations of soil feeders necessitate adoption of farming practices that conserve them in order to improve crop productivity
Seasonal abundance of western flower thrips and its natural enemies in different French bean agroecosystems in Kenya
Seasonal abundance of cotton thrips (Thysanoptera: Thripidae) across crop and non-crop vegetation in an Australian cotton producing region
Maize Lethal Necrosis (MLN), an Emerging Threat to Maize-Based Food Security in Sub-Saharan Africa
In sub-Saharan Africa, maize is a staple food and key determinant of food security for smallholder farming communities. Pest and disease outbreaks are key constraints to maize productivity. In September 2011, a serious disease outbreak, later diagnosed as maize lethal necrosis (MLN), was reported on maize in Kenya. The disease has since been confirmed in Rwanda and the Democratic Republic of Congo, and similar symptoms have been reported in Tanzania, Uganda, South Sudan, and Ethiopia. In 2012, yield losses of up to 90% resulted in an estimated grain loss of 126,000 metric tons valued at $52 million in Kenya alone. In eastern Africa, MLN was found to result from coinfection of maize with Maize chlorotic mottle virus (MCMV) and Sugarcane mosaic virus (SCMV), although MCMV alone appears to cause significant crop losses. We summarize here the results of collaborative research undertaken to understand the biology and epidemiology of MLN in East Africa and to develop disease management strategies, including identification of MLN-tolerant maize germplasm. We discuss recent progress, identify major issues requiring further research, and discuss the possible next steps for effective management of MLN