Response of sorghum varieties to the ratoon cultivation 1-Growth characteristics

Abstract

Previous studies that sorghum ratoon differs in its performance when compared with the plants resulted from direct seeding and differed varieties, therefore, afield trial was conducted in spring and fall seasons of 2017 at the field of Field Crop-College of Agriculture-University of AL-Anbar (a Hernative site-Abu-Graib) to investigate the response of five sorghum varieties (Inqath, Lilo, Ishtar, Boohooth 70 and Caffier) to the ratoon cultivation. Results indicated that cultivation pattern affected most studied characters significantly. Plants of ratoon gave the highest values of number of days to the 75% flowering, number of tillers, green forage yield and less concentration of HCN (66.15 day, 21.40 tiller m−2, 8.75 t ha-1 and 54.64%), respectively compared with the direct seeding method. However, plants of direct seeding gave the highest averages of plant higher and leaf area (191.36 cm and 4910 cm2), respectively. Varieties were significantly different in their performance for all studied characters. Boohooth 70 was superior in number of days to the 75% flowering, plant height, leaf area, number of tillers, green forge yield and dry forge yield (59.75 days, 240.8 cm, 4554 cm2, 19.00 tiller m−2, 12.73 t ha−1 and 55.10%), respectively. However, Caffier gave the lowest concentration of HCN (58.67%).

Yield and Quality in Main and Ratoon Crops of Grain Sorghum Under Different Nitrogen Rates and Planting Densities

“…There are many factors leading to this difference, including greater insect, disease, and weed damages on the ratoon crop than on the main crop ( Duncan and Gardner, 1984 ; Gerik et al, 1988 ). Under suitable environmental conditions and appropriate cultivations, the yield potential of ratoon sorghum could be fully exploited ( Al-Taweel et al, 2020 ). Afzal et al (2012) suggested that a higher level of N application was needed to prevent production differences between main and ratoon crops of sorghum.…”

“…In a ratoon crop, the basal buds of the stem grow shortly after cutting the main crop ( Wilson, 2011 ). Normally, the duration of a ratoon crop is much shorter than the direct seeded crop ( Al-Taweel et al, 2020 ), providing higher resource use efficiency per unit time and per unit land area ( Santos et al, 2003 ). Therefore, ratooning of the sorghum crop is widely practiced in this region where photothermal resources exceed the demand of single-season sorghum but are insufficient for double-season sorghum ( Yin et al, 2015 ).…”