No abstract

French bean (Phaseolus vulgaris L.) is a very important protein component of the diets of the majority of the population globally and in Kenya. It is a major vegetable export crop (48%) and income earner to the smallholder farmers who constitute more than 80% of producers in Kenya. However commercial varieties presently grown have the potential to produce more yields of above 1800 kgha -1 but are limited by pests and disease. Among the diseases is anthracnose incited by Colletotrichum lindemuthianum (sacc.et. magn.) Lams. Scrip which causes a severe rapidly developing disease that can bring about complete plant defoliation and extensive yield and or quality loss. Studies were conducted to identify commercial varieties of French beans which are resistant to anthracnose disease. The objective of this study was to screen commercial varieties of French beans in controlled environmental conditions (glasshouse) for resistance to anthracnose disease. This was achieved through evaluation of incidence and phenotypic variation in anthracnose virulence among the bean varieties in relation to yields. Ten bean varieties were used during the study, among them were two controls;

Common bean (Phaseolus vulgaris L.), is among the most important legume crop for protein source in peoples' diet globally and including Kenya. Anthracnose (Colletotrichum lindemuthianum) is a common disease of legumes that causes yield loss of upto 90-100%. Potential production of common beans in Kenya is expected to be above 2000 kg ha-1 but due to challenges of pests and diseases among them anthracnose, it remains below potential yields. The aim of the recent study was to investigate selected common bean genotypes for anthracnose resistance in Kenya. The study was done in three varied agro-ecological zones; Busia, Bungoma and University of Eldoret. Fifteen genotypes were evaluated on field experiment to ascertain anthracnose incidence and severity. Four bean genotypes were used as experimental controls; two resistant and two susceptible controls. Data was collected on incidences and severity and subjected to Analysis of variance in SAS version 9.1. Mean values were separated using Tukeys' Studentized Range Test. The results revealed tolerant and resistant genotypes with lower incidences and severity than those of resistant controls while susceptible genotypes recorded higher incidences and severity than those of the susceptible controls. Tolerant genotypes were; Ciankui, Tasha, and KK8 while the resistant genotypes were; Miezi mbili, KK15 and Chelalang. Site variation was significant at (P≤0.05) with Busia 82%, Bungoma 76% and University of 53%. KK15, Tasha and Chelalang were tolerant in all sites, and this could be attributed to their genetic resistance. The six genotypes identified to be potentially tolerant and resistant to anthracnose and high yielding could be further studied and used in breeding programs for development of resistant lines globally and in Kenya.

Citrus fruit is considered a very nutritious and delicious diet. Citrus consists of lemon, oranges, mandarin, and grapefruit which have economic value in the world. Significant losses occur in citrus due to numerous diseases. Among various diseases, citrus trees are seriously affected by a phytopathogenic mollicute Spiroplasma citri which causes stubborn disease. S. citri is transovarially transmitted by several leafhopper species. Symptoms include smaller and cupped leaves, small size, crook fruits with aborted seeds. Moreover, irregularity on the fruits such as different sizes, shapes, and typically lighter, smaller fruits than its healthy counterpart has also been observed. The affected fruits often drop before maturity. The color inversion is often seen with the stylar end remaining green and the peduncle end showing color. Various molecular and biochemical tests are conducted to identify S. citri. Under in-vitro conditions, S. citri grows on SP4 media where a fried egg-like shaped colony is observed. Keeping the importance of the stubborn citrus disease, the present short note briefly described the symptomology, detection, transmission, and management.

Common bean is among the most important legume crop for protein source in people's diet globally and including Kenya. Anthracnose is a common disease of legumes that causes yield loss of up to 90-100%. The aim of the study is to investigate the morphological traits associated with anthracnose resistance in selected common bean genotypes in Kenya. The study was done in three varied agroecological zones; University of Eldoret, Bungoma and Busia. Fifteen genotypes were evaluated on field experiment to ascertain morphological traits associated with anthracnose resistance. Field experiment was done in a random complete block design. Data were collected on morphological traits and subjected to analysis of variance in SAS version 9.1. The genotypes, Ciankui, Tasha, KK15, KK8, Miezi mbili and Chelalang showed morphological traits that were significantly (P ≤ 0.05) associated with anthracnose resistance, and also with high grain yields of 1.5 to 2.0 t/ha. Morphological traits associated with common bean anthracnose resistance included Leaf width, leaf length, length of fifth internode of the stems, bracteolate size classification and flower colour. It is recommended that management of anthracnose by use of resistant common bean genotype seeds is essential to provide increased bean yields globally and in Kenya.