Effect of different doses of glyphosate applied through rope-wick applicator for the control of Sorghum halepense L. growing in pomegranate (Punica granatum L.) orchards

Abstract

A field experiment was carried out in Diyala province/Al-Muqdadiya district during growing season of 2016–17. The aim of the present study was to control Sorghum halepense L. growth in newly planted pomegranate orchards by using glyphosate and two application methods-first by knapsack spryer in rate (4.8 kg a. i./ha) and the second use of ropewick wiper technique in different rates (1 l herbicide diluted with water from 1–6 l) parts of herbicide to water (h: w) treatments. The experiment was set out as factorial design in randomized complete block design (CRBD) with three replicates. Total eight treatments of glyphosate were used in this study. In the first control treatment (C1), only water without glyphosate. The second treatment (C2) contained 1 litre glyphosate in 1 litre of water. The third treatment (C3) contained 1 litre glyphosate in 2 litres of water. Likewise, C4, C5, C6 and C7 treatments contained 1 litre glyphosate in 3, 4, 5 and 6 litres of water, respectively. In eighth treatment (C8), herbicide glyphosate @ 4.8 kg a. i./ha was sprayed with a knap sack pressure sprayer. The results showed superiority treatment C2 1: 1 (h: w) gave high degree killing up (7.69), degrees (in a scale of 1 to 10) and treatment C2 1: 1 (h: w) and C3 1: 2 (h: w) gave average less effect in percentage of regrowth got 6.44 and 6.88, respectively, and gave time periods 90 and 120 days after control high degree killing up 8.07 and 8.34 and reduced average percentage of regrowth after control 120 and 360 days got to 6.45 and 6.78, respectively, and method application rope-wick wiping gave less effect in tree pomegranate compared with sprayer. Moreover, the efficacy of glyphosate in weed continued until 360 days after control. The treatment C4 1: 3 (h: w) gave significantly less plant height (35.66 cm) and rhizome (37.33 cm). Significantly less foliage dry weight of rhizomes (92.21 g/m2) was recorded under treatment C2 1: 1 (h: w) as compared to treatment C8 (4.8 kg a. i/ha).