Varietal Improvement
New Recommended Variety
Four (4) new sweetpotato cultivars were released and approved by PhilRootcrops as new recommended variety. The approval of the nomination to release the four genotypes as recommended would mean that diversity of sweetpotato varieties now available for farmers would have increased. Additional two studies were independently conducted under supervision of Dr. Marcelo A. Quevedo and Dr. Dilberto O. Ferraren.
BLSM 115 and BLSM 151 and PRG 813 (commonly called as Chowking) are two new entries of taro varieties in the latest evaluation under upland condition. These new genotypes are introduced through the EU Taro project.
Cassava
Breeding. Sixteen (16) accessions were selected rom the germplasm and being utilized as parent materials in the hybridization blocks. A total of 1420 open-pollinated hybrid seeds were collected and planted in field for a single seed evaluation. Sixty (60) plants survived and now are planted in the field of preliminary evaluation.
Yield trials. The national cooperative testing (NCT) for cassava was temporarily stopped due to limitation in funds giving way for NCT sweetpotato. In the meantime, outstanding varieties that perform well in various regions were mass produced using 2-nodal system.
Screening.Ten (10) genotypes were selected and planted under coconut for screening on shade tolerance due to unfavorable circumstances such as availability of tractor for land preparation, suitable area under shaded condition and inclement weather condition.
Sweetpotato
Breeding. Thirty (30) sweetpotato accessions were used as parents in the polycross breeding nursery. A total of 4,887 seeds were collected from October 2016-May 2017. From the previous collection, a total of 3,478 seeds were sown and 1,296 F1s were planted for single plant evaluation. Two new sweetpotato polycross breeding nursery were established- one at the Seed Bank area and another at the corner of Warner St. and Killbourne St.
Observational trial. From 2011 – 2015, more than 33 trials had been done. From these 33 trials, only 19 trials qualified as valid trials whose coefficients of variation per trial were less than 30%. Out of the 19 trials, 11 trials had NSIC SP 30 as a check variety, 14 trials used NSIC SP 31, 8 trials used NSIC Sp 32, and 6 trials used NSIC Sp 33 as check varieties.
Yield trial. A study on the performance of storage roots of some NSIC – released SP varieties and elite lines under postharvest ambient storage condition was conducted, and it showed that the lines and the NSIC SP varieties (NSIC Sp 30, NSIC 32 and NSIC 33) did not show signs of sprouting. However, in terms of flavor, texture and over - all general acceptability was positive. Among the lines evaluated, SG – 8 – 19 – 01, JK 10 – 14 -01, JK 10 – 24 – 7, had good quality even at 14 days in storage although shelf life was short. While, JK – 10 – 24 – 7 & SG – 19 -01, had comparable shelf life with the NSIC varieties of about 21 days under ambient conditions.
It was observed that NSIC Sp 33 out yielded all the tested varieties with a yield of 9.58 ton/ha in terms of the performance of the earlier released varieties against most NSIC SP releases.
A total of 4887 seeds were collected which 3478 F1’s seeds were sown. Only 1296 F1’s seeds were planted for single plant trial. About new 66 F1’s with desirable traits were planted in Preliminary Yield Trial. A total of 10 F1’s were evaluated for the General Yield Trial. The growth and yield of all 10 hybrids were affected by long dry season.
Regional trials. 4 F1 hybrids were used as entry for Regional Yield Trial (NCT) 2015 – 2016. 2 F1 hybrids were released; NSIC SP 34 – JK – 09 – 11 – 08 with red skin and purple flesh, and NSIC SP 35 – JK – 09 – 25 – 05 with white skin and orange flesh.
Yam
Yield evaluation across locations. Fourteen(14) recommended and promising varieties of ubi and 5 recommended varities of tugui were subjected to two advanced trials in a high elevation farm in Lake Danao, Ormoc City in order to compare the agronomic performance of the different recommended varieties that have already been released in this new environment. The ubi trial that showed the highest sett survival rates were observed in VU – 2, NSIC VU – 6, NSIC GY – 8 and LA – 539 with 82% to 96%. The best yielding tugui variety in the tugui trial under the high – elevation environment was PSB VT – 3 at 14.45 Mton/ha.
Taro
Yield evaluation. Out of the ten entries, only eight genotypes were incorporated in the 2014 – 2015 season. GO – 709, GO – 711, GC – 715 and GO – 781 are cases that have high yield under upland condition. The local accessions PRG 813 and PRG 744 could be good sources of genes for the improvement in dry matter content.