Plant Impact posted lower revenue and a bigger loss for the first half, but the crop productivity and organic pesticides firm is convinced it still presents investors with a "buying opportunity".Revenue dropped 34% to £638,409 due to weather conditions in North America, economic problems in Spain and delays in regulatory approval of natural pest controller BugOil in the UK and the US. Last year's number also included a £500,000 BugOil licence milestone payment.Crop nutrient revenue jumped 36% from £469,554 in the six months ended 30 September to £638,409 this time, though the loss before tax grew to £1.17m from £889,327 in 2009"Turnover for the current year will be lower than we originally anticipated but we remain confident in the overall outcome for the year," chairman Martin Robinson said. Second half sales always increase he told ShareCast.A few of the big industry guys have been "sweeping around", the company added, but it's determined not to be "taken over on the cheap".Key to the near term performance will be trials on the use of Plant Impact's CaT and PiNT technologies with Syngenta and Arysta.