Effect of Allelopathic Water Extract of Sorghum and Sunflower on Weed Mortality and Cotton Yield

Abstract

Sorghum and sunflower have been reported to contain several allelochemicals. Utilization of these allelochemicals is considered low-cost and natural sources for weed suppression. Field trials were undertaken at Cotton Section, Agriculture Research Institute, Tandojam Pakistan during summer 2010 and repeated during summer 2011 for validating the previous results. The experiments were laid out in three replicated randomized complete block design. The seed of cotton variety "Sindh-1" was sown through drilling in the 1 st week of May each year. The treatments consisted of: weedy check (no weeding), interculturing twice (30+60 DAS), Dual Gold 960-EC (S-metolachlor) @ 2.50 L ha -1 , sorghum water extracts @ 15 L ha -1 (twice) and 25 L ha -1 (once and twice) and sunflower water extracts @ 15 L ha -1 (twice) and 25 L ha -1 (once and twice), sorghum water extract @ 15 L ha -1 +1.25 L ha -1 Dual Gold and sunflower water extract @ 15 L ha -1 +1.25 L ha -1 Dual Gold. In interculturing the land space in between two rows of crop plants was pulverized with the help of local tool spade. The statistical analysis of data showed that interculturing, Dual Gold, and sorghum and sunflower water extracts caused significant reduction of weeds and increased seedcotton yield as compared to weedy check. The combined application of sorghum @ 15 L ha -1 + Dual Gold @ 1.25 L ha -1 resulted in weeds mortality upto 66.6%, produced seedcotton yield of 3961.4 kg ha -1 and gave net benefit of Rs. 2,20,029. Sunflower applied @ 15 L ha -1 in integration with Dual Gold @ 1.25 L ha -1 showed weeds mortality of 65.5 %, resulted in seedcotton yield of 3949.7 kg ha -1 and net monetary benefit of Rs. 2,19,821. Sole application of Dual Gold @ 2.5 L ha -1 reduced weeds by 55.9%, produced seedcotton yield of 3212.7 kg ha -1 and net resulted in net benefit of Rs. 1,77,414. It is noteworthy that interculturing twice (30+60 DAS) caused maximum (67.7%) suppression of weeds, produced maximum plant height (117.0 cm) and seedcotton yield (3977.8 kg ha -1 ) but conferred less (Rs. 2,14,151) net monetary benefits as compared to obtained in sorghum + Dual Gold and sunflower + Dual Gold. Overall results suggested that maximum net income was recorded when sorghum water extract was applied in integration with Dual Gold. The combined application of sunflower with Dual Gold ranked second in monetary benefits. Interculturing twice was found less economical due to higher costs of labour. Hence, it can be inferred from the above results that Dual Gold dose can be reduced up to 50% in combination with sorghum or sunflower water extracts for effective and environment friendly weed management and enhancing cotton yield.

Sunflower Residue Incorporation Suppresses Weeds, Enhances Soil Properties and Seed Yield of Spring-Planted Mung Bean

“…The treatments with sunflower residues showed the highest suppression of weeds as compared to treatments with sunflower water extracts (Table 4). Kandhro et al (2015) and Farooq et al (2011) reported a significant reduction in weed density (25.26%) and dry weight (14.60%) resulting from the application of sunflower water extract. The highest suppression of weeds was recorded in the wheat field as a result of sunflower residue incorporation because of the release of allelochemicals as well as the reduction of light penetration (Reberg-Horton et al, 2005;Alsaadawi et al, 2007).…”

Allelopathic effects of sorghum species on weed seed germination and dry matter accumulation in different soil types

“…The allelopathic weeds contain compounds with phytotoxic ability in their aerial and underground parts like leaves, flowers, seeds, stems and roots in varying concentrations (Tesio & Ferrero, 2010). In a study by Kandhro et al, (2015) in Pakistan, sorghum and sunflower were found to have high allelopathic potential, containing several allelochemicals such as sorgoleone, glycosides, terpenoids, flavonoids, alkaloids and phenolics. Farooq et al, (2013) also found out that allelopathic compounds secreted by sunflower suppressed the germination and growth by interruption of metabolic activities of wheat plant cells.…”

“…Naeem et al, (2018) revealed that weeds reduce the quality of the crop produce and yields, as well as increase the costs of production and harvesting. Severe weed infestations in crop fields due to abundance of weed seeds in the soil greatly affects crop yields in smallholder farming systems (Kandhro et al, 2015). In Zimbabwe, weeds continue to persist in many agro-ecological regions having a wide and large weed seed bank (Chachar et al, 2009).…”

“…Hence it is important for an ecological and biological examination and evaluation of soil weed seed banks so that farmers are capacitated in weed control and management. However, allelochemicals produced naturally by some plants can help greatly in reducing weed seed populations in the soil and the costs associated with weed control (Kandhro et al, 2015). Weeds of the grass…”

Performance of Plant Aqueous Extracts for Organic Weed Management in Groundnut (Arachis hypogaea)

“…A number of secondary metabolites / allelomones produced by some of the plants act as potential natural herbicides with considerable crop selectivity, which could be directly used in the form of aqueous plant water extracts for weed management in organic and sustainable agriculture systems. The application of allelopathic aqueous extract of sorghum 25 L ha -1 twice at 15 and 30 DAS resulted in reduced weed density as compared to all other plant aqueous extract treatments in cotton grown in clay loam soils of Peshwar, Pakistan (Kandhro et al ., 2015). In this context, there is a need to evaluate the performance of different plant aqueous extracts for weed management in groundnut and their effect in soil microorganisms in sandy loam soils.…”