Genotype-environment Interactions in Nutmeg (Myristica fragrans Houtt.)

Author: S.C. Priyanka, N. Miniraj, P. Lincydavis and H.C. Vikram

Download PDF

Abstract

Nutmeg (Myristica fragrans Houtt.) is a climate-sensitive perennial spice crop. There are several elite genotypes available in nutmeg which exhibit differential performance at various locations, due to their interactions with the environment. Very less information is available on genotype-environment interactions in nutmeg, which has got a long pre-bearing period. The present study was conducted with dual objectives of examining the performance of a set of nutmeg genotypes across diverse locations and their response to weather parameters with a view to identify genotype-specific adaptation as well as wide adaptability. Six genotypes of nutmeg which include three nutmeg varieties released from KAU, two promising farmer varieties and national check (IISR Vishwasree) were purposively selected for the study. For each genotype, three locations were chosen based on altitude. Six weather variables considered for the study were maximum temperature, minimum temperature, relative humidity, rainfall, wind speed and sunshine hours. To work out the linear relationship between yield traits (nut as well as mace yield per tree) and weather variables, Pearson’s correlation analyses were done followed by stepwise regression. The flowering phase ranged from 31st to the 44th standard meteorological week. The duration of each phenophase varied among the genotypes as well as locations. The weather variables which exerted positive influence on yield were, wind speed and rainfall in KAU Mundathanam (85.5%); maximum temperature in KAU Pullan (40.1%); relative humidity in Kadukammakkal (26.3%). In KAU Kochukudy, it was sunshine hours that influenced the dry nut yield per tree (62.6%) positively whereas it was minimum temperature that exerted a negative influence on dry mace yield per tree (69.0%). The illumination factor, sunshine hours negatively influenced all the yield traits in IISR Vishwasree (81.6%) and Kinattukara (47.2%). Highly significant differential response of nutmeg genotypes with weather was evident from all the locations. The magnitude of influence of weather variables for the yield traits was significantly different and specific to genotype. The study could indicate the suitability of each genotype in the studied locations.

Keywords

Nutmeg (Myristica fragrans Houtt.), nut yield per tree, mace yield per tree, wind speed, rainfall, sunshine hours

Conclusion

It is important to understand the influence of weather variables in perennial crops like nutmeg. The environments were diverse and there were sizeable differences in the response of genotypes to environments. Among the four phenophases of growth in nutmeg, the fruit development cum maturation phase (P3) is highly crucial with respect to the yield contributing factors in all genotypes. The duration of each phenophase varied among the genotypes as well as locations. Significant variation among genotypes, locations, and for genotype by location interactions with weather variables was observed for the two yield attributes. Considering the genotype-environment influences across the locations, the regression coefficient R2 value for KAU Mundathanam was quite high combined with highest nut and mace yield per tree. The weather variables which exerted positive influence on yield were, wind speed and rainfall in KAU Mundathanam (85.5%); maximum temperature in KAU Pullan (40.1%); relative humidity in Kadukammakkal (26.3%). Sunshine hours showed a positive influence on dry nut yield per tree (62.6%) in KAU Kochukudy whereas minimum temperature showed a negative influence on dry mace yield per tree (69.0%). The illumination factor, sunshine hours negatively influenced all the yield traits in IISR Vishwasree (81.6%) and Kinattukara (47.2%). The check genotype IISR Vishwasree was the lowest yielder across the locations, and remained unaffected by majority of weather variables.

References

-

How to cite this article

S.C. Priyanka, N. Miniraj, P. Lincydavis and H.C. Vikram (2022). Genotype-environment Interactions in Nutmeg (Myristica fragrans Houtt.). Biological Forum – An International Journal, 14(4): 394-403.