Conclusion
The use of Dithane D14+Zinc Sulfate and lime resulted in the highest yield, although not significantly higher than Zerlate, Parzate or Tri-Basic copper. Plots sprayed with C-O-C-S returned the lowest yield but not significantly lower than the yields from plots sprayed with Bordeaux, Phygon or DDT alone. Differences were not due to disease control since so little disease was present on the check.
Among the insecticides under test Parathion (3422) was outstanding in its control of aphids and resulted in the highest yield. Plots sprayed with BHC, DDT emulsion and wettable DDT were similar in yield and these yields were not significantly lower than the yield produced by the use of Parathion. DDT emulsion gave better control of aphids than DDT powder whereas DDT powder gave best control of flea beetles. Toxaphene caused severe plant injury and resulted in poor insect control.