There was big hopes that streptomycin and oxytetracycline which is frequently used with human diseases, would prove to work as well in citrus to fight HLB (citrus greening). Here are the results after approximately a year worth of use of the two bactericides to prevent/kill HLB........ 49 percent of growers said it did nothing to increase crop yields. 21 % of growers reported that they did not know if it actually helped. 30% of growers said it increased yields, but they had no control to compare.