11 Aug., 1919. J Apple Culture tJi Victoria. 4;")! 



sistant variety to Bitter Pit (Yates) is also the most 

 I'esistant to poison. Varieties specially sensitive to poison 

 are also specially sensitive to Bitter Pit. There is also a 

 close correspondence in regard to temperature effects. At low 

 temperatures the development of Bitter Pit is checked or retarded. 

 Similarly at low temperatures the resistance to poisons is greatly 

 increased, being 10 to 100 times greater at 0"C. what it is at 

 250C." 



The following extract, which explains how poisons could be absorbed 

 from the soil by the delicate hair-roots and cause pitting of the fruit, 

 is taken from the pamphlet issued, September, 1913: — 



"It is well known that the roots of various plants can absorb 

 traces of various mineral poisons which may accumulate in special 

 parts or organs, particularly such as are ultimately thrown ofl 

 (leaves, bark, fruits), without either the roots or the plant as a 

 whole being affected. The following poisonous metals may be 

 absorbed by various plants when grown on soils containing them 

 Zinc up to 13 per cent, of ash, manganese up to 14 per cent., 

 cobalt, nickel, mercury, silver, copper up to 1 per cent., lead, 

 thallium, arsenic, titanium, &c. These absorbed poisons are either 

 set aside in special parts or cells sacrificed as poison traps, or may 

 not cause any injury at all if the plant has developed the power of 

 precipitating them in an insoluble or innocuous form." 



The question of Bitter Pit has for many years engaged the attention 

 of the officers of the Orchard Sxipervision Branch. The following 

 extract is taken from a contribution by Mr. P. J. Carmody, Chief 

 Orchard Supervisor, published in the report of the Department of 

 Agriculture for 1910, in which he gives his practical experience of 

 Bitter Pit in the orchards: — 



" As regai'ds Bitter Pit, the co-operation of the practical grower 

 and the scientist affords the best means from which we can hope to 

 obtain knowledge that will lead to the amelioration of conditions 

 that at present exist. This question has alike occupied the minds 

 of, and caused anxiety to growers and exporters of fruit, and 

 great, indeed, have been the losses on the fruit shipped last season 

 From a careful study of this disease in the field for many years I 

 have found the following as amongst its principal contributory 

 causes : — 



(a) Proneness of some varieties more than others to the com- 

 plaint, e.g., Cleopatra, Annie Elizabeth, Shockley, 

 Sturmer Pippin, Northern Spy, and Winter Majetin. 



(6) Over-developed fruit from yonng trees or old trees lightly 

 cropped. 



((•) Unevenly or suddenly developed fruit. It often happens 

 that during the season a prolonged period of dry 

 weather occurs during which the development is arrested 

 or retarded, and on the fall of rain, sudden and 

 unreasonable development ensues. 



(d) Excessive nitrogenous manures, or soils in which nitrogen 

 is superabundantly inherent, produce fruit noticeably 

 susceptible to Bitter Pit. 

 1 z 



