FROST PROTECTION IN LEMON ORCHARDS, 9 



table shows that plats 1, 2, .S, and 10 were located in nonheated 

 Lisbon orchards, while plats 4, 6, and 9 were in heated orchards. 

 Plat 3 was located in a nonheated Eureka orchard, and plats 5 and 7 

 in heated Eureka orchards. Plats 2 and 3, which are listed as non- 

 heated, were partially protected by heaters in neighboring orchards. 

 Plat 5, which is listed as a heated plat, was inadequately supplied 

 with orchard heaters, as there was only one heater for every four trees. 

 This plat was included for the purpose of comparing inadequate 

 orchard heating with no heating and with adequate heating. 



METHOD OF SECURING RECORDS. 



The fruit from each individual tree at each picking was assorted 

 into four grades, namely. Green, Tree-Ripe, Frozen, and Cull. The 

 Green grade included all fruits which had either a dark-green or light- 

 green color, and wliich, from outward appearances, were apparently 

 sound. These fruits were expected after curing to constitute a first 

 grade of valuable commercial lemons. The Tree-Ripe grade included 

 the apparently sound fruits which had a yellow color. These fruits 

 were usually considered to be of some commercial value. It was not 

 necessary to cure them before shipping to the markets. The Frozen 

 grade included all fruits wliich were seriously injured by the low 

 temperature, as shown by their soft or partially dried-up condition. 

 When there was any question or doubt as to whether the fruit was 

 frozen or not it was cut open, so as to make an accurate determination 

 before classifying. The Cull fruits were those which for some reason 

 aside from frost injuries were unfit for the market. A frequent cause 

 of Culls was decay of various kinds induced by mechanical injury to 

 the fruits. Many of these injuries were brought about by punctures 

 or bruises during the violent winds that accompanied the cold 

 weather in January, 1913. 



After the assortment of the fruits from each tree the number and 

 weight of the lemons of each grade were determined and recorded in 

 special field-note forms, as shown in Table III. 



As lemons are usually picked to a certain uniform size with the aid 

 of metal picking rings, no attempt was made to size the fruits, as 

 would have been necessary with oranges or grapefruit. If desired, 

 an idea of the relative size of the lemons can be secured by comparing 

 the number with the weights of the fruits. 



Inasmuch as the frozen lemons began to dry out soon after the 

 freeze, thus altering their normal weights, the data regarding tha 

 comparative sizes of the fruits secured in this way are likely to be 

 somewhat unreliable. For this reason, also, in studying the effect of 

 the freeze upon the production of the trees in the different plats, it 

 seems desirable that most of the conclusions should be based upon the 

 number instead of the weights of the fruits. 



140207°— 20— Bull. 821 2 



