Productivity-based assessment of tolerance to high plant density stress in tropical maize (Zea mays L.) Inbred lines and their single cross hybrids

High density planting (HDP) has been used extensively to achieve high productivity in temperate maize and the same can be exploited in tropical/subtropical maize. Based on two years field evaluation of tropical maize inbred lines under different planting regimes, this study led to identification of high plant density stress tolerant (at 30 percent higher plant population than cultural practice) high yielding maize inbreds. Leaf angle of first leaf above ear, anthesis-silking interval, cob length, and 1000 kernel weight were found directly affecting grain yield under HDP. Specific cross combinations exhibiting higher grain yield under HDP (approx. 15-20 percent), than normal planting practices, were identified. This is the first report on systematic development and evaluation of parental lines under high plant population and to generate high plant density stress tolerant hybrids in tropical maize.