Evaluation of maize (Zea mays L.) hybrids for morphological traits and nitrogen use efficiency
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Date
2018-07
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AAU, Jorhat
Abstract
Maize (Zea mays L.) hybrids are potential genetic forms in which a
productive heterozygous variety may be retained. These are high yielder as well as
heavy feeder of nitrogen. There is a need to look in to such hybrids for higher yield,
resistance to important diseases as well as higher nitrogen use efficiency (NUE). The
present investigation was carried out to evaluate maize hybrids for morphological traits,
incidence of Turcicum leaf blight, nitrogen use efficiency and related traits and
determine the extent of genetic variation and correlation for the traits. Eleven companybred
maize hybrids were evaluated along with a hybrid check Vivek Maize Hybrid 47 in
RBD during rabi season of 2016-17 at ICR Farm, Assam Agricultural University,
Jorhat under two levels of N- fertilization.
The mean square due to genotype was significant for each of the
morphological and physiological traits under study. The comparison of mean
performance of the genotypes revealed that hybrids viz., CP 333 and NMH 666 recorded
the highest grain yield. CP 333 also exhibited higher estimates for other favourable
traits viz., ear diameter, 100 kernel weight, root volume, total plant nitrogen, total grain
nitrogen and nitrogen use efficiency. NMH 666 also exhibited high mean performance
for other traits viz., plant height, ear length, leaf area, root volume, total plant nitrogen
and total grain nitrogen. Vivek Maize Hybrid 47, NMH 731, NMH 713 and CP 838
were the earliest varieties in respect of days to 50% pollen shed, days to 50% silk and
days to 75% dry husk. High estimates of genotypic coefficient of variation (GCV) and
phenotypic coefficient of variation (PCV) were observed for grain yield per plant, ears
per plant, whole plant biomass, total plant nitrogen, total grain nitrogen, root biomass
and nitrogen use efficiency. Heritability (h2) coupled with genetic advance as percent
mean (Gs%) were high for grain yield per plant, ears per plant, whole plant biomass,
root biomass, total plant nitrogen, total grain nitrogen and nitrogen use efficiency.
Therefore, simple selection methods for improvement of these traits would be effective.
Grain yield per plant had significant and positive correlation with the traits ears per
plant, whole plant biomass, total plant nitrogen, total grain nitrogen and nitrogen use
efficiency at both phenotypic and genotypic levels. Hence, indirect selection for
improving grain yield based on correlated simple traits would be effective. No
symptoms of Turcicum Leaf Blight (TLB) were observed in the hybrids under the field
condition during Rabi season of 2016-2017.