Evaluation Of Pigeonpea Pod Borer And Pod Fly Tolerant Lines At Kabete And Kiboko In Kenya

Pigeonpea lines which have shown tolerance to pod borer and pod fly damage at ICRISAT, Patancheru, India, were tested in the field at Kabete and Kiboko, Kenya, and compared with five local checks. There were sprayed and unsprayed plots for each line. Endosulfan 35 E.C. was applied at 0.07% active ingredient (a.i.) starting at flower bud expansion stage, at 50% flowering, early podding, and full podding stages. At crop maturity, all pods from three plants plot-1 were sampled and seed damage by different insect pests determined. The results showed that seeds from all lines were damaged by pod borers and pod sucking bugs. Pod fly incidence was greater at Kabete than at Kiboko, and damage was lower on test lines than on checks. Spraying reduced seed damage from 57.6% to 9.3% and from 59.9% to 4.5% on pod borer lines and pod fly lines, respectively, at Kiboko, and from 19.9% to 5.4% on pod fly lines at Kabete. At Kiboko seed damage in unsprayed pod borer (57.6%) and pod fly (59.9%) lines was similar. Seed damage on pod fly lines at Kiboko (59.9%) was significantly higher than at Kabete (19.9%). Positive significant correlations were observed between seed mass and pod fly damage at Kabete (r = 0.31*) and Kiboko (r = 0.30*). The results indicated that although some lines showed tolerance to pod borer and pod fly damage, they were highly susceptible to pod sucking bugs, suggesting that such tolerance does not hold against other insect groups.Des lign\ue9es de pois d'Angole qui se sont montr\ue9es tol\ue9rantes aux foreurs des gousses et aux mouches des gousses \ue0 l'ICRISAT-Patancheru, en Inde, ont fait l'objet des essais \ue0 Kabete et \ue0 Kiboko au Kenya et ont \ue9t\ue9 mises en comparaison avec cinq t\ue9moins locaux. Pour chaque lign\ue9e, il y a eu des parcelles pulv\ue9ris\ue9es et non pulv\ue9ris\ue9es. On a appliqu\ue9 l'endosulfan 35 E.C. \ue0 0,07% de mati\ue8re active d'abord \ue0 l'\ue9tape d'expansion des bourgeons florales, ensuite \ue0 50% de floraison, au d\ue9but et \ue0 la fin de la formation des gousses. Au stade de maturation, toutes les gousses pr\ue9lev\ue9es sur trois pieds par parcelle ont \ue9t\ue9 mises \ue0 l'\ue9chantillonnage afin de d\ue9terminer les d\ue9g\ue2ts caus\ue9s aux grains par des insectes ravageurs diff\ue9rents. Les r\ue9sultats ont r\ue9v\ue9l\ue9 que les grains de toutes les lign\ue9es ont \ue9t\ue9 atteints par des foreurs des gousses et des punaises suceuses de gousse. L'incidence des mouches des gousses a \ue9t\ue9 plus \ue9lev\ue9e \ue0 Kabete qu'\ue0 Kiboko. Les d\ue9g\ue2ts dus aux mouches des gousses ont \ue9t\ue9 plus faibles sur les lign\ue9es d'essais que sur les t\ue9moins. La pulv\ue9risation a permis de r\ue9duire les d\ue9g\ue2ts aux grains de 57,6% \ue0 9,3% chez des lign\ue9es tol\ue9rantes aux foreurs des gousses et de 59,9% \ue0 4,5% chez des lign\ue9es tol\ue9rantes aux mouches des gousses \ue0 Kiboko. A Kabete, la pulv\ue9risation a r\ue9duit les d\ue9g\ue2ts de 19,9% \ue0 5,4% chez des lign\ue9es tol\ue9rantes aux mouches des gousses. A Kiboko, les d\ue9g\ue2ts aux grains chez des lign\ue9es non pulv\ue9ris\ue9es tol\ue9rantes aux foreurs des gousses (57,6%) et aux mouches des gousses (59,9%) ont \ue9t\ue9 similaires. Les d\ue9g\ue2ts chez des lign\ue9es tol\ue9rantes aux mouches des gousses ont \ue9t\ue9 significativement plus \ue9lev\ue9s \ue0 Kiboko (59,9%) qu'\ue0 Kabete (19,9%). Des correlations significatives positives ont \ue9t\ue9 observ\ue9es entre le poids des grains et les d\ue9g\ue2ts dus aux mouches des gousses \ue0 Kabete (r = 0,31*) et \ue0 Kiboko (r = 0,30*). Les r\ue9sultats ont indiqu\ue9 que certaines lign\ue9es se sont montr\ue9es tol\ue9rantes aux d\ue9g\ue2ts dus aux foreurs des gousses et aux mouches des gousses. Cependant, elles ont \ue9t\ue9 tr\ue8s sensibles aux punaises suceuses de gousse, ce qui laisse sugg\ue9rer que de telle tol\ue9rance ne pourrait pas r\ue9sussir contre d'autres groupes d'insectes

