240 EXPERIMENT STATION RECORD. 



lower than the Livingston Stone i^arent. In all cases the yield of the standard 

 parent was much greater than that of the dwarf parent. 



In the light of this and similar investigations here reviewed, the author con- 

 cludes that the increase in vigor and size produced by crossing is undoubtedly 

 due either to the heterozygous condition, which stimulates the growth of either 

 the size or the number of ceUs, or to a combination of two or more size- increas- 

 ing characters, such as thick internodes and long intemodes, which dominate 

 over characters of decreasing dimensions. All of the crosses gave consistent 

 gains in favor of the yield of Fi seedlings. The yields from the F2 and F3 

 seedlings appear to have fallen off in direct ratio to the decrease in the number 

 of heterozygous plants. When, however, a homozygous condition for all the 

 plants in a strain has been obtained, the average yield of the plant should 

 remain constant from year to year, varying only with the external factors. 

 The author further concludes that the results as a whole warrant the production 

 of Fi generation tomato seed, not only by the gi'owers but by all seedsmen who 

 wish to furnish the best grade of seed to the buyers. 



Crossing tomatoes to increase the yield, F. H. Hall {New York State Sta. 

 Bui. 3Ji6, popular ed., pp. 8). — A popular edition of the above. 



Preliminary report on tomato culture, L. L. Corbett (Virginia Truck, Sta. 

 Bui. 8, pp. 157-171, figs. 5). — This comprises popular directions for growing 

 tomatoes in eastern Virginia. Consideration is given to propagation, including 

 the use of the hotbed and cold frame; hardening; soil and preparation; plant- 

 ing; spraying; diseases and insects; types of fruit; harvesting and packing; 

 marketing; and canning. Results are also given of varieties tested at the 

 station showing the character of growth, form and color of fruit, date of 

 first ripening, duration of picking period, and number and weight of fruit. 



[Pheiiological notes: Blooming dates for Iowa plants, 1911], Charlotte M. 

 King et al. (Trans. loica IJort. Sac, J/S (1911), pp. 200-211). — ^A continuation 

 of previous reports (E. S. II.. 26, p. 237). The records for 1911 are given 

 by a number of observers from different parts of the State showing the dates 

 of first blooming of trees, shrubs, and flowering plants. 



The avoidance and prevention of frost in the fruit belts of Nevada, J. E. 

 Church and S. P. Fergusson (Nevada Sta. Bui. 79, pp. 58, pis. 16). — Part 1 

 of this bulletin, which deals with the prevention of frost, describes in detail 

 heating experiments conducted by the station in 3 orchards during the spiing 

 season of 1911, and discusses methods of preventing frost by the use of wind- 

 breaks and orchard heaters. A brief account is given of frost phenomena 

 and general w^eather changes, together with a discussion of the methods of 

 foi'ecasting frost, including descriptions with illustrations of the necessary 

 apparatus. Estimates are also given on the cost of orchard heating. 



The second part of the bulletin deals with the avoidance of frost. A series 

 of temperature measurements taken in 1910 are given to show the value of 

 higher ground as a natural site for orchards. A temperature survey of the 

 agricultural land of the State has been inaugurated with the view of determin- 

 ing large areas suitable for fruit raising under all forms of economic frost 

 prevention and also to delimit thermal belts in these areas into (1) belts where 

 frost does no material damage to fruit crops; (2) belts where frost can be 

 successfully combated at reasonable expense; and (3) belts where frost is 

 so severe as to make fruit raising unprofitable. A progress report is given 

 of this work, which during the past season included the establishment of 

 5 different stations in the Truekee Meadows and located at different altitudes. 

 The temperature records secured at these stations are given and discussed. 

 They indicate a preponderance of low temperatures at the lower stations. 



