Aeroclimatlc reculrementl. Early maturing rice varieties planted Resource utilization. The principal advantage of DSB Is that it
Ic June are ready for harver': !n ti roximately 110 days from the date of allows the early establishment of a rice crop at the beginning of the
initial planting, allowing for the possibility of planting a subsequent wet season. This Increases the potential for growing a second rice crop
rice crop or an upland crop.1 A second rice crop, however, would face a under relatively favorable moisture supply conditions (Figure 7). If
high probability of drought stress In the flowering and maturity periods the second rice crop can be planted and harvested soon enough, the
(Fig. 5). Information gathered from CSP cropping pattern trials in possibility also exists for a third planting under conditions favorable
Iloilo demonstrates that expected yields from second rice crops are on for the growth of upland crops. Adoption of the DSR technique would
average one-half those of rice crops established at the beginning of the increase the requirement for land preparation labor during a period when
wet season. Moreover, while first crop yields tend to be somewhat little or no farm work usually takes place. Capital requirements are
stable, second rice crop yields exhibit large year to year variations, similar to those required for planting early maturing varieties using
other seeding methods with the possible exception of herbicide. Since
1ilt to farmers. During interviews of sample farmers, the dry land preparation does not effectively control weeds, the use of
question was raised as to why. they had adopted, or were in the process herbicide appears to be a necessary pre-condition for the adoption of
of adopting, new rice varieties. The reasons expressed, in order of DSR.
their importance were: a) increased potential for multiple cropping; b)
increased yield levels per crop; c) early harvest replenishes rice Contribution to household objectives. To the extent that DSR fastocks at an opportune time; d) lower incidence of pests and diseases; cilitate3 increased cropping intensity, the ability to meet household
e) resistance to lodging, food requirements and increase farm incomes will be enhanced. Because
planting takes place early In the season, rice stocks can be replenished
Ten out of twelve farmers interviewed listed increased multiple at an early date.
cropping potential as the principal advantage of new varieties. All
farmers mentioned increased per crop yields as important, though Institutional requirements. The institutional requirements for DSR
generally less significant than multiple cropping potential. Farmers would be similar to those for establishing any new early maturing, high
with the smallest areas suitable for rice crop establishment mentioned yielding rice variety.
early harvest as important for replenishing their family's dwindling or
non-existant rice stocks. Peast, disease and lodging resistance were Managerial requirements. Three significant problems have been enmentioned by less than one-half of the sample, countered with DSH as a planting strategy: (a) poor and uneven
germination; (b) death of germinated seedlings due to drought; and (c)
The reaction to EMVs Is not entirely favorable, however. The excessive weed growth.
harvest of a crop planted at the beginning of the wet season occurs
during the part of the season when the frequency and intensity of Problems (a) and (b) are influenced by the nature of the rainfall
rainfall are high. The rice must be harvested wet, causing the manual distribution before the onset of heavy sustained rains. Thus, they are
threshing process to be more difficult and time consuming. Significant beyond the farmer's control once the fields have been prepared and
grain losses may also be incurred due to grain rotting and germination seeded. Problem (c), excessive weed growth, is controllable by farmers
If rice is allowed to remain wet over a long period. The most common assuming that sufficient labor and cash resources are available.
method of drying rice is the use of solar energy, a scarce resource in
the wet season. Timing In DSR is critical, as fields must be prepared and planted
at the very beginning of the wet season. After seeding, rainfall causes
On balance, the advantages of the new.varietieS seem to outweigh both weed and rice seeds to germinate. Since fields are never perfectly
the disadvantages, as evidenced by both the adoption behavior of farmers level, soil moisture conditions differ in different parts of the field,
(Figure 6) and their verbal responses, causing uneven germination. Due to their low photoperiod sensitivity,
new varieties will mature in roughly a constant period of time after
Existing Technology 2 Dry seeded rice crop establishment (DSR) germination. Therefore, if germination occurs unevenly, maturation will
also be uneven, thus delaying or complicating the harvesting process.
Dry seeded rice is not a new technology. The use of DSH in conjunction with new varieties, however, Is new. Aroclimatic requirements. Poor initial crop stands are likely if
there is either too little or too much rainfall. If rainfall is heavy
soon after dry seeding and sufficient water accumulates, seeds and young
lWhen transplanted, EMVs take slightly longer to mature (one to two seedlings may drown. On the other hand, a two to three week dry spell
weeks) due to time lost as each plant *recovers" from transplanting. after seeds have germinated can cause the death of a high proportion of
young seedlings.
610 61L