A091 The effect of a seaweed biostimulant, Kelpak, on banana (Musa acuminata) yields in South Africa Adriaan F. Lourens 1 and Errol L. Tozer 2 1 Kelp Products (Pty) Ltd P.O. Box 325, Simon’s Town 7995, South Africa. Ph:+27824661401 E-mail: [email protected] 2 Agrisearch P.O. Box 868, White River 1240, South Africa. E-mail:[email protected] ® Introduction Seaweed has been used in farming practices for centuries. In recent times more refined seaweed products are used as biostimulants in crop production. Kelpak, produced from the seaweed species Ecklonia maxima, uses unique low temperature cell burst technology. This process maintains the raw kelp’s delicate, active compounds in Kelpak, making it a unique auxin dominant product. Kelpak application rates, methods and timings were evaluated in three trials on banana. Results and discussion Trunk injection – 2004: Two 50 ml applications of 0.5% and 1% Kelpak solutions were injected 30 cm above soil level with a sharp hollow needle at pre-flower and fruit fill stages. A negative effect was observed in bunch mass at harvest (data not shown). 2008: Application method terminated. Bell injection – 2004: Two 50 ml applications of 10% and 20% Kelpak solutions were injected at cigar leaf emergence (photograph) and before bell drop. No effect on bunch mass was recorded (data not shown due to 10-fold rate error). 2008: 1% and 2% Kelpak increased bunch mass by 15% and 12% respectively. 2010: 1% Kelpak increased yield by 11%. Soil drench – 2004: Two 400 ml applications of 0.5% and 1% Kelpak solutions were poured on the soil around the plant base at pre-flower stage and again at fruit fill. Treatment had no effect on bunch mass. 2008: 200 ml of 0.5% and 1% Kelpak applications gave increases of 5% and 10% respectively. 2010: Application method terminated. Foliar spray – 2004: Mist blower applications at 2 L and 4 L Kelpak in 300 L water/ha applied 5, 4, 3 and 2 months before estimated harvest gave 10% and 15% increases in bunch mass respectively. 2008: 2 L/ha and 3 L/ha Kelpak gave increases of 16% and 17% respectively. 2010: 2 L/ha and 3 L/ha Kelpak applied four times increased bunch mass by 11% and 17% respectively. Two 3 L/ha applications 5 and 3 months before harvest also gave 17% yield increase, while two applications 4 and 2 months before harvest had no effect. None of the treatments had an effect on hands per bunch or fingers per hand, indicating larger fruit rather than more fruit (data not shown). Conclusion Similar to many other crops, the results indicate that Kelpak foliar application at 3 L/ha on banana may improve yields significantly, with returns of US$4000/ha at current market value. If bell injection is used for pest control, it provides an option for Kelpak application at a 1% rate (improvement of US$3000/ha). Kelpak continues to be a valuable asset to the farmer in improving banana yields. Period of study Locations Crop Statistical design Treatments Cultivation Measurements 2004 to 2011 Commercial farms in Mpumalanga Province, South Africa Williams variety banana Randomized block, 6 single plant replicates per trial Soil drench, trunk injection, bell injection, foliar spray Standard fertilizer and pest and disease control practices Bunch mass, hands per bunch, fingers per hand Materials and methods Fig 1. Effect of Kelpak on Banana Yield 2004 - 05 season Bunch mass (kg) Bell inj. 10 % 31.3 40 30 20 Bell inj. 20 % 31.3 Drench 0.5 % 32.5 Drench 1 % 28.3 Spray 4 x 2 L 34.5 Spray 4 x 4 L 36.3 Control 31.5 bc bc ab c ab a bc Fig 2. Effect of Kelpak on Banana Yield 2008 - 09 season Bunch mass (kg) Bell inj. 1 % 35.5 40 30 20 Bell inj. 2 % 34.8 Drench 0.5 % 32.5 Drench 1 % 34.2 Spray 4 x 2 L 36.1 Spray 4 x 3 L 36.1 Control 31 abc bc d c ab a e Fig 3. Effect of Kelpak on Banana Yield 2010 - 11 season Bunch mass (kg) Bell inj. 1 % 32.3 40 30 20 Bell inj. 2 % 30.8 Control 29 ab bc Spray 4 x 2 L 32.1 ab Spray 4 x 3 L 34 a Spray E 2 x 3 L 33.9 a Spray L 2 x 3 L 28.8 c c