An on-farm study of Striga as constraint to improved sorghum cultivar production in Mali

Sorghum (Sorghum bicolor) is the most important food crop in savanna areas of the West and Central Africa (WCA) region, including Mali, where grain yield averaged 0.71 t in 1999 (FAO 2001). Improved caudatum sorghum cultivars have not been widely adopted in Mali (Yapi and Debrah 1998). However, some of these cultivars such as ICSV 1063 and ICSV 1079 were introduced in the Kolokani area (about 130 km north of Bamako) by Catholic missionaries in the late 1980s. They have since spread and are being cultivated under the name “Gadiabani” by many farmers in over 100 villages (SEPD 1995)

Combined on-farm effect of plot size and sorghum genotype on sorghum panicle-feeding bug infestation in Mali

The reaction of four sorghum cultivars to panicle-feeding bugs was assessed in small (15 m2) and large (0.5–1.0 ha) plots for 2 years in three villages of the Kolokani region (Mali). The aim was to explain the somewhat contradictory earlier observations of pest infestation and damage in small experimental plots (on-station and on-farm) as well as in farmers’ field surveys. Irrespective of the plot size, the local guinea sorghum cultivar Bibalawili was consistently the least infested and damaged, followed by bug-resistant compact-headed cv Malisor 84-7, whereas the improved caudatum cultivar Gadiabani, which had been disseminated for nearly a decade in the region, and the improved hybrid ICSH 89002, were the most heavily damaged. When located along the border of large plots of a susceptible cultivar, small plots of the four cultivars overall were less infested and damaged than when located along the border of plots of resistant cultivars. However, they were more infested and damaged when located in the centre of large plots of susceptible cultivars than when they were in the centre of resistant cultivar plots. In large plots, bug populations and damage decreased from the border to the centre. These results suggest that, in addition to the mere plot size, plant breeders should take the genotypic environment of their experimental plots into account, namely the vicinity of large plots of pest-susceptible or -resistant cultivars, and the position of the test plots (border or centre) relative to these large plots

Reducing the oral quinine-quinidine-cinchonin (Quinimax) treatment of uncomplicated malaria to three days does not increase the recurrence of attacks among children living in a highly endemic area of Senegal

A 3 d shortened course of the quinine-quinidine-cinchonin association Quinimax (trademark) was compared to the usual 7 d regimen for routinely treating 462 acute uncomplicated #Plasmodium falciparum$malaria attacks in 72 children under the age of 10 years in Dielmo, a holoendemic village in Senegal. 25 mg/kg Quinimax (trademark) salt daily, given in 3 equal doses, improved clinical status in 99.6$ and the partial acquired immunity of the children were probably responsible for the absence of any difference between the courses. Oral Quinimax (trademark) for 3 d is a possible alternative regimen to chloroquine and sulfadoxine-pyrimethamine for treating uncomplicated malaria in highly endemic areas of Africa where clinical resistance to these drugs exists. (Résumé d'auteur

Performances agronomiques des amendements a base de biochar en milieu paysan a l’ouest du Burkina Faso

Au Burkina Faso, la baisse de la fertilité des sols représente une contrainte importante pour la durabilité de l’agriculture. Dans cette étude, l’influence du compost, du biochar et du co-compost au biochar sur les propriétés chimiques du sol, le rendement du cotonnier et du maïs a été évaluée sur un lixisol endoplinthique en milieu paysan. Le dispositif était en blocs randomisés comportant trois traitements en quatre répétitions : T= compost + NPK + Urée, T2 = biochar pristine + NPK + urée, et T3=co-compost au biochar + NPK + urée. La dose d’apport des amendements était de 2,5t.ha-1.an-1 pendant deux ans, associée à la dose recommandée d’engrais minéraux (coton : NPK = 150 kg.ha-1 et urée = 50 kg.ha-1 ; maïs : NPK = 200 kg.ha-1 et urée = 100 kg.ha-1). L’adjonction du biochar pendant le compostage a augmenté les teneurs en azote total, magnésium total et phosphore total de l’amendement obtenu, respectivement de 48 %, 64 % et 68 % comparativement au compost. Même si les paramètres physico-chimiques du sol, deux ans après, n’ont pas été améliorés, une augmentation significative du rendement du coton graine de 14 % (biochar) et 19 % (co-compost au biochar) comparativement au compost a été observée la troisième année. Les amendements à base de biochar peuvent être suggérés aux producteurs pour l’amélioration du rendement des cultures à moyen terme.   English title: Agronomic Performance of Biochar-Based Amendments in Farmers’ environment in western Burkina Faso In Burkina Faso, declining soil fertility is a major constraint to agricultural productivity and sustainability. In the present study, compost, biochar and co-composted biochar were applied to endoplinthic lixisol, and the effects on soil physicochemical properties, cotton and maize yield over three  years (i.e., three cropping seasons) were investigated. The trial was a completely randomized block design included three treatments and four  repetitions: T1= compost + NPK + Urea, T2= pristine biochar + NPK + Urea and T3= co-composted biochar + NPK + Urea. The amendments rate were  2.5 t.ha-1 each year (2018 and 2019) combined with the recommended rate of mineral fertilizer (cotton: 150 kg.ha-1 NPK , 50 kg.ha-1 Urea; maize:  200 kg.ha-1 NPK, 100 kg.ha-1 Urea). The addition of biochar during the composting process increased the total nitrogen, total magnesium and total  phosphorus contents of co-composted biochar by 48%, 64% and 68% respectively compared to compost. Although the biochar-based amendments  did not improve the physico-chemical parameters of the soil, two years after their application, a significant increase in cotton yield by 14% (biochar)  and 19% (co-composted biochar) compared to compost in the third year was observed. Biochar-based amendments can be suggested to producers  for medium-term crop yield improvement

