Morphophysiological changes of Acca sellowiana (Myrtaceae: Myrtoideae) saplings under shade gradient

Understanding morphological and physiological changes under different light conditions in native fruit species in juveniles’ stage is important, as it indicate the appropriate environment to achieve vigorous saplings. We aimed to verify growth and morphophysiological changes under shade gradient in feijoa (Acca sellowiana (O. Berg) Burret) to achieve good quality saplings adequate to improve cultivation in orchards. The saplings were grown for twenty-one-month under four shading treatments (0%, 30%, 50%, and 80%). Growth, photosynthetic pigments, gas exchanges, chlorophyll fluorescence, and leaf anatomy parameters were evaluated. Saplings under full sun and 30% shade had higher height and diameter growth and dry mass accumulation due to higher photosynthesis rate. As main acclimatization mechanisms in feijoa saplings under 80% shade were developed larger leaf area, reduced leaf blade thickness, and enhanced quantum yield of photosystem II. Even so, the net CO2 assimilation and the electron transport rate was lower and, consequently, there was a restriction on the growth and dry mass in saplings under deep shade. Therefore, to obtain higher quality feijoa saplings, we recommend that it be carried out in full sun or up to 30% shade, to maximize the sapling vigor in nurseries and, later, this light environment can also be used in orchards for favor growth and fruit production.

Natural parasitism in fruit fly (Diptera: Tephritidae) and interaction with wild hosts surrounding apple orchards adjacent to Atlantic Forest fragments in Paraná State, Brazil

The South American fruit fly, Anastrepha fraterculus (Wiedemann, 1830) (Diptera: Tephritidae), is an important pest in the subtropical region of Brazil. This insect has tritrophic relation between wild fruits and parasitoids and is associated with apple (Malus domestica Borkh.) orchards adjacent to the Atlantic Forest in Paraná. We thus investigated the degree of infestation of the fruit fly and natural parasitism in wild and cultivated fruits surrounding apple orchards. For this purpose, we collected fruits of Acca sellowiana (Berg.) Burret, Campomanesia xanthocarpa (Mart), Eugenia uniflora L., Eugenia pyriformis Cambessèdes, Psidium cattleianum Sabine, Psidium guajava (L.), Annona neosericea Rainer and Eriobotrya japonica (Thumb) in apple orchards adjacent to the Atlantic Forest located in Campo do Tenente, Lapa and Porto Amazonas counties. In total, we collected 18,289 fruits during four growing years. The occurrence of A. fraterculus depends on the susceptible period of apple fruits. A. sellowiana and P. cattleianum were considered primary fruit fly multipliers and P. guajava was secondary, all occurring after the apple harvest (IS period). The group of parasitoids with A. fraterculus was Aganaspis pelleranoi (Brèthes, 1924) (Hymenoptera: Figitidae), Opius bellus (Gahan, 1930), Doryctobracon areolatus (Szépligeti, 1911) and Doryctobracon brasiliensis (Szépligeti, 1911) (Hymenoptera: Braconidae) all of which are first records in the Atlantic Forest in Paraná. First record of O. bellus occurring in the State of Paraná, as well as, first record of the tritrophic association between host plant A. neosericea, parasitoids D. areolatus and O. bellus and fruit fly A. fraterculus. The host P. cattleianum stood out among the Myrtaceae species in regard to the high diversity of parasitoid species (81% of parasitoids). The total number of Figitidae species (76.5%) was higher than that of Braconidae species. The influence of climatic events in southern Brazil on wild fruit production should be further studied to understand the association of A. fraterculus with the tritrophic relationship.

