scholarly journals Effects of drip irrigation on canopy and soil temperature, leaf gas exchange, flowering and nut setting of mature coconut (Cocos nucifera L.)

2008 ◽  
Vol 36 (1) ◽  
pp. 33 ◽  
Author(s):  
A Nainanayake ◽  
CS Ranasinghe ◽  
NA Tennakoon
CORD ◽  
2002 ◽  
Vol 18 (02) ◽  
pp. 34
Author(s):  
Gomes, F.P. ◽  
Mielke, M.S. ◽  
Almeida, A. F. ◽  
Muniz, W. S.

Net photosynthetic (A) and leaf transpiration (E) rates and stomatal conductance to water vapour (gs) of Malayan Yellow Dwarf (MYD) and Brazilian Green Dwarf (BGD) coconut accessions (Cocos nucifera var. ‘nana’ L.) were studied and discussed in terms of the technical aspects related to light-response curves in field conditions. Measurements of gas exchange were performed during four days, in April and may 2000, at the Cocoa Research Center Experimental Station (Una - BA, Brazil). The A, gs and E parameters were significantly (P < 0.05) different between the two genotypes. The mean maximum values of A, gs and E were 10.4 and 12.0 µmol CO2 m-2 s-1, 0.21 and 0.35 mol H2O m-2 s-1 and 3.07 and 3.69 mmol m-2 s-1 for MYD and BGD, respectively. For both genotypes a good fitting of the light-response curve models were obtained, indicating that A and gs were dependent of the photosynthetically active radiation incident on leaf surface (Qi), in spite of high genotipic variation. Interesting results were achieved when an empirical multiplicative model was used. The model relating A or gs with Qi and with leaf-to-air water vapour pressure deficit inside the chamber (VPDL) was tested for both genotypes and showed a negative influence of the latter on the stomatal behavior and consequently on A. Such effect was more pronounced in BGD than in MYD. These and others relationships involving leaf gas exchange and microclimatic variables in coconut palm trees are discussed


CORD ◽  
1997 ◽  
Vol 13 (02) ◽  
pp. 34
Author(s):  
K.V. Kasturi Bai ◽  
V. Rajagopal ◽  
D. Balasimha ◽  
P. Gopalasudaram

The response of local West Coast Tall (WCT) and the two hybrids viz., WCT x Chowghat Orange dwarf (COD) and COD x WCT to moisture availability in terms of water relation, gas exchange and dry matter (DM) production was studied. Discernible differences were noticed between the irrigation treatment (viz., irrigated vs unirrigated) with lower stomatal conductance and transpiration rate in the palms with out irrigation. Irrespective of the cultivar of hybrid leaf water potential was also significantly higher in irrigated palms. Net assimilation rate was lower under uniriigated condition. However genotypic or treatment differences were not significant. Annual DM production also vaned markedly between the irrigation treatments. Treatment differences were significant on the reproductive (RDM) rather then vegetative DM (VDM) production. Under the irrigation treatment the hybrids performed better than the local tall However the percentage reduction in the DM production was relatively less in the local WCT cultivar under unirrigated as compared with irrigated condition. The studies clearly highlighted the beneficial effects of irrigation on DM production and yield in coconut and the adaptability of the local WCT variety under limited water supply than the two hybrids.


CORD ◽  
2004 ◽  
Vol 20 (01) ◽  
pp. 34
Author(s):  
R. Dhanapal ◽  
H. P. Maheswarappa ◽  
P. Subramanian ◽  
Ajay Kumar Upadhyay

A field experiment on drip irrigation for Chowghat Orange Dwarf X West Coast Tall (COD X WCT) coconut hybrid was conducted in laterite soil at Central Plantation Crops Research Institute, Kasaragod (Kerala, India) to study the drip irrigation requirement and its influence on growth and yield.  The treatments included were three levels of drip irrigation (at 33, 66 and 100% E0 daily), basin irrigation  (100%  E0)  and  rainfed  control.     The  experimental  results  revealed  that  annual  leaf production and leaf nutrient status of coconut palm was significantly higher in the irrigated treatments compared to the rainfed control. The female flower production and nut yield with 66 per cent of Eo was on par with 100 per cent of Eo through drip and 100 per cent of Eo through basin irrigation and significantly  superior  compared  to drip irrigation  at 33 per cent of E0  and rainfed  control.   Drip irrigation equal to 66 per cent of open pan evaporation (Eo) proved to be the economically efficient method of irrigation with water saving of 34 per cent compared to 100 per cent of Eo through basin and drip method.


2020 ◽  
Vol 43 (3) ◽  
pp. 532-547 ◽  
Author(s):  
Anna Lintunen ◽  
Teemu Paljakka ◽  
Yann Salmon ◽  
Roderick Dewar ◽  
Anu Riikonen ◽  
...  

2009 ◽  
Vol 45 (1) ◽  
pp. 93-106 ◽  
Author(s):  
E. E. M. PASSOS ◽  
C. H. B. A. PRADO ◽  
W. M. ARAGÃO

SUMMARYDaily courses of leaf gas exchange and leaf water potential (Ψleaf) of green dwarf coconut palm (Cocos nucifera) were measured in irrigated plantations on the wet coastal plateau and in a dry semi-arid area of northeast Brazil. At both sites, significant correlations were obtained between stomatal conductance (gs) and vapour pressure deficit (VPDair), Ψleaf and VPDair, leaf transpiration (E) and gs, and E-Ψleaf. Despite these similar relationships between sites, stronger correlations involving gs-VPDair and E-Ψleaf were found at the semi-arid site, where whole-plant hydraulic conductance (gp) was correlated significantly with VPDair. In addition, at the semi-arid site, only, the net photosynthesis (PN) was not correlated with E and Ψleaf, and the intrinsic water use efficiency (WUEi) was disconnected from VPDair and Ψleaf. The different behaviour of leaf gas exchange and Ψleaf between sites was probably caused by low gs in response to high VPDair at the semi-arid site. Our results indicate potential for significant alterations in the pattern of leaf gas exchange during future climatic changes with increasing temperature and concomitant increases in VPDair. The atmospheric water stress will probably reinforce the strength of connection among water relation variables (E, Ψleaf, gs, gp, and VPDair), but it will disrupt the linear relationship between net CO2 assimilation and leaf water relations such as PN-E, PN-Ψleaf, WUEi-VPDair and WUEi-Ψleaf.


CORD ◽  
2003 ◽  
Vol 19 (02) ◽  
pp. 34
Author(s):  
R. Dhanapal ◽  
H. P. Maheswarappa ◽  
P. Subramanian ◽  
Ajay Kumar Upadhyay

A field experiment on drip irrigation for Chowghat Orange Dwarf X West Coast Tall (COD X WCT) coconut hybrid was conducted in laterite soil at Central Plantation Crops Research Institute, Kasaragod (Kerala, India) to study the drip irrigation requirement and its influence on growth and yield.  The treatments included were three levels of drip irrigation (at 33, 66 and 100% E0 daily), basin irrigation (100% E0) and rainfed control.  The experimental results revealed that annual leaf production and leaf nutrient status of coconut palm was significantly higher in the irrigated treatments compared to the rainfed control. The female flower production and nut yield with 66 per cent of Eo was on par with 100 per cent of Eo through drip and 100 per cent of Eo through basin irrigation and significantly superior compared to drip irrigation at 33 per cent of E0 and rainfed control.  Drip irrigation equal to 66 per cent of open pan evaporation (Eo) proved to be the economically efficient method of irrigation with water saving of 34 per cent compared to 100 per cent of Eo through basin and drip method. 


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