The apple variety, ‘Honeycrisp’ has been extensively planted in North America during the last two decades. However, it suffers from several agronomic problems that limit productivity and postharvest quality. To reduce losses, new information is needed to better describe the impact of crop load on productivity and postharvest fruit quality in a desert environment and the major region where ‘Honeycrisp’ expansion is occurring. Here, 7-year-old ‘Honeycrisp’ trees on the M9-Nic29 rootstock (2.5 × 0.9 m) were hand thinned to five different crop loads [from 4.7 to 16.0 fruit/cm2 of trunk cross-sectional area (TCSA)] to compare fruit quality, maturity, fruit size, elemental concentration, and return bloom. Fruit size distribution was affected by crop load. Trees with the highest crop load (16 fruit/cm2) produced smaller fruit. Index of absorbance difference (IAD) measurements (absorption difference between 670 and 720 nm), a proxy indicator of the chlorophyll content below the skin of fruit measured by a DA-meter, were made shortly after harvest (T0) and after 6 months of storage (T1). Fruit from the trees with the lowest crop load had lower IAD values indicating advanced fruit ripeness. The comparison between the IAD classes at T0 and T1 showed that fruit belonging to the lowest IAD class had significantly higher red-blushed overcolor percentage, firmness, dry matter, and soluble solid content than those in the “most unripe” class (highest IAD readings) regardless of crop load. The percentage of blushed color, firmness, titratable acidity (TA), soluble solids content, and dry matter were all higher in the lowest crop loads at both T0 and T1. Fruit calcium (Ca) concentration was lowest at the lowest crop load. The (K + Mg + N):Ca ratio decreased as crop load increased until a crop load of 11.3 fruit/cm2, which was not significantly different from higher crop loads. For return bloom, the highest number of flower clusters per tree was reported for 4.7 fruit/cm2 crop load, and generally it decreased as crop load increased. Here, we highlight the corresponding changes in fruit quality, storability, and elemental balance with tree crop load. To maintain high fruit quality and consistency in yield, careful crop load management is required to minimize bienniality and improve fruit quality and storability.

The development of an integrated rodent pest management strategy requires the adoption of protocols that should be based on a good knowledge of species-habitat relationships. Vole damage to orchards has increased in Italy in recent decades, as new cultivation practices have been introduced, despite the use of rodenticides. To improve our understanding of factors influencing Savi's pine vole abundance in Italian apple orchards, we monitored the relationship between environmental and agronomic variables and population densities. Vole population sizes were influenced by the abundance of voles in the neighbouring fields and the presence of kiwifruit orchards, usually not treated with rodenticides, bordering on apple orchards. The type of irrigation system had the strongest influence on vole abundance and flood-irrigated fields had fewer voles than drip-irrigated fields. Apple tree age and tilling practices also had an influence on vole abundance. Our research provides evidence that vole populations are influenced mostly by agronomic practices and type and extension of fruit orchards. An integrated management strategy in the apple orchard district should include coordination in chemical treatments between farmers and the experimentation of flood irrigation and regular soil tillage management as a possible costeffective way to reduce vole populations. Keywords Abundance index • agro-ecosystems • Italy • Microtus savii • rodents • species-habitat relationship IntroductionThe development of an integrated rodent pest management strategy as an alternative to the heavy use of rodenticides, requires the adoption of protocols for species under specific production systems (Byers 1984;White et al. 1997;Singleton et al. 1999). These protocols should be based on a good knowledge of species-habitat relationships and the effects of environmental variables, as well as agronomic activities on species presence and abundance (Singleton et al. 1999;Palis et al. 2007Palis et al. , 2010). This information is generally derived either from intensive field work (Maisonneuve and Voles are common rodent species in agro-ecosystems, where they can cause extensive damage

One advantage of high-density apple orchard systems is homogeneity in fruit maturity and quality. However, even in modern orchard systems, variation in fruit quality occurs. ‘Honeycrisp’ apple is susceptible to numerous disorders including bitter pit, soft scald, and poor colour development. Heterogeneity in fruit quality and nutrient distribution can lead to variation in fruit storability. Here, we tested the effect of within-canopy position on fruit calcium and potassium concentrations, quality, and disorder development for fruit across nine representative high-density orchards. Calcium concentrations were greater in the upper part of the canopy compared with the lower part. Potassium was more evenly distributed within the canopy. Calcium concentrations and potassium-to-calcium ratios were significantly correlated with mean bitter pit incidence, which was between 20% and 30% in the lower half of the tree and <15% in the upper half. Fruit quality was significantly affected by the position in the canopy and was not constrained to only colour, but also other quality metrics such as dry matter, size, and firmness. Additionally, the internal ethylene concentrations (IECs) of fruit in the upper canopy were approximately 50% of the IECs for fruit from the lower canopy. With an increased emphasis on uniformity and predictability of fruit for long-term storage, these results underscore the importance of understanding variation within the canopy. Even for high-density systems, significant variation in fruit quality can occur and fruit from the upper canopy has lower disorder incidence and higher fruit quality than fruit from the lower canopy.

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