In Huai Teecha village in Northern Thailand, local cowpeas were grown on acidic low phosphorus soil without stress symptoms. Arbuscular mycorrhizal fungi from this system have been found to promote growth of many crops but there is no information about their benefit in cowpea. In a field experiment, three improved cowpea lines (ITD-1131, Ubon Ratchathani and IT90K-227-2) and a local line (Teecha 1) were grown in 3 farmer's fields on acid low P soils. Roots of the cowpea lines were all heavily colonized by the fungi and their leaf P was within the sufficient range. In a pot experiment, the cowpea line Ubon Ratchathani was grown in acidic and non acidic (pH 5 and 6.7, respectively) soil with three rates of phosphorus (50, 104 and 141 mg phosphorus pot-1) with and without arbuscular mycorrhizal fungi inoculation. Total dry weight of inoculated cowpea was not affected by soil acidity while it was depressed in un-inoculated plants. The fungi increased total dry weight at 50 and 104 mg phosphorus ha-1 but had no effect at 141 mg phosphorus pot-1. Therefore, the fungi had been shown to enhance P uptake by cowpea roots, which resulted in direct benefit to cowpea growth in acidic low P soil.

Nitrogen (N) is commonly applied in rice crop production for improving grain quality and productivity. This experiment aimed to evaluate how applying N fertilizer affects the concentration of 2-Acetyl-1-Pyrroline (2AP), the major fragrant compound in rice grains, between two selected rice varieties with high yield potential and fragrant scent, Pathum Thani 1 (PTT1) and RD22. Rice plants were grown in pot conditions and N fertilizer was applied in three rates at 2.44, 3.82 and 5.66 g N/pot designated as N1, N2 and N3, respectively. Rice samples were harvested at maturity and evaluated for grain yield, grain N and 2AP concentration. The results revealed that grain yield and concentration of N and 2AP were affected by N rates differently between the varieties; RD22 had higher grain yield and the concentrations of N and 2AP than PTT1 with all N rates. Grain N concentration in both varieties increased when increasing N rates. There was highly positive correlation between grain N and grain 2AP concentration among the N rates and varieties. We conclude that applying N in rice cultivation not only improves productivity but also enhances the quality of rice grains by improving the concentrations of N and 2AP, the magnitude of the effect depending on the rice variety.

This paper studied the monthly seasonally-adjusted surface temperature patterns in Southeast Asia from 1973 to 2008. The study area comprised 40 regions of 10° by 10° grid-boxes in latitudes 25°S to 25°N and longitudes 75°E to 160°E. The data were fitted with a second-order auto-regressive process to reduce auto-correlations at lags 1 and 2 months. Factor analysis was used to account for spatial correlation between grid-boxes, giving six contiguous layer regions that extended beyond the original study area to form larger regions. Exploration extended from latitudes 35°S to 25°N and longitudes 65°E to 160°E. Multivariate linear regression models were then fitted to data within these larger regions. Temperatures were found to have increased in all regions, with the increases ranging from 0.091 to 0.240°C per decade.