Response of pigeonpea genotypes of differrent maturity duration to temperature and photoperiod in Kenya

Pigeonpea (Cajanus cajan (L.) Millsp.) is one of the major grain legumes grown in the tropics and subtropics. The crop is grown rainfed in prone drought areas where day length varies from 11 to 14 h and large differences in temperature are experienced, largely due to variations in altitude and latitude. Field studies were conducted with different pigeonpea [Cajanus cajan (L.) Millsp.] in Kenya to determine the effect of photoperiod and temperature on flowering. Variation in temperature was achieved by planting six genotypes at four locations varying inaltitude where temperature decreased with increase in altitude and variation in photoperiod was achieved through artificial lighting (about 12.6 hr - natural day length, 14.5 hr and 16.0 hr). The genotypes used in the study were carefully selected to represent different maturity duration (extra-short-, short-, medium- and long maturityduration) and major piegonpea production regions. Equations that describe the rates of development (1/f) were used to determine rates of progress of each genotype towards flowering as influenced by temperature and photoperiod. For photoperiods below 13 hr, rates of progress towards flowering were influenced by temperaturein give genotypes (ICPL 90011, ICPL 87091, ICP 7035, ICP 6927 and ICEAP 00040). The optimum temperature for rapid flowering were 24.7 oC for the extra-short-duration genotype, 23.1 oC for the shortduration genotye, 23.8 and 22.2 oC for medium-duration genotypes and 18.3 oC for the long-duration genotypes,22.2 oC for medium-duration genotypoes and 18.3 oC for the long-duration genotypes which indicated that the area of origin had a strong influence on adaptation. The effects of photoperiod on rates of progress towards flowering were investigated only under sub-optimal temperatures. The extra-short-duration genotype (ICPL 90011) was the least responsive to variation in photoperiod, while the two long duration genotypes (ICEAP 00040 and T-7) were to most sensitive to photoperiod variation with flowering rate reduced by 0.001 d-1 per hourincrease in day length

Use of Economic Compensation to Increase Demand for Voluntary Medical Male Circumcision in Kenya: Qualitative Interviews With Male Participants in a Randomized Controlled Trial and Their Partners

Interventions to increase demand for medical male circumcision are urgently needed in eastern and southern Africa. Following promising evidence that providing economic compensation can increase male circumcision uptake in Kenya, there is a need to understand the role of this intervention in individuals' decision-making regarding circumcision and explore perceptions of the intervention and concerns such as coercion

Promoting male partner HIV testing and safer sexual decision making through secondary distribution of self-tests by HIV-negative female sex workers and women receiving antenatal and post-partum care in Kenya: a cohort study

Identifying interventions to increase men’s uptake of HIV testing in sub-Saharan Africa is essential for the success of combination HIV prevention. HIV self-testing is an emerging approach with high acceptability, but limited evidence exists on optimal strategies for distributing self-tests. We explored a novel approach of providing multiple self-tests to women at high risk of HIV acquisition in order to promote partner HIV testing and facilitate safer sexual decision-making

The response of short-duration pigeonpea lines to variation in temperature under field conditions in Kenya

Field studies with pigeonpea (Cajanus cajan (L.) Millsp.) were conducted at four locations in Kenya varying in altitude and where temperature decreased with increase in altitude. Warm temperatures (most inductive temperatures, mean 23.5°C) hastened the times from sowing to flowering (f) and maturity (m), and between flowering and maturity (fm). Cool temperatures (17.8°C) delayed f, m, and fm but the delay was most pronounced for fm. In the least inductive cool environment, variation in f, m and fm was greatest among 63 lines developed in India. Compared to the most inductive temperature, the delay in cool environment was 2.2 for f, 3.1 for m, and 5.5 for fm, which indicates that fm is the most sensitive phase to low (sub-optimal) temperatures. Equations that describe the rates of development (1/f, 1/m, and 1/fm) were used to determine progress to different stages of development. Results revealed that optimum temperature for fastest time to flowering varied from 23.1 to 26.1°C. The 1/f at mean temperature of 26.8°C was slower, indicating that the mean temperature experienced was supra-optimal. Since the mean temperature of 26.8°C was not very different from the range considered optimal, further analysis revealed that this was mainly due to the high night temperatures. The 1/fm was strong and positive in the range of temperature tested indicating that warm temperatures shortened the duration between flowering and maturity. The optimum temperature range for this effect varied from 24 to 32°C. Cool temperatures at Kabete retarded plant growth while warm temperatures enhanced i

