Littleseed canarygrass (Phalaris minor Retz.), a troublesome weed of wheat in India, has evolved multiple herbicide resistance across three modes of action: photosynthesis at the photosystem II site A, acetyl-coA carboxylase (ACCase), and acetolactate synthase inhibition.The multiple herbicide-resistant (MHR) populations had a low level of sulfosulfuron resistance but a high level of resistance to clodinafop and fenoxaprop (ACCase inhibitors). Some of the populations had GR50 (50% growth reduction) values for clodinafop that were 11.7-fold greater than that of the most susceptible population.The clodinafop-resistant populations also showed a higher level of cross-resistance to fenoxaprop (fop group) but a low level of cross-resistance to pinoxaden (den group). Although clodinafop and pinoxaden are from two different chemical families (fop and den groups), their same site of action is responsible for cross-resistance behavior. The populations that were resistant to four groups of herbicides (phenylureas, sulfonylurea, aryloxyphenoxypropionate, and phenylpyrazolin) were susceptible to the triazine (metribuzin and terbutryn) and dinitroaniline (pendimethalin) herbicides.The P. minor populations that were resistant to the aryloxyphenoxypropionate and phenylurea herbicides were effectively controlled by the sulfonylurea herbicide, sulfosulfuron. In the fields infested with P. minor that was resistant to clodinafop, a sulfosulfuron application (25 g ha -1 ) increased the wheat yield by 99.2% over that achieved using the recommended rate of clodinafop (60 g ha -1 ). However, the evolution of multiple resistance against the four groups is a threat to wheat production.To prevent the spread of MHR P. minor populations, as well as the extension of multiple resistance to new chemicals, concerted efforts in developing and implementing a sound, integrated weed management program are needed.The integrated approach, consisting of crop and herbicide rotation with cultural and mechanical weed control tactics, should be considered as a long-term resistance management strategy that will help to sustain wheat productivity and farmers' income.
Phalaris minor, the most serious weed in wheat in northwestern India, has developed extensive isoproturon resistance due to continuous isoproturon use. For its control, alternative herbicides (flufenacet, metribuzin and sulfosulfuron) at different application rates and timing were evaluated in wheat. In addition, herbicide carryover risk onto rotational crops (sorghum; maize and green gram, Vigina radiata) was also assessed. Isoproturon at 1 and 2 kg a.i. ha )1 provided only 10.5% and 51.8% P. minor control respectively. Of the other herbicides, early post-emergent [15-21 days after sowing (DAS)] flufenacet at 180-480 g a.i. ha )1 provided acceptable control of P. minor, but failed to control broad-leaved weeds and was phytotoxic to the wheat crop. Metribuzin at 210 g a.i. ha )1 was effective in controlling both Phalaris and dicotyledonous weeds. Mixtures of both flufenacet and metribuzin at reduced rates were better than flufenacet for weed control and grain yield. The efficacy of flufenacet and metribuzin was drastically reduced with later growth stages of P. minor (four to five leaf). Whereas sulfosulfuron at 25-30 g a.i. ha )1 , applied either early post-emergence (19 DAS) or post-emergence (30-42 DAS), was quite effective. Overall, sulfosulfuron was the most effective treatment with regard to weed control and crop yield. However, maize and sorghum grown in rotation after harvest of sulfosulfuron-treated wheat plots showed 65-73% crop biomass inhibition. The residual effect of sulfosulfuron was also noticed on Trianthema portulacastrum (Horse purslane), causing 73.5% dry matter reduction. By contrast, no carryover damage with flufenacet was observed on maize, sorghum and green gram. Glasshouse pot experiments and field trials investigating crop sensitivity to pre-plant applications of sulfosulfuron found the decreasing order: sorghum > maize > green gram. The risk of carryover onto rotational crops should be considered when choosing alternative herbicides for P. minor control in wheat.
Craniosynostosis is a premature pathologic fusion of one or more cranial vault sutures that leads to abnormal shape of the skull. The fused sutures lead to restricted growth in some areas and compensatory bossing in other areas. The head may assume different shapes depending upon the site and timing of the abnormally fused suture. The exact cause of this suture pathology is still unknown, but the local dura, cranial base and the fibroblast growth factors seem to influence this. The diagnosis rests on clinical examination and confirmation is generally on the computed tomography scan. The need for surgery is both for cosmetic and functional reasons. Many cases may be associated with raised intracranial pressure with its attendant deleterious effects on vision and brain. The aim of treatment is to increase the cranial volume and reshape the skull. The surgery can be safely undertaken around 9-12 months in most of the cases. The conventional management is through an open surgical approach; although, some centres have claimed impressive results with limited endoscopic techniques in selected cases. The review article deals with the aetiopathogenesis, clinical presentations and management of the common varieties of craniosynostoses seen in the Indian scenario.
The hearing loss in a cleft patient is a well known complication, but generally gets ignored. These children continue to have recurrent otitis media with effusion that affects the hearing abilities. Unfortunatley the middle ear function may not improve with palatoplasty.Cleft palate teams need to follow up all such children beginning at birth and going into adulthood, decades after a ‘successful’ palate repair. These patients should have careful otological and audiological surveillance with appropriate interventions whenever required. The review article discusses the current status of hearing management in patients with cleft palate.
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