Effect of hierarchy of the production of tillers in wheat (Triticum aestivum L.) cultivar (KM5180) under the influence of planting dates

Abstract

Sowing dates are an important factor in determining grain yield as they fall within the climatic changes, as the temperature plays an important role in increasing the yield. For the purpose of evaluating the planting dates during the winter season, a field experiment was conducted at Experiments Station, affiliated to the Department of Field Crops/College of Agricultural Engineering Sciences, University of Baghdad during 2020-21. The aim was to study the effect of planting dates on soft wheat cultivar (KM5180). A randomized complete block design (R. C. B. D.) was used with three replications. Sowing dates were used as main parameters viz., November 22nd (D1), December 6th (D2) and December 20th (D3). The results showed the superiority of the sowing date (D1) by giving the highest average grain yield of 5.740 t/ha as a result of the superiority of the plants of this date in the number of spikes/m2 (441.7), the biological yield (17.896 t/ha), the harvest index (32.09%) and the plant height (101.387 cm) and the weight of 1000 grains/g was 39.97 g, significantly superior to dates (D2) and (D3), which gave an average of 4.423 and 2.428 t/ha, 358.3 and 331.7 spikes/m2, 14.556 and 11.353 t/ha, 30.38 and 21.39%, 89.033 and 85.387 cm and 39.11 and 28.28 cm, respectively, The reason for the superiority was due to the appropriate environmental conditions accompanying during the growth period, including the appropriate temperature that gave the products of photosynthesis sufficient to meet the requirements to complete the stages of its growth and form the initiators of its organs in an optimal form, which was positively reflected on the components of the appointment (D1). As for the delay in the dates D2 and D3, the high temperatures coincided with the critical growth stages of plant growth, which reflected negatively on some traits. 7. Sequentially a grain/spike and (11.43, 11.54 and 11.29 cm, respectively. While date D3 was significantly superior in terms of the number of spikelets/spike with an average of (16,800) spikelets/spike over dates D2 and D1, and they gave an average of (16,300 and 16,200) spikelets/spike, respectively. In the light of the obtained results, we conclude that the shares of the total dates (D2) and (D3) reached 54% higher than the contribution of the sowing date (D1), which amounted to 46%, while the late sowing date (D3) achieved half of the share of the share in the grain yield.