Adaptability to water stress of sitao (Vigna sesquipedales Fruw.) grown before and after rice / by Maria M. Malixi-Paje.
Material type:
TextLanguage: English Publication details: Los Baños, Laguna : 1984. Cavite State University- Main Campus,Description: 313 pages : illustrations ; 28 cmContent type: - text
- unmediated
- volume
- 635.65 P16 1984
| Item type | Current library | Collection | Call number | Materials specified | URL | Status | Notes | Date due | Barcode |
|---|---|---|---|---|---|---|---|---|---|
Theses / Manuscripts
|
Ladislao N. Diwa Memorial Library Theses Section | Non-fiction | 635.65 P16 1984 (Browse shelf(Opens below)) | Link to resource | Room use only | T-1437 | 00007073 |
Thesis (PhD--Horticulture) University of the Philippines
Includes bibliographical references.
PAJE, MARIA M. MALIXI-, University of the Philippines at Los Banos, March, 1984. Adaptability to Water Stress of Sitao (Vigna sesquipedales Fruw.} Grown Before and After Rice. Major Professor: Dr. Dafrosa A. del Rosario.
This study sought to characterize the adaptability of sitao (Vigna sesquipedales Fruw.) under pre~rice and post~rice conditions. Morphological and physiological characteristics as well as carliness, germinability and seedling establishment were
determined.
The findings show that sitao is generally not adaptable to pre-rice conditions. The pre~rice condition was characterized by drought during the early growth of the plant and by three cycles of waterlogging from the peak of the vegetative growth until the plants flowered and formed pods. Considerable reduction in yield was obtained which was brought about by markedly reduced total leaf area, reduced total shoot dry matter, and degeneration of the tap roots as well as the inability of the plants to produce branched surface rooting. The crop also exhibited poor germinability and non-uniform growth of seedlings under low levels of soil moisture and low levels of osmotic potential.
On the other hand, more conclusive evidence regarding the adaptability of sitao to post-rice conditions was obtained. The post~-rice condition was characterized by a water-saturated soil from germination and early seedling growth and thereafter a continuous depletion of soil moisture until the crop matured. Fresh pod yields were comparable to the control. The following mechanisms were responsible for the crop’s adaptability: (1) reduction in total leaf area; (2) maintenance of high relative water content, (3) increased stomatal resistance; and (4) consequent decrease in the amount of water lost through transpiration. Good germinability and early establishment of seedlings under high levels of soil moisture and hiqh osmotic potentials as well as earliness also proved to be of adaptive significance to the crop.
Based on ocular observations, development of long, dcep-penetrating roots and changes in leaf orientation with respect to the incident solar radiation might have contributed to the overall crop's adaptation.
Both bush and pole types of sitao can be grown successfully after rice. However, among the bush sitao varieties studied, UPBS-1 is suggested to be highly adaptable to post-rice conditions regardless of the year of planting. Whereas the performance of the four pole sitao varieties, particularly their yield, was highly influenced by the pattern and degree of water stress that prevailed. Considering their overall performance, Acc 43 and Acc 44 would be more suitable for post~rice planting.
No single plant characteristic was found to correlate with fresh pod yield under the post-rice conditions indicating the significance of yield measurement when screening and selecting for geno-types adaptable to this condition.
Submitted to the University Library 01-07-1994 T-1437