Saline water irrigation strategies and potassium fertilization on physiology and fruit production of yellow passion fruit

ABSTRACT The objective of this study was to evaluate the effects of saline water irrigation management strategies and potassium doses on the concentration of photosynthetic pigments, gas exchange, and fruit production of ‘BRS GA1’ yellow passion fruit. The experiment was carried out under field conditions using a randomized block design, with treatments based on a 6 × 2 factorial scheme, related to six management strategies for irrigation with saline water (irrigation with low-salinity water throughout the crop cycle-WS; irrigation with high-salinity water in the vegetative stage-VE; flowering stage-FL; fruiting stage-FR; and successively in vegetative/flowering stages-VE/FL and vegetative/fruiting stages-VE/FR) and two doses of potassium (60 and 100% of the recommendation), with four replicates. The dose of 100% recommendation corresponded to 345 g of K2O plant-1 year-1. High electrical conductivity irrigation water (4.0 dS m-1) was used in different phenological stages according to treatment, alternating with water of low electrical conductivity (1.3 dS m-1). The synthesis of chlorophyll a and b, stomatal conductance, instantaneous carboxylation efficiency and water use efficiency of ‘BRS GA1’ yellow passion fruit were reduced under irrigation with water of 4.0 dS m-1 in all strategies adopted. Fertilization with 60% of the K recommendation promoted greater number of fruits and yellow passion fruit yield. Irrigation with 4.0 dS m-1 water in the vegetative/flowering and flowering stages reduced the yield of yellow passion fruit.

Potassium and growth-promoting fungi improve the postharvest quality of grape tomato

Tomato plants respond well to potassium fertilization, whose insufficiency leads to a drop in fruit production and quality. On the other hand, the association of growth-promoting fungi (GPF) with roots has been shown to be able to optimize nutrient absorption, which implies lower financial costs and a decreased risk of loss of K applied to the soil. The objective of this study was to investigate the effects of inoculation with GPF and K rates on the postharvest quality of grape tomato hybrid ‘Mascot’ grown in a hydroponic system. The plants were cultivated in a hydroponic drip system using washed and sterilized sand as substrate. They were trained with two stems, leaving three bunches per stem. The experiment was carried out in a splitsplit-plot arrangement in a completely randomized design with three replicates. Ripe fruits were stored for 30 days in PET containers in storage chambers at a temperature of 25 °C. After 0, 10, 20 and 30 days of storage, five fruits were collected to determine the titratable acidity (TA) and soluble solids (SS), reducing sugars (RS) and vitamin C contents. The K rates provided an increase in the quality attributes. At low K rates, inoculation with GPF led to higher TA, SS, RS and vitamin C values. Inoculation of the plants with GPF improved the postharvest preservation of the fruits, especially when the plants underwent nutritional stress during cultivation.

Phenology and fruit set of peach trees cultivated in Dois Vizinhos, Paraná State, Brazil

Understanding the dormancy phases and dynamics of commercial cultivars in the regions where they are grown allows for the implementation of different cultural practices and aids in the understanding of the temperature requirements for collaboration with genetic improvement programs. The objective of this study was to determine the budding, flowering, and fruit set rates of peach trees cultivated in the municipality of Dois Vizinhos, Southwestern Paraná, Brazil. The present work was developed using the collection of peach trees in the fruit growing sector of the Universidade Tecnológica Federal do Paraná. Sixteen peach cultivars were evaluated: Rubimel, Leonense, Coral, Marli, Charme, Riograndense, Douradão, Chimarrita, Granada, BR-1, Bonão, and Eldorado (all planted in 2009), as well as Regalo, Kampai, Fascínio, and Zilli (planted in 2014). The experimental design was completely randomized with four replications of one plant each, in a 16 × 2 bifactorial arrangement (cultivars × year/harvest). Phenology evaluations were performed weekly by counting open (anthesis) and sprouted flower buds, and the fruit set rate was measured just before fruit thinning. Flowering (%), budding (%), and fruit set (%) rates were calculated. It was found that the year/harvest 2016 promoted the highest rates of sprouting and fruit set. The Bonão cultivar showed greater flowering intensity and regularity in the crop years evaluated (2016 and 2017). Coral and Kampai present fruit sets with greater intensities and regularities when compared to the other cultivars evaluated under the climatic condition of the municipality of Dois Vizinhos. The Riograndense cultivar showed greater irregularity in flowering and fruit production.

