Effect of temperature, sowing depth and nitrogen on germination and dry matter production of borage (Borago officials) and meadowfoam (Limnanthes alba): A dissertation submitted in partial fulfilment of the requirements for the degree of Bachelor of Agricultural Science with Honours

Abstract

This work was conducted to investigate the effect of sowing depth and temperature on the germination of borage (Baraga officials) and meadowfoam (Limnanthes alba). A further trial investigated the effect of fertiliser nitrogen on plant growth. The germination temperature trial was started on 19 May 2000 for a first set of treatments and on 7 June for a second set. Five temperatures were tested 5, 10, 15, 20 and 25 °C. A sowing depth trial was started on 31 August. There were seven depths 0.5, 1, 1.5, 2, 3, 4, 5 cm. The seed was germinated at the optimum temperature from the optimum temperature gemination trial (borage 25 °C; meadowfoam 5 °C). Borage germinated at all temperatures but there was a delay in germination at 5 °C, and there was no germinatjon until after 14 days. Borage germination increased with temperature. Meadowfoam did not germinate at all temperatures. It appears there was secondary dormancy at temperature over 15 °C. Meadowfoam therefore showed an opposite reaction to increased temperature f:t;"om borage as ge1mination decreased with increased temperature. A nitrogen pot trial was sown on 18 April 2000. Four nitrogen levels were tested 0, 25 , 50 and 75 kg N/ha. Seedlings were thinned to one seedling/pot. The effect of nitrogen was significant (P < 0.005) between species and nitrogen level. The species by nitrogen interaction was significant (P < 0.05). Based on the total dry matter at final harvest it appeared that the response to nitrogen levelled off at the two highest levels with meadowfoam.