Evaluation of nutrients removed and recycled in a commercial peach orchard over a 14-years-production cycle

Understanding nutrient dynamics within a peach orchard is fundamental to the development of accurate nutrient management practices. The present study investigated the nutrient uptake and redistribution in a 14-years-old commercial orchard in the Po valley. At the end of the experiment, trees were harvested, biomass and organ nutrient concentration were determined. Skeleton and roots accounted for the highest plant biomass, followed by fruits at harvest, pruned wood and abscised leaves; thinned fruits were less than 1 kg tree-1. The difference between the amounts of nutrients in leaves sampled in summer and in autumn (at abscission) was used to estimate the fraction of nutrients remobilized during the vegetative season inside the tree. The decrease of N, P, S, Cu, Mn and Zn concentration in abscised, compared to summer-sampled leaves was the result of the translocation of nutrients into fruits and storage organs. Nutrient circulation in a commercial nectarine orchard was calculated by determination of the fractions of each nutrient recycled (sum of nutrients in abscised leaves, thinned fruits and pruned wood) and remobilized (sum of nutrients in fruits at harvest, roots and skeleton). In our experimental conditions, on average, nectarine Stark RedGold showed an annual request of (in kg ha-1) 100, 17, 73, 129, 16, and 6 of N, P, K, Ca, Mg and S, respectively. More than half of these quantities were recycled in the orchard and returned back to the soil; consequently, if the nutrient use efficiency is maximized, the fertilization of nectarine requires only small amount of external inputs.

MATING DISRUPTION OF GRAPHOLITA MOLESTA BUSCK. TO IMPROVE QUALITY AND HEALTHY OF PEACH FRUITS

In Bulgarian fruit growing agriculture mainly chemical plant protection is applied. Applications with organophosphates and pyrethroids are carried out to control the economically most important peach pest - the oriental fruit moth (Grapholita molesta Busck.). Annually during the vegetation season 7-8 insecticide treatments are applied. This leads to contamination of fruit products and the environment, which is a prerequisite for seeking other approaches. Regarding to fruit moth, sex pheromones are one of the most widely used environmental control methods, but they are most commonly used in apples. Their introduction in the monitoring of the main peach pest can lead to a reduction of chemical treatments and production with less pesticide residues. A promising direction is the use of pheromones to control the pests through sexual disorientation of males. The trial of mating disruption in the present study were carried out with ISOMATE® OFM TT dispensers in 0.9 ha peach orchard in 2020 and 2021. Pheromone traps type "Delta" of the Hungarian company CSALOMON® were used. The ISOMATE OFM TT dispensers, installed before the first flight of OFM at the rate of 250 units per ha, efficiently reduced fruit damages - down to 0.1-0.2% at harvest. In the reference orchard with 6 insecticide treatment against OFM, the damages reached 3.0-3.6%. The results indicate that mating disruption for control of Grapholita molesta Busck. can be used in production of quality and healthy peach fruits.

Peach-Morchella intercropping mode affects soil properties and fungal composition

Objective This study aims to explore a three-dimensional planting mode in orchards and provide theoretical basis for the efficient peach-Morchella planting and soil management after Morchella cultivation. Methods Next-generation sequencing was performed to investigate the variations in soil physicochemical properties, enzyme activities and fungal composition under peach-Morchella intercropping for one year and two years, by using the soil without peach-Morchella intercropping as the control group. Results Peach-Morchella intercropping decreased the soil bulk density, and significantly increased the maximum field capacity, non-capillary porosity and total porosity, organic matter, available potassium and available zinc, which together improved soil structure and soil fertility. Besides, the intercropping mode obviously enhanced soil enzyme activities and mineral absorption and transformation in peach orchard soils. The intercropping also resulted in a decline of soil fungal diversity, and the 2-year soil samples were of higher abundance of Zygomycota. More importantly, peach-Morchella intercropping elevated the yields of both peach and Morchella, bringing about obviously higher economic benefits. Conclusion Continuous peach-Morchella intercropping improves the soil structure and fertility while decreases soil fungal diversity, which can contribute to greater economic benefits of the peach orchard. Our findings shed new light on the intercropping-fungus-soil relationship, and may facilitate the further development of peach-Morchella intercropping.