Orange, Virginia (1970): Yield was significantly improved
South Africa (1989-90): Best yield was achieved with applications at first bud break
Hebei, China (2011): Yield increase of 7.03% as compared with routine fertilization
Jilin, China (2011): Yield increase of 8.3% as compared with application of mixed fertilizer containing no zinc
Java, Indonesia (2011-12): Yield increase of 7.57%
Tennessee, USA (2004): Significant increase in yield
Tennessee, USA (1994): Treatments increased yield over the control
East Java, Indonesia (2013): Savings in fertilizer cost and rapid leaf growth compared to previous year
West Java, Indonesia (2011): Yield increase of 8-20%
Punjab, India (2003-04): Significant yield increase over the control
Norwich/Norfolk, United Kingdom (1990)
Central Java, Indonesia (2012-13)