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The husk, cotyledon, epidermis, and the clean rice constitute the whole of the paddy. Therefore, calling the amount of mineral matter in the paddy 100 per cent, we have:

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Now, the planter who sells paddy retains and returns to the soil the 72.16 per cent of the total mineral matter of the plant which is contained in the stubble, root, straw, and leaves, while he loses the 27.84 per cent which is contained in the paddy, but the planter who sells clean rice loses only the 1.94 per cent contained in the clean rice, or say 2 per cent. Unfortunately for fertilization the 27.84 per cent must be lost, since the husking and pounding of the paddy upon the plantation can not be made to pay as far as large commercial crops are concerned, because of the cost of machinery, as has been above explained. There is a certain compensation, however, in the fertilization of rice swamps by alluvial deposit from the river every year.

The mineral matter of the plant finds its way back to the soil by various channels. The stubble and roots are plowed under at the fall plowing after harvest and have the whole winter in which to rot. The straw and leaves may be used as forage for live stock, and are thus converted into manure, or, if used as litter, they may be rotted in the manure heap. Even if burned their ashes are valuable. The husk and chaff, mixed as they usually are with a small proportion of broken rice and flour, make an excellent fodder for live stock, especially for swine, being richer in nitrogenous matter (gluten) and in saccharine matter than clean rice, and are thus returned to the soil under favorable circumstances as manure. The value of the plant as a fertilizer, however, depends more upon the quality than upon the amount of the mineral matters which it contains, and some parts are more valuable than others in this respect. Thus of the mineral constituents of the epidermis lost to the soil when the crop is sold as paddy, over 50 per cent consists of most valuable salts, while in those of the root, straw, and husk such salts do not amount to 10 per cent. Prof. Shepard goes on to say that the husk of the rice, which suffers conversion into humus with extreme slowness unless fermented with stable litter, seems to be overlooked by planters, and that as it contains over 30 per cent of carbon it must be capable, when incorporated with the soil, of performing to a considerable extent the functions of humus, that is, gradually giv ing rise to carbonic acid and of raising temperature by eremacausis. Besides this its minutely divided silica is in a more favorable condition for absorption by the roots of plants than that found in the soil itself. The husk also acts mechanically in opening the soil to air and moisture, but, unlike the stalk and leaf, it does not contain any alkali, so that perhaps the addition of wood ashes might be of benefit.

DISEASES AND ENEMIES OF RICE.

In the United States rice has but few diseases, and none of them have been thoroughly investigated by scientists. One or two smuts of rice are known but have not yet been written up. One of the commonest diseases of the plant is rust, which may generally be remedied by lowering the level of the water upon the fields. Another is a disease called by the Italians "Brusone," and which entirely destroys the crop; its causes and nature are more fully discussed under the account of rice-growing in Italy (page 70). In fact our agricultural literature is extremely poor in information upon this subject, which should form an interesting field for investigation.

On the contrary, the insect and bird enemies of rice are well known, and have been attentively studied and described. The following description of the more important insect enemies of the plant and of their work is condensed from the report of the entomologist of this Department for 1881, the observations having been made upon the rice fields of South Carolina and Georgia by Mr. L. O. Howard, principally upon the plantation of Col. John Screven upon the South Carolina side of the Savannah River, about 5 miles below the city of Savannah.

The water weevil (Lissorhoptrus simplex Say).-This is one of the principal of these insects, and is a beetle of the family of the Curculionida. For many years the rice planters of the Savannah and elsewhere along the Atlantic coast have been familiar with two insects, the one a minute white, legless grub, infesting the roots of the rice plant, and known as the "maggot," and the other a small gray beetle affecting the leaves of the plant, and called the "water weevil." It has now been ascertained that these two insects are one and the same, the maggot being the larva of the beetle. The adult insect makes its appearance in April and May, feeding upon the leaves of the young rice during the "stretch flow," and unless present in enormous numbers does not cause any very extensive damage. It generally feeds during the morning, and being semiaquatic in its habits and as much at home under the water as out of it, escapes the heat of midday by crawling down the stalk into the water below. The insect breeds at this season, the female laying her eggs among the roots of the plant.

