Leaching, Phytotoxicity, and Weed Control of New Formulations of Alachlor

Abstract

The use of commercially available formulations of alachlor has resulted in a serious environmental problem due to its leaching and migration to water sources. The objective of this study was to develop organo-clay based formulations that can significantly reduce leaching and improve weed control efficacy. We adsorbed the herbicide to montmorillonite clay particles whose surfaces were modified from hydrophilic to hydrophobic by preadsorbing to the clay an organic cation, such as benzyltrimethylammonium (BTMA) to reduce release of the herbicide into the soil. Alachlor adsorption was determined by gas chromatography. Organo-clay complexes of 0.5 mmol BTMA/g of clay gave larger adsorbed amounts and better formulations of alachlor as compared to BTMA preadsorbed up to the cation exchange capacity (0.8 mmol/g), whereas formulations without organic cations were not effective and gave little adsorption of the herbicide. The use of Fourier transform infrared spectroscopy showed that the optimal formulation also yielded the largest shifts of the stretching vibrations of the phenyl ring. The organo-clay formulations yielded slow release of the herbicide to the environment, maintaining the herbicidal activity in the top soil as measured by a bioassay using green foxtail and wheat as test plants. Laboratory and field experiments showed improved weed control at significantly reduced applied rate when alachlor was applied as organoclay formulations.

A New Field Protocol for Determination of Forest Structure, Biodiversity and Heath Status by Means of GPS Tools: A Case Study from Gaza Forest

“…So far, the presented results clearly show practical application of field protocol for determining forest tree population relative density and biodiversity. These data agree with previous reports [46] and desert land. For instance, if we estimated the population of salt plants (Mesembryanthemum acinaciforme) in the coastal area, the abundance of the salt plant will be very close to the sea shore and become very rare far away from the shore due to the decline of salt concentration.…”

“…The test with Omer Al-Mukhtar street shows 7% difference which is in the acceptable range of field difference [46] [47]. Further support to our field protocol came from testing the field protocol in a protected area (Wadi Gaza) ( Figure 3) and found differences less that 5% in the planted trees such as fruit trees (olive trees, grapes, palm) but we found 19% differences in weed population in the Wadi and in urban trees (Figure 4).…”

Slow-Release Formulations of Sulfometuron Incorporated in Micelles Adsorbed on Montmorillonite

“…The pH of the soil is 7.5, carbonate content 0.0%, organic matter content 0.2%, sand 95.5%, silt 3.3%, and clay 1.2% (14). A sorghum (Sorghum bicolor) cultivar, R.S.-610 (Hazera-Quality Seeds, Israel), was used as a test plant.…”

“…A few approaches were taken to prepare controlled release formulations: formulations based on alginate (9), cyclodextrin complexes (10), formulations based on lignin (11), polymer encapsulation (12), formulations based on starch (13), and formulations based on organo-clays (14,15). These formulations were designed for hydrophobic herbicides.…”

Acute Poisoning among Farmers by Chlorpyrifos: Case Report from Gaza Strip

“…Pesticides poisoning may occur via indirect ways such as ingestion of contaminated food [1] [2] [3] [4], drinking of contaminated water [5] [6] [7], inhalation of contaminated air [8] and exposure contaminated soil [9] [10] [11] [12].…”