Martinez V. R. Controlled deficit irrigation effect in the productivity of the banana crop
Agricultural Technical Sciences Magazine , ISSN -1010-2760 , RNPS -0111, Vol 22, No. 2 (April-June , p. 51-55) , 2013 , Cuba .
Research Institute of Agricultural Engineering , Havana, Cuba
Banana is a very sensitive species to water deficit , so it is not expected to respond positively to the lack of moisture in the soil at any development stage. However the lack of rain that has characterized the country in recent years advises determine phases where the most problems occur, with the aim of establishing effective irrigation strategies in times of low water availability. To this end, this research was conducted , using one witness that was irrigated throughout the all cycle crop and four treatments in which irrigation was suspended in different months for which transited their respective cycles . The results indicate that the most affected phases, where there should be no water deficit were those which goes from planting to reach 50 % flowering and other from 90 % bloom to the end of the harvest , both affectation values above 20% productivity. The treatment less affected was between 50 to 90% of blooming, where the productivity is only affected by less than 15%.
MATERIALS AND METHODS
The research was conducted at the Experimental Station of Irrigation and Drainage in the town Alquízar province Artemisa, on a Red Ferralitic compacted soil , the rainfall regime of the area is characterized by two distinct periods , one in which occurs around 80 % of the total volume of rain that runs from May to October and other from November to April where the rest falls. In this case during the experimental period fell 2 152 mm , distributed over 24 months. Banana clone used was the Giant Cavendish (Musa AAA) , planted in May , with a frame 1.8 m between plants and 2.7 meters between rows , which led to a density of 2057 plants / ha. Agrotecnia crop except irrigation was applied as indicated by the instructions for the cultivation of Banana ( Cuba , Ministry of Agriculture).
The irrigation technique used was sprinkler under the foliage, using sprinklers MAR- 50F, with a square arrangement (6 x 6 meters) situated 30 cm. on the surface of the soil , irrigation doses corresponded to the calculated applied when soil moisture decreased to 85 % of field capacity during the first 40 cm . depth of soil, irrigation time was determined by the gravimetric method . In the experiment, five treatments and four replicates, which were distributed in a randomized block design was used. Treatments consisted of maintaining a witness -T-1 with irrigation at 85% field capacity throughout the all cycle crop and just four treatments irrigated , but where irrigation is suspended during different months , as shown in table 1 .
TABLE 1 . Experimental treatments applied.
|T-1 85 % CC|
X suspension irrigation for months
RESULTS AND DISCUSSION
Because the treatments was framed in months were not in phase , usually the affected segments covering periods of phases and no full phases . Neither affected by water deficit in each treatment was complete , due to the characteristics of the climate where development research.
As seen in Table 2 almost all stages were achieved at some degree affect with the water stress applied .
TABLE 2. Months of irrigation suspension in each treatment and segments of phases which coincided .
|Treatments||.Months of irrigation suspension by treatment||Harvests||Crop phases|
|1||No irrigation suspension||————————–|
|2||September- October||3th month -5% of blooming|
|3||November- December||5th month -31% of blooming|
|4||January- February||59% bloom -90% bloom|
|5||March- April||92% bloom -5% of harvest|
|1||No irrigation suspension||————————–|
|2||July- August||Foment cycle end -8% bloom|
|3||September- October||2 cycle month -53% blooming|
|4||November- December||66% bloom -27% of harvest|
|5||January- February||94% bloom -67% of harvest|
In Table 3, where the yield components and the percentage of affected productivity treatments is presented , it appears that in general all variants that were affected by water deficit in some phases of their life cycle , had a decreased productivity relative to the control , indicating the sensitivity of the crop to water deficit . This coincides with the point made by Crane & Balerdi ( 1998), who claim that the banana requires large amounts of water and is very sensitive to drought , which is manifested in the increased time to flowering and fruiting occurs, reducing the size and number of fruits as well as the total yield .
Likewise , Goenaga & Irizarri (1995 and 1998 ) found higher yield ( over 30% ) and better fruit quality in plants that are delivered 100% of the water lost by evapotranspiration than in those just were wet by the rain .
TABLE 3. Yield components and percentage of affect by treatments
|Number of total average fingers per bunch .||Fingers average weight
|Bunch average weight
|Percentage of affected productivity with witness relation (%)|
|1||149,0 a||165,4 a||25, 58 a||52, 61 a||Witness|
|2||126,8 c||162,2 a||21, 41 c||44, 04 c||16, 28|
|3||121,3 c||151,8 b||19, 27 d||39, 63 d||24, 67|
|4||138,8 b||152,3 b||21, 97 c||45, 19 c||14, 10|
|5||140,0 b||163,4 a||23, 82 b||48, 99 b||6, 88|
|CV %||1,33||3,00||3, 26||3, 26|
|Es +/-||0,04||2,37||0, 34||0, 34|
|1||157,7 a||163,7 a||26, 59 a||54, 69 a||Witness|
|2||154,2 a||140,7 b||22, 56 b||46, 40 b||15, 15|
|3||128,5 c||161,5 a||21, 60 c||44, 43 c||18, 76|
|4||138,7 b||141,7 b||20, 65 c||42, 47 c||22, 34|
|5||135,2 b||138,5 b||19, 63 d||40, 37 d||26, 18|
|CV %||1,31||2,84||2, 92||2, 92|
|Es +/-||0,07||2,11||0, 33||0, 33|
Means with unequal superscripts differ at 5% probability .
These results also indicate that the last phase from 90 % bloom to the end of the harvest , are highly sensitive to water stress , so it is not advisable deficit irrigation at this stage.
Zamora (1997 ), argues that bananas are considered very critical phases of initial training since the end of the vegetative phase up to 50 % flowering , when moisture is essential to maintain at least 85 % CC,which coincides with the results. However, the same author notes that the crop is tolerant , with minor impacts on the yields in the early vegetative stage and after harvest began , which differs from the results obtained in this work .
According to Socarras and Martinez (1989 ) , moisture deficit between the fourth and seventh months of the first harvest, the period within which the number of finger can be defined , whether litle time, show a tendency to decrease the number of fingers and yield. Moisture deficit in the formation phase of the fruit, but not influence the count, if they decrease the development of fingers and bunch weight and affect the final yield .
– In all phases in which there was a level of water deficit in relation to demand , there was an affect of productivity , which ranged from 6.88 to 26.18 % depending on the stage and level of water deficit .
– During the first cycle , the phase most affected productivity was framed between 3 months of planting crop and 50% flowering stage that significantly defines the total number of hands and fingers per bunch .
– During the second cycle , the phase more affected was during the critical period of fruit formation (90 % bloom – to harvest end), showing how important this phase is .
– The results indicate that between 50-90 % bloom could be preliminarily phase less affected , if irrigation is suspended .