BUREAU OF PLANT INDUSTRY. 173 



In view of the fact that very many of the pecan orchards that have 

 been phmted in southern Georn:ia and elsewhere are on soil that is 

 very ditferent from that which occurs where most of the native 

 stands of pecans are to be found, there is a growing conviction that 

 there are some important soil factors that are very definitely involved 

 in the success of these planted orchards. It is with a view to deter- 

 mining some of these factors that extensive fertilizer, cover-crop, 

 and other cultural activities are being prosecuted. 



The bearing records of a number of pecan orchards are being se- 

 cured annually by this bureau. These results show that some orchards 

 regarded by the oAvners as profitable contain a surprisingly high 

 percentage of trees that are unproductive. Such trees are main- 

 tained at the expense of the higher yielding trees. The profits on an 

 acreage basis, therefore, are very much reduced as compared with 

 what they would be if all the trees yielded as well as the better pro- 

 ducing trees. Some attention has been given also to the matter 

 of grading and sizing pecans for market. Because of opposing con- 

 ditions that exist in certain pecan-growing regions, it is difficult to 

 secure unanimity of opinion among the growers with reference to 

 what ought to constitute grade standards. This matter is being con- 

 sidered from the standpoint of tlie industry, since it is felt that onl}^ 

 one set of grade standards should be recognized and promulgated. 



In the case of almonds in California there appears to be a rather 

 acute varietal problem in that a great number of varieties are being 



frown. This makes considerable trouble in marketing tlie product, 

 'he study of varieties that has been inaugurated is being carried 

 forward with a view to determining from actual records and observa- 

 tions what varieties are the most profitable; also the adaptability of 

 different varieties to different conditions. As a result of such studies 

 it is hoped that all but a certain few of the best sorts can be eventually 

 eliminated. 



The studies of Persian Avalnuts and filberts have been in the nature 

 of surveys for the purpose of getting in touch with the production 

 problems, to compile the data relative to cultural methods, and to 

 formulate some adequate conception of the methods and practices 

 that are yielding the best results under different conditions. 



Incidental attention has been given to the study of hickories, black 

 walnuts, and other nuts which possess more or less value for growing 

 somewhat widely throughout the North. 



FRUIT JUICES. 



In the clarification of fruit juices it is felt that some very mate- 

 rial and important progress has been made. During the season of 

 1919 samples of juice were obtained from G2 varieties of grapes and 

 167 varieties of apples. These were pasteurized by routine methods 

 in glass containers as promptly as possible after being pressed out 

 and were stored in a cool room for study during the winter and spring 

 months. As had been anticipated from the icsults of earlier work, 

 all the samples of apple juice remained persistently turbid at the end 

 of four to six months storage, and none of these could be materially 

 improved by ordinary filtration, as much of the suspended colloidal 

 matter passed tiiiough the filter. Filtration was also in all cases ex- 

 ceedingly slow. In the grape-juice samjjles, some '20 of the 02 varie- 

 tal samples underwent complete or practically complete sedimenta- 



