190 



THE AGRICULTUKAL NEWS. 



Junk 3, 1916. 



EXPERIMENTS WITH TROPICAL CROPS 



IN CALIFORNIA. 



The following extracts have been taken from the 

 Report of the College of Agriculture and the Agricul- 

 tural Experiment Station of the University of Cali- 

 fornia for 1914-15. The information is of interest in 

 relation to "West Indian agriculture: — 



FERTILIZEK EXPEEIMENTt* UPOX OKANGES AND LEMONS. 



During the past eight years the station has been con- 

 ducting a fertilizer experiment upon oranges and lemons at 

 Pdverside. The trees are not yet in full bearing, but already 

 some indication of the trend is becoming apparent. With 

 these young trees distinct effects have been obtained from 

 the u.se of stable manure, from a complete fertilizer, and from 

 nitrogenous fertilizers. Some apparent ettect has been 

 obtained from phosphoric acid, but little if any from potash 

 salts, at least as far as the yield is concerned. In another 

 area of the same type of soil it has been conclusively shown 

 that corn, potatoes and sugar beet were increased by plough- 

 ing down a leguminous cover crop over that which was 

 obtained by turning under a cover crop of barley. A legu- 

 minous cover crop supplied as much nitrogen to the soil 

 apparently as was supplied by 1,000 ft. of nitrate of soda. 

 In other "words, it is not only desirable to supply organic 

 matter to the soil, but preferably this organic matter should 

 be from a leguminous crop. 



These investigations have not continued long enough to 

 justify definite conclusions, but the present indications are 

 that "steamed bone meal may be wisely added to a young 

 bearing orange orchard if a leguminous cover crop is ploughed 

 under annually, on soils similar to the one on which our 

 investigations have been made. If, however, a leguminous 

 cover crop is not used, a liberal application of nitrogen in 

 some form of low-grade nitrogenous fertilizer, and sulphate of 

 ammonia is indicated.* While the investigations have not 

 thu.s far shown it, it may be that when the orchard gets 

 under the strain of heavy bearing, potash will also be found 

 u.seful. This, at least, has been found to be the case with 

 crops ill a humid climate. Extended experiments seem 

 to .show, beyond a doubt, that there it is possible by means 

 of leguminous crops to keep up the nitrogen supply of the 

 soil, but that pho.sphoiu.* and potassium mu.st be added 

 from some other .source in order to maintain a maximum 

 production. 



THK EFFECT OF FKKl'H.IZKH.s ON .SUGAlt ANU AOH CONTKNT 

 OF CITEl'S FKUITS. 



Young reports that dirt'erencfs in sugar and acid contents 

 of citrus fruits under difierent fertilizer treatments have been 

 found to be comparatively slight. In general, fruits from 

 plats containing potash alone are slightly sweeter than 

 those from other plats. Phosphoric acid plats range second, 

 and nitrogen third, in sweetness. Fruits from nitrogen 

 plats have uniformly shown a higher percentage of nitrogen. 

 Navel oranges grown on sweet stock have more sugar and 

 less acid than those grown on .sour stock. 



SUDAN (iRASS. 



The Sudan grass experiment, started at the University 

 l-'anii, Davis, in April 14)1.3, through co-operation with the 



♦Kxeellent results liave been iil)tained in the experiments 

 jit Uiverside with dried blrM.il, and with steiiuied bone meal 

 -which carries a small percentage of nitrogen. 



Bureau of Plant Industry, has shown this plant to be- 

 a valuable annual forage crop in subhumid sections where- 

 irrigation is not practised. In 1914, the average yield of 

 cured hay under irrigation was 7 61 tons per acre, while thfr 

 average yield under dry-farming methods was 661 tons per 

 acre. As a seed crop the average yield with irrigation wa& 

 1,643 lb., and without irrigation 1,771 lb. per acre. Additional 

 trials are being made to determine the best methods of seeding 

 and handling this crop. Care must be taken in the purchase 

 of seed, owing to the fact that there is no known method 

 of distinguishing between the .seed of Sudan grass and that 

 of Johnson grass. 



(3L0SE I'LANTING OF ECYPTAIN COTTON. 



Egyptain cotton, when allowed to grow under ordinary 

 condition, at the Imperial Valley Experiment Farms reaches a 

 height of 6 or 7 feet, with large vegetative branches, which 

 make picking difficult. Different distances of planting were 

 tried and resulted in very striking advantages in favour of 

 close planting. The cotton plants were smaller, with fewer 

 vegetative branches than when planted far apart, and the 

 yield per acre was greater, although the yield per plant was 

 reduced. Most of the cotton was produced on the fruiting 

 branches of the main stock, and very little on the vegetative 

 branches. The same general results were obtained with 

 Durango cotton, although the differences were not so marked. 

 The quality of the fibre seems to be maintained by this method 

 of planting. 



Zebu Crosses in Italy. Results, which are also 

 the first reported in Italy, are given in connexion with cross- 

 ing Zebus with the Maremma, Eomagnola and Perugia breeds. 



The zebu bull u.sed, belongs to the Gujerat breed, one of 

 the most esteemed breeds of India; it is about 3A years old 

 and weighs 1,430 R). It combines an elegant shape with 

 great robustness and remarkable agility. This bull served 

 113 cows between November 1912 and May 1914. Of this 

 number only nine remained .sterile, or 8 per cent: among them, 

 were some Schwyz and Dutch cows. 



From an examination of the characters of the crosses 

 obtained from the male Zebu with the Komagnola and 

 Perugia females as well as of those from the Schwyz and 

 Dutch dams, which some farmers have bred out of curiosity, 

 though they had Lecn warned that the Gujerat cows jiroduce 

 only enough milk for their own calves, the writer has been 

 able to collect the following data: — 



1 . That in all the crosses the characters of the Zebu are 

 dominant where the fineness of the skeleton, the abundance 

 of dewlap, develojjment of the ear, slope of the rump and 

 muscular .system are concerned. 



2. That the coat-colour and size of horns seem recessive. 



3. That in general all the crosses show remarkable 

 agility" in their movements and great robustne.ss. 



4. That they show niuch aptitude to produce ttesh. 



.5. That they seem to possess considerable resistance to 

 foot-and-mouth disease; this resistance seems to be due to 

 heredity, as would appear from observations made at the 

 Gorio dairy near JJrescia, where a male and a female Zebu of 

 the Gujerat breed which were kept together with a herd of 

 seventy brown Alpine cows were spared by the foot-and- 

 mouth disease. {Monthly Jiullitin of Af/riculliual Intelli- 

 geitce and Plan'. Diseases.) 



