P. Hongthong - Program on System Approaches in Agriculture, Department of Plant Science and Agricultural Resources, Faculty of Agriculture, Khon Kaen University, Khon Kaen ۴۰۰۰۲, Thailand.
A. Patanothai - System Approaches in Agriculture Program, Department of Plant Science and Agricultural Resources, Khon Kaen University, Khon Kaen, Thailand.

Information on variations in crop yield among farmer fields in a specific area and theircausal factors is important for efficiently targeting efforts to increase production of the crop inthe target area. This study determined the yield variations and their causal factors for sugarcanegrown in the service area of a sugar mill in Northeast Thailand. Two villages with the dominantsandy and clayey soil types in the area were selected as the study sites. A questionnaire wasused to collect information on management practices and crop yields for the individual fields inthe 2012/2013 and 2014/2015 cropping seasons for 369 fields, of which 134 were planted cropand 235 were ratoon crop. A stepwise multiple regression was used in determining thesignificant factors influencing yields and their order of importance. The results show greatvariations of sugarcane yields among farmers’ fields in all crop classes, locations and years.However, their significant causal factors differed among crop classes, locations and years. Thenumber of weedings was the most frequent yield constraint identified, followed by pre-harvestburning, number of fertilizer applications and land type. Soil type, diseases and insects, cultivarand frequency of irrigation were sporadically significant. Yield influencing factors in fields atdifferent yield levels also varied, indicating the need for targeting improved management onindividual fields. A participatory approach is suggested in the design and implementation ofcultural managements for improving sugarcane yield of the individual fields.

Yield Gap, Yield constraints, Sugarcane production, Sugarcane cultivation