LLAVALLOL, ARGENTINA
Instituto Fitotecnico de Santa Catalina (FCAyF, UNLP)
CIGEN (UNLP, CONICET, CIC)
Yield of waxy and high quality protein maize hybrids developed in Argentina
--Corcuera,VR, Naranjo,CA
It is commonly believed that waxy maize hybrids, as well as quality protein
ones, yield less than their normal counterparts. This premise is set upon
the lower density of their starch, soft endosperm, and consequently lower
grain weight. During 1990, a maize breeding program aimed at obtaining
waxy maize hybrids, as well as quality protein ones, in Argentina, was
initiated at the Instituto Fitotécnico de Santa Catalina in Llavallol.
Since then, several inbreds have been developed and tested. Crosses among
the best inbreds were done, and finally during the growing season 2001/02,
numerous single-cross hybrids were first tested at this location, situated
at 35°S and 58°W. The hybrids tested can be classified into three
categories: waxy hybrids, quality protein hybrids and double recessives
combining modified starch with quality protein. The single-crosses, as
well as their parental inbreds, were arranged in a 3 replicate complete
randomised block design field trial. Each plot consisted of a single row
of 5.5 m, sown at a density of 71,500 plants/ha (see Figures 1 and 2).
At maturity, each plot was hand harvested, and many ear and kernel traits
were measured. Some of these traits are summarized in Tables 1, 2 and 3
according to the type of hybrid. Potential yield was calculated as the
product of ears/plant x grams of kernels/ear x plants/ha. Yields ranged
from 8.9 to 20.9 tons/ha, 1000-kernel-weights varied from 200 to 350 grams,
and 91 to 171 grams of kernels/ear were obtained (see Figures 3 to 5).
Generally, lower yields are consistent with lower 1000-kernel-weights,
smaller ears and/or a lower number of ears/plant. Thus, the yield of individual
plants is an important factor to be considered, and comes not only from
specific ear traits, but also from prolificity. It must be said that the
parental inbreds used to develop these single-cross hybrids were selected
among other traits because of their high prolificity. New trials at multiple
locations must be made to verify the surprisingly good preliminary results
obtained. By breeding, high yielding parentals may be selected, and choosing
the most appropriate single-crosses among them will make it possible to
develop high yielding modified starch or quality protein maize hybrids
adapted to our growing conditions.
Table 1. Waxy maize hybrids.
| Hybrid No |
Number of rows |
Kernels/row |
1000-kernel-weight |
Grams of kernels/ear |
No. Ears/Plant |
Potential Yield(1) |
| 3123 |
16 |
34 |
300.0 grams |
102.1 |
"1.7" |
12.0 |
| 3166 |
16 |
17 |
330.0 grams |
134.7 |
"1.7" |
16.0 |
| 3167 |
14 |
27 |
310.0 grams |
107.0 |
"2.0" |
14.1 |
| 3168 |
14 |
36 |
350.0 grams |
149.1 |
"1.9" |
18.4 |
| 3170 |
16 |
33 |
350.0 grams |
147.1 |
"1.6" |
15.8 |
| 3172 |
12 |
38 |
340.0 grams |
146.8 |
"1.5" |
15.2 |
| 3173 |
14 |
31 |
310.0 grams |
131.3 |
"1.6" |
14.1 |
| 3175 |
18 |
33 |
265.0 grams |
136.3 |
"1.8" |
15.9 |
| 3176 |
16 |
34 |
340.0 grams |
170.2 |
"1.8" |
20.9 |
| 3177 |
16 |
30 |
270.0 grams |
113.8 |
"1.5" |
11.7 |
| 3178 |
disordered |
disordered |
380.0 grams |
90.2 |
"2.0" |
12.5 |
| 3179 |
15 |
36 |
210.0 grams |
81.8 |
"1.7" |
9.0 |
| 3180 |
16 |
36 |
310.0 grams |
125.9 |
"1.5" |
12.4 |
| 3182 |
14 |
31 |
310.0 grams |
119.6 |
"1.2" |
9.4 |
| 3184 |
14 |
36 |
320.0 grams |
159.2 |
"1.5" |
15.5 |
| 3185 |
16 |
36 |
320.0 grams |
146.2 |
"1.7" |
16.6 |
| 3186 |
16 |
31 |
290.0 grams |
140.4 |
"1.6" |
14.8 |
| 3187a |
16 |
33 |
330.0 grams |
130.9 |
"1.7" |
13.7 |
| 3187b |
16 |
35 |
350.0 grams |
134.3 |
"1.7" |
16.2 |
| 3190 |
16 |
30 |
270.0 grams |
118.4 |
"1.3" |
10.0 |
| 3192 |
16 |
33 |
330.0 grams |
171.0 |
"1.3" |
14.1 |
| 3196 |
14 |
37 |
320.0 grams |
132.4 |
"1.2" |
10.7 |
| 3197 |
16 |
30 |
310.0 grams |
121.8 |
"1.5" |
12.1 |
(1) Tons/hectare corrected at 15% moisture content in kernels.
Table 2. High quality protein maize hybrids.
| Hybrid No. |
Number or rows |
Kernels/row |
1000-kernel-weight |
Grams of kernels/ear |
No. Ears/Plant |
Potential Yield(1) |
| 3126 |
18 |
32 |
230.0 grams |
119.2 |
"1.3" |
10.8 |
| 3145 |
14 |
28 |
290.0 grams |
96.1 |
"2.0" |
14.9 |
| 3146 |
14 |
32 |
290.0 grams |
129.3 |
"2.0" |
18.4 |
| 3147 |
16 |
27 |
250.0 grams |
91.3 |
"1.4" |
8.9 |
| 3148 |
16 |
32 |
260.0 grams |
127.6 |
"1.6" |
13.8 |
| 3150 |
14 |
28 |
200.0 grams |
99.0 |
"1.7" |
10.6 |
| 3151 |
14 |
31 |
280.0 grams |
120.5 |
"1.6" |
13.0 |
(1) Tons/hectare corrected at 15% moisture content in kernels.
Table 3: Modified starch and quality protein (double recessives) maize
hybrids.
| Hybrid No. |
Number of rows |
Kernels/row |
1000-kernel-weight |
Grams of kernels/ear |
No. Ears/plant |
Potential Yield(1) |
| 3159 |
14 |
35 |
280.0 grams |
129.5 |
"2.0" |
17.1 |
| 3160 |
14 |
36 |
345.0 grams |
115.3 |
"1.9" |
14.7 |
| 3161 |
16 |
33 |
280.0 grams |
140.3 |
"1.7" |
16.4 |
| 3163 |
14 |
36 |
300.0 grams |
140.1 |
"1.7" |
16.4 |
| 3164 |
18 |
31 |
330.0 grams |
162.0 |
"1.3" |
13.8 |
| 3165 |
16 |
32 |
280.0 grams |
135.7 |
"1.1" |
9.9 |
| 3198 |
14 |
27 |
340.0 grams |
111.4 |
"1.3" |
10.0 |
| 3199 |
14 |
35 |
340.0 grams |
145.0 |
"1.7" |
18.8 |
(1) Tons/hectare corrected at 15% moisture content in kernels.
Figures
1-5. Waxy and Quality Protein Hybrids. Left: 2001/02 field trial.
Upper right: original waxy inbred. Center: waxy hybrid. Bottom right: quality
protein maize hybrid.
Please Note: Notes submitted to the Maize Genetics Cooperation Newsletter may be cited only with consent of the authors.
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