CITRUS CULTURE IN PORTO RICO 



19 



discarded in the nursery. The trees may be transplanted when they 

 are 3 feet high. Old, overgrown nursery trees are not as desirable 

 as young, vigorous ones. About two months before transplanting is 

 done, watering and cultivation of the nursery should be discontinued 

 in order to allow the } 7 oung growth to mature. Frequently the 

 weather is rainy and growth continues, in which case transplanting 

 can be done without loss of the immature growth. 



PREPARATION OF THE FIELD 



The present-day field practice is based upon the experience gained 

 during the first few years of commercial citrus growing in Porto 

 Rico. Some of the growers who have come to the island within the 

 past 15 years are prone to deviate from this practice, and others 

 who are starting to plant now are not always convinced that it is 

 right under all conditions. Nevertheless, with some minor changes, 

 the earlier practice will continue to prevail because, as was shown by 

 the data collected in field studies, it is built upon correct premises. 



The two principal facts to be borne in mind are that (1) the trees 

 must be planted on mounds, and (2) wind protection must be pro- 

 vided before planting is done. Preparation should therefore be 

 started several months in advance of planting. The field should be 

 measured off and stakes placed where the trees are to be planted. 

 Usually the trees are planted at distances of 25 or '30 feet each way. 

 The latter distance is not too great to accommodate grapefruit trees 

 after they reach the age of about 20 years, but until that time 25 by 25 

 feet is sufficient, and budded orange trees do not usually need more 

 room at any age. Planting 25 by 25 feet will permit of the growing 

 of 69 or 70 trees to the acre. A mound of soil with a diameter of 

 4 to 6 feet is usually built up around each stake to a height of 18 

 inches or more, and the trees are planted on top of these to safeguard 

 them from foot rot. On heavy soil where the water table is high 

 the following practice is recommended for trial : Plow as deep as is 

 practicable and follow the plow with a subsoil breaker. Make the 

 beds to extend across the slope of the land, and use each line of 

 stakes as the center of a bed. This may be done most economically 

 by using a road scraper, proceeding in the same manner as when 

 building a road. If this practice is followed the size of the mounds 

 can be greatly lessened. 



WINDBREAKS 



Protection against wind may be provided by planting annuals or 

 biennials broadcast in the field, and tall-growing perennials in strips 

 at suitable intervals so that they will cross the field at a right angle 

 to the prevailing wind direction. Leguminous plants are desirable 

 for planting in the field because they supply the soil with nitrogen. 

 The crotalarias make efficient windbreaks, and especially C Total aria 

 juncea because of its tall growth. The pigeon pea or gandul 

 {Cajanus indicus) is perhaps the second choice among the legumes 

 although Tephrosia Candida seems to be equally desirable. The 

 gallito (Agati grandiflora) grows well wherever the soil is not too 

 dry, and is an excellent nitrogen gatherer. (Fig. 10.) The seeds 