The Effects of Providing Fixed Compensation and Lottery-Based Rewards on Uptake of Medical Male Circumcision in Kenya: A Randomized Trial

Effective demand creation strategies are needed to increase uptake of medical male circumcision and reduce new HIV infections in eastern and southern Africa. Building on insights from behavioral economics, we assessed whether providing compensation for opportunity costs of time or lottery-based rewards can increase male circumcision uptake in Kenya

Distribution and potential importance of plant-parasitic nematodes associated with pigeonpea in Kenya.

The distribution of plant parasitic nematodes in different agroecological zones representing the major pigeonpea-producing regions in northeastern Kenya was studied in January 1992. Forty two nematode species belonging to 25 genera were associated with pigeonpea in these regions. Aphelenchus avenae and Ditylenchus spp. were frequently detected. Scutellonema unum, Meloidogyne javanica and Rotylenchulus parvus were potentially important species associated with pigeonpea; S. unum was detected in 44% of the samples, M. javanica in 40%, and R. parvus in 37%. Incidence of the root-knot disease caused by Meloidogyne spp. was 19.5%. Crop growth was stunted and patchy in many of the root-knot nematode infested fields. All the nematode species except Meloidogyne sp. have been reported for the first time in association with pigeonpea in Kenya., 16 ref., The distribution of plant parasitic nematodes in different agroecological zones representing the major pigeonpea-producing regions in northeastern Kenya was studied in January 1992. Forty two nematode species belonging to 25 genera were associated with pigeonpea in these regions. Aphelenchus avenae and Ditylenchus spp. were frequently detected. Scutellonema unum, Meloidogyne javanica and Rotylenchulus parvus were potentially important species associated with pigeonpea; S. unum was detected in 44% of the samples, M. javanica in 40%, and R. parvus in 37%. Incidence of the root-knot disease caused by Meloidogyne spp. was 19.5%. Crop growth was stunted and patchy in many of the root-knot nematode infested fields. All the nematode species except Meloidogyne sp. have been reported for the first time in association with pigeonpea in Kenya

Genetic analysis of grain yield in pigeonpea using male sterile lines

Three male sterile pigeonpea (Cajanus cajan) lines (MS-3A, MS-4A and MS-Prabhat) were used as female parents and pollinated by 7 fertile testers, chosen for their wide genetic and geographical diversity. The 10 parents and 21 F1 hybrids were planted in 1982. Data for yield and 6 other agronomic traits were recorded on randomly selected fertile plants and analysed for combining ability. GCA variance was higher than SCA for yield, pods/plant, seeds/pod, seed size and days to flowering. MS-Prabhat was a good general combiner for dwarfness, earliness and seeds/pod. Tester C11 was the best general combiner for yield (54 g/plant)., 14 ref., Three male sterile pigeonpea (Cajanus cajan) lines (MS-3A, MS-4A and MS-Prabhat) were used as female parents and pollinated by 7 fertile testers, chosen for their wide genetic and geographical diversity. The 10 parents and 21 F1 hybrids were planted in 1982. Data for yield and 6 other agronomic traits were recorded on randomly selected fertile plants and analysed for combining ability. GCA variance was higher than SCA for yield, pods/plant, seeds/pod, seed size and days to flowering. MS-Prabhat was a good general combiner for dwarfness, earliness and seeds/pod. Tester C11 was the best general combiner for yield (54 g/plant)