The effect of different farming procedures and plant density on the quantitative and qualitative characteristics of some varieties of corn

To investigate the effect of different farming procedures and plant density on the quantitative and qualitative characteristics of some varieties of corn, an experiment was conducted in Qarakhyl Agricultural Research Station in Mazandaran in 1389. The study was carried out in 4 replications following the vertical, split-plot factorial and random-full-block designs. The factors analyzed in this study included: the types of the farming procedures applied at three levels (non-plow, minimal-plow, and conventional plow), three levels of density (65,000, 75,000, and 85,000 plants per hectare), and the corn variety at three levels (DC370, SC500, and SC540). The characteristics investigated in the experiment included: the height of the plant, the tassel length, the stem diameter, the grain length, the grain yield, the harvest index, 1000-grain weight, dried-root weight, and the protein. The results indicated that the farming systems significantly influenced dried-root weight, the harvest index, the grain length, and the grain protein at P< 0.05. The highest and lowest dried-root weights were obtained from the minimal plow (rotary) and conventional plow (plow and disk) systems respectively. The maximum grain yield was observed in the plant density of 65,000 per hectare (5.64t/ha) and the minimum yield was obtained from the plant density of 85,000 per hectare (4.58t/ ha). Similarly, the highest and lowest 1000-grain weights were respectively obtained from the plant densities of 65,000 and 85,000 per hectare. The interaction effect of plow and density (plow × density) on all of the characteristics was significant at the probability level of 5%. The highest and lowest grain yields under this interaction effect were respectively obtained from the minimal-plow system with 65,000 per hectare plant density (5.80 t/ha) and the non-plow system with 85,000 per hectare plant density (4.33 t/ha). The interaction effect of plow, density, and variety on all of the characteristics was significant at P< 0.05. The highest and lowest grain yields under this interactive effect were obtained from the minimal plow system with the density of 75,000 plants per hectare and Sc540 (7.54 t/ha) and the non-plow system with the density of 85,000 plants per hectare and Dc370(2.07 t/ha) respectively.