Pollination is essential in the production of many agricultural crops. Insufficient pollination can lead to reduced yield and lower harvest quality in many fruit and vegetables. Recent declines in insect pollinators and the use of cultural systems where compatible pollen is limiting have caused pollen-related production problems in many crops. Supplemental mass pollination (SMP) may be beneficial in such cases. However, the high cost of pollen may prohibit its use unless pollen is efficiently and uniformly applied. Our objective was to evaluate the feasibility of using selected dry particulate materials as pollen diluents for SMP. Viability was assessed in apple pollen mixed and held with selected powders (i.e., two formulations of Rilsan® nylon, polyester resin, diatomaceous earth, wheat flour, and CaCO3). Also, an assessment of inhibitory substances was made using in vitro germination tests with extracts obtained from liquid suspensions of the different particulates. Several powders, viz., Rilsan® nylon formulations, polyester resin, and wheat flour were identified as nontoxic to pollen held for 1 h as dry pollen: particle mixtures. Likewise, leachates from these diluents had no significant effect on pollen germination. Diatomaceous earth exhibited slight, but statistically significant, inhibitory effects on germination, while CaCO3 completely inhibited germination. The morphology and size of particulates were evaluated using scanning electron microscopy and will be discussed vis-a-vis pollen dispersion and metering requirements.
If the inline PDF is not rendering correctly, you can download the PDF file here.