Olive nutrition: what actually leaves the grove
The real annual nutrient removals in kg per hectare from long-term Spanish trials, the limits of leaf analysis, why nitrogen is usually a problem of excess, and what actually drives alternate bearing.
Technical articles
Articles — page 4
Kiwifruit nutrition: what it takes up when, and why calcium is decided in fifty days
The vine takes up more calcium than any other element, yet only 8 kg per hectare leave with the fruit, and 80% of it enters within fifty days of fruit set. How many kilograms of each element are actually removed, why excess nitrogen halves storage firmness, and what a 2025 trial failed to confirm.
Leonardite in agriculture: properties, rates and what the law says
Leonardite is oxidised lignite with up to 85% humic acids, but pH below 3, up to 6% sulphur and almost no phosphorus. What the analyses and meta-analyses show, where it delivers and where it does not, and what Regulation (EU) 2019/1009 and the organic farming rules require.
The fig wax scale, Ceroplastes rusci, on fig and persimmon
No synthetic active substance is authorised against it on fig or persimmon in Greece - only paraffin oils, maltodextrin and potassium salts of fatty acids, all of which act physically. That makes the crawler stage the whole of the treatment window, and coverage more important than dose.
Removing astringency from Rojo Brillante persimmon
Rojo Brillante is harvested firm and intensely astringent. Astringency goes only when enough acetaldehyde accumulates to make the tannins insoluble. The mechanism, the CO2 and ethanol protocols as applied in Spain, and what goes wrong when the chamber leaks, the batch is uneven or the treatment runs too long.
Almond nutrition: calculating the potassium and phosphorus requirement
The almond removes 76 kg of potassium and only 8 kg of phosphorus per tonne of kernel. Why the winter compound gets all three elements wrong, and how to calculate the real requirement from yield.
Kiwifruit physiology: why Brix misleads and dry matter does not
What happens inside the fruit from bloom to the cold store, why the 6.2 Brix threshold was transferred uncritically from New Zealand, and the trial showing that early harvest costs storage life.
Biostimulants: what the science says and what the EU regulation requires
The seven categories, the molecular mechanisms, the EU legal framework since 2022, and the six questions to ask a supplier before buying.
Calcium and its importance for plants
Calcium has the widest gap between what growers think they are doing and what actually happens. 83% of the fruit's calcium enters in the first four weeks; at 60 days the door closes; the pedicel holds 3 to 10 times more than the fruit; and blossom end rot is not primarily a calcium deficiency at all.
Brown rot of stone fruit: cause, symptoms and control
Three hours of wetness at 24 C infect the blossom. Latent infections decide the harvest months in advance, and 156 products are only 26 active substances.
Bacterial canker of kiwifruit (Psa)
The most serious disease of the crop worldwide, and it cannot be cured. Pruning cuts stay susceptible for at least 64 days, not a few. Summer leaf spots predict winter cankers. And all 22 strains tested from Pella in northern Greece proved resistant to copper.
Esca of kiwifruit: wood decay, an Esca-like disease
Symptomatic plants in 96% of Italian orchards, and no correlation with soil or grower practice. Prevention at the pruning cut is the only tool there is.