Abstract:

The aim is to guide the field production of different summer maize plant types. The horizontal variety ‘Ludan981’ and compact variety ‘Ludan818’ were selected as the test materials, three different planting densities (D1, 30000 plant/hm ²; D2, 60000 plant/hm ²; D3, 90000 plant/hm ²) were set up, the effects of planting densities on the yield, leaf area duration (LAD), leaf area index (LAI), and net assimilation rate (NAR) of different summer maize plant types were studied. The results showed that the yield of ‘Ludan981’ and ‘Ludan818’ was the highest at D2 (11452 kg/hm ²) and D3 (13024 kg/hm ²), respectively. Under D3, compact variety ‘Ludan818’ had a higher LAD [452 (m ²·d)/m ²] and proportion after flowering (50%), ear LAI and NAR during whole growth period [6.87 g/(m ²·d)]. The above results indicate that compact variety has a more compact canopy, leaves in the middle and lower layers intercept more light, which could extend the LAD and contribute to the dry matter accumulation and yield increase. Thus, the variety is more suitable for high density cultivation.

Key words: summer maize, plant type, planting density, canopy characteristics, yield