Northern Highbush Blueberry Cultivars Differed in Yield and Fruit Quality in Two Organic Production Systems from Planting to Maturity

Abstract

<jats:p>Northern highbush blueberry (<jats:italic>Vaccinium corymbosum</jats:italic> L.) cultivars were evaluated from planting (Oct. 2006) through 2014 in a certified organic research site in Aurora, OR. The treatments included cultivar (Duke, Bluecrop, Reka, Bluejay, Bluegold, Draper, Legacy, Liberty, Ozarkblue, and Aurora), amendment-mulch [“compost + sawdust” (included preplant amendment and a surface mulch of either an agricultural on-farm crop waste compost or yard-debris compost and sawdust), and “weed mat” (no preplant amendments but with a sawdust mulch topped with weed mat)]. Adding on-farm compost as a preplant amendment and as part of the mulching program increased soil pH from 4.9 to 6.9, organic matter content (OM), and calcium (Ca), magnesium (Mg), and potassium (K) levels compared with the weed mat treatment. The reduced plant growth and yield in some cultivars grown in the compost + sawdust treatment was likely due to the higher soil pH. ‘Bluegold’ and ‘Draper’ were among the cultivars with consistently high flower bud set (40% to 57%), whereas others had consistently low values (e.g., 22% to 45% in ‘Bluecrop’). The number of flowers per bud was affected only by cultivar. There was no effect of year or amendment-mulch treatment on percent fruit set which averaged 93% during the study; however, ‘Ozarkblue’ had a significantly lower fruit set (88%) than only ‘Aurora’ (96%). Berry weight was affected by year (plant age), cultivar, and amendment-mulch treatment. ‘Ozarkblue’ produced the largest berries. Type of amendment-mulch had little effect on berry weight, except in ‘Ozarkblue’, ‘Aurora’, and ‘Reka’ where plants grown with weed mat produced larger fruit than those grown with compost + sawdust. On average, ‘Bluejay’, ‘Draper’, and ‘Liberty’ fruit had the highest percent soluble solids (TSS) and ‘Ozarkblue’ the lowest. Fruit harvested from plants grown with weed mat were firmer than when compost + sawdust was used. ‘Draper’ fruit were much firmer than those of the other cultivars in all years of the study. The number of flower buds per plant multiplied by the number of flowers/bud and berry weight (cultivar specific) and average fruit set was a good predictor of yield in young plants. Yield per plant increased from the second through seventh growing seasons as plants matured in all cultivars except for ‘Duke’ which had the greatest yield in 2014. Cumulative yield was highest in ‘Legacy’ and lowest in ‘Bluejay’ and in ‘Draper’, which had relatively low yield when plants were young. Most cultivars had greater yield when grown with weed mat, whereas ‘Bluegold’ and ‘Liberty’ were unaffected by amendment-mulch treatment. Because weeds were managed in all plots, the cultivar response to amendment-mulch was likely a reflection of sensitivity to preplant amendment with on-farm compost and the resulting higher soil pH. It is possible that the cultivars differed in their adaptability to the various fertility regimes caused by the amendment-mulch treatments and fertilizers used in our study.</jats:p>

Amending Sandy Soil with Biochar Promotes Plant Growth and Root Colonization by Mycorrhizal Fungi in Highbush Blueberry

“…This coating adds hydrophilicity, redoxactive moieties, and additional mesoporosity, which strengthens biochar-water interactions and enhances nutrient retention. However, compost is often high in pH and electrical conductivity and, therefore, can be unsuitable for blueberry (Costello et al, 2019;Strik et al, 2017;Sullivan et al, 2014).…”

Canopy spray deposition and related mortality impacts of commonly used insecticides on Drosophila suzukii Matsumura (Diptera: Drosophilidae) populations in blueberry

“…Plant height and diameter were 2 ± 0.1 and 1 ± 0.1 m, respectively. The blocks were managed based on industry‐standard practices for pruning, irrigation and fertilization in both years . The application row was divided into three subplots, each of which consisted of six individual plants, giving a total of 18 plants in the row.…”

Mulching as a cultural control strategy for Drosophila suzukii in blueberry

“…Together, these effects can increase fruit yield and quality. For example, blueberry plants of various cultivars grown on a black weedmat mulch produce higher yields and larger berries than plants grown on sawdust without weedmat . Additionally, weedmats can improve sanitation, as fallen fruit can be more easily removed, thereby minimizing favorable conditions for the development of disease and insect pest populations.…”

“…For example, blueberry plants of various cultivars grown on a black weedmat mulch produce higher yields and larger berries than plants grown on sawdust without weedmat. 13 Additionally, weedmats can improve sanitation, as fallen fruit can be more easily removed, thereby minimizing favorable conditions for the development of disease and insect pest populations. The deployment of weedmats into blueberry crops can also increase soil temperatures and moisture levels, 14 and modify light intensity in the plant canopy.…”