Factors affecting production of Chinese Chestnut in Xinxian County, Henan Province, China

Chestnuts, Castanea mollissima Blume, are an important non-wood forest prod uct in XinXian County, Henan Province, China. As part of an effort to impro ve capacity to reduce crop losses caused by insects and other damaging fact ors, a monitoring system was established in four orchards representing vari ous ages, growing conditions and management practices. Monitoring consisted of periodic observations of the condition of chestnuts through a portion o f the 2000 season on sample trees. Resulting data were summarized into life tables. The monitoring indicated that less than 50% of the chestnut burrs present o n the trees in early July survived to harvest. Missing burrs were the highe st cause of chestnut loss in three of the four orchards sampled. This may i n part be the result of chestnut burrs aborting because of insect attack, s pontaneous abortion or early maturation of chestnuts. Losses that could be directly attributed to insects ranged between 12.75 and 28.58%, caused main ly by several species of caterpillars that bore into chestnuts. Occurrence of "empty burrs" was roughly equal to insect damage levels in two orchards that did not receive a supplemental boron fertilizer treatment at the time of flowering. Based on monitoring data obtained during the 2000 growing season, opportuni ties to increase chestnut production in XinXian County include application of boron to increase nut set and development of an Integrated Pest Manageme nt (IPM) system with emphasis on management of lepidopterous borers.