I044 DISEASKS OV N'AKIOt.'H CROPS 



recommended : Sulphur i lb, soft soap 6 lbs, water 12 ^/^ gallons ; 3) remove 

 and destroy all vegetable remains among which the parasite is capable of 

 living as a saprophyte. 



819 - Investigations into a Disease of the Cones of Pinus pinea in Italy. — tetri 1,. 



and Adani A. in Aniuili ilcllu R. Accadcmiii ili A'^iicdlluni di iLriiin, \'f)l. 1,IX, 23 pp., 

 12 Fig., I ri. Turin, 191 6. . 



The disease of the cones of Pinus Pinea I^., long known to gatherers 

 of cones in the pine groves of Migliarino, San Rossore, Cecina and Castel 

 Fusano, i;nder the name of " pine gallerone " and " pine pagliose ", are 

 due to the same identical pathogenic agent. The sj-mptoms caused by the 

 latter however differ to some considerable extent, according to whether 

 the disease develops in autumn or spring. 



" Pine gallerone ". — An ochre hued spot first appears in May or June, 

 and from the line of contact between two adjoining scales rapidly spreads 

 right through the cone. The loss of water being fairly large, the outer sur- 

 face of the scales' appears shrunken. Resin exudes here and there from the 

 blackest portions. At the points where the infertion is oldest, black pus- 

 tules cf irregular shape form, pusliing up and .splitting the epiderm of the 

 scales. The shell cf the seeds is normal, biit the kernel is reduced to a grey 

 or 5'ellowish powder. The weight of these cones is lighter than that of 

 healthy cones which have reached the same stage cf development. 



The browning of the scale tissue and the destruction of the kernels are 

 accompanied b}^ the presence of the mycelium of a fungus, which spreads 

 from the upper surface of the scales through their thickness and penetrates 

 the endosperm of the seeds, the oily substance of which a^^pears to act as 

 a powerful stimulant on the mycelium in question. The black external bhsters 

 are the pycnidia of the fungus, which may be classified as a new species of 

 Sphaeropsis {Sph. nccatrix Petri et Adani). 



" Pine pagliose " . — The first spots marking the infection are observ- 

 able in September and throughout the month cf October. The external char- 

 acters of the diseased cones do not differ very much from those of the " pine 

 gallerone ". Thus, the discolouration of the scales, the exudation of resin, 

 destruction of the endosperm, the presence of the mycelium and the pycnidia 

 of Sphaeropsis are characters common to the two forms of degeneration ; 

 in " pine pagliose " however the weight is equal, or nearly so, to that of 

 healthy cones, the surface of the scales does not shrink, a number of seeds 

 remain intact and retain their commercial value. 



In these cones, owing to the more advanced lignification of the tissues 

 and the less favourable season, the infection proceeds more slowly ; it was 

 therefore easier to ascertain the course it take« inside the cone. The myce- 

 lium penetrates between the scales and rapidly attacks the soft parenchyma 

 which envelopes the seed. From this point it spreads through the thickness 

 of the scale towards the lower (external) surface from which the sporigenic 

 organs afterwards escape. 



From what has just been said, it will readily be understood that the two 

 names given by pine cone gatherers to the diseased cones only correspond 

 to two slightly different aspects produced by the same i)athogenic cause in 



