Haskap (Lonicera caerulea L.) Response to Plastic Mulch Colours and Fertility Amendments

Abstract

Haskap (Lonicera caerulea L.) is a new berry crop in Canada. Crop growth and productivity largely depend on soil and plant microclimate conditions. Therefore, this study was conducted to determine the effect of plastic mulch colours (Black and White) and fertility amendments levels (Control, Low, High) on flowering, growth, yield, and total soluble solids (TSS) of three-year old haskap under irrigated conditions. Treatments had no significant effect on flower timing, flower number, fruit set, or yield after one year. However, delaying harvest for one week significantly increased 100-berry-weight and TSS, and reduced berry number per bush. The absence of significant response to fertility treatment likely due to adequate background soil fertility. Compared with White plastic, Black plastic had statistically higher mean soil temperature (during the growing season) and lower reflected photosynthetically active radiation but differences did not produce biologically significant changes in growth, flowering or yield. To have a better understanding of the effects of plastic mulch colours and fertility amendments on haskap under irrigation, further studies need to be performed beginning at haskap establishment on lower fertility sites and without wood mulch.