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HomePosts Tagged "Agricultural Research Service"
Bee keeping, North America

When Pol-line colonies and standard colonies were treated against Varroa mites in both fall and December, Pol-line bees had a winter survival rate of 72 per cent while standard bees had a survival rate of 56 per cent

Pol-line honey bees, a type of Varroa mite resistant honey bee developed by the Agricultural Research Service (ARS), are more than twice as likely to survive through the winter than standard honey bees, according to a study published in Scientific Reports.

Although ARS developed Pol-line bees in 2014, the study was the first time that they were tested head-to-head alongside standard honey bee stock in commercial apiaries providing pollination services and producing honey. Colonies’ ability to survive winter without being treated to control Varroa mites was followed in four states: Mississippi, California, and North and South Dakota.

In this study, Pol-line colonies that were given no treatment to control Varroa mites in the fall had a survival rate of 62.5 per cent compared to standard bees colonies in commercial apiaries also given no fall Varroa treatment, which had a winter survival rate of 3 per cent.

When Pol-line colonies and standard colonies were treated against Varroa mites in both fall and December, Pol-line bees had a winter survival rate of 72 per cent while standard bees had a survival rate of 56 per cent. So, Pol-line bees still had a better winter survival rate regardless of receiving double Varroa mite treatment.

This research was the culmination of breeding efforts to develop honey bee colonies with naturally low Varroa populations that began at the Baton Rouge lab in the late 1990s.

Winter colony survival is crucial for beekeepers because in February each year, about 2.5 million honey bee colonies are needed in California to pollinate almond crops. Larger, healthier colonies bring beekeepers premium pollination contracts at about $220 a colony.

Varroa mites can cause massive colony losses; they are the single largest problem facing beekeepers since they spread to the US from South East Asia in 1987. While miticides used to control Varroa exist, resistance is developing to some of them.

In addition, overall winter survival, the scientists examined the levels of viruses in Pol-line and standard bee colonies that are commonly transmitted by varroa mites.

The Pol-line colonies showed significantly lower levels of three major viruses: Deformed wing virus A, Deformed wing virus B and Chronic bee paralysis virus, all of which can cause significant problems for colonies.

When Pol-line colonies and standard colonies were

R&D

The study has demonstrated that the crop water use model MOPECO can be adapted to many different scenarios

In a collaborative work between the Agricultural Research Service (ARS) Soil and Water Management Research, the University of Castilla-La Mancha (UCLM) in Spain, West Texas A&M University, and Texas A&M AgriLife, researchers have adapted a crop model for use in the Texas High Plains to simulate crop water use and corn yield to help producers adjust center-pivot irrigation strategies and maximise profitability with limited water.

Crop producers in this semi-arid region of the Texas High Plains largely depend on groundwater irrigation. Each season, crop producers in the region evaluate how much land area could be irrigated under the pivot with limited water. Addressing this is not straightforward because producers must consider reducing irrigated areas, which influences grain yield, input costs, and the timing of the irrigation applications.

To help producers with these decisions, researchers completed a study that uses 25 years of climatic data to simulate corn production using a range of irrigation capacities, the maximum amount of water that can be delivered to an irrigated acre in a day, to evaluate water allocation strategies that could increase profitability and improve the efficient use of water. 

The model showed that for irrigation capacities representative of the region and a growing season with average rainfall, maximum profitability was achieved by irrigating about 75 per cent of entire pivot area with the remaining area in fallow or dryland cotton. Concentrating water generated greater net returns because of lower seed and fertiliser costs and greater corn yields that compensated for lack of production in fallow areas. In years with seasonal drought, the irrigated area would need to be further constrained to avoid crop failure and maximise profits.

“This study has demonstrated that the crop water use model MOPECO can be adapted to many different scenarios and is a useful tool for improving the environmental and economic sustainability of agricultural systems where water is limiting,” said Alfonso Domínguez researcher of the Centro Regional de Estudios del Agua (CREA) of UCLM.

The study has demonstrated that the crop