Postharvest Losses in Quantity and Quality of Pear (cv. Packham’s Triumph) along the Supply Chain and Associated Economic, Environmental and Resource Impacts

Approximately one third of the food produced globally is lost or wasted along the supply chain. Reducing this would be an important measure to increase the global food supply as the world continues the struggle to feed its people sustainably. Not merely a waste of food, these losses also represent a waste of human effort and agricultural inputs from expensive fertilizers to natural resources as well as contributing to global greenhouse gas emissions. Measuring the extent of, and understanding the reasons for, these losses can assist in developing appropriate measures required to prevent or reduce such losses. Therefore, the objective of this research was to quantify postharvest losses in quantity and quality of ‘Packham’s Triumph’ pears at farm and simulated retail levels. Pears were sampled from two farms in the Western Cape Province of South Africa, the largest deciduous fruit production and export region in Southern Africa. The greatest losses measured along the supply chain were on-farm immediately after harvest, with 18% recorded. The main reasons for on-farm losses were small size (65%), deformity (26%), and chafed peel (9%). After 14 days in cold storage (−0.3 ± 0.7 °C, 81.3 ± 4.1% RH), mean pear losses were 0.86% which increased to 1.49% after 28 days. After 10 days of further storage under simulated market conditions (5.4 ± 0.6 °C, 83.7 ± 2.9% RH), fruit losses were 1.52% during retail marketing and 2.09% during export. Storing pears under ambient conditions (25.1 ± 1.3 °C and 46.6 ± 6.0% RH) resulted in a higher incidence of losses, increasing from 0.90 to 1.55 and 2.25% after 3, 7, and 10 days, respectively. The socio-economic impacts of these postharvest losses amounted to financial losses of between ZAR 492 million (USD 34.1 million according to the conversion rate of 14 April 2021) to over ZAR 831 million annually, and this was associated with the loss of 301 million MJ of fossil energy, 69 million m3 of fresh water and contributed to the emission of approximately 19,690 tons of CO2 equivalent. The fresh water lost could sustain 3.7 million individuals daily for a whole year at a daily minimum usage rate of 0.05 m3 per day while it will require planting 0.5 million trees to sink the 19,690 tons GHG emissions of the pear losses (0.039 metric ton per urban tree planted). Decreasing postharvest losses will conserve resources as well as improve food security and nutrition, objectives of the post-2015 sustainable development agenda led by the United Nations.

Evaluation of the Characteristics of Native Wild Himalayan Fig (Ficus palmata Forsk.) from Pakistan as a Potential Species for Sustainable Fruit Production

Wild Himalayan figs (Ficus palmata Forsk.), native to East Asia and the Himalayan region, are closely related to the well-known cultivated fig (Ficus carica L.), which is grown mainly in the Mediterranean region. The Pakistani state of Azad Jammu and Kashmir has a rich variety of figs. However, no comprehensive study has been carried out to utilise the diversity of these wild figs for possible use in sustainable fruit production. Therefore, the present study was designed to assess the variability of 35 wild fig accessions using quantitative and qualitative traits. Descriptive statistics were used to measure quantitative characteristics, while the coefficient of variance (CV %) was analysed using SAS® version 9.1. A principal component analysis (PCA) and multivariate analysis were performed using R Studio (v1.1.4). Pearson correlation coefficients between characteristics were obtained using SPSS software. The studied accessions showed high variability and the coefficient of variation (CV) ranged from 4.46–14.81%. Days to maturity varied from 71 to 86, leaf area from 38.55 to 90.06 cm2. The fruit length, fruit diameter and fruit weight ranged from 11.25 to 29.85 mm, 11.85 to 27.49 mm and 2.65 to 9.66 g, respectively. The photosynthetic activity and total chlorophyll content also varied from 7.94 to 10.22 μmol CO2 m−2s−1 and 37.11 to 46.48 μgml−1. In most of the fig accessions studied, apical dominance was found to be ‘absent’ while fruit shape was observed to be ‘globular’. A strong correlation was observed between all the studied characteristics. In the PCA analysis, all 35 fig accessions were distributed in four quadrants and showed a great diversity. This could be a valuable gene pool for future breeding studies and provide improved quality varieties. Wild Himalayan figs from the wild are well adapted to local pedoclimatic conditions and, combined with easy propagation and production can contribute to the local economy and have a significant impact on the socio-economic and ecological balance. The results of this study show high variability in some of the studied traits of 35 accessions from different parts of Northeast Pakistan, indicating their good potential for further enhancement and utilisation in sustainable agricultural production.