clustering

To study 38 corn hybrids, an experiment based on randomized complete blocks design with three replications at the Moghan and Karj was carried out during the 2020 cropping season. The results showed that there was a significant difference between corn hybrids for grain yield, grains per ear, ear length, rows per ear, 1000-grain weight, ear diameter, and grain depth. Hybrid No. 26 (KLM81027 × K47/3) with the highest yield and ear length was identified as the best hybrid. The correlation between grain yield with grain depth and 1000-grain weight was significant. The heritability value was between 19.01% (grain yield) and 87.59% (row per ear). The regression analysis indicated that rows per ear and ear diameter had positively related to grain yield. Cluster analysis with grain yield, grains per ear, ear length, rows per ear, 1000-grain weight, ear diameter, and grain depth of 38 corn hybrids classified into four different groups, one of which has a hybrid of No. 26 (KLM81027 × K47/3), and No. 37 (TWC647) was the most desirable groups. In addition, hybrids No. 4, 9, 13, 15, 19, 20, 23, 25, 32, 37, and 38 were identified as superior and stable hybrids for cropping in warm dry climates. As a result, it seems that corn hybrids of FAO 600 can be suitable for cropping in warm dry climates, alsothe K74/2-2-1-4-1-1-1 × K3640/3 hybrid was identified as superior and stable.

One of the main approaches to control and prevent the aquifers from contamination is to identify the critical contaminated areas in relation to the water application. Most of the researchers considered only one type of contamination or one type of water application. In this research, using cluster analysis and water application, a multi-parameter groundwater quality classification map is developed. Three water quality parameters including arsenic, total suspended solids, and nitrate for three different applications including agricultural, industrial and drinking purposes are used to develop a classified contamination map for an aquifer in central Iran, Qazvin aquifer. The optimal number of clusters is five and it is determined using Davies-Bouldin Index. Based on the standard of World Health Organization for drinking water and considering the three selected quality parameters, the results show that the most suitable class of the aquifer, Class C1, with 22 percent of total area is mostly in northern areas of the aquifer with minimum human activity. In central areas with increase in industrial and agricultural activities, the lower classes, C4 and C5, with 35 percent of total area are appeared.