After the "stretch flow" is drawn off the fields and the period of dry growth commences, the eggs seem to lie in a dormant state, only hatching after the "harvest flow" is put upon the fields, which is in July or August. Hence the popular idea that "the maggot is generated by stale water" during this flow. The presence of water seems necessary to the existence of the larva, and in practice the drawing off of the water for a day or two during the "harvest flow" affords a partial remedy and the maggot may sometimes be thus killed off, though generally the drying of the field sufficiently to do this effectually causes more injury to the crop than is done by the insect. The presence of this

insect at the roots may be detected by the appearance of the plant, clumps here and there, or sometimes even whole patches, having a sickly, yellowish appearance, very different from that caused by the white blast described further on. The Lissorhoptrus, says Prof. Riley, is extremely common in all parts of the United States (east of the dry regions of the west) wherever there are swampy places, and may be found at all seasons of the year. It feeds upon a great variety of plants, mostly aquatic, such as the water lily, bulrush, sedge, and arrow head, besides upon wild and cultivated rice. Hence if the larvæ were effectually driven out from a rice field the field would soon become repopulated with them from other sources.

The rice grub (Chalepus trachypygus Burm.)-This is the larva of a large beetle of the family of the Scarabæida, closely related to the sugar-cane beetle and the sunflower beetle. This insect makes its appearance in May, at times when the rice fields are dry, and works its way into the ground, feeding upon the young roots of the rice and laying its eggs there. The larvæ hatch by June, and as long as the ground remains dry do much damage, but when the "harvest flow" occurs both the adult insects and the larvæ are drowned, since they are not of aquatic habits like the water weevil. Among upland rice fields where there is no irrigation this grub might do serious damage. This insect breeds among the dry lands at the back of the rice swamps where "volunteer" rice has been suffered to grow unchecked, and thence descends upon the cultivated fields. It is not known to attack any other plant than rice, and hence an easy remedy is suggested. The affected fields should be planted with some other crop for a year or two, while all the "volunteer" rice should be carefully removed.

The rice stalk borer.-This is the larva of a moth (Chilo plejadellus Trinck.) of the family of the Crambida, and is allied to the insect which attacks maize and sugar cane in a similar manner.

Mr. Howard, in the report of his observations at Savannah, writes as follows of this insect:

I noticed while passing through the fields that many of the rice heads were dead and white. I learned that this appearance was known as "white blast," and that the popular explanation of its cause was "poison of the soil." Such an explanation, however, would not account for the dying of one stalk in a bunch, as was almost invariably the case, so I immediately suspected insect work. I examined several of the blasted heads without finding any satisfactory cause, the head seeming dead from the base of the grain cluster, but below that point the stalk appearing sound. I soon, however, found a stalk where, at the first joint below the head, concealed by the sheath of the leaf, and inside the stalk, was working a very minute Lepidopterous larva, whitish in color, and striped longitudinally with subdorsal stripes of reddish brown. Soon after I found other larvæ of the same species lower down in the stalk, and at last reached a spot at the intersection of two ditches, where I found full-grown larva an inch long, quite at the base of the stalk, and also one or two healthy pupae. In these cases the stalk appeared dead quite to the roots, all the leaves being brown and withered. In perhaps one-fifth of the stalks afflicted with the blast, this larva, either large or small, was found. I never found more than one

full-grown individual in a stalk, but frequently found from one to six or eight young ones. All sections of the stalk seemed equally liable to be infested, the smaller larvæ being usually found nearer the head where the stalk is smaller, while the larger individuals from necessity were found lower down. The larva, as it increases in size, does not, however, continue to burrow down the center of the stalk to roomier quarters, as it might easily do, but apparently, when the stalk becomes too small for it at any one point, it bores its way out through a circular hole and crawls down the outside of the stalk to a lower point and enters again. The holes of exit and entrance are usually hidden, except at the very base of the stalk, by the clasping base of a leaf, the larva being obliged apparently to work its way into this tightly fitting crevice in order to get sufficient purchase to bore through the hard stalk.

There seems little enough for the larva to feed upon in the stalk, and it only eats the layer lining of the stalk cavity. When a larva is ready to transform (it is then at the base of the stalk) it continues its hole of entrance through the inclosing leaves, making it at the same time larger. It then returns to a higher position in the stalk (from 1 to 2 inches above the aperture) and transforms without reversing its position and with its head always from the opening. The duration of the pupa state is not more than five or six days. No observations have yet been made on the eggs, but they are probably laid on the upper leaves close to the stalk.

