244 EXPERIMENT STATION RECORD. 



The past history and present position of the bitter pit question, D. 

 McAlpine (Prog. Rpt. Bitter Pit Invest. [Australia}, 1 {1911-12), pp. 197, 

 pis. 34; at)S. in Bot. Centhl., 122 (1913), No. 18, p. //Si).— This is the full report 

 (E. S. R., 29. p. 246) of these investigations to date. 



It is stated that the delicate skeleton of vessels which remains, preserving 

 a model of the fruit after the softening and removal of the flesh, normally- 

 functions in the distribution and regulation of the food supply to the periphery 

 of the fruit, vphere the most rapid grovpth takes place. Bitter pit is said to be 

 an internal disease found in association with discoloration of the vascular 

 bundles and probably not due to an organism. The brown spots are generally- 

 first found in the subcutaneous zone occupied by the vascular network. Bitter 

 pit may be noted when the fruit is about the size of a walnut, but most gen- 

 erally after it is half grown, and it most commonly occurs in the upper half, 

 Where the openings in the skin are more numerous and water is less abundant 

 owing to evaporation. 



This injury appears to stand in relation with intermittent weather condi- 

 tions at a critical period of growth; the amount and rapidity of transpiration 

 and sudden checking thereof at night while the roots are still active owing 

 to heat in the soil ; a failure of supplies at the periphery- of the fruit, followed 

 by spasmodic and irregular recovery; an inequality of growth resulting in 

 irregular formation of the vascular network controlling the distribution of 

 nutritive material ; fluctuations of temperature in stored fruit ; and the specific 

 nature of the variety in question. The relation of each of these factors to 

 the development of bitter pit is under investigation. 



It is stated that pitting may be noted in case of fruit on young, rapidly growing 

 trees, as also in the case of light crops with abnormally large fruit. The quince is 

 less liable to pitting than is either the apple or pei'.r. In stored fruit the safest 

 temperature is that at which respiration is practically suspended, that is, 30 

 to 32° F. The delicate structure of the apple and its supply of vessels show the 

 necessity of careful handling and skilled packing for transportation. 



An extensive bibliography is appended. 



The diseases of the banana, J. E. van deb Laat (Las Enfermedades del 

 Banano. San Jose, Costa Rica: Dept. Agr., 1914, pp. 19, figs. 3). — Some diseases 

 of bananas in Costa Rica are described, particular attention being given to that 

 known as the Panama disease. 



Two species of Fusarium are said to attack bananas, one of which is the 

 cause of the so-called Panama disease. The difi:erence in susceptibility of 

 ■varieties of bananas to this disease is pointed out and the author suggests more 

 rational methods of cultivation as factors in its control. The disease is said 

 to be favored by an unbalanced condition of the nitrogen in the soil, a lack of 

 soluble potash, and the accumulation of excretions from the banana plant. 



Report on some of the diseases of citrus fruits, O. Ross (Queensland Agr. 

 Jour., n. ser., 1 (1914), No. 1, pp. 48-54; noted in No. 2, p. 107). — Reporting on 

 a tour of investigation on diseases and pests affecting citrus fruits, the author 

 states that collar rot (Fusarium Umonis), was found in two places. The com- 

 mon rough lemon, now abundant in a wild state and practically immune to 

 this disease, is recommended for use as a stock. In addition to thorough cul- 

 tivation, judicious manuring, good drainage, and close planting as preventive 

 measures, cutting and burning affected parts, aseptic treatment, etc., are 

 insisted upon. 



Root rot (Phoma omnivora) is reported at one locality and is distinguished 

 from somewhat similar fungi. Lemon bark blotch (Ascochyta corticola) was 

 observed in one instance. Scabbing of fruit and leaves was abundant and 

 highly injurious in some places named. Anthracnose (P. citricarpa) was 