Potential of sorghum and physic nut (Jatropha curcas) for management of plant bugs (Hemiptera: Miridae) and cotton bollworm (Helicoverpa armigera) on cotton in an assisted trap-cropping strategy

The cotton bollworm (CBW) Helicoverpa armigera and to a lesser extent plant bugs (PB) (Hemiptera: Miridae) are important pests of cotton in Africa. For sustainability reasons, it is necessary to reduce use of chemical control measures for these pests. A promising alternative to chemical control of both CBW and PB is trap cropping, assisted with botanical pesticides sprays, if needed. We report studies conducted from 1995–98 on sorghum attractiveness to PB and CBW, on the potential of physic nut (Jatropha curcas) extracts [particularly the phorbol ester (PE) fraction of the oil] for sorghum protection fromPB damage, and on the insecticidal activity of Jatropha extracts on CBW. At the ICRISAT research station (Samanko, Mali), infestation by the five main species of PB (accounting for 96% of total) was much higher on sorghum than on cotton. In the Kolokani region, CBW infestation was negligible on the Guinea loose-panicled sorghum cultivar Bibalawili, while it was significant on both compact-panicled PB susceptible ICSH 89002 and PB resistant Malisor 84-7. At Samanko, Jatropha oil application on sorghum panicles showed some effect on PB when damage level was high, better than Jatropha and neem aqueous extracts. However, it did not compete with pyrethroid protection level. PE contact toxicity on CBW larvae was too low to determine a LC 50. Aningestion insecticidal activity of PE was found on all tested larval instars. Contact toxicity LC 50 of PE on eggs was 1.66 g ml-1. Development of larvae and reproductive ability of adults derived from new-laid eggs treated with solutions of 0.35 g ml-1 PE and above were considerably affected. Prospects for using sorghum and Jatropha extracts for cotton protection against insect pests in an assisted trap-cropping strategy are discussed

Hsp70–Bag3 complex is a hub for proteotoxicity-induced signaling that controls protein aggregation

Protein abnormalities in cells are the cause of major pathologies, and a number of adaptive responses have evolved to relieve the toxicity of misfolded polypeptides. To trigger these responses, cells must detect the buildup of aberrant proteins which often associate with proteasome failure, but the sensing mechanism is poorly understood. Here we demonstrate that this mechanism involves the heat shock protein 70–Bcl-2–associated athanogene 3 (Hsp70–Bag3) complex, which upon proteasome suppression responds to the accumulation of defective ribosomal products, preferentially recognizing the stalled polypeptides. Components of the ribosome quality control system LTN1 and VCP and the ribosome-associated chaperone NAC are necessary for the interaction of these species with the Hsp70–Bag3 complex. This complex regulates important signaling pathways, including the Hippo pathway effectors LATS1/2 and the p38 and JNK stress kinases. Furthermore, under proteotoxic stress Hsp70–Bag3–LATS1/2 signaling regulates protein aggregation. We established that the regulated step was the emergence and growth of abnormal protein oligo-mers containing only a few molecules, indicating that aggregation is regulated at very early stages. The Hsp70–Bag3 complex therefore functions as an important signaling node that senses proteo-toxicity and triggers multiple pathways that control cell physiology, including activation of protein aggregation