634 THE SMALL GRAINS 



714. Blackbirds. In the Texas-Louisiana rice dis- 

 trict, the ricebird is not important, but the blackbirds are 

 the chief offenders. These birds, which are winter resi- 

 dents, are everywhere, in all rice fields, early in the spring. 

 They begin their daily forage soon after sunrise, emerging 

 from the wooded banks of bayous, and feeding in the old 

 rice stubble, and also in the newly planted ricefields. 

 They are found in particularly large numbers on the 

 levees, where there is much shattered grain lying under 

 the mat of fallen stalks of both white and red rice. 



Other birds that feed on rice to some extent are the 

 meadow lark, the mourning dove, the English sparrow, 

 and the wild duck. 



715. Straight-head. Rice is affected by few diseases 

 in this country. Two of these, the straight-head and rice 

 blast, are sometimes very serious but do not occur in 

 California. Probably the most destructive rice disease 

 is the straight-head, so called because of the appearance 

 of characteristic upright, unfilled panicles late in the 

 season, when normal panicles are drooping from the weight 

 of ripe grain. The affected plants are normal in color and 

 foliage at time of heading, but the panicles remain erect 

 and unfilled and the glumes are frequently distorted, or 

 in extreme cases may be entirely absent. The cause of 

 this disease is not yet known, and at present it is referred 

 to as a physiological disease. No effective method is yet 

 known for preventing straight-head. 



716. Rice blast or rotten-neck (Piricularia grisea) occurs 

 generally in the rice-growing districts of the South. It 

 develops throughout the ripening season and exhibits two 

 main types as follows : (1) a leaf spot, in the form of a 

 large elongated brownish lesion, with a light center and 

 dark border, fading to yellow at its outer edge; (2) a 



