lyoS dise;ases of various crops 



CROPS 



equal parts, the first being planted with Phiinomen, the second with 

 Klosterfrauen and the third with Ohne Gleichen. By September 15, 1915 

 the writer had been able to prove that Phanomen was very severely attack- 

 ed by rust, while Klosterfrauen on the next plot was attacked very slightly. 

 The third plot planted with Ohne Gleichen behaved exactly like the first. 

 The first field planted with the three first mentioned varieties was 

 attacked fairly severely all over. 



1228 -The Resistance of Lucerne to Pseudopeziza Medicaginis in Uruguay 

 Attributed to tfie Use of Nitragin. — See No. 1180 of this Bulletin. 



DISEASES 1229- Diseases and Insect Pests which Attack Rice in Java. — Rutgers, a. a. i<., iu 



OF VARIOUS Teyxmannia, Year 27, No. 6, pp. 313-3.12. Batavia, 1916. 



Rice in Java is very considerably damaged by diseases and enemies 

 of one sort or another. For the last four years the total loss of plantations 

 wa s estmated at an average of 242 172 acres. In addition there is a consi- 

 derable loss due to the decreased productivity when the rice is attacked by 

 insects. In 191 2 complete failure of the crop was caused in several parts 

 of the island by insects. The monetary loss was estimated at about 

 L. 200 000. 



Although most of the diseases and pests have been fully investigated, 

 the relations that exist between the methods of cultivation and the attacks 

 of the pests still require further study so that means of suppressing the latter 

 can be discovered. 



Most of the mischief is done by insects; fungal diseases are not of 

 of any great importance. Diseases due to climate or to soil conditions some- 

 times play quite a large part. 



The following pests are mentioned: i) « Omo IMentek », root rot caused 

 by shortcomings of the soil; to combat this disease improvement of the soil 

 by cultivation should be aimed at; above everything stagnant water should 

 be avoided, as it encourages de-oxidation of the soil; 2) «Omo Djenoe », 

 caused b}^ Tilletia horrida, only once seen in Java without doing much 

 harm; 3) « Djamoer Parah », caused by UstUaginoidea virens; the cases ob ' 

 served are rare and the losses inconsiderable: 4) blotches on the leaves 

 are caused by Napicladiwn, Helminthosporium and Piricidaria spp.; it 

 remains to be proved whether the attacks of these fungi can result in a to- 

 tal loss of the plant; 5) Sclerotimn Rolfsii which sometimes leads to the loss 

 of several leaves; 6) « Omo Wereng », caused by the Cicadellidae or by the 

 Delphacinae, which can result in serious losses; the insects attack the flower- 

 ing stems which in consequence produce no caryopsis; 7) '( Omo Walang 

 sangit )), caused by Leptocorisa acuta; this insect attacks the young grains 

 and sucks out their contents; the loss can be considerable; 8) « Omo I,em- 

 bing », caused by Antestis histrio {Pentatomidae) or by Nezara viridida, 

 N. griseipennis and Podops vermiculatus; these insects by attacking the 

 stems prevent the ripening of the caryopsis; 9) « Omo Soendep », caused 

 by Schoenohius hipunctifer or by Scirpophaga sericea, Sesamia inferens 

 or Chilo sp., all these insects make their way into the flowering stems 

 where the lar^^ae bring about a total loss; «Omo Soendep » is one of the 



