MAIZE GENOTYPES IDENTIFICATION VIA TDM AND HI

Abstract

Two experiments were conducted on the farm of the Dept. of field Crop Sciences, College of Agric. , university of Baghdad . Those to investigate to what extent that grain yield of maize is counting on total dry matter (TDM) and harvest index (HI) to be used in breeding . The first experiment include three population densities ( 47619 , 71429 , and 142857 ) plants /ha. Resulted from (30×70),(20×70) and (10×70)cm between plants and rows respectively (The main treatments) whereas the sub treatments were six maize cultivars; talar, ezz, B-106 , 5012 –all synthetics, hybrids 5052 and 3001 .the randomize complete block desine with three replication was used . The second experiment involved three levels of N ; 160 ,320 , and 480 kg /ha. as main – plots and same cultivars as sub – plots using the same design . each experiment were planted for three seasons fall 1998 and spring and fall 1999 . The data obtained showed that hybrid 3001 gave higher grain yield in the first experiment , it gave 127.4,61.27 and 112.6 g/plant for the three seasons of the experiment . However ,the same hybrid gave TDM of 222, 146.6 and 203 g/plant for same three seasons ,respectively .This led to give HI values of 58% ,42% and 55% , respectively . Lower planting density gave higher grain yield /plant ;they were ; 133.9 , 52.36 and 116.46 g/plant , respectively .Adding 320 kg N /ha gave grain yield /plant 128.55 and 109.72 g for both fall seasons . The hybrid 3001 gave grain yield of 127.4 , 60.83 , and 112.11 g / plant according to N levels ; 160 ,320 , and 480 kg N /ha respectively . This implies that source – sink relationship was well balanced . We concluded that we can select maize plants of higher partition when they give higher TDM .This should be accompanied with TDM accumulation through anthesis from vegetative plants to reproduction to improve HI