EFFECT OF PLANTING DENSITY, NITROGEN FERTILIZER LEVEL AND ORGANIC MANURE RATE ON YELLOW MAIZE (Zea mays L.) YIELD AND ITS ATTRIBUTES UNDER SANDY SOIL CONDITIONS.

Two field experiments were conducted at the Agricultural Research Station, Faculty of Agriculture, Zagazig University at El-Khattara Region, Sharkia Governorate, Egypt, during two summer successive seasons (2012 and 2013) to study the effect of three plant densities (24000, 28000 and 32000 plants/ fad.), four nitrogen fertilizer levels (50, 75, 100 and 125 kg N/fad.) and three organic manure rates (check, 2.5 and 5 tons/fad.) on yield and its attributes of yellow maize (single cross 173). The results of the combined analysis revealed that low and moderate densities significantly increased ear and kernel yields/plant as well as kernel and biological yields/fad. In addition, increasing plant density more than 24000 plants/fad., significantly increased shelling %, while plant densities had no significant effect on number of ears/plant, ear diameter, ear length, number of rows/ear, number of kernels/row and hundred kernel weight. Data of the combined analysis also showed that increasing nitrogen fertilizer level from 50 to 75 and 100 kg N/fad., significantly increased number of ears/plant, ear diameter, ear length, number of kernels/row, 100 kernel weight, ear yield/plant, kernel yield/plant, ear, kernel and biological yields (ton/fad.) with the exception of number of rows/ear and shelling % (combined data). Application of organic manure up to 5 tons /fad., significantly increased ear length, number of rows/ear, number of kernels/row, hundred kernel weight, ear and kernel yields/plant, ear, kernel and biological yields/fad., as compared to other rates (combined data). The obtained data showed that maize plants received 100 kg N/fad., and 5 tons organic manure /fad., under light density (24000 plants/fad.) and medium density (28000 plants/fad.) produced the highest value of kernel yield/fad. While, under the high density (32000 plants/fad.) kernel yield/fad., was higher when 75 kg N/fad., and 2.5 tons organic manure/fad was used. [ABSTRACT FROM AUTHOR]