The adult moth is of a pale yellow color, with golden patches and scales, having as a rather distinctive mark a row of seven black dots at the end of each anterior wing. It seems to do no further damage to the rice plant after laying its eggs upon the leaves in order to produce the destructive borer, and in this respect differs from the water weevil, both the larva and the perfect insect of which feed upon the plant. There is apparently but one brood in a season upon the fields themselves, though a second brood is generally developed upon patches of volunteer rice beyond the fields later in the season. The stalk borer has an enemy of its own, which may serve in a measure to lessen its numbers. This is the larva of a small fly (Phora aletic Comstock), which may be found preying upon the pupa inside the stalk. The best way to rid a plantation of the borer is to cut the stubble, "volunteer "rice, and weeds after harvest as close to the ground as possible, and then to burn them thoroughly in some safe place where the fire can not be communicated to the peaty tanks. The ravages of the stalk borer are somewhat limited upon the lowland swamps, and it would naturally do much more damage upon the upland fields.

White blast. The exact nature of this effect upon rice is as yet but imperfectly understood. It may be caused by an insect, and it may be due to fungous disease or to other causes. It is discussed in substance as follows in the above-mentioned Entomological Report:*

According to the observations of Col. Screven, it is not unusual among the rice fields to observe here and there a few heads of rice, singly or in groups of from two to seven, which have an unhealthy, dead-white, gray, or "blasted" appearance. When this number of affected heads is not exceeded in a patch of 150 feet square the injury is pretty certain to be due to the attack of the above-described stalk borer; but when,

Report of the Commissioner of Agriculture for 1881 and 1882: Report of the Entomologist, "Insects affecting the rice plant" (pp. 127-138).

14257-No. 63

as is sometimes the case, the injury is widespread and many heads are affected, the presence of white blast may be suspected. At first it was supposed that this disease was due to the presence of deleterious elements in the soil, popularly called "poison of the soil," aggravated, perhaps, by insect attack; but it was soon seen that this could not be the case, as all the rice was not affected alike, and as healthy plants could be seen growing upon suspected spots, and even a healthy and a diseased head could be found growing from the same root, and having originated from the same individual seed. It was also thought that a brackish condition of the water from accidental admixture of sea water might be the cause, but this idea was refuted by the fact that of two fields equally brackish one was badly affected by the disease and the other hardly at all. Another surmise was that certain localities might be especially favorable to insects, but this was also disproved. The attack of insects upon the pollen of the flowers and the presence of fungus have also been suggested as causes. It was observed that this appearance of white blast occurred after the "harvest flow" had lain upon the soil for about forty days, and generally affected the first heads which shot out, subsequent heads being generally free from attack.

The appearance of a rice plant affected by white blast is very similar to that of one affected by the stalk borer at first sight, but upon closer inspection one or two points of difference may be noticed. In stalk-borer attack the head is of a deadwhite color, becoming afterwards gray from exposure to the weather, while generally the whole stalk and leaves of the plant, at least above the point where the larva is at work, are withered and brown. In white-blast attack it is generally the head alone which is affected, the stalk and leaves remaining green, and to all appearances perfectly sound and healthy, while the head at first becomes yellowish and then dead white, the distal end of each grain having a brownish spot, while later on the whole head becomes black, possibly from the presence of a fungus, the growth of which is favored by the diseased state of the plant. Very different from this is the appearance of a plant poisoned by sea water; the head shoots out covered with black spots upon the husk, and there is no dead-white appearance at all, while the leaves are red at the ends, and are also covered with black spots, and the whole plant finally dries up, the grains turning black and the husks remaining empty.

In examining rice heads affected by white blast, Mr. Howard found several insects, namely, Scymnus fratemus Lee, a species of Orchelimum, a species of Thrips, and also the common chinch bug (Blissus leucopterus). It is possible that white blast is the after effect of some insect injury earlier in the season, although no traces of extensive work either upon stalks or heads was to be seen. It may be due to the puncture of some insect, possibly by the chinch bug, which arrests the nourishment of the head and predisposes it to the attack of fungous growth, though no fungus was detected other than the black spots upon the husk, which might have been the result rather than the cause of the disease. The work of the water weevil may also have some influence in causing the disease as an after effect.

Several other insects are found upon the rice fields. One of these is the common "grass worm" of the Southern States (Laphygma frugiperda Sm. and Abb.), the moth of which lays its eggs upon the stalks. The worms, when hatched, cut the plants badly, and, when in great numbers, eat them quite down to the ground during "dry growth." When water is upon the fields they may be easily destroyed by drowning when knocked off the plant. In August and September the fields are frequented by myriads of the "lubber grasshopper" (Romalea microptera), which, however, seems to do little or no damage.

The ricebird (Dolichonyx oryzivorus).-There are many species of birds which prey upon the rice plant, but this one does more injury than all the rest together; it is also known as the reed bird along the Chesapeake, and the bobolink in the Northern States. The habits and

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