Options for delivering pesticides in melons post emergence are generally limited to spraying due to their viney growth habit. Injecting soil applied pesticides sufficiently close to the root zone for effective uptake with knife injectors in not possible without clogging equipment or causing crop injury. Several years ago, we investigated the use of an alternative device for delivering liquid chemicals post emergence called a point injection system. Point injection systems were developed in the late 1980’s as a method for applying ag chemicals post emergence with minimal root damage and soil disturbance.  These systems utilize hollow, pointed tips attached to a rotatable wheel to inject liquid products into the root zone at precise intervals and depths (Fig. 1).  Point injection technology has been used primarily as a fertilizer applicator in wheat and corn, however the system also has potential to improve the efficacy and usefulness of soil applied pesticides since it can be used to apply product to mature plants without damaging plant roots or causing crop injury.

In the fall of 2014, in cooperation with Mark White, Bayer CropScience, we tested a point injection system with Sivanto in cantaloupe. Traditionally, the product is soil applied at planting. The objective of the project was to determine if the technology can be used to apply Sivanto after plants have emerged to extend the window when the pesticide can be soil applied. Treatments included applications of 1) Sivanto at planting, 2) Scorpion 35SL at planting, 3) Sivanto post-emergence, 4) Scorpion 35SL post-emergence and 5) a combination of Scorpion 35SL at planting plus Sivanto post-emergence (Table 1). The target pest in these trials was whitefly. Results of the trials in Table 1 showed that use of point injection significantly reduced adult whitefly populations by about 2/3rds 6 (DAT) (45 DAP) as compared to other treatments. At the end of the trial, 24 DAT (63 DAP) cucurbit yellow stunting disorder virus (CYSDV) was about 25% lower. This was a 1-year trial and so conclusions should be considered preliminary, but the results do show good promise for late season soil application of Sivanto.

Over the years, we have conducted trials with point injection systems applying fungicides in cotton (Siemens, 2016, unpublished data) and fertilizers in broccoli, iceberg lettuce and romaine lettuce with improved pesticide efficacy, nutrient use efficiency and higher crop yields as compared to conventional application methods (Siemens and Gayler, 2016). Point injection systems are commercially available from several manufacturers. The Ag Mechanization Extension Program at the Yuma Ag Center has a commercial 4-row unit that is available for field demos. If anyone is interested, please contact me.

References
Siemens, M.C. & Gayler. R.R. (2016). Alternative systems for cultivating and side dressing specialty crops for improved nitrogen use efficiency. ASABE paper No. 162456725, pp. 9. St. Joseph, Mich.: ASABE.

You can link article to here - https://arizona.pure.elsevier.com/en/publications/alternative-systems-for-cultivating-and-side-dressing-specialty-c