تأثير مواعيد الزراعة و مراحل القطع في حاصل العلف الأخضر و نوعيته للذرة البيضاء صنف أبو سبعين : 2-المادة الجافة و نوعية العلف

Abstract EN

The study was carried out at the experimental station of the College of Agriculture in Abu – Ghraib, University of Baghdad during the period form mid, of March to end of September of 2013 to investigate the effect of sowing dates and cutting stages on dry matter and forage quality of Sorghum bicolor (L) Moench (var.Abu - Sabeen).

The Layout of the experiment was (R.C.B.D) with three replicates arranged in split- plot .

Sowing dates (16 , 30 March, 13, 27 April) were taken as main plots while cutting stages (Vegetative growth, 25%, 50%, 75% flowering) were taken as sub plots.

Results showed, that sowing dates on 30 March gave highest mean of dry matter (12.25 , 9.57 , 5.37) t.ha -1, percentage of protein in leaves (11.09, 10.83, 10.57) and stems (8.40, 8.13, 7.94) for the 1st, 2nd, 3th cuts respectively.

Delay the sowing date until 27 April resulted in significant increasment in the percentage of crude fiber in the plant (26.97, 26.66) for the1st, 2nd cuts respectively.

Cutting the plants at 75% flowering gave highest percentage and yield of dry matter, yield of each protein and fiber.

While cutting the plants at Vegetative growth gave highest percentage of protein.

it is clear that in order to obtain high dry matter it shoud be to sowing this variety on30 March and cut the plants at 75% flowering stage, while if it is interest to obtain forage with high quality with regardless to quantity of dry matter then it shoud cuts the plants at the end of Vegetative growth stage.