Natural occurrence of fumonisins B1 (FB1) and B2 (FB2), a promoter for hepato-carcinogenesis, was investigated in corn and corn - based products sampled in Japan, Nepal, and China by high - performance liquid chromatographic method. From the 9 imported corn kernel and 6 gluten feed samples, FB1 was detected in 8 corn (0.6 ∼ 4.1μg/g) and all gluten feed (0.3 ∼ 2.4μg/g) samples, while FB2 was found in the same corn (0.3 ∼ 10μg/g) and 3 gluten feed (0.8 ∼ 8.5μg/g) samples. ELISA analysis also revealed the contamination of aflatoxin B1 in 2 corn and all gluten feed samples along with fumonisins. Of 17 corn grit samples, 14 and 5 samples were contaminated with fumonisin B1 and B2, with maximum levels of 2.6 and 2.8μg/g, respectively. As for corn-based foodstuffs marketed in Japan, no significant contamination of fumonisins was observed. Among 24 corn kernel samples in Nepal, 12 and 7 samples were positive for FB1 and FB2, and averaged to 0.6 and 1.6μg/g, respectively. One sample showed the highest fumonisin contents as 4.6 and 5.5μg/g, respectively. In corn samples harvested at Shanghai and Beijing, China, FB1 and FB2 were detected in various concentrations. Mycological survey has also revealed the presence of a fumonisin - producing fungus in a crop field of Japan. These findings have for the first time demonstrated high levels of contamination of fumonisins in corn and corn - based products in Asian countries. Natural co - occurrence of fumonisins and aflatoxin B1 was also detected in raw materials for mixed feed.

To verify and up scale promising cold tolerant rice genotypes in the western hills, participatory variety selection (PVS) activities viz; coordinated farmer's field trials (CFFTs), FFTs prepared from Lumle , farmers' acceptance tests (FATs), larger plot demonstrations, and upscaling activities were conducted during 2008 to 2009. Yield and yield related parameters considering farmers' preferences were also recorded and analyzed for PVSs under FATs. In 2008, genotypes NR10481-B-11-1-1-1, NR10479-B-33-2-1-1 and NR10482-B-10-3-2-2 had been preferred by farmers because of high grain yield and desired parameters. In 2008, grain yield of Machapuchhre-3, Chhomrong Dhan, and Lumle 5-2 over yielded Farmers' Local (2.2 mt/ha) by 83, 89 and 81%, respectively whereas in 2009, grain yield increment of Machapuchhre-3, Chhomrong Dhan, Lumle-2, and Chandannath-3 over Farmers' Local (2.1 t/ha ) was 98 %, 97%, 1078% and 49 %, respectively. Farmers of upper high hills (>2000-m) and high hills (1500-2000-m) preferred Chandannath-3, Machapuchhre-3, and Chhomrong Dhan while Lumle-2 was liked by farmers of mid hills (1000-1500-m )

A study was carried out using three maize genotypes with three levels of nitrogen (30 kg, 60 kg and 120 kg per hectare) during the summer season of 2010 and 2011with the aim of predicting maize (Zea mays L.) yield through the Normalized difference vegetation index (NDVI). The NDVI was recorded at different times throughout the growing season using a Greenseeker™ handheld sensor. Significant effect of genotypes and nutrient levels on the NDVI was observed at different growth stages of maize. There was positive correlation between the NDVI and grain yield. In the first season, the correlation coefficients were 0.90, 0.92, 0.76 and 0.73, respectively at 15, 45, 75 and 110 days after seeding. In the second season, the correlation coefficients were 0.80, 0.92, 0.77 and 0.75 respectively at 15, 45, 75 and 110 days after seeding. The NDVI based N calculator showed that irrespective of genotypes, yield potentials under farmers' levels of nutrient management were almost half of the recommended doses of nitrogen. The amount of N to be top dressed decreased with increased crop duration. Grain yield varied significantly due to season, genotypes and nutrient levels. NDVI was affected due to season, stages of the crop (DAS), genotypes and nutrient levels. Interaction effects were significant for season x genotype, growth stage x genotype, growth stage x nutrient levels, genotype x nutrient levels and genotype x growth stage x nutrient levels. There was a strong positive correlation between NDVI and grain yields of hybrid maize at 15 and 45 DAS, but this correlation declined thereafter. This means that N top-dressed at or after 75 days of seed sowing will not increase grain yield as significantly as N applied earlier in the season. In contrast, topdressed N was producing significant effects on the open pollinated Rampur Composite even after 75 days of seed sowing. Further confirmation of the finding could be useful for top dressing N in the maize crop. Agronomy Journal of Nepal (Agron JN) Vol. 3. 2013, Page 82-88 DOI: http://dx.doi.org/10.3126/ajn.v3i0.9009

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