Haskap Preharvest Fruit Drop and Stop-drop Treatment Testing

Abstract

Haskap (Lonicera caerulea), also known as honeyberry, is a relatively new fruit crop in North America. To date, most academic activity and research in North America involving haskap has focused on cultivar development and health benefits, with relatively few field experiments providing information to guide field planning and harvest management for the recently released cultivars. In 2020, we documented preharvest fruit drop (PHFD) rates for 15 haskap cultivars planted in a randomized block design at our research center in western Montana with the aim of preliminarily determining whether certain cultivars may be prone to this phenomenon. Additionally, we evaluated two plant growth regulators (PGRs) to reduce PHFD in two cultivars previously observed to have high rates of PHFD. Results suggest cultivar-specific variations in PHFD near berry maturation. Because haskap harvest indices are not well-defined and may be cultivar-specific, we share our 1-year study results as preliminary information and as a call for further research. Cultivars Aurora, Boreal Blizzard, Borealis, Indigo Gem, Kapu, and Tana all had PHFD rates less than 12% of yield, where yield is the weight of berries lost to PHFD plus marketable yield and marketable yield is fruit remaining on the shrub at harvest. Cultivars Chito, Kawai, and Taka had the highest rates of PHFD, although marketable yields were still relatively high, especially for Kawai. We note that ease of fruit detachment is an important consideration in mechanical harvest, and this characteristic could be advantageous if managed appropriately. The PGRs evaluated (1-napthaleneacetic acid and aminoethoxyvinylglycine) did not influence PHFD rates; however, our study was limited by the sample size and by the lack of information regarding haskap abscission physiology. In summary, the haskap cultivars evaluated exhibited variable PHFD rates in the year of the study, and further research is needed to understand haskap fruit maturation, harvest indices, and abscission.

Breeding trends on blue honeysuckle (Lonicera caerulea L.)

“…Valuable new varieties have been rapidly obtained through asexual propagation techniques, and rapid propagation technique has been applied to blue honeysuckle (Kadhim et al, 2019;Podwyszyńska et al, 2022;Tab ara et al, 2022), and the research on water and fertilizer, cultivation environment and soil demand of blue honeysuckle is gradually carried out, for example, the effect of soil fertility and soil moisture on the yield and fruit quality of blue honeysuckle and a cultivation method that regulates soil fertility and water and fertilizer by means of soil mulch. In addition, the nutrient requirements of blue honeysuckle were explained by the determination of macro-and microelements in soil of different countries and regions (Bieniasz et al, 2019;Grewal, 2020;Hayes & Peterson, 2020;Leisso et al, 2021;Liu et al, 2022;Syso et al, 2021).…”