Sweet maize differs from maize of standard grain quality by many important traits that affect the ear appearance, and especially by traits controlling taste. The ear appearance trait encompasses the kernel row number, configuration, row pattern (direction and arrangement), seed set, kernel width and depth, ear shape and size. The quality of immature kernels is controlled by genes by which sweet maize differs from common maize. In order to obtain high-ranking and high-quality yields, it is necessary to provide the most suitable cropping practices for sweet maize hybrids developed at the Maize Research Institute, Zemun Polje. The adequate sowing density is one of more important elements of correct cropping practices. The objective of the present study was to determine the effect of four sowing densities in four ZP sweet maize hybrids of different FAO maturity groups on ear qualitative traits and yields obtained on chernozem type of soil in Zemun Polje. The observed traits of sweet maize (ear length, kernel row number, number of kernels per row, yield and shelling percentage) significantly varied over years. The higher sowing density was the higher yield of sweet maize was, hence the highest ear yield of 9.67 t ha-1 , on the average for all four hybrids, was recorded at the highest sowing density of 70,000 plants ha-1. The highest yield was detected in the hybrid ZP 424su. The highest shelling percentage (67.81%) was found in the hybrid ZP 521su at the sowing density of 60,000 plants ha-1. Generally, it can be stated that sweet maize hybrids of a shorter growing season (FAO 400) could be cultivated up to 70,000 plants ha-1, while those of a longer growing season (FAO 500) could be grown up to 60,000 plants ha-1. In such a way, the most favorable parameters of yields and the highest yields can be obtained.
Effect of elevated CO2 and high temperature on seed-set and grain quality of rice