Studies Of Pigeonpea Insect Pests And Their Management In Kenya, Malawi, Tanzania And Uganda

Systematic surveys were conducted in farmers' fields in Kenya, Malawi, Tanzania, and Uganda to determine the incidence, distribution and damage levels due to insect pests of pigeonpea seeds. Three surveys were conducted in eastern Kenya, one in 1992 and two in 1995. Two surveys, one per country per year - were conducted in Malawi, Tanzania, and Uganda in 1995 and 1996. Key insect pests were pod sucking bugs (dominated by Clavigralla tomentosicollis St\ue5l), pod and seed boring Lepidoptera (Helicoverpa armigera H\ufcbner, Maruca vitrata (= testulalis) Geyer, Etiella zinkenella Treitschke), and pod fly (Melanagromyza chalcosoma Spencer). Seed damage due to insect pests were 22, 15, 14, and 16% in Kenya, Malawi, Tanzania, and Uganda, respectively. Damage levels indicated that pod sucking bugs were more damaging in Malawi (caused 69% of total seed damage) and Kenya (43%), while pod borers caused more damage in Tanzania (50%) and Uganda (54%). Pod fly caused more damage in Kenya than in the other countries. Pod borer damage was high in early maturing crops and pod fly in late maturing crops, while pod sucking bugs damage was high regardless of crop maturity period. Greater variations in seed damage were observed between locations in Kenya, Malawi, and Tanzania than in Uganda. Warm and dry locations had less seed damage than warm and humid, cool and dry, or cool and humid locations in Kenya, Malawi and Tanzania. None of the farmers visited in Malawi, Tanzania, and Uganda used conventional pesticides on pigeonpea in the field. Over 80% of these farmers used traditional methods in storage pest management. In contrast, 35 and 53% of farmers in Kenya had used conventional pesticides on long-duration pigeonpea genotypes in their fields.On a conduit une s\ue9rie d'enqu\ueates en champs paysans au Kenya, au Malawi, en Tanzanie, et en Ouganda afin de d\ue9terminer l'incidence et la r\ue9partition des ravageurs de pois d'Angole ainsi que les taux de d\ue9g\ue2ts aux grains dus \ue0 ces ravageurs. Trois enqu\ueates ont \ue9t\ue9 men\ue9es dans l'est du Kenya, une en 1992 et deux en 1995. Chacun des trois pays - Malawi, Tanzanie et Ouganda - ont fait l'objet d'enqu\ueates une fois en 1995 et une autre fois en 1996. Les ravageurs importants ont compris des punaises suceuses de gousse (surtout Clavigralla tomentosicollis Stal), des foreurs des gousses et des grains (Helicoverpa armigera Hubner, Maruca vitrata (=testulalis) Geyer, Etiella zinkenella Treitschke), ainsi que des mouches des gousses (Melanagromyza chalcosoma Spencer). En milieu r\ue9el, les d\ue9g\ue2ts aux grains dus aux ravageurs ont \ue9t\ue9 22% au Kenya, 15% au Malawi, 14% en Tanzanie, et 16% en Ouganda. Les taux de d\ue9g\ue2ts ont indiqu\ue9 que les punaises suceuses de gousse ont \ue9t\ue9 les plus graves au Malawi (69% des d\ue9g\ue2ts totaux aux grains) et au Kenya (43%), tandis que les foreurs des gousses ont occasion\ue9 plus d'atteintes en Tanzanie (50%) et en Ouganda (54%). Les mouches des gousses ont caus\ue9 plus de d\ue9g\ue2ts au Kenya que dans d ' autres pays. Les foreurs des gousses ont provoqu\ue9 des d\ue9g\ue2ts importants chez les cultures pr\ue9coces et les mouches des gousses chez les cultures tardives. Les punaises suceuses de gousse ont caus\ue9 des atteintes graves sur tous les cycles de maturation. Il y a eu plus de variations dans les taux de d\ue9g\ue2ts parmi les localit\ue9s au Kenya, au Malawi et en Tanzanie qu'en Ouganda. Les localit\ue9s chaudes et s\ue8ches ont eu moins de d\ue9g\ue2ts que les localit\ue9s chaudes et humides, fra\ueeches et s\ue8ches, ou fra\ueeches et humides au Kenya, au Malawi et en Tanzanie. Les paysans qu'on a rencontr\ue9s au cours des enqu\ueates au Malawi, en Tanzanie et en Ouganda n'ont pas appliqu\ue9 de pesticides conventionnels sur le pois d'Angole aux champs. Plus de 80% de ces paysans emploient des m\ue9thodes de lutte traditionnelles contre les insectes des denr\ue9es. Par contre, 35% des paysans rencontr\ue9s au Kenya en juillet 1995 et 53% en ao\ufbt 1995 ont appliqu\ue9 des pesticides conventionnels sur les g\ue9notypes de pois d'Angole tardifs dans leurs champs

