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

Efficacy of some cu.ltural management methods on Callosobruchus chinensis (L) infestation during storage of pigeonpea seed

Studies were conducted at Kawanda Agricultural Research lnstiuite to determine the efficacies of three storage practices viz: traditional mud-straw-cowdung silo " tua" storage, pod storage and storage of split seeds, on the management of Callosobruchus chinensis infestations in dried pigeon pea seeds. Lowest pigeonpea seed infestation was observed in sealed "tua", followed by loosely covered "tua" (2,512 insects and 3.81% seed damage), and the highest in .sack stored pigeonpea. Higher temperatures were observed in the " tua" (scaled " tua" 36.2°C, loosely covered "tua" 31.8°C) than in sack storage (25.5°C). Seed viability was also higher in " tua" (sealed 72.7% , loosely covered 76.3%) than in sack stored seeds (35.0%). Pod stored pigeonpea was effective in controlling C. chinensis populations, with infestation and seed damage of only 3.9 insects (all dead) and 0.04% respectively, compared to 45,000 insects and 19.8% respectively, in seed stored trials. Pod stored pigeonpea also ma intained higher seed viability (85.8%) than sack stored pigeonpea (45.1 %). Pigieonpea splitting depressed infestation by C. chinensis, reducing pest numbers, from 320 insects on the first month of storage to 10 insects on the third month. Whereas in whole stored seeds, there wns a sharp rise in pest population from 900 in first month of storage to over 10,000 on third mouth.Key words: Cultural management, Callosobruchus chinensis, Cajanus caja

New regional initiatives in pigeonpea improvement

peer reviewe

Field evaluation of xpert HPV point-of-care test for detection of human papillomavirus infection by use of self-collected vaginal and clinician-collected cervical specimens

The World Health Organization has recommended that testing for high-risk human papillomavirus (HPV) (hrHPV) infection be incorporated into cervical screening programs in all settings worldwide. In many high-burden, low-income countries, it will not be feasible to achieve high cervical screening coverage using hrHPV assays that require clinician-collected samples. We conducted the first evaluation of self-collected vaginal specimens compared with clinician-collected cervical specimens for the detection of hrHPV infection using the Xpert HPV test. Women aged 30 to 54 years attending two well-woman clinics in Papua New Guinea were invited to participate and provided self-collected vaginal and clinician-collected cervical cytobrush specimens. Both specimen types were tested at the point of care by using the Xpert HPV test. Women were given their cervical test result the same day. Those with a positive hrHPV test and positive examination upon visual inspection of the cervix with acetic acid were offered same-day cervical cryotherapy. A total of 1,005 women were enrolled, with 124 (12.3%; 95% confidence interval [CI], 10.3%, 14.4%) being positive for any hrHPV infection. There was a 99.4% overall percent agreement (OPA) between vaginal and cervical tests for HPV-16 (95% CI, 98.9%, 99.9%), a 98.5% OPA for HPV-18/45 (95% CI, 97.7%, 99.3%), a 94.4% OPA for other hrHPV infections (95% CI, 92.9%, 95.9%), and a 93.4% OPA for all hrHPV types combined (95% CI, 91.8%, 95.0%). Self-collected vaginal specimens had excellent agreement with clinician-collected cervical specimens for the detection of hrHPV infection using the Xpert HPV test. This approach provides for the first time an opportunity to incorporate point-of-care hrHPV testing into clinical cervical screening algorithms in high-burden, low-income settings

Performance of clinical screening algorithms comprising point-of-care HPV-DNA testing using self-collected vaginal specimens, and visual inspection of the cervix with acetic acid, for the detection of underlying high-grade squamous intraepithelial lesions in Papua New Guinea

The performance of different clinical screening algorithms comprising point-of-care HPV-DNA testing using self-collected vaginal (‘V’) specimens, and visual inspection of the cervix with acetic acid (VIA) was evaluated in Papua New Guinea. Women aged 30–59 years provided V specimens that were tested at point-of-care using the Xpert HPV Test (Cepheid, Sunnyvale, CA). A clinician-collected cervical (‘C’) specimen was then collected for point-of-care Xpert testing, and liquid-based cytology (LBC). Following this, VIA examination was conducted, blind to HPV test results, and ablative cervical cryotherapy provided if indicated. Detection of high-grade squamous intraepithelial lesion (HSIL) by LBC was the reference standard used to evaluate clinical screening algorithms. Of 1005 women, 36 had HSIL+. Xpert HPV Test performance using V specimens (sensitivity 91.7%, specificity 87.0%, PPV 34.0%, NPV 99.3%) was superior to VIA examination alone (51.5%, 81.4%, 17.5%, 95.6% respectively) in predicting underlying HSIL+. A screening algorithm comprising V specimen HPV testing followed by VIA examination had low sensitivity (45.5%) but comparable specificity, PPV and NPV to HPV testing alone (96.3%, 45.5%, 96.3% respectively). A ‘test-and-treat’ screening algorithm based on point-of-care HPV testing of V specimens had superior performance compared with either VIA examination alone, or a combined screening algorithm comprising HPV testing plus VIA