Information from 1998 Missouri Rice Research Update, February 1999.

Effects of Nitrogen on Baldo Rice

Gene Stevens and Eric Tanner1

Abstract

Baldo rice is a variety developed in Italy that has potential for export at premium prices. However, since Baldo is very sensitive to over fertilization special attention must be paid to the management of this crop. A study was conducted to determine the effect of different pre-flood nitrogen rates on lodging and yield of Baldo rice. When nitrogen rates were less than 100 lbs./acre, lodging was 3% and lower. As nitrogen rates increased over 100 lbs./acre, small increases in fertilizer caused increases in lodging percentage. An increase from 120 lbs./acre of nitrogen to 150 lbs./A caused lodging to increase significantly from 39% to 82%.

Introduction

Baldo was bred in Italy in 1954. It is utilized mainly for risotto dishes and for the parboiling process. Baldo has good resistance to cold water, good resistance to cold during sprouting, a medium resistance to cold during flowering, and medium to low resistance to lodging. Baldo is a very short season variety that will stand 3.5 to 4 feet tall with the ability to yield from 95 to 110 Bu/acre.

Materials and Methods

Baldo was drill seeded at a rate of 2 Bu/acre with varying rates of nitrogen applied at the pre-flood stage. The seven rates applied were 0 lb. N/acre, 30 lb. N/acre, 60 lb. N/acre, 90 lb. N/acre, 120 lb. N/acre, 150 lb. N/acre, and 180 lb. N/acre. All treatments received one mid-season application of 30 lb. N/acre. All nitrogen was applied in form of Urea.

Results

As with most other rice varieties, if nitrogen rates are too high chances for lodging occur. This is extremely prevalent with Baldo. The plant uses the excess nitrogen for vegetative growth. The increases in plant height not only results in lodging but could also be a cause in yield reduction.

For each treatment there were varying rates of pre-flood nitrogen applied and 30 lbs. N/acre applied at mid-season on all treatments. As table 1 indicates an increase in nitrogen up to 120 lbs. N/acre caused yields to increase. When applied nitrogen levels were higher than 90 lbs./acre though, lodging increased significantly.

Table 1. Nitrogen rates applied and the effect on yield and lodging.

    Pre-flood           Total N,        Percent            Yield,
     N, lb./a            lb./a          Lodging             Bu/a
        0                  30              0                 71
       30                  60              3                 73
       60                  90              3                 78
       90                 120             39                 96
      120                 150             82                 80
      150                 180             79                 87
      180                 210             96                 73

All treatments received mid-season N applications at the same time (30 lbs. N/acre).

Conclusion:
The sensitivity of Baldo to nitrogen causes extra concerns for growers. Specific management practices must be employed to achieve maximum yields with minimal lodging. Over fertilization can occur easily with this variety. The total amount of nitrogen applied should not exceed 100 lbs./acre. Supplying nitrogen to the plant at critical periods of grain formation is essential. The need to make more applications will in turn increase the production cost of raising the Baldo variety. It is uncertain at this time of the yield potential of Baldo. However, yields will most likely be lower than other varieties.


1Crop Production Specialist, Rice Farm Manager, University of Missouri-Delta Center.


Nitrogen Timing on Cypress Rice

Gene Stevens and Eric Tanner1

Introduction

This test was designed to determine the best timing of nitrogen application. Each year the cost of producing rice continues to increase. The objective of this study was to determine the most profitable method of applying nitrogen fertilizer.

Materials and Methods

The test was planted with Cypress rice. Each treatment received a total of 150 lbs. N/acre. Five different treatments were applied to determine efficient timing. The first treatment was applied according to the current recommendation for Cypress, 90 lbs. N/acre pre-flood, one 30 lb. N/acre at one-half inch internode elongation (I.E.) and one 30-lb. N/acre one week later. The second treatment had 90 lbs. N/acre applied pre-flood and 60 lbs. N/acre at one-half inch I.E. The third treatment had 105 lbs. N/acre applied pre-flood and 45 lbs. N/acre at one-half I.E. The fourth treatment had 60 lbs. N/acre applied pre-flood, 45 lbs. N/acre at one-half inch I.E., and 45 lbs. N/acre applied one week later. The fifth treatment had the entire 150-lbs. N/acre applied pre-flood. These different applications provide a wide variety of methods of applying 150 lbs. N/acre.

Results

The first treatment, which had the recommended nitrogen application, yielded 119 Bu./acre. The second treatment, which only had one midseason application, yielded 120 Bu./acre. The third treatment yielded 118 Bu./acre. The treatment that received 60 lbs. N/acre only yielded 110 Bu./acre and the treatment that received 150 lbs. N/acre all at pre-flood yielded 107 Bu./acre.

Table 1. Nitrogen timing applications.

Preflood          ½-inch IE        ½-IE + 1 week        Yield, Bu./a
   90                30                  30                  119
   90                60                   0                  120
  105                45                   0                  118
   60                45                  45                  110
  150                 0                   0                  107

All treatments received a total of 150 lbs. N/acre.

Conclusion

Applying all the nitrogen pre-flood reduced rice yields by 12 Bu./acre. A split application of mid-season nitrogen was not necessary. We found that one large midseason nitrogen application resulted in the same yield as two smaller applications. Saving one midseason nitrogen application could save growers $4 to $6 per acre.


1Crop Production Specialist, Rice Farm Manager, University of Missouri-Delta Center.