Successes and Challenges of Precision Application of Fumigants in Cotton

Successes and Challenges of Precision Application of Fumigants for Control of Nematodes in Cotton

Research conducted in Louisiana and Arkansas the past 10 years demonstrated that root knot nematodes cause more damage to cotton and subsequent greater yield reductions in low-density soils than in heavier clay soils. No obvious yield reductions were obtained on some soils in spite of the presence of nematode populations previously considered to be “extremely” damaging.  The areas of responsive and non-responsive soils were best represented by the deep electrical conductivity values, as obtained using the Veris 3100 EC Mapping Cart.  Thus, yield response is more related to nematode populations in conjuction with soil texture than nematode populations alone in many field situations. 

Veris EC data is now being used in several states to map low-density, or “responsive”, soils in root knot nematode infested fields.  GPS guided, precision application equipment can then be used to apply Telone only to those responsive areas resulting in lower input costs (often 30 – 40%) and greater profitability for the grower.  The results are not as well defined for reniform infested fields, thus species composition must be taken into account. 

Site specific application of Telone is not an exact science, but we are rapidly increasing our experience and ability to interpret results.  A grower must have a yield monitor on the picker to determine the effectiveness of the management decisions.  In addition, there must be effective communications between software, hardware and equipment manufacturers / dealers.