Tag Archives: bitter pit

2269–2276 L. Heinmaa,, P. Põldma, K. Loit, R. Kiiker and U. Moor
Physiological disorders affect apple susceptibility to Penicillium expansum infection and increase probability for mycotoxin patulin occurrence in apple juice
Abstract |
Full text PDF (347 KB)

Physiological disorders affect apple susceptibility to Penicillium expansum infection and increase probability for mycotoxin patulin occurrence in apple juice

L. Heinmaa¹,*, P. Põldma¹, K. Loit², R. Kiiker² and U. Moor¹

¹Estonian University of Life Sciences, Institute of Agricultural and Environmental
Sciences, Chair of Horticulture, Kreutzwaldi 1, EE51006 Tartu, Estonia
²Estonian University of Life Sciences, Institute of Agricultural and Environmental
Sciences, Chair of Plant Health, Kreutzwaldi 1, EE51006 Tartu, Estonia
*Correspondence: lagle.heinmaa@student.emu.ee

Abstract:

Penicillium expansum infection of apples and mycotoxin patulin (PAT) production has previously been associated with many pre- and postharvest factors other than physiological disorders. In the current study, ‘Antei’ and ‘Krameri tuviõun’ apples with and without bitter pit (BP) symptoms and ‘Talvenauding’ apples with and without superficial scald (SS) symptoms were used in order to determine if the named physiological disorders may influence susceptibility to P. expansum infection and PAT production. Apples were inoculated with 10 μL P. expansum spore suspension with the concentration of 1×105 conidia mL-1 and stored at 24 °C with relative humidity (RH) 80%. After 7 and 11 days, lesion diameters were measured, and apples were pressed into juice. PAT content was determined in pasteurized juice. Two cultivars out of three showed that in fruit with physiological disorders, Penicilllium infection and PAT production proceeded significantly faster compared to apples, which did not have physiological disorders. SS increased the risk for PAT occurrence in juice more than BP: while the juice pressed from BP–affected apples with no visual signs of fungal diseases did not contain PAT, juice pressed from apples with SS contained PAT three times above legislative limits defined by the World Health Organization (50 μg L-1).

Key words:

, ,




31–36 J. Lanauskas and N. Kvikliené
Effect of calcium foliar application on some fruit quality characteristics of ‘Sinap Orlovskij’ apple
Abstract |
Full text PDF (137 KB)

Effect of calcium foliar application on some fruit quality characteristics of ‘Sinap Orlovskij’ apple

J. Lanauskas¹ and N. Kvikliené²

¹Lithuanian Institute of Horticulture, Kauno 30, LT-54333 Babtai, Kaunas distr., Lithuania; e-mail: j.lanauskas@lsdi.lt
²Lithuanian Institute of Horticulture, Kauno 30, LT-54333 Babtai, Kaunas distr., Lithuania;e-mail: n.kvikliene@lsdi.lt

Abstract:

Effect of calcium fertiliser sprays on eight-ten-year-old apple trees of the cv. ‘Sinap Orlovskij’ on rootstock 62-396 was investigated at the Lithuanian Institute of Horticulture in 2001–2003. Calcium chloride, calcium nitrate, liquid experimental calcium fertilisers and Wuxal Calcium were used. Calcium chloride was applied twice at the time close to harvest (total CaO rate – 5.9 kg ha-1). Other fertilisers were used fivefold from the beginning of June (total CaO rate – 6 kg ha-1) in the combination of two sprays with calcium chloride (CaO rate – 5.9 kg/ha-1). The most significant effect of calcium fertilisers on fruit calcium content was found in 2003. When fertilisers were applied sevenfold, fruit calcium increased by 50–120 mg/kg of dry fruit weight in comparison with the control. The most unfavourable for calcium accumulation was the warm and dry weather in year 2002. Apples contained only 170–230 mg of calcium per kg of fruit dry matter and bitter pit affected up to 35% of apples. In years 2001 and 2003 fruit calcium content was 300–330 and 340–460 mg/kg, respectively, bitter pit affected up to 2% of apples. Sevenfold applied calcium fertilisers decreased bitter pit incidence about twice in comparison with the control and two applications of calcium chloride. All tested fertilisers had a similar effect on bitter pit reduction. Calcium fertilisers had not a consistent effect on fruit flesh firmness, soluble solids content and natural weight loss.

Key words:

, , , ,