TITLE:
Influence of Carbohydrates, Mineral Nutrients and Plant Hormones in Alternate Bearing of Black Pepper (Piper nigrum L.)
AUTHORS:
K. S. Krishnamurthy, S. J. Ankegowda, V. Srinivasan, S. Hamza
KEYWORDS:
Remobilization; Starch; IAA; Zeatin Riboside; Reducing Sugars; Essential Oil; Oleoresin
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.4 No.10,
October
9,
2013
ABSTRACT: Alternate bearing habit, a common phenomenon prevalent
in some of the fruit trees is observed in black pepper variety Panniyur-1 also.
In this study, an attempt was made to investigate the role of carbohydrates,
mineral nutrients and plant hormones (IAA and zeatin riboside) in alternate
bearing in Panniyur-1 variety. The experiment was conducted for three
consecutive years at Murugarajendra estate, Madikeri, Karnataka, India (12.42。N, 75.73。E). Carbohydrate, mineral nutrient and plant hormone (IAA
and zeatin riboside) statuses of the leaves as well as fruiting branches (stem)
were compared between good fruiting year (on year) and low fruiting year (off
year). Results revealed that concentration of mineral nutrients in leaves was
more during on year compared to off year while the reverse was true on the
stem. Both stem and leaf metabolite levels at harvest were higher in off year
compared to on year suggesting that remobilization of nutrients to the
developing berries must have been affected during off year, thus leading to
accumulation of more nutrients at harvest in off year compared
to on year. Leaf had higher concentration of most of mineral
nutrients compared to stem. Spraying of 1% solution of complex
fertilizer 19:19:19 (percent N:P:K) three times at an interval of 3 weeks from
flower primordial initiation to flowering period enhanced the yield to the
extent of around 30% during off year. Auxin to cytokinin ratio
was 6.6 and 6.1 in on year and 6.3 and 5.7 in off year at flowering and 3
months after flowering respectively, suggesting that this ratio itself may not
play a major role in flowering during on and off years, though the ratio was
slightly more during on year. Results of the study indicate that efficient
utilization of metabolites and nutrients in on year may render vine
weak in the subsequent year coupled with poor remobilization into developing
berries, which could make it an off year.