The major objective of this study was to assess grain yield and its components in some genotypes of maize under different levels of drought stress. Therefore, eight medium maturity hybrids of maize were evaluated using a split-plot arrangement in randomized complete block design with four replications in three stress (the vegetative, reproductive and grain filling phases) and normal conditions, at the Agricultural Research station of Miando'ab, West Azerbaijan, North West of Iran. Some phenological and morphological characteristics were recorded during cropping season. Analysis of variance and mean comparisons revealed that yield loss due to drought stress at vegetative growth phase recorded highest role in crop yield reduction comparing to other stress media. The analysis of variability parameters revealed presence of substantial variability for all traits. The phenotypic correlation coefficients unfolded positive and significant associations of grain yield with 300-kernel weight, kernel girth, kernel rows/ear and kernels/row, at normal conditions. The maturity traits recorded significant and negative correlation with yield, at stress prone conditions. The path analysis revealed that the most important direct effects on grain yield are number of kernels/row, ear length, ear girth and kernel rows/ear thus, should be used as target traits for tailoring an ideal plant type for higher yield of maize exposed to drought stress at vegetative period. According to the results, at drought condition, anthesis to silking interval, days to silk emergence, green cover percentage and much more kernel number in row are major traits which recommended for selecting drought tolerant hybrid varieties of corn.

Abiotic stresses --- drought tolerance --- path analysis --- maize (Zea mays L.)

Nine advanced tropical sweet corn (Zea mays L. saccharata) inbred lines were evaluated to determine their performance, to estimate broad-sense heritability of the traits measured and to determine phenotypic correlations among the traits. The inbred lines showed a wide range of performance for husked fresh ear yield and its components. Based on performance and earliness, inbred lines Bakti-1-S₇, TSS Melaka-S₅, Thailand-S₆, MM x Indonesia-S₄ and Manis Madu-S₇ were found to be superior and could be short-listed for further testing for general and specific combining ability analysis towards development of hybrid varieties. Broad-sense heritability (h²_B) estimates obtained from the variance components method were found to be high for number of days to silking (80.5%), plant height (79.9%), number of days to tasseling (66.9%) and ear height (63.7%), moderate for husked ear yield (56.7%), total soluble solid concentration (54.2%), number of kernel rows per ear (53.9%), ear diameter (46.7%), dehusked ear yield (43.1%), number of kernels per row (42.6%) and number of ear per hectare (34.5%), while lowest estimates for dehusked ear length (12.9%) and husked ear length (0.3%). Traits found to be highly correlated with husked ear yield were dehusked ear yield (0.97), number of kernel rows per ear (0.71), plant height (0.69), husked ear length (0.67), ear height (0.66), dehusked ear length (0.63), ear diameter (0.55), number of kernels per row (0.50) and number of ears per hectare (0.49). For selection purposes, it is therefore suggested that emphasis should be given on traits like number of kernel rows per ear, plant and ear height and ear length for yield improvement among the inbred lines.

heritability --- inbred line --- Zea mays L. saccharata --- correlation