þ MAJOR ENERGY INPUTS

Over half the energy use in rice production goes into the production and application of fertilizer, plus the transport and application of irrigation water. Clearly, the most advanced information available on conserving fertilizer and water becomes more important than ever.

þ CHEMICAL APPLICATIONS IMPROVED

The application of chemicals took strides forward with tests of thickeners and the University's new nozzle systems. Spray thickening agents reduced drift without hampering weed control. No thickener tested, however, was as effective as the Microfoil® device on a helicopter or the University's NDS system. Ram air spreaders in granular tests still, couldn't operate well at volumes below 25 lb/A. (RP4) .

þ ADVANTAGES OF SMOOTH-HULLED VARIETIES

Priority has been given to the development of smooth-hulled varieties because they offer several economic and ecological advantages, including better use of storage space and less dust in drying and storage. Those advantages are particularly important to rice mills, where air pollution regulations are being strictly enforced. The smooth-hulled varieties have less itchy dust. Growers and dryers will have to adjust their operations in various ways, however, just as the industry has done in the Southern rice states, where smooth-hulled varieties are now used practically 100%.

þ SMOOTH-HULLS DRY DIFFERENTLY

The special characteristics of smooth-hailed rice varieties call for slightly different handling in flat or bin dryers and in storage.

The slightly greater density allows about 5% more of the smooth-grains to be stored in a given volume - thus adding resistance to the flow of air. Tests show that drying smooth-hulled varieties at the same rate as rough-hulled varieties will take 25% greater static pressure (the extra needed to give the same air flow).

The greater resistance to air flow can be a problem in deep-bed dryers that are barely able to dry rough-hulled varieties. This problem is particularly bad in flat-bed storage with inadequate air supply. Reduced air flow can slow drying so much that mold or heat damage can lower quality.

Dryer operators storing large amounts of smooth-hulled varieties can solve the problem through several approaches:

1. Reduce the moisture level in the grain that goes into storage. For example, smooth-hulled varieties to be dried in flat storage must have a little less moisture than rough-hulled varieties for equally satisfactory drying under the same conditions. Smooth-hulled varieties dried in column dryers may require extra passes.
2. Speed up the fan, but only if its performance chart or someone really informed on its use indicates that faster speed will in fact increase air flow enough - and also that the fan will not fly apart!
3. Reduce the depth by storing less. You might need 15 % less than the depth that barely allows rough-hulled varieties to dry. Typically, however, smooth-hulled varieties are mixed with other varieties, so that depth might need to be reduced only by 5% or so. If drying has been no problem with standard varieties, maybe no reduction will be necessary - particularly when other varieties are mixed with the smooth-hulled.
4. Build additional storage. If the above procedures are not possible, additional flat storage may be required - including fans that can deliver the 25% greater static pressure needed.

A caution: Mixing as presently done may decrease in the future as smooth-hulled varieties become grown more widely. So prepare now for future possibilities.

Best advice of all: Consult a qualified engineer to make sure your capacity will in fact cope with this potential problem. (RM5)