Spot blotch is an important disease of wheat (Triticum aestivum L.) in South Asia. Division of test sites for this disease into homogenous subregions is expected to contribute to more efficient evaluation and better differentiation of cultivars. Data from a collaborative regional program of South Asia conducted by CIMMYT were analyzed to group testing sites into relatively homogenous subregions for spot blotch area under the disease progress curve (AUDPC). Five‐year data of eight locations from Eastern Gangetic Plains Nursery (EGPSN) and five locations of the Eastern Gangetic Plains Yield Trial (EGPYT) conducted in three countries (India, Nepal, and Bangladesh) of South Asia were used. A hierarchical cluster analysis was used to group locations on the basis of genotype × location interaction effects for spot blotch AUDPC. Cluster analysis divided South Asia into two broad regions and four subregions. This classification was not entirely consistent with the geographic distribution of locations, but clusters mostly followed general geographic‐climatic locations. The locations Varanasi (India) and Bhairahawa (Nepal) were identified as the most suitable sites for evaluation of spot blotch, followed by Rampur (Nepal). The major determinant for the clustering was mean temperature. The results suggest that the major wheat region of South Asia can be divided into subregions, which may reduce the cost of resistance evaluation and aid in developing wheat with resistance to this disease.

Helminthosporium leaf blight (HLB) is the most important disease constraint to wheat (Triticum aestivum L.) cultivation in the eastern Gangetic Plains of South Asia. A Helminthosporium Monitoring Nursery (HMN) including potential adapted and exotic sources of HLB resistance was developed in Bangladesh, India and Nepal to assess the stability of genetic resistance across locations. The 8th, 9th and 10th HMN assessed the HLB resistance and agronomic traits of 17 wheat genotypes across 20 environments of Bangladesh, India and Nepal in the

Sclerotinia stem rot (SSR) is a significant agricultural problem worldwide. Finding sources of resistance is crucial to the ongoing search for better management of this disease. Brassica germplasm from Australia, China and India was screened for resistance to SSR under Western Australian field conditions following stem inoculation, application of a spray of mycelial suspension, or as a consequence of myceliogenic germination originating from sclerotia resident in soil. Significant differences in response were observed among 53 genotypes using each of the three screening methods. There was a variable impact of the time of inoculation on the disease level depending upon time of assessment post-stem inoculation. However, this impact could be reduced to an insignificant level provided the assessment after stem inoculation was delayed until 3 weeks post-inoculation. The results of these studies indicate that the use of appropriate inoculation and assessment methods could significantly reduce variability in the responses commonly observed in screening for resistance in crop plants against Sclerotinia sclerotiorum.

Spot blotch, caused by Cochliobolus sativus, is considered one of the most destructive diseases of wheat (Triticum aestivum) in the warm areas of South Asia. Over the past 20 years, wheat breeding efforts in the region have improved spot blotch resistance in susceptible commercial cultivars. This study assessed resistance and spot blotch-induced yield losses in newly released wheat cultivars developed in Bangladesh since the release of the landmark wheat variety ÔKanchanÕ. Replicated field studies were conducted during the 2003 and 2004 wheat seasons at two sites: a farmer's field and a research station in a warm region of Bangladesh where spot blotch has been a serious problem. Spot blotch affected 60% of the crop and caused yield losses of from 2% to 22%. Disease severity and disease-induced grain yield reductions were less in wheat genotypes developed since 1983, with a corresponding trend towards higher yield in newly developed varieties. The level of resistance to spot blotch in the new cultivars and advanced breeding lines represents considerable progress in breeding for resistance over the past two decades.www.blackwell-synergy.com

An experiment was conducted at the Soil Science Field Laboratory of Bangladesh Agricultural University, Mymensingh during April to November, 2012 to study the combined effects of Sesbania green manure incorporation with different levels of nitrogen fertilizer on the growth and yield of BINA dhan7. There were five treatments for using Sesbania as pre-rice green manure (GM): Fallow (No GM), GM for incorporation at 40, 50, 60, and 70 days after sowing (DAS). T. Aman was planted after chopping the GM. For T. aman there were 9 treatments: Fallow plot received full dose (180 kg urea ha ) were recorded with GM incorporated at 40 DAS + 50% RDN. The N content and uptake by the grain and straw were differed significantly due to different treatments and maximum uptake was recorded with the application of 75% recommended dose of nitrogen (RDN) and green manure incorporated at 50 DAS. The overall results indicate that application of Sesbania green manure incorporated at 50 DAS in combination with 75% recommended dose of nitrogen could be considered more effective for BINA dhan7 production.