The Potential for Treatment Shortening With Higher Rifampicin Doses: Relating Drug Exposure to Treatment Response in Patients With Pulmonary Tuberculosis

Contains fulltext : 193274.pdf (Publisher’s version ) (Open Access)Background: Tuberculosis remains a huge public health problem and the prolonged treatment duration obstructs effective tuberculosis control. Higher rifampicin doses have been associated with better bactericidal activity, but optimal dosing is uncertain. This analysis aimed to characterize the relationship between rifampicin plasma exposure and treatment response over 6 months in a recent study investigating the potential for treatment shortening with high-dose rifampicin. Methods: Data were analyzed from 336 patients with pulmonary tuberculosis (97 with pharmacokinetic data) treated with rifampicin doses of 10, 20, or 35 mg/kg. The response measure was time to stable sputum culture conversion (TSCC). We derived individual exposure metrics with a previously developed population pharmacokinetic model of rifampicin. TSCC was modeled using a parametric time-to-event approach, and a sequential exposure-response analysis was performed. Results: Higher rifampicin exposures increased the probability of early culture conversion. No maximal limit of the effect was detected within the observed range. The expected proportion of patients with stable culture conversion on liquid medium at week 8 was predicted to increase from 39% (95% confidence interval, 37%-41%) to 55% (49%-61%), with the rifampicin area under the curve increasing from 20 to 175 mg/L.h (representative for 10 and 35 mg/kg, respectively). Other predictors of TSCC were baseline bacterial load, proportion of culture results unavailable, and substitution of ethambutol for either moxifloxacin or SQ109. Conclusions: Increasing rifampicin exposure shortened TSCC, and the effect did not plateau, indicating that doses >35 mg/kg could be yet more effective. Optimizing rifampicin dosage while preventing toxicity is a clinical priority

A phase IIb, open-label, randomized controlled dose ranging multi-centre trial to evaluate the safety, tolerability, pharmacokinetics and exposure-response relationship of different doses of delpazolid in combination with bedaquiline delamanid moxifloxacin in adult subjects with newly diagnosed, uncomplicated, smear-positive, drug-sensitive pulmonary tuberculosis.

BACKGROUND: Linezolid is an effective, but toxic anti-tuberculosis drug that is currently recommended for the treatment of drug-resistant tuberculosis. Improved oxazolidinones should have a better safety profile, while preserving efficacy. Delpazolid is a novel oxazolidinone developed by LegoChem Biosciences Inc. that has been evaluated up to phase 2a clinical trials. Since oxazolidinone toxicity can occur late in treatment, LegoChem Biosciences Inc. and the PanACEA Consortium designed DECODE to be an innovative dose-ranging study with long-term follow-up for determining the exposure-response and exposure-toxicity relationship of delpazolid to support dose selection for later studies. Delpazolid is administered in combination with bedaquiline, delamanid and moxifloxacin. METHODS: Seventy-five participants with drug-sensitive, pulmonary tuberculosis will receive bedaquiline, delamanid and moxifloxacin, and will be randomized to delpazolid dosages of 0 mg, 400 mg, 800 mg, 1200 mg once daily, or 800 mg twice daily, for 16 weeks. The primary efficacy endpoint will be the rate of decline of bacterial load on treatment, measured by MGIT liquid culture time to detection from weekly sputum cultures. The primary safety endpoint will be the proportion of oxazolidinone class toxicities; neuropathy, myelosuppression, or tyramine pressor response. Participants who convert to negative liquid media culture by week 8 will stop treatment after the end of their 16-week course and will be observed for relapse until week 52. Participants who do not convert to negative culture will receive continuation phase treatment with rifampicin and isoniazid to complete a six-month treatment course. DISCUSSION: DECODE is an innovative dose-finding trial, designed to support exposure-response modelling for safe and effective dose selection. The trial design allows assessment of occurrence of late toxicities as observed with linezolid, which is necessary in clinical evaluation of novel oxazolidinones. The primary efficacy endpoint is the change in bacterial load, an endpoint conventionally used in shorter dose-finding trials. Long-term follow-up after shortened treatment is possible through a safety rule excluding slow-and non-responders from potentially poorly performing dosages. TRIAL REGISTRATION: DECODE was registered in ClinicalTrials.gov before recruitment start on 22 October 2021 (NCT04550832)