Rice Production Systems and Miscellaneous Studies-69

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As the first phase of this new project, methods were developed to coat dry rice seed with various materials to add weight and thus eliminate pre-soaking. Selected as primary coating materials were kaolinite clay and an agricultural talc (Agtalc), each cheap and inert, and forming smooth, dust-free coatings. These were combined with fungicides, activated charcoal, micronutrients, and other materials that may improve stands or seedling protection.

Several field trials are under way to evaluate the performance of new herbicide formulations and methods of herbicide use: 1) methods of molinate application (including combination with liquid suspension fertilizers); 2) preliminary evaluation of herbicides; 3) advanced evaluation of herbicides in 1000-sq-ft plots; and 4) final evaluation of Hydrothol 191 for control of submerged weeds. Other weed-control trials are being planned, including a large-scale application of Hydrothol 191 for submerged weed control and an evaluation of new herbicides for drill-seeded rice.

The main objective of this seed-coating work is to provide a means of saving time and cost of planting through the numerous possibilities of combining operations and improvement of stand establishment. Coated seed may be better adapted for drill seeding or for water seeding by air than the usual pre-soaked seed. Seeds coated with activated charcoal may have the additional advantage of heat absorption for better tolerance of cold water. If new herbicides are found for pre-emergence weed control, it should be feasible to combine the operations of herbicide application and sowing seeds with protective coatings.


Economic analysis of potential modifications to rice production systems has not yet progressed beyond initial organization.

The first project element to be undertaken will be to quantify a PERT model for current rice production systems so that it may serve as a guide for those planning research involving modifications in timing and sequence of the rice production system.


Three rice varieties were sown at Davis at four planting dates spaced 10 days apart in 1969. The varieties were Earlirose, Colusa, and Bluebelle, and planting dates were May 1, 10, 20, and 30. The approximate respective flowering dates for these four planting dates were August 12, 20, and 30, and September 12. The last two planting dates failed to produce a crop, because of late maturity.

The Davis location has cooler nights and lower early spring and fall temperatures than the main part of the rice-growing area. Yields exceeded 8,000 lb per acre for the early plantings of Earlirose and Colusa, whereas Blueb elle showed some blanking even at the earliest planting date and dropped nearly 50% when sown on May 10.


Two contract studies are in progress in the U.S. under the P.L. 480 program, and one grant in Japan. These are in addition to our small in-house research program.

The P.L. 480 grant, under the direction of Dr. Takashi Akazawa of Nagoya University, Japan, involves basic studies on the enzyme governing starch formation and degradation.

One of our contracts, sponsored by both the Western and Southern Utilization Research and Development Divisions, is with UC-Berkeley and is concerned with evaluations of the deep-milling process to provide high-protein rice flours. The other contract is with URS Systems, Burlingame, California. It is a survey of potentialities for several possible uses for rice hulls in light of current economics and technology.

Our contract at UC has been a two-stage investigation. In the first stage, two short-grain, two medium-grain, and two long-grain representative milled rices were each remilled three times to remove some 3% as flour at each milling. Compositions and properties of the three flours were compared with those of the original and residual kernels. The changes in composition and properties are being evaluated in relation to the degree of milling to determine what is optimum. In other words, what amount of milling will provide at least cost flours with maximum nutrients and desirable processing characteristics and at the same time residual kernels with the best cooking quality. Although these final evaluations have not been completed, it does look as if a single milling removing 2- 3% of the kernel as flour might prove most suitable.

Based on results of this first phase, six special rices were additionally chosen for less extensive evaluation. Samples were a first and a second crop Texas Belle Patna (long-grain), California Belle Patna and Calrose, and a Belle Patna and a Calrose parboiled rice. The flours and kernels from these are being analyzed for amino acids, nutritional value, thiamine, and niacin. Phosphorus, calcium, and iron are being determined on the parboiled samples. Proximate analyses are also being made on all samples. Data on these rices should allow partial evaluation of effects of location, crop year, and within-season variations, as well as differences resulting from parboiling.

The high nutrient content of these outer-layer flours (e.g. 12-20% protein) makes them very nutritious foods. They can b e used as porridges, gravies, meat extenders, etc. We have partially developed a milk-like beverage from them, and are making further refinements in this preparation.

The second contract--on utility of rice hulls--is sponsored only by WRRL, and is of an engineering nature. The contractor is making initial surveys of the technical and economic feasibility in the context of present conditions of some fifteen selected potential uses for rice hulls. There are aside from present feed uses. Numerous others have been suggested over the decades, but these were chosen as potentially feasible at present. From this preliminary survey, four processes are being selected for a more complete feasibility study.


Equipment has been purchased for use on a pool basis to help local farm advisors working on field research projects. A full-time extension research technician has been at work since November 16, 1969, helping farm advisors conduct field and greenhouse rice experiments. He also helps backstop other rice research projects (fertility, genetic studies, etc.) wherever peak requirements for field assistance may develop.

Because he is especially interested in designing and making equipment for field experiments, we have made excellent progress in obtaining a part of the special field equipment needed for field phases of the accelerated rice research program:

A new rice combine with a 7-ft. header should make it possible for farm advisors to field-harvest at least a part of their plots without tying up the large commercial harvesters of cooperating farmers.

Two older plot harvesters have been reconditioned which will be ready for hand-harvesting small plots of the type used for herbicide screening micronutrient test work.

A precision fertilizer drill has been designed and custom-manufactured. It has a rate range of a few ounces up to 800 pounds per acre.

A precision field sprayer has been designed and custom-manufactured. It is being used for herbicide and growth-regulator work.


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