Published online by Cambridge University Press: 27 March 2009
A trial to investigate possibilities of berry control by cultivation depth is described. Tubers planted at 10 cm produced significantly more potato plants in flower than those planted at 30 cm at the commencement of flowering. However, 3 weeks later the difference in numbers of flowers had disappeared. Emergence of overwintered tubers was about 53%, and of spring-planted tubers about 97%. Depth of planting did not affect emergence. A comparison of overwintered and spring-planted potato tubers showed earlier flowering and berry production by the overwintered tubers of about 1 week on average compared with the spring-planted tubers.
Six chemical treatments were compared at different concentrations and growth stages of potatoes and peas to assess potential control of berry production in potato volunteers growing in a vining pea crop.
Best control was found to be achieved with a combination of 4-(2-methyl-4-chlorophenoxy) butyric acid (MCPB) at 8300 mg a.i./l and Bentazone at 7300 mg a.i./l applied with the potato volunteers at full foliage to flowering stage, and before the pea crop reached the flowering bud stage, or by application of MCPB alone at 8300 mg a.i./l with the potato plants at full foliage to the pre-flowering stage. No chemical treatment either totally destroyed potato foliage, or completely suppressed potato flower and berry production, but it is argued that growers may reduce the effects considerably by careful observation and use of the appropriate chemical at the appropriate time.