Influence of Some Abiotic Risk Factors on Parental Forms in Some Registered Corn Hybrids (Zea mays, L)

Abstract

Corn is one of the most important crops, and yield may be affected by risks that manifest more strongly in recent years. In hybrid seed production activity, these risks are even greater importance for breeder and for hybrid seed multiplier. Considering the risks mentioned, the objectives are to test the reaction of certain genotypes in different phenophases with manifestation of abiotic factors (low temperatures and hail). Genotypes analyzed were parental forms of hybrids homologated by ARDS Turda, and inbred lines used in the creation of hybrids. The analyzed risk factors were frost in phenophases of 5-6 leaves and 7-8 leaves, and we simulated a soft hail in 8-10 leaves and after pollination, an average hail, a “defoliation” of 50% of the leaves and “defoliation” of 80-90% of the leaves. The effect of frost was almost insignificant in first phenophase, yield losses to 8% in hybrids, and 12% in inbred lines. In the second phenological phase, low temperatures losses of 51% in hybrids, and 70% in inbred lines. Hail causes insignificant losses before pollination of 1% in hybrids and 0.5% in inbred lines. Instead total defoliation of hail, produce 71% losses in hybrids, and 70% in inbred lines. If the phenomena occurring in the later phenophases, both hybrids and inbred lines respond negatively in terms of yield, thousand grain weight, and corn cob yield. For inbred lines, negative temperatures have a stronger effect compared to hail. For both hybrids and inbred lines, hail caused a greater damage compared with frost.